Version and history for 9.7.4

Fix a leak of open Blob files (#13106 )
Summary: An earlier change (https://github.com/facebook/rocksdb/commit/b34cef57b798520791312f2f40681c4d12d5d33c) removed apparently unused functionality where an obsolete blob file number is passed for removal from TableCache, which manages SST files. This was actually relying on broken/fragile abstractions wherein TableCache and BlobFileCache share the same Cache and using the TableCache interface to manipulate blob file caching. No unit test was actually checking for removal of obsolete blob files from the cache (which is somewhat tricky to check and a second order correctness requirement). Here we fix the leak and add a DEBUG+ASAN-only check in DB::Close() that no obsolete files are lingering in the table/blob file cache. Fixes https://github.com/facebook/rocksdb/issues/13066 Important follow-up (FIXME): The added check discovered some apparent cases of leaked (into table_cache) SST file readers that would stick around until DB::Close(). Need to enable that check, diagnose, and fix. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13106 Test Plan: added a check that is called during DB::Close in ASAN builds (to minimize paying the cost in all unit tests). Without the fix, the check failed in at least these tests: ``` db_blob_basic_test DBBlobBasicTest.DynamicallyWarmCacheDuringFlush db_blob_compaction_test DBBlobCompactionTest.CompactionReadaheadMerge db_blob_compaction_test DBBlobCompactionTest.MergeBlobWithBase db_blob_compaction_test DBBlobCompactionTest.CompactionDoNotFillCache db_blob_compaction_test DBBlobCompactionTest.SkipUntilFilter db_blob_compaction_test DBBlobCompactionTest.CompactionFilter db_blob_compaction_test DBBlobCompactionTest.CompactionReadaheadFilter db_blob_compaction_test DBBlobCompactionTest.CompactionReadaheadGarbageCollection ``` Reviewed By: ltamasi Differential Revision: D65296123 Pulled By: pdillinger fbshipit-source-id: 2276d76482beb2c75c9010bc1bec070bb23a24c0
2026-11-06 19:12:36 -05:00 · 2024-11-01 08:32:35 -07:00 · 2024-11-01 08:31:29 -07:00 · 2024-11-01 08:31:29 -07:00 · 2024-10-17 12:29:59 -07:00 · 2024-10-17 11:02:06 -07:00
265 changed files with 11199 additions and 4079 deletions
@@ -1,13 +1,13 @@
 name: facebook/rocksdb/benchmark-linux
 on: workflow_dispatch
-jobs:
-  # FIXME: when this job is fixed, it should be given a cron schedule like
+permissions: {}
+  # FIXME: Disabled temporarily
  # schedule:
-  # - cron: 0 * * * *
-  # workflow_dispatch:
+  # - cron: 7 */2 * * *  # At minute 7 past every 2nd hour
+jobs:
  benchmark-linux:
    if: ${{ github.repository_owner == 'facebook' }}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-latest # FIXME: change this back to self-hosted when ready
    steps:
    - uses: actions/checkout@v4.1.0
    - uses: "./.github/actions/build-for-benchmarks"
@@ -1,5 +1,6 @@
 name: facebook/rocksdb/nightly
 on: workflow_dispatch
+permissions: {}
 jobs:
  # These jobs would be in nightly but are failing or otherwise broken for
  # some reason.
@@ -3,6 +3,7 @@ on:
  schedule:
  - cron: 0 9 * * *
  workflow_dispatch:
+permissions: {}
 jobs:
  build-format-compatible:
    if: ${{ github.repository_owner == 'facebook' }}
@@ -59,12 +60,15 @@ jobs:
    container:
      image: zjay437/rocksdb:0.6
      options: --shm-size=16gb
+    env:
+      CC: clang-13
+      CXX: clang++-13
    steps:
    - uses: actions/checkout@v4.1.0
    - uses: "./.github/actions/pre-steps"
    - uses: "./.github/actions/setup-folly"
    - uses: "./.github/actions/build-folly"
-    - run: CC=clang-13 CXX=clang++-13 LIB_MODE=static USE_CLANG=1 USE_FOLLY=1 COMPILE_WITH_UBSAN=1 COMPILE_WITH_ASAN=1 make -j32 check
+    - run: LIB_MODE=static USE_CLANG=1 USE_FOLLY=1 COMPILE_WITH_UBSAN=1 COMPILE_WITH_ASAN=1 make -j32 check
    - uses: "./.github/actions/post-steps"
  build-linux-valgrind:
    if: ${{ github.repository_owner == 'facebook' }}
@@ -76,7 +80,7 @@ jobs:
    steps:
    - uses: actions/checkout@v4.1.0
    - uses: "./.github/actions/pre-steps"
-    - run: PORTABLE=1 make V=1 -j32 valgrind_test
+    - run: make V=1 -j32 valgrind_test
    - uses: "./.github/actions/post-steps"
  build-windows-vs2022-avx2:
    if: ${{ github.repository_owner == 'facebook' }}
@@ -1,5 +1,6 @@
 name: facebook/rocksdb/pr-jobs-candidate
 on: workflow_dispatch
+permissions: {}
 jobs:
  # These jobs would be in pr-jobs but are failing or otherwise broken for
  # some reason.
@@ -1,5 +1,6 @@
 name: facebook/rocksdb/pr-jobs
 on: [push, pull_request]
+permissions: {}
 jobs:
  # NOTE: multiple workflows would be recommended, but the current GHA UI in
  # PRs doesn't make it clear when there's an overall error with a workflow,
@@ -1,6 +1,110 @@
 # Rocksdb Change Log
 > NOTE: Entries for next release do not go here. Follow instructions in `unreleased_history/README.txt`

+## 9.7.4 (10/31/2024)
+### Bug Fixes
+* Fix a leak of obsolete blob files left open until DB::Close(). This bug was introduced in version 9.4.0.
+
+## 9.7.3 (10/16/2024)
+### Behavior Changes
+* OPTIONS file to be loaded by remote worker is now preserved so that it does not get purged by the primary host. A similar technique as how we are preserving new SST files from getting purged is used for this. min_options_file_numbers_ is tracked like pending_outputs_ is tracked.
+
+## 9.7.2 (10/08/2024)
+### Bug Fixes
+* Fix a bug for surfacing write unix time: `Iterator::GetProperty("rocksdb.iterator.write-time")` for non-L0 files.
+
+## 9.7.1 (09/26/2024)
+### Bug Fixes
+* Several DB option settings could be lost through `GetOptionsFromString()`, possibly elsewhere as well. Affected options, now fixed:`background_close_inactive_wals`, `write_dbid_to_manifest`, `write_identity_file`, `prefix_seek_opt_in_only`
+* Fix under counting of allocated memory in the compressed secondary cache due to looking at the compressed block size rather than the actual memory allocated, which could be larger due to internal fragmentation.
+* Skip insertion of compressed blocks in the secondary cache if the lowest_used_cache_tier DB option is kVolatileTier.
+
+## 9.7.0 (09/20/2024)
+### New Features
+* Make Cache a customizable class that can be instantiated by the object registry.
+* Add new option `prefix_seek_opt_in_only` that makes iterators generally safer when you might set a `prefix_extractor`. When `prefix_seek_opt_in_only=true`, which is expected to be the future default, prefix seek is only used when `prefix_same_as_start` or `auto_prefix_mode` are set. Also, `prefix_same_as_start` and `auto_prefix_mode` now allow prefix filtering even with `total_order_seek=true`.
+* Add a new table property "rocksdb.key.largest.seqno" which records the largest sequence number of all keys in file. It is verified to be zero during SST file ingestion.
+
+### Behavior Changes
+* Changed the semantics of the BlobDB configuration option `blob_garbage_collection_force_threshold` to define a threshold for the overall garbage ratio of all blob files currently eligible for garbage collection (according to `blob_garbage_collection_age_cutoff`). This can provide better control over space amplification at the cost of slightly higher write amplification.
+* Set `write_dbid_to_manifest=true` by default. This means DB ID will now be preserved through backups, checkpoints, etc. by default. Also add `write_identity_file` option which can be set to false for anticipated future behavior.
+* In FIFO compaction, compactions for changing file temperature (configured by option `file_temperature_age_thresholds`) will compact one file at a time, instead of merging multiple eligible file together (#13018).
+* Support ingesting db generated files using hard link, i.e. IngestExternalFileOptions::move_files/link_files and IngestExternalFileOptions::allow_db_generated_files.
+* Add a new file ingestion option `IngestExternalFileOptions::link_files` to hard link input files and preserve original files links after ingestion.
+* DB::Close now untracks files in SstFileManager, making avaialble any space used
+by them. Prior to this change they would be orphaned until the DB is re-opened.
+
+### Bug Fixes
+* Fix a bug in CompactRange() where result files may not be compacted in any future compaction. This can only happen when users configure CompactRangeOptions::change_level to true and the change level step of manual compaction fails (#13009).
+* Fix handling of dynamic change of `prefix_extractor` with memtable prefix filter. Previously, prefix seek could mix different prefix interpretations between memtable and SST files. Now the latest `prefix_extractor` at the time of iterator creation or refresh is respected.
+* Fix a bug with manual_wal_flush and auto error recovery from WAL failure that may cause CFs to be inconsistent (#12995). The fix will set potential WAL write failure as fatal error when manual_wal_flush is true, and disables auto error recovery from these errors.
+
+## 9.6.0 (08/19/2024)
+### New Features
+* *Best efforts recovery supports recovering to incomplete Version with a clean seqno cut that presents a valid point in time view from the user's perspective, if versioning history doesn't include atomic flush.
+* New option `BlockBasedTableOptions::decouple_partitioned_filters` should improve efficiency in serving read queries because filter and index partitions can consistently target the configured `metadata_block_size`. This option is currently opt-in.
+* Introduce a new mutable CF option `paranoid_memory_checks`. It enables additional validation on data integrity during reads/scanning. Currently, skip list based memtable will validate key ordering during look up and scans.
+
+### Public API Changes
+* Add ticker stats to count file read retries due to checksum mismatch
+* Adds optional installation callback function for remote compaction
+
+### Behavior Changes
+* There may be less intra-L0 compaction triggered by total L0 size being too small. We now use compensated file size (tombstones are assigned some value size) when calculating L0 size and reduce the threshold for L0 size limit. This is to avoid accumulating too much data/tombstones in L0.
+
+### Bug Fixes
+* *Make DestroyDB supports slow deletion when it's configured in `SstFileManager`. The slow deletion is subject to the configured `rate_bytes_per_sec`, but not subject to the `max_trash_db_ratio`.
+* Fixed a bug where we set unprep_seqs_ even when WriteImpl() fails. This was caught by stress test write fault injection in WriteImpl(). This may have incorrectly caused iteration creation failure for unvalidated writes or returned wrong result for WriteUnpreparedTxn::GetUnpreparedSequenceNumbers().
+* Fixed a bug where successful write right after error recovery for last failed write finishes causes duplicate WAL entries
+* Fixed a data race involving the background error status in `unordered_write` mode.
+* *Fix a bug where file snapshot functions like backup, checkpoint may attempt to copy a non-existing manifest file. #12882
+* Fix a bug where per kv checksum corruption may be ignored in MultiGet().
+* Fix a race condition in pessimistic transactions that could allow multiple transactions with the same name to be registered simultaneously, resulting in a crash or other unpredictable behavior.
+
+## 9.5.0 (07/19/2024)
+### Public API Changes
+* Introduced new C API function rocksdb_writebatch_iterate_cf for column family-aware iteration over the contents of a WriteBatch
+* Add support to ingest SST files generated by a DB instead of SstFileWriter. This can be enabled with experimental option `IngestExternalFileOptions::allow_db_generated_files`.
+
+### Behavior Changes
+* When calculating total log size for the `log_size_for_flush` argument in `CreateCheckpoint` API, the size of the archived log will not be included to avoid unnecessary flush
+
+### Bug Fixes
+* Fix a major bug in which an iterator using prefix filtering and SeekForPrev might miss data when the DB is using `whole_key_filtering=false` and `partition_filters=true`.
+* Fixed a bug where `OnErrorRecoveryBegin()` is not called before auto recovery starts.
+* Fixed a bug where event listener reads ErrorHandler's `bg_error_` member without holding db mutex(#12803).
+* Fixed a bug in handling MANIFEST write error that caused the latest valid MANIFEST file to get deleted, resulting in the DB being unopenable.
+* Fixed a race between error recovery due to manifest sync or write failure and external SST file ingestion. Both attempt to write a new manifest file, which causes an assertion failure.
+
+### Performance Improvements
+* Fix an issue where compactions were opening table files and reading table properties while holding db mutex_.
+* Reduce unnecessary filesystem queries and DB mutex acquires in creating backups and checkpoints.
+
+## 9.4.0 (06/23/2024)
+### New Features
+* Added a `CompactForTieringCollectorFactory` to auto trigger compaction for tiering use case.
+* Optimistic transactions and pessimistic transactions with the WriteCommitted policy now support the `GetEntityForUpdate` API.
+* Added a new "count" command to the ldb repl shell. By default, it prints a count of keys in the database from start to end. The options --from=<key> and/or --to=<key> can be specified to limit the range.
+* Add `rocksdb_writebatch_update_timestamps`, `rocksdb_writebatch_wi_update_timestamps` in C API.
+* Add `rocksdb_iter_refresh` in C API.
+* Add `rocksdb_writebatch_create_with_params`, `rocksdb_writebatch_wi_create_with_params` to create WB and WBWI with all options in C API
+
+### Public API Changes
+* Deprecated names `LogFile` and `VectorLogPtr` in favor of new names `WalFile` and `VectorWalPtr`.
+* Introduce a new universal compaction option CompactionOptionsUniversal::max_read_amp which allows user to define the limit on the number of sorted runs separately from the trigger for compaction (`level0_file_num_compaction_trigger`) #12477.
+
+### Behavior Changes
+* Inactive WALs are immediately closed upon being fully sync-ed rather than in a background thread. This is to ensure LinkFile() is not called on files still open for write, which might not be supported by some FileSystem implementations. This should not be a performance issue, but an opt-out is available with with new DB option `background_close_inactive_wals`.
+
+### Bug Fixes
+* Fix a rare case in which a hard-linked WAL in a Checkpoint is not fully synced (so might lose data on power loss).
+* Fixed the output of the `ldb dump_wal` command for `PutEntity` records so it prints the key and correctly resets the hexadecimal formatting flag after printing the wide-column entity.
+* Fixed an issue where `PutEntity` records were handled incorrectly while rebuilding transactions during recovery.
+* Various read operations could ignore various ReadOptions that might be relevant. Fixed many such cases, which can result in behavior change but a better reflection of specified options.
+
+### Performance Improvements
+* Improved write throughput to memtable when there's a large number of concurrent writers and allow_concurrent_memtable_write=true(#12545)
+
 ## 9.3.0 (05/17/2024)
 ### New Features
 * Optimistic transactions and pessimistic transactions with the WriteCommitted policy now support the `GetEntity` API.
@@ -630,6 +630,11 @@ VALGRIND_VER := $(join $(VALGRIND_VER),valgrind)
 VALGRIND_OPTS = --error-exitcode=$(VALGRIND_ERROR) --leak-check=full
 # Not yet supported: --show-leak-kinds=definite,possible,reachable --errors-for-leak-kinds=definite,possible,reachable

+# Work around valgrind hanging on systems with limited internet access
+ifneq ($(shell which git 2>/dev/null && git config --get https.proxy),)
+  export DEBUGINFOD_URLS=
+endif
+
 TEST_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(TEST_LIB_SOURCES) $(MOCK_LIB_SOURCES)) $(GTEST)
 BENCH_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(BENCH_LIB_SOURCES))
 CACHE_BENCH_OBJECTS = $(patsubst %.cc, $(OBJ_DIR)/%.o, $(CACHE_BENCH_LIB_SOURCES))
@@ -1164,16 +1169,16 @@ ubsan_crash_test_with_best_efforts_recovery: clean
 	$(MAKE) clean

 full_valgrind_test:
-	ROCKSDB_FULL_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check
+	ROCKSDB_FULL_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 PORTABLE=1 $(MAKE) valgrind_check

 full_valgrind_test_some:
-	ROCKSDB_FULL_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check_some
+	ROCKSDB_FULL_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 PORTABLE=1 $(MAKE) valgrind_check_some

 valgrind_test:
-	ROCKSDB_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check
+	ROCKSDB_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 PORTABLE=1 $(MAKE) valgrind_check

 valgrind_test_some:
-	ROCKSDB_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 $(MAKE) valgrind_check_some
+	ROCKSDB_VALGRIND_RUN=1 DISABLE_JEMALLOC=1 PORTABLE=1 $(MAKE) valgrind_check_some

 valgrind_check: $(TESTS)
 	$(MAKE) DRIVER="$(VALGRIND_VER) $(VALGRIND_OPTS)" gen_parallel_tests
@@ -2139,8 +2144,8 @@ ZLIB_DOWNLOAD_BASE ?= http://zlib.net
 BZIP2_VER ?= 1.0.8
 BZIP2_SHA256 ?= ab5a03176ee106d3f0fa90e381da478ddae405918153cca248e682cd0c4a2269
 BZIP2_DOWNLOAD_BASE ?= http://sourceware.org/pub/bzip2
-SNAPPY_VER ?= 1.1.8
-SNAPPY_SHA256 ?= 16b677f07832a612b0836178db7f374e414f94657c138e6993cbfc5dcc58651f
+SNAPPY_VER ?= 1.2.1
+SNAPPY_SHA256 ?= 736aeb64d86566d2236ddffa2865ee5d7a82d26c9016b36218fcc27ea4f09f86
 SNAPPY_DOWNLOAD_BASE ?= https://github.com/google/snappy/archive
 LZ4_VER ?= 1.9.4
 LZ4_SHA256 ?= 0b0e3aa07c8c063ddf40b082bdf7e37a1562bda40a0ff5272957f3e987e0e54b
@@ -2237,7 +2242,7 @@ libsnappy.a: snappy-$(SNAPPY_VER).tar.gz
 	-rm -rf snappy-$(SNAPPY_VER)
 	tar xvzf snappy-$(SNAPPY_VER).tar.gz
 	mkdir snappy-$(SNAPPY_VER)/build
-	cd snappy-$(SNAPPY_VER)/build && CFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' CXXFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CXXFLAGS} ${EXTRA_CXXFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON ${PLATFORM_CMAKE_FLAGS} .. && $(MAKE) ${SNAPPY_MAKE_TARGET}
+	cd snappy-$(SNAPPY_VER)/build && CFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CCFLAGS} ${EXTRA_CFLAGS}' CXXFLAGS='$(ARCHFLAG) ${JAVA_STATIC_DEPS_CXXFLAGS} ${EXTRA_CXXFLAGS}' LDFLAGS='${JAVA_STATIC_DEPS_LDFLAGS} ${EXTRA_LDFLAGS}' cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DSNAPPY_BUILD_BENCHMARKS=OFF -DSNAPPY_BUILD_TESTS=OFF --compile-no-warning-as-error ${PLATFORM_CMAKE_FLAGS} .. && $(MAKE) ${SNAPPY_MAKE_TARGET}
 	cp snappy-$(SNAPPY_VER)/build/libsnappy.a .

 lz4-$(LZ4_VER).tar.gz:
@@ -2484,13 +2489,11 @@ checkout_folly:
 	fi
 	@# Pin to a particular version for public CI, so that PR authors don't
 	@# need to worry about folly breaking our integration. Update periodically
-	cd third-party/folly && git reset --hard 17054c85c2dee0e84cbee7ef28d7bae7d0b1630e
+	cd third-party/folly && git reset --hard 03041f014b6e6ebb6119ffae8b7a37308f52e913
 	@# NOTE: this hack is required for clang in some cases
 	perl -pi -e 's/int rv = syscall/int rv = (int)syscall/' third-party/folly/folly/detail/Futex.cpp
 	@# NOTE: this hack is required for gcc in some cases
 	perl -pi -e 's/(__has_include.<experimental.memory_resource>.)/__cpp_rtti && $$1/' third-party/folly/folly/memory/MemoryResource.h
-	@# NOTE: this hack is only needed if building target build_folly in the future
-	perl -pi -e 's,https://github.com/jedisct1/libsodium/releases/download/1.0.17/libsodium-1.0.17.tar.gz,https://download.libsodium.org/libsodium/releases/old/unsupported/libsodium-1.0.17.tar.gz,' third-party/folly/build/fbcode_builder/manifests/libsodium
 	@# NOTE: boost source will be needed for any build including `USE_FOLLY_LITE` builds as those depend on boost headers
 	cd third-party/folly && $(PYTHON) build/fbcode_builder/getdeps.py fetch boost

@@ -362,9 +362,9 @@ cpp_library_wrapper(name="rocksdb_lib", srcs=[
        "//folly/experimental/coro:coroutine",
        "//folly/experimental/coro:task",
        "//folly/synchronization:distributed_mutex",
-    ], headers=None, link_whole=False, extra_test_libs=False)
+    ], headers=glob(["**/*.h"]), link_whole=False, extra_test_libs=False)

-cpp_library_wrapper(name="rocksdb_whole_archive_lib", srcs=[], deps=[":rocksdb_lib"], headers=None, link_whole=True, extra_test_libs=False)
+cpp_library_wrapper(name="rocksdb_whole_archive_lib", srcs=[], deps=[":rocksdb_lib"], headers=[], link_whole=True, extra_test_libs=False)

 cpp_library_wrapper(name="rocksdb_test_lib", srcs=[
        "db/db_test_util.cc",
@@ -378,7 +378,7 @@ cpp_library_wrapper(name="rocksdb_test_lib", srcs=[
        "tools/trace_analyzer_tool.cc",
        "utilities/agg_merge/test_agg_merge.cc",
        "utilities/cassandra/test_utils.cc",
-    ], deps=[":rocksdb_lib"], headers=None, link_whole=False, extra_test_libs=True)
+    ], deps=[":rocksdb_lib"], headers=[], link_whole=False, extra_test_libs=True)

 cpp_library_wrapper(name="rocksdb_tools_lib", srcs=[
        "test_util/testutil.cc",
@@ -386,9 +386,9 @@ cpp_library_wrapper(name="rocksdb_tools_lib", srcs=[
        "tools/db_bench_tool.cc",
        "tools/simulated_hybrid_file_system.cc",
        "tools/trace_analyzer_tool.cc",
-    ], deps=[":rocksdb_lib"], headers=None, link_whole=False, extra_test_libs=False)
+    ], deps=[":rocksdb_lib"], headers=[], link_whole=False, extra_test_libs=False)

-cpp_library_wrapper(name="rocksdb_cache_bench_tools_lib", srcs=["cache/cache_bench_tool.cc"], deps=[":rocksdb_lib"], headers=None, link_whole=False, extra_test_libs=False)
+cpp_library_wrapper(name="rocksdb_cache_bench_tools_lib", srcs=["cache/cache_bench_tool.cc"], deps=[":rocksdb_lib"], headers=[], link_whole=False, extra_test_libs=False)

 rocks_cpp_library_wrapper(name="rocksdb_stress_lib", srcs=[
        "db_stress_tool/batched_ops_stress.cc",
@@ -410,13 +410,15 @@ rocks_cpp_library_wrapper(name="rocksdb_stress_lib", srcs=[
        "test_util/testutil.cc",
        "tools/block_cache_analyzer/block_cache_trace_analyzer.cc",
        "tools/trace_analyzer_tool.cc",
-    ], headers=None)
+    ], headers=[])


 cpp_binary_wrapper(name="ldb", srcs=["tools/ldb.cc"], deps=[":rocksdb_tools_lib"], extra_preprocessor_flags=[], extra_bench_libs=False)

 cpp_binary_wrapper(name="db_stress", srcs=["db_stress_tool/db_stress.cc"], deps=[":rocksdb_stress_lib"], extra_preprocessor_flags=[], extra_bench_libs=False)

+cpp_binary_wrapper(name="db_bench", srcs=["tools/db_bench.cc"], deps=[":rocksdb_tools_lib"], extra_preprocessor_flags=[], extra_bench_libs=False)
+
 cpp_binary_wrapper(name="cache_bench", srcs=["cache/cache_bench.cc"], deps=[":rocksdb_cache_bench_tools_lib"], extra_preprocessor_flags=[], extra_bench_libs=False)

 cpp_binary_wrapper(name="ribbon_bench", srcs=["microbench/ribbon_bench.cc"], deps=[], extra_preprocessor_flags=[], extra_bench_libs=True)
@@ -5024,7 +5026,7 @@ cpp_unittest_wrapper(name="dynamic_bloom_test",
            extra_compiler_flags=[])


-cpp_library_wrapper(name="env_basic_test_lib", srcs=["env/env_basic_test.cc"], deps=[":rocksdb_test_lib"], headers=None, link_whole=False, extra_test_libs=True)
+cpp_library_wrapper(name="env_basic_test_lib", srcs=["env/env_basic_test.cc"], deps=[":rocksdb_test_lib"], headers=[], link_whole=False, extra_test_libs=True)

 cpp_unittest_wrapper(name="env_basic_test",
            srcs=["env/env_basic_test.cc"],
@@ -11,7 +11,7 @@ import json
 import os
 import sys

-from targets_builder import TARGETSBuilder
+from targets_builder import TARGETSBuilder, LiteralValue

 from util import ColorString

@@ -150,6 +150,7 @@ def generate_targets(repo_path, deps_map):
            "//folly/experimental/coro:task",
            "//folly/synchronization:distributed_mutex",
        ],
+        headers=LiteralValue("glob([\"**/*.h\"])")
    )
    # rocksdb_whole_archive_lib
    TARGETS.add_library(
@@ -158,7 +159,6 @@ def generate_targets(repo_path, deps_map):
        deps=[
            ":rocksdb_lib",
        ],
-        headers=None,
        extra_external_deps="",
        link_whole=True,
    )
@@ -201,6 +201,10 @@ def generate_targets(repo_path, deps_map):
    TARGETS.add_binary(
        "db_stress", ["db_stress_tool/db_stress.cc"], [":rocksdb_stress_lib"]
    )
+    # db_bench binary
+    TARGETS.add_binary(
+        "db_bench", ["tools/db_bench.cc"], [":rocksdb_tools_lib"]
+    )
    # cache_bench binary
    TARGETS.add_binary(
        "cache_bench", ["cache/cache_bench.cc"], [":rocksdb_cache_bench_tools_lib"]
@@ -9,17 +9,28 @@ import pprint

 import targets_cfg

+class LiteralValue:
+    def __init__(self, value):
+        self.value = value
+
+    def __str__(self):
+        return str(self.value)
+
+def smart_quote_value(val):
+    if isinstance(val, LiteralValue):
+        return str(val)
+    return '"%s"' % val

 def pretty_list(lst, indent=8):
    if lst is None or len(lst) == 0:
        return ""

    if len(lst) == 1:
-        return '"%s"' % lst[0]
+        return smart_quote_value(lst[0])

-    separator = '",\n%s"' % (" " * indent)
-    res = separator.join(sorted(lst))
-    res = "\n" + (" " * indent) + '"' + res + '",\n' + (" " * (indent - 4))
+    separator = ',\n%s' % (" " * indent)
+    res = separator.join(sorted(map(smart_quote_value, lst)))
+    res = "\n" + (" " * indent) + res + ',\n' + (" " * (indent - 4))
    return res


@@ -48,7 +59,12 @@ class TARGETSBuilder:
        extra_test_libs=False,
    ):
        if headers is not None:
-            headers = "[" + pretty_list(headers) + "]"
+            if isinstance(headers, LiteralValue):
+                headers = str(headers)
+            else:
+                headers = "[" + pretty_list(headers) + "]"
+        else:
+            headers = "[]"
        with open(self.path, "ab") as targets_file:
            targets_file.write(
                targets_cfg.library_template.format(
@@ -65,8 +81,7 @@ class TARGETSBuilder:
        self.total_lib = self.total_lib + 1

    def add_rocksdb_library(self, name, srcs, headers=None, external_dependencies=None):
-        if headers is not None:
-            headers = "[" + pretty_list(headers) + "]"
+        headers = "[" + pretty_list(headers) + "]"
        with open(self.path, "ab") as targets_file:
            targets_file.write(
                targets_cfg.rocksdb_library_template.format(
@@ -133,19 +133,23 @@ Status Cache::CreateFromString(const ConfigOptions& config_options,
                               std::shared_ptr<Cache>* result) {
  Status status;
  std::shared_ptr<Cache> cache;
-  if (value.find('=') == std::string::npos) {
-    cache = NewLRUCache(ParseSizeT(value));
-  } else {
-    LRUCacheOptions cache_opts;
-    status = OptionTypeInfo::ParseStruct(config_options, "",
-                                         &lru_cache_options_type_info, "",
-                                         value, &cache_opts);
-    if (status.ok()) {
-      cache = NewLRUCache(cache_opts);
+  if (value.find("://") == std::string::npos) {
+    if (value.find('=') == std::string::npos) {
+      cache = NewLRUCache(ParseSizeT(value));
+    } else {
+      LRUCacheOptions cache_opts;
+      status = OptionTypeInfo::ParseStruct(config_options, "",
+                                           &lru_cache_options_type_info, "",
+                                           value, &cache_opts);
+      if (status.ok()) {
+        cache = NewLRUCache(cache_opts);
+      }
    }
-  }
-  if (status.ok()) {
-    result->swap(cache);
+    if (status.ok()) {
+      result->swap(cache);
+    }
+  } else {
+    status = LoadSharedObject<Cache>(config_options, value, result);
  }
  return status;
 }
@@ -886,6 +886,32 @@ TEST_P(CacheTest, ApplyToAllEntriesDuringResize) {
  ASSERT_EQ(special_count, kSpecialCount);
 }

+TEST_P(CacheTest, ApplyToHandleTest) {
+  std::string callback_state;
+  const auto callback = [&](const Slice& key, Cache::ObjectPtr value,
+                            size_t charge,
+                            const Cache::CacheItemHelper* helper) {
+    callback_state = std::to_string(DecodeKey(key)) + "," +
+                     std::to_string(DecodeValue(value)) + "," +
+                     std::to_string(charge);
+    assert(helper == &CacheTest::kHelper);
+  };
+
+  std::vector<std::string> inserted;
+
+  for (int i = 0; i < 10; ++i) {
+    Insert(i, i * 2, i + 1);
+    inserted.push_back(std::to_string(i) + "," + std::to_string(i * 2) + "," +
+                       std::to_string(i + 1));
+  }
+  for (int i = 0; i < 10; ++i) {
+    Cache::Handle* handle = cache_->Lookup(EncodeKey(i));
+    cache_->ApplyToHandle(cache_.get(), handle, callback);
+    EXPECT_EQ(inserted[i], callback_state);
+    cache_->Release(handle);
+  }
+}
+
 TEST_P(CacheTest, DefaultShardBits) {
  // Prevent excessive allocation (to save time & space)
  estimated_value_size_ = 100000;
@@ -1444,6 +1444,22 @@ const Cache::CacheItemHelper* BaseHyperClockCache<Table>::GetCacheItemHelper(
  return h->helper;
 }

+template <class Table>
+void BaseHyperClockCache<Table>::ApplyToHandle(
+    Cache* cache, Handle* handle,
+    const std::function<void(const Slice& key, Cache::ObjectPtr value,
+                             size_t charge, const CacheItemHelper* helper)>&
+        callback) {
+  BaseHyperClockCache<Table>* cache_ptr =
+      static_cast<BaseHyperClockCache<Table>*>(cache);
+  auto h = static_cast<const typename Table::HandleImpl*>(handle);
+  UniqueId64x2 unhashed;
+  auto hash_seed = cache_ptr->GetShard(h->GetHash()).GetTable().GetHashSeed();
+  callback(
+      ClockCacheShard<Table>::ReverseHash(h->hashed_key, &unhashed, hash_seed),
+      h->value, h->GetTotalCharge(), h->helper);
+}
+
 namespace {

 // For each cache shard, estimate what the table load factor would be if
@@ -1128,6 +1128,12 @@ class BaseHyperClockCache : public ShardedCache<ClockCacheShard<Table>> {

  const CacheItemHelper* GetCacheItemHelper(Handle* handle) const override;

+  void ApplyToHandle(
+      Cache* cache, Handle* handle,
+      const std::function<void(const Slice& key, Cache::ObjectPtr obj,
+                               size_t charge, const CacheItemHelper* helper)>&
+          callback) override;
+
  void ReportProblems(
      const std::shared_ptr<Logger>& /*info_log*/) const override;
 };
@@ -79,7 +79,11 @@ std::unique_ptr<SecondaryCacheResultHandle> CompressedSecondaryCache::Lookup(
    data_ptr = GetVarint32Ptr(data_ptr, data_ptr + 1,
                              static_cast<uint32_t*>(&source_32));
    source = static_cast<CacheTier>(source_32);
-    handle_value_charge -= (data_ptr - ptr->get());
+    uint64_t data_size = 0;
+    data_ptr = GetVarint64Ptr(data_ptr, ptr->get() + handle_value_charge,
+                              static_cast<uint64_t*>(&data_size));
+    assert(handle_value_charge > data_size);
+    handle_value_charge = data_size;
  }
  MemoryAllocator* allocator = cache_options_.memory_allocator.get();

@@ -169,13 +173,15 @@ Status CompressedSecondaryCache::InsertInternal(
  }

  auto internal_helper = GetHelper(cache_options_.enable_custom_split_merge);
-  char header[10];
+  char header[20];
  char* payload = header;
  payload = EncodeVarint32(payload, static_cast<uint32_t>(type));
  payload = EncodeVarint32(payload, static_cast<uint32_t>(source));
+  size_t data_size = (*helper->size_cb)(value);
+  char* data_size_ptr = payload;
+  payload = EncodeVarint64(payload, data_size);

  size_t header_size = payload - header;
-  size_t data_size = (*helper->size_cb)(value);
  size_t total_size = data_size + header_size;
  CacheAllocationPtr ptr =
      AllocateBlock(total_size, cache_options_.memory_allocator.get());
@@ -210,6 +216,8 @@ Status CompressedSecondaryCache::InsertInternal(

    val = Slice(compressed_val);
    data_size = compressed_val.size();
+    payload = EncodeVarint64(data_size_ptr, data_size);
+    header_size = payload - header;
    total_size = header_size + data_size;
    PERF_COUNTER_ADD(compressed_sec_cache_compressed_bytes, data_size);

@@ -222,14 +230,21 @@ Status CompressedSecondaryCache::InsertInternal(

  PERF_COUNTER_ADD(compressed_sec_cache_insert_real_count, 1);
  if (cache_options_.enable_custom_split_merge) {
-    size_t charge{0};
-    CacheValueChunk* value_chunks_head =
-        SplitValueIntoChunks(val, cache_options_.compression_type, charge);
-    return cache_->Insert(key, value_chunks_head, internal_helper, charge);
+    size_t split_charge{0};
+    CacheValueChunk* value_chunks_head = SplitValueIntoChunks(
+        val, cache_options_.compression_type, split_charge);
+    return cache_->Insert(key, value_chunks_head, internal_helper,
+                          split_charge);
  } else {
+#ifdef ROCKSDB_MALLOC_USABLE_SIZE
+    size_t charge = malloc_usable_size(ptr.get());
+#else
+    size_t charge = total_size;
+#endif
    std::memcpy(ptr.get(), header, header_size);
    CacheAllocationPtr* buf = new CacheAllocationPtr(std::move(ptr));
-    return cache_->Insert(key, buf, internal_helper, total_size);
+    charge += sizeof(CacheAllocationPtr);
+    return cache_->Insert(key, buf, internal_helper, charge);
  }
 }

@@ -398,6 +413,21 @@ const Cache::CacheItemHelper* CompressedSecondaryCache::GetHelper(
  }
 }

+size_t CompressedSecondaryCache::TEST_GetCharge(const Slice& key) {
+  Cache::Handle* lru_handle = cache_->Lookup(key);
+  if (lru_handle == nullptr) {
+    return 0;
+  }
+
+  size_t charge = cache_->GetCharge(lru_handle);
+  if (cache_->Value(lru_handle) != nullptr &&
+      !cache_options_.enable_custom_split_merge) {
+    charge -= 10;
+  }
+  cache_->Release(lru_handle, /*erase_if_last_ref=*/false);
+  return charge;
+}
+
 std::shared_ptr<SecondaryCache>
 CompressedSecondaryCacheOptions::MakeSharedSecondaryCache() const {
  return std::make_shared<CompressedSecondaryCache>(*this);
@@ -139,6 +139,8 @@ class CompressedSecondaryCache : public SecondaryCache {
                        const Cache::CacheItemHelper* helper,
                        CompressionType type, CacheTier source);

+  size_t TEST_GetCharge(const Slice& key);
+
  // TODO: clean up to use cleaner interfaces in typed_cache.h
  const Cache::CacheItemHelper* GetHelper(bool enable_custom_split_merge) const;
  std::shared_ptr<Cache> cache_;
@@ -39,6 +39,8 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
 protected:
  void BasicTestHelper(std::shared_ptr<SecondaryCache> sec_cache,
                       bool sec_cache_is_compressed) {
+    CompressedSecondaryCache* comp_sec_cache =
+        static_cast<CompressedSecondaryCache*>(sec_cache.get());
    get_perf_context()->Reset();
    bool kept_in_sec_cache{true};
    // Lookup an non-existent key.
@@ -66,6 +68,8 @@ class CompressedSecondaryCacheTestBase : public testing::Test,
    ASSERT_OK(sec_cache->Insert(key1, &item1, GetHelper(), false));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 1);

+    ASSERT_GT(comp_sec_cache->TEST_GetCharge(key1), 1000);
+
    std::unique_ptr<SecondaryCacheResultHandle> handle1_2 =
        sec_cache->Lookup(key1, GetHelper(), this, true, /*advise_erase=*/true,
                          /*stats=*/nullptr, kept_in_sec_cache);
@@ -677,6 +677,17 @@ const Cache::CacheItemHelper* LRUCache::GetCacheItemHelper(
  return h->helper;
 }

+void LRUCache::ApplyToHandle(
+    Cache* cache, Handle* handle,
+    const std::function<void(const Slice& key, ObjectPtr value, size_t charge,
+                             const CacheItemHelper* helper)>& callback) {
+  auto cache_ptr = static_cast<LRUCache*>(cache);
+  auto h = static_cast<const LRUHandle*>(handle);
+  callback(h->key(), h->value,
+           h->GetCharge(cache_ptr->GetShard(0).metadata_charge_policy_),
+           h->helper);
+}
+
 size_t LRUCache::TEST_GetLRUSize() {
  return SumOverShards([](LRUCacheShard& cs) { return cs.TEST_GetLRUSize(); });
 }
@@ -452,6 +452,12 @@ class LRUCache
  size_t GetCharge(Handle* handle) const override;
  const CacheItemHelper* GetCacheItemHelper(Handle* handle) const override;

+  void ApplyToHandle(
+      Cache* cache, Handle* handle,
+      const std::function<void(const Slice& key, ObjectPtr obj, size_t charge,
+                               const CacheItemHelper* helper)>& callback)
+      override;
+
  // Retrieves number of elements in LRU, for unit test purpose only.
  size_t TEST_GetLRUSize();
  // Retrieves high pri pool ratio.
@@ -271,7 +271,8 @@ Status CacheWithSecondaryAdapter::Insert(const Slice& key, ObjectPtr value,
  // Warm up the secondary cache with the compressed block. The secondary
  // cache may choose to ignore it based on the admission policy.
  if (value != nullptr && !compressed_value.empty() &&
-      adm_policy_ == TieredAdmissionPolicy::kAdmPolicyThreeQueue) {
+      adm_policy_ == TieredAdmissionPolicy::kAdmPolicyThreeQueue &&
+      helper->IsSecondaryCacheCompatible()) {
    Status status = secondary_cache_->InsertSaved(key, compressed_value, type);
    assert(status.ok() || status.IsNotSupported());
  }
@@ -253,6 +253,7 @@ TEST_F(DBTieredSecondaryCacheTest, BasicTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));

  // Disable paranoid_file_checks so that flush will not read back the newly
@@ -364,6 +365,7 @@ TEST_F(DBTieredSecondaryCacheTest, BasicMultiGetTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));

  options.paranoid_file_checks = false;
@@ -506,6 +508,7 @@ TEST_F(DBTieredSecondaryCacheTest, WaitAllTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));

  options.paranoid_file_checks = false;
@@ -606,6 +609,7 @@ TEST_F(DBTieredSecondaryCacheTest, ReadyBeforeWaitAllTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
  options.statistics = CreateDBStatistics();

@@ -717,6 +721,7 @@ TEST_F(DBTieredSecondaryCacheTest, IterateTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));

  options.paranoid_file_checks = false;
@@ -760,6 +765,54 @@ TEST_F(DBTieredSecondaryCacheTest, IterateTest) {
  Destroy(options);
 }

+TEST_F(DBTieredSecondaryCacheTest, VolatileTierTest) {
+  if (!LZ4_Supported()) {
+    ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
+    return;
+  }
+
+  BlockBasedTableOptions table_options;
+  // We want a block cache of size 5KB, and a compressed secondary cache of
+  // size 5KB. However, we specify a block cache size of 256KB here in order
+  // to take into account the cache reservation in the block cache on
+  // behalf of the compressed cache. The unit of cache reservation is 256KB.
+  // The effective block cache capacity will be calculated as 256 + 5 = 261KB,
+  // and 256KB will be reserved for the compressed cache, leaving 5KB for
+  // the primary block cache. We only have to worry about this here because
+  // the cache size is so small.
+  table_options.block_cache = NewCache(256 * 1024, 5 * 1024, 256 * 1024);
+  table_options.block_size = 4 * 1024;
+  table_options.cache_index_and_filter_blocks = false;
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+
+  // Disable paranoid_file_checks so that flush will not read back the newly
+  // written file
+  options.paranoid_file_checks = false;
+  options.lowest_used_cache_tier = CacheTier::kVolatileTier;
+  DestroyAndReopen(options);
+  Random rnd(301);
+  const int N = 256;
+  for (int i = 0; i < N; i++) {
+    std::string p_v;
+    test::CompressibleString(&rnd, 0.5, 1007, &p_v);
+    ASSERT_OK(Put(Key(i), p_v));
+  }
+
+  ASSERT_OK(Flush());
+
+  // Since lowest_used_cache_tier is the volatile tier, nothing should be
+  // inserted in the secondary cache.
+  std::string v = Get(Key(0));
+  ASSERT_EQ(1007, v.size());
+  ASSERT_EQ(nvm_sec_cache()->num_insert_saved(), 0u);
+  ASSERT_EQ(nvm_sec_cache()->num_misses(), 0u);
+
+  Destroy(options);
+}
+
 class DBTieredAdmPolicyTest
    : public DBTieredSecondaryCacheTest,
      public testing::WithParamInterface<TieredAdmissionPolicy> {};
@@ -784,6 +837,7 @@ TEST_P(DBTieredAdmPolicyTest, CompressedOnlyTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));

  size_t comp_cache_usage = compressed_secondary_cache()->TEST_GetUsage();
@@ -836,6 +890,7 @@ TEST_P(DBTieredAdmPolicyTest, CompressedCacheAdmission) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));

  size_t comp_cache_usage = compressed_secondary_cache()->TEST_GetUsage();
@@ -937,6 +992,7 @@ TEST_F(DBTieredSecondaryCacheTest, FSBufferTest) {
  table_options.cache_index_and_filter_blocks = false;
  Options options = GetDefaultOptions();
  options.create_if_missing = true;
+  options.compression = kLZ4Compression;
  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
  options.statistics = CreateDBStatistics();
  options.env = wrap_env.get();
@@ -45,20 +45,23 @@ void ArenaWrappedDBIter::Init(
    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iteration,
    uint64_t version_number, ReadCallback* read_callback,
    ColumnFamilyHandleImpl* cfh, bool expose_blob_index, bool allow_refresh) {
-  auto mem = arena_.AllocateAligned(sizeof(DBIter));
-  db_iter_ = new (mem) DBIter(
-      env, read_options, ioptions, mutable_cf_options, ioptions.user_comparator,
-      /* iter */ nullptr, version, sequence, true,
-      max_sequential_skip_in_iteration, read_callback, cfh, expose_blob_index);
-  sv_number_ = version_number;
  read_options_ = read_options;
-  allow_refresh_ = allow_refresh;
-  memtable_range_tombstone_iter_ = nullptr;
-
  if (!CheckFSFeatureSupport(env->GetFileSystem().get(),
                             FSSupportedOps::kAsyncIO)) {
    read_options_.async_io = false;
  }
+  read_options_.total_order_seek |= ioptions.prefix_seek_opt_in_only;
+
+  auto mem = arena_.AllocateAligned(sizeof(DBIter));
+  db_iter_ = new (mem) DBIter(env, read_options_, ioptions, mutable_cf_options,
+                              ioptions.user_comparator,
+                              /* iter */ nullptr, version, sequence, true,
+                              max_sequential_skip_in_iteration, read_callback,
+                              cfh, expose_blob_index);
+
+  sv_number_ = version_number;
+  allow_refresh_ = allow_refresh;
+  memtable_range_tombstone_iter_ = nullptr;
 }

 Status ArenaWrappedDBIter::Refresh() { return Refresh(nullptr); }
@@ -138,10 +141,10 @@ Status ArenaWrappedDBIter::Refresh(const Snapshot* snapshot) {
            reinit_internal_iter();
            break;
          } else {
-            delete *memtable_range_tombstone_iter_;
-            *memtable_range_tombstone_iter_ = new TruncatedRangeDelIterator(
-                std::unique_ptr<FragmentedRangeTombstoneIterator>(t),
-                &cfd->internal_comparator(), nullptr, nullptr);
+            *memtable_range_tombstone_iter_ =
+                std::make_unique<TruncatedRangeDelIterator>(
+                    std::unique_ptr<FragmentedRangeTombstoneIterator>(t),
+                    &cfd->internal_comparator(), nullptr, nullptr);
          }
        }
        db_impl->ReturnAndCleanupSuperVersion(cfd, sv);
@@ -55,7 +55,8 @@ class ArenaWrappedDBIter : public Iterator {
    db_iter_->SetIter(iter);
  }

-  void SetMemtableRangetombstoneIter(TruncatedRangeDelIterator** iter) {
+  void SetMemtableRangetombstoneIter(
+      std::unique_ptr<TruncatedRangeDelIterator>* iter) {
    memtable_range_tombstone_iter_ = iter;
  }

@@ -110,7 +111,8 @@ class ArenaWrappedDBIter : public Iterator {
  bool allow_refresh_ = true;
  // If this is nullptr, it means the mutable memtable does not contain range
  // tombstone when added under this DBIter.
-  TruncatedRangeDelIterator** memtable_range_tombstone_iter_ = nullptr;
+  std::unique_ptr<TruncatedRangeDelIterator>* memtable_range_tombstone_iter_ =
+      nullptr;
 };

 // Generate the arena wrapped iterator class.
@@ -42,6 +42,7 @@ Status BlobFileCache::GetBlobFileReader(
  assert(blob_file_reader);
  assert(blob_file_reader->IsEmpty());

+  // NOTE: sharing same Cache with table_cache
  const Slice key = GetSliceForKey(&blob_file_number);

  assert(cache_);
@@ -98,4 +99,13 @@ Status BlobFileCache::GetBlobFileReader(
  return Status::OK();
 }

+void BlobFileCache::Evict(uint64_t blob_file_number) {
+  // NOTE: sharing same Cache with table_cache
+  const Slice key = GetSliceForKey(&blob_file_number);
+
+  assert(cache_);
+
+  cache_.get()->Erase(key);
+}
+
 }  // namespace ROCKSDB_NAMESPACE
@@ -36,6 +36,15 @@ class BlobFileCache {
                           uint64_t blob_file_number,
                           CacheHandleGuard<BlobFileReader>* blob_file_reader);

+  // Called when a blob file is obsolete to ensure it is removed from the cache
+  // to avoid effectively leaking the open file and assicated memory
+  void Evict(uint64_t blob_file_number);
+
+  // Used to identify cache entries for blob files (not normally useful)
+  static const Cache::CacheItemHelper* GetHelper() {
+    return CacheInterface::GetBasicHelper();
+  }
+
 private:
  using CacheInterface =
      BasicTypedCacheInterface<BlobFileReader, CacheEntryRole::kMisc>;
@@ -532,6 +532,42 @@ struct rocksdb_universal_compaction_options_t {
  ROCKSDB_NAMESPACE::CompactionOptionsUniversal* rep;
 };

+struct rocksdb_callback_logger_t : public Logger {
+  static const ssize_t STACK_BUFSZ = 512;
+  rocksdb_callback_logger_t(InfoLogLevel log_level,
+                            void (*logv_cb)(void*, unsigned, char*, size_t),
+                            void* priv)
+      : Logger(log_level), logv_cb_(logv_cb), priv_(priv) {}
+
+  using Logger::Logv;
+  void Logv(const InfoLogLevel level, const char* fmt, va_list ap0) override {
+    char stack_buf[STACK_BUFSZ];
+    char* alloc_buf = nullptr;
+    char* buf = stack_buf;
+    int len = 0;
+    va_list ap1;
+    if (!logv_cb_) return;
+    va_copy(ap1, ap0);
+    len = vsnprintf(buf, STACK_BUFSZ, fmt, ap0);
+    if (len <= 0)
+      goto cleanup;
+    else if (len >= STACK_BUFSZ) {
+      buf = alloc_buf = reinterpret_cast<char*>(malloc(len + 1));
+      if (!buf) goto cleanup;
+      len = vsnprintf(buf, len + 1, fmt, ap1);
+      if (len <= 0) goto cleanup;
+    }
+    logv_cb_(priv_, unsigned(level), buf, size_t(len));
+  cleanup:
+    va_end(ap1);
+    free(alloc_buf);
+  }
+
+ private:
+  void (*logv_cb_)(void*, unsigned, char*, size_t) = nullptr;
+  void* priv_ = nullptr;
+};
+
 static bool SaveError(char** errptr, const Status& s) {
  assert(errptr != nullptr);
  if (s.ok()) {
@@ -1802,6 +1838,26 @@ void rocksdb_approximate_sizes_cf(
  delete[] ranges;
 }

+extern ROCKSDB_LIBRARY_API void rocksdb_approximate_sizes_cf_with_flags(
+    rocksdb_t* db, rocksdb_column_family_handle_t* column_family,
+    int num_ranges, const char* const* range_start_key,
+    const size_t* range_start_key_len, const char* const* range_limit_key,
+    const size_t* range_limit_key_len, uint8_t include_flags, uint64_t* sizes,
+    char** errptr) {
+  Range* ranges = new Range[num_ranges];
+  for (int i = 0; i < num_ranges; i++) {
+    ranges[i].start = Slice(range_start_key[i], range_start_key_len[i]);
+    ranges[i].limit = Slice(range_limit_key[i], range_limit_key_len[i]);
+  }
+  Status s = db->rep->GetApproximateSizes(
+      column_family->rep, ranges, num_ranges, sizes,
+      static_cast<DB::SizeApproximationFlags>(include_flags));
+  if (!s.ok()) {
+    SaveError(errptr, s);
+  }
+  delete[] ranges;
+}
+
 void rocksdb_delete_file(rocksdb_t* db, const char* name) {
  db->rep->DeleteFile(name);
 }
@@ -2230,6 +2286,32 @@ class H : public WriteBatch::Handler {
  }
 };

+class HCF : public WriteBatch::Handler {
+ public:
+  void* state_;
+  void (*put_cf_)(void*, uint32_t cfid, const char* k, size_t klen,
+                  const char* v, size_t vlen);
+  void (*deleted_cf_)(void*, uint32_t cfid, const char* k, size_t klen);
+  void (*merge_cf_)(void*, uint32_t cfid, const char* k, size_t klen,
+                    const char* v, size_t vlen);
+  Status PutCF(uint32_t column_family_id, const Slice& key,
+               const Slice& value) override {
+    (*put_cf_)(state_, column_family_id, key.data(), key.size(), value.data(),
+               value.size());
+    return Status::OK();
+  }
+  Status DeleteCF(uint32_t column_family_id, const Slice& key) override {
+    (*deleted_cf_)(state_, column_family_id, key.data(), key.size());
+    return Status::OK();
+  }
+  Status MergeCF(uint32_t column_family_id, const Slice& key,
+                 const Slice& value) override {
+    (*merge_cf_)(state_, column_family_id, key.data(), key.size(), value.data(),
+                 value.size());
+    return Status::OK();
+  }
+};
+
 void rocksdb_writebatch_iterate(rocksdb_writebatch_t* b, void* state,
                                void (*put)(void*, const char* k, size_t klen,
                                            const char* v, size_t vlen),
@@ -2242,6 +2324,21 @@ void rocksdb_writebatch_iterate(rocksdb_writebatch_t* b, void* state,
  b->rep.Iterate(&handler);
 }

+void rocksdb_writebatch_iterate_cf(
+    rocksdb_writebatch_t* b, void* state,
+    void (*put_cf)(void*, uint32_t cfid, const char* k, size_t klen,
+                   const char* v, size_t vlen),
+    void (*deleted_cf)(void*, uint32_t cfid, const char* k, size_t klen),
+    void (*merge_cf)(void*, uint32_t cfid, const char* k, size_t klen,
+                     const char* v, size_t vlen)) {
+  HCF handler;
+  handler.state_ = state;
+  handler.put_cf_ = put_cf;
+  handler.deleted_cf_ = deleted_cf;
+  handler.merge_cf_ = merge_cf;
+  b->rep.Iterate(&handler);
+}
+
 const char* rocksdb_writebatch_data(rocksdb_writebatch_t* b, size_t* size) {
  *size = b->rep.GetDataSize();
  return b->rep.Data().c_str();
@@ -3037,6 +3134,15 @@ rocksdb_logger_t* rocksdb_logger_create_stderr_logger(int log_level,
  return logger;
 }

+rocksdb_logger_t* rocksdb_logger_create_callback_logger(
+    int log_level, void (*callback)(void*, unsigned, char*, size_t),
+    void* priv) {
+  rocksdb_logger_t* logger = new rocksdb_logger_t;
+  logger->rep = std::make_shared<rocksdb_callback_logger_t>(
+      static_cast<InfoLogLevel>(log_level), callback, priv);
+  return logger;
+}
+
 void rocksdb_logger_destroy(rocksdb_logger_t* logger) { delete logger; }

 void rocksdb_options_set_env(rocksdb_options_t* opt, rocksdb_env_t* env) {
@@ -3969,6 +4075,15 @@ void rocksdb_options_set_write_dbid_to_manifest(
  opt->rep.write_dbid_to_manifest = write_dbid_to_manifest;
 }

+unsigned char rocksdb_options_get_write_identity_file(rocksdb_options_t* opt) {
+  return opt->rep.write_identity_file;
+}
+
+void rocksdb_options_set_write_identity_file(
+    rocksdb_options_t* opt, unsigned char write_identity_file) {
+  opt->rep.write_identity_file = write_identity_file;
+}
+
 unsigned char rocksdb_options_get_track_and_verify_wals_in_manifest(
    rocksdb_options_t* opt) {
  return opt->rep.track_and_verify_wals_in_manifest;
@@ -199,6 +199,79 @@ static void CheckDel(void* ptr, const char* k, size_t klen) {
  (*state)++;
 }

+// Callback from rocksdb_writebatch_iterate_cf()
+static void CheckPutCF(void* ptr, uint32_t cfid, const char* k, size_t klen,
+                       const char* v, size_t vlen) {
+  int* state = (int*)ptr;
+  switch (*state) {
+    case 0:
+      CheckEqual("bar", k, klen);
+      CheckEqual("b", v, vlen);
+      CheckCondition(cfid == 1);
+      break;
+    case 1:
+      CheckEqual("box", k, klen);
+      CheckEqual("c", v, vlen);
+      CheckCondition(cfid == 1);
+      break;
+    case 4:
+      CheckEqual("foo", k, klen);
+      CheckEqual("f", v, vlen);
+      CheckCondition(cfid == 0);
+      break;
+    case 6:
+      CheckEqual("baz", k, klen);
+      CheckEqual("a", v, vlen);
+      CheckCondition(cfid == 0);
+      break;
+    default:
+      CheckCondition(false);
+      break;
+  }
+  (*state)++;
+}
+
+// Callback from rocksdb_writebatch_iterate_cf()
+static void CheckDelCF(void* ptr, uint32_t cfid, const char* k, size_t klen) {
+  int* state = (int*)ptr;
+  switch (*state) {
+    case 2:
+      CheckEqual("bar", k, klen);
+      CheckCondition(cfid == 1);
+      break;
+    case 5:
+      CheckEqual("foo", k, klen);
+      CheckCondition(cfid == 0);
+      break;
+    default:
+      CheckCondition(false);
+      break;
+  }
+  (*state)++;
+}
+
+// Callback from rocksdb_writebatch_iterate_cf()
+static void CheckMergeCF(void* ptr, uint32_t cfid, const char* k, size_t klen,
+                         const char* v, size_t vlen) {
+  int* state = (int*)ptr;
+  switch (*state) {
+    case 3:
+      CheckEqual("box", k, klen);
+      CheckEqual("cc", v, vlen);
+      CheckCondition(cfid == 1);
+      break;
+    case 7:
+      CheckEqual("baz", k, klen);
+      CheckEqual("aa", v, vlen);
+      CheckCondition(cfid == 0);
+      break;
+    default:
+      CheckCondition(false);
+      break;
+  }
+  (*state)++;
+}
+
 static void CmpDestroy(void* arg) { (void)arg; }

 static int CmpCompare(void* arg, const char* a, size_t alen, const char* b,
@@ -699,6 +772,8 @@ int main(int argc, char** argv) {
  rocksdb_options_set_write_buffer_size(options, 100000);
  rocksdb_options_set_paranoid_checks(options, 1);
  rocksdb_options_set_max_open_files(options, 10);
+  /* Compatibility with how test was written */
+  rocksdb_options_set_write_dbid_to_manifest(options, 0);

  table_options = rocksdb_block_based_options_create();
  rocksdb_block_based_options_set_block_cache(table_options, cache);
@@ -889,15 +964,24 @@ int main(int argc, char** argv) {
    rocksdb_options_t* options_dbid_in_manifest = rocksdb_options_create();
    rocksdb_options_set_create_if_missing(options_dbid_in_manifest, 1);

+    rocksdb_options_set_write_dbid_to_manifest(options_dbid_in_manifest, false);
    unsigned char write_to_manifest =
        rocksdb_options_get_write_dbid_to_manifest(options_dbid_in_manifest);
    CheckCondition(!write_to_manifest);
    rocksdb_options_set_write_dbid_to_manifest(options_dbid_in_manifest, true);
-    CheckCondition(!write_to_manifest);
    write_to_manifest =
        rocksdb_options_get_write_dbid_to_manifest(options_dbid_in_manifest);
    CheckCondition(write_to_manifest);

+    rocksdb_options_set_write_identity_file(options_dbid_in_manifest, true);
+    unsigned char write_identity_file =
+        rocksdb_options_get_write_identity_file(options_dbid_in_manifest);
+    CheckCondition(write_identity_file);
+    rocksdb_options_set_write_identity_file(options_dbid_in_manifest, false);
+    write_identity_file =
+        rocksdb_options_get_write_identity_file(options_dbid_in_manifest);
+    CheckCondition(!write_identity_file);
+
    db = rocksdb_open(options_dbid_in_manifest, dbbackupname, &err);
    CheckNoError(err);

@@ -1688,6 +1772,21 @@ int main(int argc, char** argv) {
    CheckPinGetCF(db, roptions, handles[1], "bar", NULL);
    CheckPinGetCF(db, roptions, handles[1], "box", "c");
    CheckPinGetCF(db, roptions, handles[1], "buff", "rocksdb");
+    rocksdb_writebatch_clear(wb);
+    // Test WriteBatch iteration with Column Family
+    int pos = 0;
+    rocksdb_writebatch_put_cf(wb, handles[1], "bar", 3, "b", 1);
+    rocksdb_writebatch_put_cf(wb, handles[1], "box", 3, "c", 1);
+    rocksdb_writebatch_delete_cf(wb, handles[1], "bar", 3);
+    rocksdb_writebatch_merge_cf(wb, handles[1], "box", 3, "cc", 2);
+    rocksdb_writebatch_put(wb, "foo", 3, "f", 1);
+    rocksdb_writebatch_delete(wb, "foo", 3);
+    rocksdb_writebatch_put(wb, "baz", 3, "a", 1);
+    rocksdb_writebatch_merge(wb, "baz", 3, "aa", 2);
+    rocksdb_writebatch_iterate_cf(wb, &pos, CheckPutCF, CheckDelCF,
+                                  CheckMergeCF);
+    CheckCondition(pos == 8);
+    rocksdb_writebatch_clear(wb);
    rocksdb_writebatch_destroy(wb);

    rocksdb_flush_wal(db, 1, &err);
@@ -1201,8 +1201,10 @@ Status ColumnFamilyData::RangesOverlapWithMemtables(
  read_opts.total_order_seek = true;
  MergeIteratorBuilder merge_iter_builder(&internal_comparator_, &arena);
  merge_iter_builder.AddIterator(super_version->mem->NewIterator(
-      read_opts, /*seqno_to_time_mapping=*/nullptr, &arena));
+      read_opts, /*seqno_to_time_mapping=*/nullptr, &arena,
+      /*prefix_extractor=*/nullptr));
  super_version->imm->AddIterators(read_opts, /*seqno_to_time_mapping=*/nullptr,
+                                   /*prefix_extractor=*/nullptr,
                                   &merge_iter_builder,
                                   false /* add_range_tombstone_iter */);
  ScopedArenaPtr<InternalIterator> memtable_iter(merge_iter_builder.Finish());
@@ -1565,28 +1567,6 @@ Status ColumnFamilyData::SetOptions(
  return s;
 }

-// REQUIRES: DB mutex held
-Env::WriteLifeTimeHint ColumnFamilyData::CalculateSSTWriteHint(int level) {
-  if (initial_cf_options_.compaction_style != kCompactionStyleLevel) {
-    return Env::WLTH_NOT_SET;
-  }
-  if (level == 0) {
-    return Env::WLTH_MEDIUM;
-  }
-  int base_level = current_->storage_info()->base_level();
-
-  // L1: medium, L2: long, ...
-  if (level - base_level >= 2) {
-    return Env::WLTH_EXTREME;
-  } else if (level < base_level) {
-    // There is no restriction which prevents level passed in to be smaller
-    // than base_level.
-    return Env::WLTH_MEDIUM;
-  }
-  return static_cast<Env::WriteLifeTimeHint>(
-      level - base_level + static_cast<int>(Env::WLTH_MEDIUM));
-}
-
 Status ColumnFamilyData::AddDirectories(
    std::map<std::string, std::shared_ptr<FSDirectory>>* created_dirs) {
  Status s;
@@ -1652,6 +1632,9 @@ bool ColumnFamilyData::ShouldPostponeFlushToRetainUDT(
  }
  for (const Slice& table_newest_udt :
       imm()->GetTablesNewestUDT(max_memtable_id)) {
+    if (table_newest_udt.empty()) {
+      continue;
+    }
    assert(table_newest_udt.size() == full_history_ts_low.size());
    // Checking the newest UDT contained in MemTable with ascending ID up to
    // `max_memtable_id`. Return immediately on finding the first MemTable that
@@ -401,6 +401,7 @@ class ColumnFamilyData {
                         SequenceNumber earliest_seq);

  TableCache* table_cache() const { return table_cache_.get(); }
+  BlobFileCache* blob_file_cache() const { return blob_file_cache_.get(); }
  BlobSource* blob_source() const { return blob_source_.get(); }

  // See documentation in compaction_picker.h
@@ -511,8 +512,6 @@ class ColumnFamilyData {
    return initial_cf_options_;
  }

-  Env::WriteLifeTimeHint CalculateSSTWriteHint(int level);
-
  // created_dirs remembers directory created, so that we don't need to call
  // the same data creation operation again.
  Status AddDirectories(
@@ -3067,12 +3067,20 @@ TEST_P(ColumnFamilyTest, CompactionSpeedupForMarkedFiles) {
  WaitForCompaction();
  AssertFilesPerLevel("0,1", 0 /* cf */);

+  // We should calculate the limit by obtaining the number of env background
+  // threads, because the current test case will share the same env
+  // with another case that may have already increased the number of
+  // background threads which is larger than kParallelismLimit
+  const auto limit = env_->GetBackgroundThreads(Env::Priority::LOW);
+
  // Block the compaction thread pool so marked files accumulate in L0.
-  test::SleepingBackgroundTask sleeping_tasks[kParallelismLimit];
-  for (int i = 0; i < kParallelismLimit; i++) {
+  std::vector<std::shared_ptr<test::SleepingBackgroundTask>> sleeping_tasks;
+  for (int i = 0; i < limit; i++) {
+    sleeping_tasks.emplace_back(
+        std::make_shared<test::SleepingBackgroundTask>());
    env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask,
-                   &sleeping_tasks[i], Env::Priority::LOW);
-    sleeping_tasks[i].WaitUntilSleeping();
+                   sleeping_tasks[i].get(), Env::Priority::LOW);
+    sleeping_tasks[i]->WaitUntilSleeping();
  }

  // Zero marked upper-level files. No speedup.
@@ -3091,9 +3099,9 @@ TEST_P(ColumnFamilyTest, CompactionSpeedupForMarkedFiles) {
  ASSERT_EQ(kParallelismLimit, dbfull()->TEST_BGCompactionsAllowed());
  AssertFilesPerLevel("2,1", 0 /* cf */);

-  for (int i = 0; i < kParallelismLimit; i++) {
-    sleeping_tasks[i].WakeUp();
-    sleeping_tasks[i].WaitUntilDone();
+  for (int i = 0; i < limit; i++) {
+    sleeping_tasks[i]->WakeUp();
+    sleeping_tasks[i]->WaitUntilDone();
  }
 }

@@ -63,7 +63,9 @@ uint64_t TotalFileSize(const std::vector<FileMetaData*>& files) {
  return sum;
 }

-void Compaction::SetInputVersion(Version* _input_version) {
+// TODO(hx235): consider making this function part of the construction so we
+// don't forget to call it
+void Compaction::FinalizeInputInfo(Version* _input_version) {
  input_version_ = _input_version;
  cfd_ = input_version_->cfd();

@@ -684,12 +686,11 @@ bool Compaction::KeyRangeNotExistsBeyondOutputLevel(
 };

 // Mark (or clear) each file that is being compacted
-void Compaction::MarkFilesBeingCompacted(bool mark_as_compacted) {
+void Compaction::MarkFilesBeingCompacted(bool being_compacted) const {
  for (size_t i = 0; i < num_input_levels(); i++) {
    for (size_t j = 0; j < inputs_[i].size(); j++) {
-      assert(mark_as_compacted ? !inputs_[i][j]->being_compacted
-                               : inputs_[i][j]->being_compacted);
-      inputs_[i][j]->being_compacted = mark_as_compacted;
+      assert(being_compacted != inputs_[i][j]->being_compacted);
+      inputs_[i][j]->being_compacted = being_compacted;
    }
  }
 }
@@ -733,7 +734,7 @@ uint64_t Compaction::CalculateTotalInputSize() const {
  return size;
 }

-void Compaction::ReleaseCompactionFiles(Status status) {
+void Compaction::ReleaseCompactionFiles(const Status& status) {
  MarkFilesBeingCompacted(false);
  cfd_->compaction_picker()->ReleaseCompactionFiles(this, status);
 }
@@ -864,6 +865,11 @@ bool Compaction::ShouldFormSubcompactions() const {
    return false;
  }

+  if (cfd_->ioptions()->table_factory->Name() ==
+      TableFactory::kPlainTableName()) {
+    return false;
+  }
+
  // Round-Robin pri under leveled compaction allows subcompactions by default
  // and the number of subcompactions can be larger than max_subcompactions_
  if (cfd_->ioptions()->compaction_pri == kRoundRobin &&
@@ -230,7 +230,7 @@ class Compaction {
  // Delete this compaction from the list of running compactions.
  //
  // Requirement: DB mutex held
-  void ReleaseCompactionFiles(Status status);
+  void ReleaseCompactionFiles(const Status& status);

  // Returns the summary of the compaction in "output" with maximum "len"
  // in bytes.  The caller is responsible for the memory management of
@@ -289,14 +289,7 @@ class Compaction {
  // is the sum of all input file sizes.
  uint64_t OutputFilePreallocationSize() const;

-  // TODO(hx235): eventually we should consider `InitInputTableProperties()`'s
-  // status and fail the compaction if needed
-  // TODO(hx235): consider making this function part of the construction so we
-  // don't forget to call it
-  void FinalizeInputInfo(Version* input_version) {
-    SetInputVersion(input_version);
-    InitInputTableProperties().PermitUncheckedError();
-  }
+  void FinalizeInputInfo(Version* input_version);

  struct InputLevelSummaryBuffer {
    char buffer[128];
@@ -333,6 +326,16 @@ class Compaction {
      int output_level, VersionStorageInfo* vstorage,
      const std::vector<CompactionInputFiles>& inputs);

+  // TODO(hx235): eventually we should consider `InitInputTableProperties()`'s
+  // status and fail the compaction if needed
+  //
+  // May open and read table files for table property.
+  // Should not be called while holding mutex_.
+  const TablePropertiesCollection& GetOrInitInputTableProperties() {
+    InitInputTableProperties().PermitUncheckedError();
+    return input_table_properties_;
+  }
+
  const TablePropertiesCollection& GetInputTableProperties() const {
    return input_table_properties_;
  }
@@ -432,14 +435,13 @@ class Compaction {
                                      const int start_level,
                                      const int output_level);

+  // mark (or clear) all files that are being compacted
+  void MarkFilesBeingCompacted(bool being_compacted) const;
+
 private:
-  void SetInputVersion(Version* input_version);

  Status InitInputTableProperties();

-  // mark (or clear) all files that are being compacted
-  void MarkFilesBeingCompacted(bool mark_as_compacted);
-
  // get the smallest and largest key present in files to be compacted
  static void GetBoundaryKeys(VersionStorageInfo* vstorage,
                              const std::vector<CompactionInputFiles>& inputs,
@@ -251,12 +251,13 @@ void CompactionJob::Prepare() {

  // Generate file_levels_ for compaction before making Iterator
  auto* c = compact_->compaction;
-  ColumnFamilyData* cfd = c->column_family_data();
+  [[maybe_unused]] ColumnFamilyData* cfd = c->column_family_data();
  assert(cfd != nullptr);
-  assert(cfd->current()->storage_info()->NumLevelFiles(
-             compact_->compaction->level()) > 0);
+  const VersionStorageInfo* storage_info = c->input_version()->storage_info();
+  assert(storage_info);
+  assert(storage_info->NumLevelFiles(compact_->compaction->level()) > 0);

-  write_hint_ = cfd->CalculateSSTWriteHint(c->output_level());
+  write_hint_ = storage_info->CalculateSSTWriteHint(c->output_level());
  bottommost_level_ = c->bottommost_level();

  if (c->ShouldFormSubcompactions()) {
@@ -297,8 +298,8 @@ void CompactionJob::Prepare() {
    for (const auto& each_level : *c->inputs()) {
      for (const auto& fmd : each_level.files) {
        std::shared_ptr<const TableProperties> tp;
-        Status s =
-            cfd->current()->GetTableProperties(read_options, &tp, fmd, nullptr);
+        Status s = c->input_version()->GetTableProperties(read_options, &tp,
+                                                          fmd, nullptr);
        if (s.ok()) {
          s = seqno_to_time_mapping_.DecodeFrom(tp->seqno_to_time_mapping);
        }
@@ -468,6 +469,11 @@ void CompactionJob::GenSubcompactionBoundaries() {
  ReadOptions read_options(Env::IOActivity::kCompaction);
  read_options.rate_limiter_priority = GetRateLimiterPriority();
  auto* c = compact_->compaction;
+  if (c->immutable_options()->table_factory->Name() ==
+      TableFactory::kPlainTableName()) {
+    return;
+  }
+
  if (c->max_subcompactions() <= 1 &&
      !(c->immutable_options()->compaction_pri == kRoundRobin &&
        c->immutable_options()->compaction_style == kCompactionStyleLevel)) {
@@ -621,6 +627,7 @@ Status CompactionJob::Run() {
  const size_t num_threads = compact_->sub_compact_states.size();
  assert(num_threads > 0);
  const uint64_t start_micros = db_options_.clock->NowMicros();
+  compact_->compaction->GetOrInitInputTableProperties();

  // Launch a thread for each of subcompactions 1...num_threads-1
  std::vector<port::Thread> thread_pool;
@@ -799,6 +806,12 @@ Status CompactionJob::Run() {
    }
  }

+  // Before the compaction starts, is_remote_compaction was set to true if
+  // compaction_service is set. We now know whether each sub_compaction was
+  // done remotely or not. Reset is_remote_compaction back to false and allow
+  // AggregateCompactionStats() to set the right value.
+  compaction_job_stats_->is_remote_compaction = false;
+
  // Finish up all bookkeeping to unify the subcompaction results.
  compact_->AggregateCompactionStats(compaction_stats_, *compaction_job_stats_);
  uint64_t num_input_range_del = 0;
@@ -1077,6 +1090,7 @@ void CompactionJob::ProcessKeyValueCompaction(SubcompactionState* sub_compact) {
    }
    // fallback to local compaction
    assert(comp_status == CompactionServiceJobStatus::kUseLocal);
+    sub_compact->compaction_job_stats.is_remote_compaction = false;
  }

  uint64_t prev_cpu_micros = db_options_.clock->CPUMicros();
@@ -209,6 +209,8 @@ class CompactionJob {
  // Returns true iff compaction_stats_.stats.num_input_records and
  // num_input_range_del are calculated successfully.
  bool UpdateCompactionStats(uint64_t* num_input_range_del = nullptr);
+  virtual void UpdateCompactionJobStats(
+      const InternalStats::CompactionStats& stats) const;
  void LogCompaction();
  virtual void RecordCompactionIOStats();
  void CleanupCompaction();
@@ -279,8 +281,7 @@ class CompactionJob {
                                  bool* compaction_released);
  Status OpenCompactionOutputFile(SubcompactionState* sub_compact,
                                  CompactionOutputs& outputs);
-  void UpdateCompactionJobStats(
-      const InternalStats::CompactionStats& stats) const;
+
  void RecordDroppedKeys(const CompactionIterationStats& c_iter_stats,
                         CompactionJobStats* compaction_job_stats = nullptr);

@@ -377,9 +378,7 @@ class CompactionJob {
 // doesn't contain the LSM tree information, which is passed though MANIFEST
 // file.
 struct CompactionServiceInput {
-  ColumnFamilyDescriptor column_family;
-
-  DBOptions db_options;
+  std::string cf_name;

  std::vector<SequenceNumber> snapshots;

@@ -398,13 +397,12 @@ struct CompactionServiceInput {
  bool has_end = false;
  std::string end;

+  uint64_t options_file_number;
+
  // serialization interface to read and write the object
  static Status Read(const std::string& data_str, CompactionServiceInput* obj);
  Status Write(std::string* output);

-  // Initialize a dummy ColumnFamilyDescriptor
-  CompactionServiceInput() : column_family("", ColumnFamilyOptions()) {}
-
 #ifndef NDEBUG
  bool TEST_Equals(CompactionServiceInput* other);
  bool TEST_Equals(CompactionServiceInput* other, std::string* mismatch);
@@ -418,19 +416,22 @@ struct CompactionServiceOutputFile {
  SequenceNumber largest_seqno;
  std::string smallest_internal_key;
  std::string largest_internal_key;
-  uint64_t oldest_ancester_time;
-  uint64_t file_creation_time;
-  uint64_t epoch_number;
+  uint64_t oldest_ancester_time = kUnknownOldestAncesterTime;
+  uint64_t file_creation_time = kUnknownFileCreationTime;
+  uint64_t epoch_number = kUnknownEpochNumber;
+  std::string file_checksum = kUnknownFileChecksum;
+  std::string file_checksum_func_name = kUnknownFileChecksumFuncName;
  uint64_t paranoid_hash;
  bool marked_for_compaction;
-  UniqueId64x2 unique_id;
+  UniqueId64x2 unique_id{};

  CompactionServiceOutputFile() = default;
  CompactionServiceOutputFile(
      const std::string& name, SequenceNumber smallest, SequenceNumber largest,
      std::string _smallest_internal_key, std::string _largest_internal_key,
      uint64_t _oldest_ancester_time, uint64_t _file_creation_time,
-      uint64_t _epoch_number, uint64_t _paranoid_hash,
+      uint64_t _epoch_number, const std::string& _file_checksum,
+      const std::string& _file_checksum_func_name, uint64_t _paranoid_hash,
      bool _marked_for_compaction, UniqueId64x2 _unique_id)
      : file_name(name),
        smallest_seqno(smallest),
@@ -440,6 +441,8 @@ struct CompactionServiceOutputFile {
        oldest_ancester_time(_oldest_ancester_time),
        file_creation_time(_file_creation_time),
        epoch_number(_epoch_number),
+        file_checksum(_file_checksum),
+        file_checksum_func_name(_file_checksum_func_name),
        paranoid_hash(_paranoid_hash),
        marked_for_compaction(_marked_for_compaction),
        unique_id(std::move(_unique_id)) {}
@@ -456,9 +459,6 @@ struct CompactionServiceResult {
  // location of the output files
  std::string output_path;

-  // some statistics about the compaction
-  uint64_t num_output_records = 0;
-  uint64_t total_bytes = 0;
  uint64_t bytes_read = 0;
  uint64_t bytes_written = 0;
  CompactionJobStats stats;
@@ -504,6 +504,9 @@ class CompactionServiceCompactionJob : private CompactionJob {
 protected:
  void RecordCompactionIOStats() override;

+  void UpdateCompactionJobStats(
+      const InternalStats::CompactionStats& stats) const override;
+
 private:
  // Get table file name in output_path
  std::string GetTableFileName(uint64_t file_number) override;
@@ -50,7 +50,8 @@ void VerifyInitializationOfCompactionJobStats(
  ASSERT_EQ(compaction_job_stats.num_output_records, 0U);
  ASSERT_EQ(compaction_job_stats.num_output_files, 0U);

-  ASSERT_EQ(compaction_job_stats.is_manual_compaction, true);
+  ASSERT_TRUE(compaction_job_stats.is_manual_compaction);
+  ASSERT_FALSE(compaction_job_stats.is_remote_compaction);

  ASSERT_EQ(compaction_job_stats.total_input_bytes, 0U);
  ASSERT_EQ(compaction_job_stats.total_output_bytes, 0U);
@@ -545,14 +546,14 @@ class CompactionJobTestBase : public testing::Test {
    ASSERT_OK(s);
    db_options_.info_log = info_log;

-    versions_.reset(new VersionSet(
-        dbname_, &db_options_, env_options_, table_cache_.get(),
-        &write_buffer_manager_, &write_controller_,
-        /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr,
-        /*db_id=*/"", /*db_session_id=*/"", /*daily_offpeak_time_utc=*/"",
-        /*error_handler=*/nullptr, /*read_only=*/false));
+    versions_.reset(
+        new VersionSet(dbname_, &db_options_, env_options_, table_cache_.get(),
+                       &write_buffer_manager_, &write_controller_,
+                       /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr,
+                       test::kUnitTestDbId, /*db_session_id=*/"",
+                       /*daily_offpeak_time_utc=*/"",
+                       /*error_handler=*/nullptr, /*read_only=*/false));
    compaction_job_stats_.Reset();
-    ASSERT_OK(SetIdentityFile(WriteOptions(), env_, dbname_));

    VersionEdit new_db;
    new_db.SetLogNumber(0);
@@ -575,7 +576,8 @@ class CompactionJobTestBase : public testing::Test {
    }
    ASSERT_OK(s);
    // Make "CURRENT" file that points to the new manifest file.
-    s = SetCurrentFile(WriteOptions(), fs_.get(), dbname_, 1, nullptr);
+    s = SetCurrentFile(WriteOptions(), fs_.get(), dbname_, 1,
+                       Temperature::kUnknown, nullptr);

    ASSERT_OK(s);

@@ -1567,17 +1569,7 @@ TEST_F(CompactionJobTest, InputSerialization) {
  const int kStrMaxLen = 1000;
  Random rnd(static_cast<uint32_t>(time(nullptr)));
  Random64 rnd64(time(nullptr));
-  input.column_family.name = rnd.RandomString(rnd.Uniform(kStrMaxLen));
-  input.column_family.options.comparator = ReverseBytewiseComparator();
-  input.column_family.options.max_bytes_for_level_base =
-      rnd64.Uniform(UINT64_MAX);
-  input.column_family.options.disable_auto_compactions = rnd.OneIn(2);
-  input.column_family.options.compression = kZSTD;
-  input.column_family.options.compression_opts.level = 4;
-  input.db_options.max_background_flushes = 10;
-  input.db_options.paranoid_checks = rnd.OneIn(2);
-  input.db_options.statistics = CreateDBStatistics();
-  input.db_options.env = env_;
+  input.cf_name = rnd.RandomString(rnd.Uniform(kStrMaxLen));
  while (!rnd.OneIn(10)) {
    input.snapshots.emplace_back(rnd64.Uniform(UINT64_MAX));
  }
@@ -1605,10 +1597,10 @@ TEST_F(CompactionJobTest, InputSerialization) {
  ASSERT_TRUE(deserialized1.TEST_Equals(&input));

  // Test mismatch
-  deserialized1.db_options.max_background_flushes += 10;
+  deserialized1.output_level += 10;
  std::string mismatch;
  ASSERT_FALSE(deserialized1.TEST_Equals(&input, &mismatch));
-  ASSERT_EQ(mismatch, "db_options.max_background_flushes");
+  ASSERT_EQ(mismatch, "output_level");

  // Test unknown field
  CompactionServiceInput deserialized2;
@@ -1664,20 +1656,30 @@ TEST_F(CompactionJobTest, ResultSerialization) {
  };
  result.status =
      status_list.at(rnd.Uniform(static_cast<int>(status_list.size())));
+
+  std::string file_checksum = rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen));
+  std::string file_checksum_func_name = "MyAwesomeChecksumGenerator";
  while (!rnd.OneIn(10)) {
    UniqueId64x2 id{rnd64.Uniform(UINT64_MAX), rnd64.Uniform(UINT64_MAX)};
    result.output_files.emplace_back(
-        rnd.RandomString(rnd.Uniform(kStrMaxLen)), rnd64.Uniform(UINT64_MAX),
-        rnd64.Uniform(UINT64_MAX),
-        rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen)),
-        rnd.RandomBinaryString(rnd.Uniform(kStrMaxLen)),
-        rnd64.Uniform(UINT64_MAX), rnd64.Uniform(UINT64_MAX),
-        rnd64.Uniform(UINT64_MAX), rnd64.Uniform(UINT64_MAX), rnd.OneIn(2), id);
+        rnd.RandomString(rnd.Uniform(kStrMaxLen)) /* file_name */,
+        rnd64.Uniform(UINT64_MAX) /* smallest_seqno */,
+        rnd64.Uniform(UINT64_MAX) /* largest_seqno */,
+        rnd.RandomBinaryString(
+            rnd.Uniform(kStrMaxLen)) /* smallest_internal_key */,
+        rnd.RandomBinaryString(
+            rnd.Uniform(kStrMaxLen)) /* largest_internal_key */,
+        rnd64.Uniform(UINT64_MAX) /* oldest_ancester_time */,
+        rnd64.Uniform(UINT64_MAX) /* file_creation_time */,
+        rnd64.Uniform(UINT64_MAX) /* epoch_number */,
+        file_checksum /* file_checksum */,
+        file_checksum_func_name /* file_checksum_func_name */,
+        rnd64.Uniform(UINT64_MAX) /* paranoid_hash */,
+        rnd.OneIn(2) /* marked_for_compaction */, id);
  }
  result.output_level = rnd.Uniform(10);
  result.output_path = rnd.RandomString(rnd.Uniform(kStrMaxLen));
-  result.num_output_records = rnd64.Uniform(UINT64_MAX);
-  result.total_bytes = rnd64.Uniform(UINT64_MAX);
+  result.stats.num_output_records = rnd64.Uniform(UINT64_MAX);
  result.bytes_read = 123;
  result.bytes_written = rnd64.Uniform(UINT64_MAX);
  result.stats.elapsed_micros = rnd64.Uniform(UINT64_MAX);
@@ -1708,6 +1710,10 @@ TEST_F(CompactionJobTest, ResultSerialization) {
    ASSERT_FALSE(deserialized_tmp.TEST_Equals(&result, &mismatch));
    ASSERT_EQ(mismatch, "output_files.unique_id");
    deserialized_tmp.status.PermitUncheckedError();
+
+    ASSERT_EQ(deserialized_tmp.output_files[0].file_checksum, file_checksum);
+    ASSERT_EQ(deserialized_tmp.output_files[0].file_checksum_func_name,
+              file_checksum_func_name);
  }

  // Test unknown field
@@ -62,8 +62,9 @@ class CompactionOutputs {
  }

  // TODO: Remove it when remote compaction support tiered compaction
-  void SetTotalBytes(uint64_t bytes) { stats_.bytes_written += bytes; }
+  void AddBytesWritten(uint64_t bytes) { stats_.bytes_written += bytes; }
  void SetNumOutputRecords(uint64_t num) { stats_.num_output_records = num; }
+  void SetNumOutputFiles(uint64_t num) { stats_.num_output_files = num; }

  // TODO: Move the BlobDB builder into CompactionOutputs
  const std::vector<BlobFileAddition>& GetBlobFileAdditions() const {
@@ -133,7 +133,8 @@ CompactionPicker::CompactionPicker(const ImmutableOptions& ioptions,
 CompactionPicker::~CompactionPicker() = default;

 // Delete this compaction from the list of running compactions.
-void CompactionPicker::ReleaseCompactionFiles(Compaction* c, Status status) {
+void CompactionPicker::ReleaseCompactionFiles(Compaction* c,
+                                              const Status& status) {
  UnregisterCompaction(c);
  if (!status.ok()) {
    c->ResetNextCompactionIndex();
@@ -104,7 +104,7 @@ class CompactionPicker {
  // Free up the files that participated in a compaction
  //
  // Requirement: DB mutex held
-  void ReleaseCompactionFiles(Compaction* c, Status status);
+  void ReleaseCompactionFiles(Compaction* c, const Status& status);

  // Returns true if any one of the specified files are being compacted
  bool AreFilesInCompaction(const std::vector<FileMetaData*>& files);
@@ -294,7 +294,7 @@ Compaction* FIFOCompactionPicker::PickSizeCompaction(
 Compaction* FIFOCompactionPicker::PickTemperatureChangeCompaction(
    const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
    const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
-    LogBuffer* log_buffer) {
+    LogBuffer* log_buffer) const {
  const std::vector<FileTemperatureAge>& ages =
      mutable_cf_options.compaction_options_fifo
          .file_temperature_age_thresholds;
@@ -344,12 +344,10 @@ Compaction* FIFOCompactionPicker::PickTemperatureChangeCompaction(
  Temperature compaction_target_temp = Temperature::kLastTemperature;
  if (current_time > min_age) {
    uint64_t create_time_threshold = current_time - min_age;
-    uint64_t compaction_size = 0;
    // We will ideally identify a file qualifying for temperature change by
    // knowing the timestamp for the youngest entry in the file. However, right
    // now we don't have the information. We infer it by looking at timestamp of
    // the previous file's (which is just younger) oldest entry's timestamp.
-    Temperature cur_target_temp;
    // avoid index underflow
    assert(level_files.size() >= 1);
    for (size_t index = level_files.size() - 1; index >= 1; --index) {
@@ -374,7 +372,7 @@ Compaction* FIFOCompactionPicker::PickTemperatureChangeCompaction(
        // cur_file is too fresh
        break;
      }
-      cur_target_temp = ages[0].temperature;
+      Temperature cur_target_temp = ages[0].temperature;
      for (size_t i = 1; i < ages.size(); ++i) {
        if (current_time >= ages[i].age &&
            oldest_ancestor_time <= current_time - ages[i].age) {
@@ -382,35 +380,20 @@ Compaction* FIFOCompactionPicker::PickTemperatureChangeCompaction(
        }
      }
      if (cur_file->temperature == cur_target_temp) {
-        if (inputs[0].empty()) {
-          continue;
-        } else {
-          break;
-        }
+        continue;
      }

      // cur_file needs to change temperature
-      if (compaction_target_temp == Temperature::kLastTemperature) {
-        assert(inputs[0].empty());
-        compaction_target_temp = cur_target_temp;
-      } else if (cur_target_temp != compaction_target_temp) {
-        assert(!inputs[0].empty());
-        break;
-      }
-      if (inputs[0].empty() || compaction_size + cur_file->fd.GetFileSize() <=
-                                   mutable_cf_options.max_compaction_bytes) {
-        inputs[0].files.push_back(cur_file);
-        compaction_size += cur_file->fd.GetFileSize();
-        ROCKS_LOG_BUFFER(
-            log_buffer,
-            "[%s] FIFO compaction: picking file %" PRIu64
-            " with next file's oldest time %" PRIu64 " for temperature %s.",
-            cf_name.c_str(), cur_file->fd.GetNumber(), oldest_ancestor_time,
-            temperature_to_string[cur_target_temp].c_str());
-      }
-      if (compaction_size > mutable_cf_options.max_compaction_bytes) {
-        break;
-      }
+      assert(compaction_target_temp == Temperature::kLastTemperature);
+      compaction_target_temp = cur_target_temp;
+      inputs[0].files.push_back(cur_file);
+      ROCKS_LOG_BUFFER(
+          log_buffer,
+          "[%s] FIFO compaction: picking file %" PRIu64
+          " with next file's oldest time %" PRIu64 " for temperature %s.",
+          cf_name.c_str(), cur_file->fd.GetNumber(), oldest_ancestor_time,
+          temperature_to_string[cur_target_temp].c_str());
+      break;
    }
  }

@@ -418,7 +401,9 @@ Compaction* FIFOCompactionPicker::PickTemperatureChangeCompaction(
    return nullptr;
  }
  assert(compaction_target_temp != Temperature::kLastTemperature);
-
+  // Only compact one file at a time.
+  assert(inputs.size() == 1);
+  assert(inputs[0].size() == 1);
  Compaction* c = new Compaction(
      vstorage, ioptions_, mutable_cf_options, mutable_db_options,
      std::move(inputs), 0, 0 /* output file size limit */,
@@ -53,9 +53,10 @@ class FIFOCompactionPicker : public CompactionPicker {
                                 VersionStorageInfo* version,
                                 LogBuffer* log_buffer);

+  // Will pick one file to compact at a time, starting from the oldest file.
  Compaction* PickTemperatureChangeCompaction(
      const std::string& cf_name, const MutableCFOptions& mutable_cf_options,
      const MutableDBOptions& mutable_db_options, VersionStorageInfo* vstorage,
-      LogBuffer* log_buffer);
+      LogBuffer* log_buffer) const;
 };
 }  // namespace ROCKSDB_NAMESPACE
@@ -925,11 +925,15 @@ bool LevelCompactionBuilder::PickSizeBasedIntraL0Compaction() {
  }
  uint64_t l0_size = 0;
  for (const auto& file : l0_files) {
-    l0_size += file->fd.GetFileSize();
+    assert(file->compensated_file_size >= file->fd.GetFileSize());
+    // Compact down L0s with more deletions.
+    l0_size += file->compensated_file_size;
  }
-  const uint64_t min_lbase_size =
-      l0_size * static_cast<uint64_t>(std::max(
-                    10.0, mutable_cf_options_.max_bytes_for_level_multiplier));
+
+  // Avoid L0->Lbase compactions that are inefficient for write-amp.
+  const double kMultiplier =
+      std::max(10.0, mutable_cf_options_.max_bytes_for_level_multiplier) * 2;
+  const uint64_t min_lbase_size = MultiplyCheckOverflow(l0_size, kMultiplier);
  assert(min_lbase_size >= l0_size);
  const std::vector<FileMetaData*>& lbase_files =
      vstorage_->LevelFiles(/*level=*/base_level);
@@ -214,7 +214,10 @@ class CompactionPickerTest : public CompactionPickerTestBase {
  explicit CompactionPickerTest()
      : CompactionPickerTestBase(BytewiseComparator()) {}

-  ~CompactionPickerTest() override = default;
+  ~CompactionPickerTest() override {
+    SyncPoint::GetInstance()->ClearAllCallBacks();
+    SyncPoint::GetInstance()->DisableProcessing();
+  }
 };

 class CompactionPickerU64TsTest : public CompactionPickerTestBase {
@@ -1116,48 +1119,6 @@ TEST_F(CompactionPickerTest, FIFOToCold1) {
  ASSERT_EQ(3U, compaction->input(0, 0)->fd.GetNumber());
 }

-TEST_F(CompactionPickerTest, FIFOToCold2) {
-  NewVersionStorage(1, kCompactionStyleFIFO);
-  const uint64_t kFileSize = 100000;
-  const uint64_t kMaxSize = kFileSize * 100000;
-  uint64_t kColdThreshold = 2000;
-
-  fifo_options_.max_table_files_size = kMaxSize;
-  fifo_options_.file_temperature_age_thresholds = {
-      {Temperature::kCold, kColdThreshold}};
-  mutable_cf_options_.compaction_options_fifo = fifo_options_;
-  mutable_cf_options_.level0_file_num_compaction_trigger = 100;
-  mutable_cf_options_.max_compaction_bytes = kFileSize * 100;
-  FIFOCompactionPicker fifo_compaction_picker(ioptions_, &icmp_);
-
-  int64_t current_time = 0;
-  ASSERT_OK(Env::Default()->GetCurrentTime(&current_time));
-  uint64_t threshold_time =
-      static_cast<uint64_t>(current_time) - kColdThreshold;
-  Add(0, 6U, "240", "290", 2 * kFileSize, 0, 2900, 3000, 0, true,
-      Temperature::kUnknown, static_cast<uint64_t>(current_time) - 100);
-  Add(0, 4U, "260", "300", 1 * kFileSize, 0, 2500, 2600, 0, true,
-      Temperature::kUnknown, threshold_time);
-  // The following two files qualify for compaction to kCold.
-  Add(0, 3U, "200", "300", 4 * kFileSize, 0, 2300, 2400, 0, true,
-      Temperature::kUnknown, threshold_time - 3000);
-  Add(0, 2U, "200", "300", 4 * kFileSize, 0, 2100, 2200, 0, true,
-      Temperature::kUnknown, threshold_time - 4000);
-  UpdateVersionStorageInfo();
-
-  ASSERT_EQ(fifo_compaction_picker.NeedsCompaction(vstorage_.get()), true);
-  std::unique_ptr<Compaction> compaction(fifo_compaction_picker.PickCompaction(
-      cf_name_, mutable_cf_options_, mutable_db_options_, vstorage_.get(),
-      &log_buffer_));
-  ASSERT_TRUE(compaction.get() != nullptr);
-  ASSERT_EQ(compaction->compaction_reason(),
-            CompactionReason::kChangeTemperature);
-  ASSERT_EQ(compaction->output_temperature(), Temperature::kCold);
-  ASSERT_EQ(2U, compaction->num_input_files(0));
-  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
-  ASSERT_EQ(3U, compaction->input(0, 1)->fd.GetNumber());
-}
-
 TEST_F(CompactionPickerTest, FIFOToColdMaxCompactionSize) {
  NewVersionStorage(1, kCompactionStyleFIFO);
  const uint64_t kFileSize = 100000;
@@ -1199,10 +1160,10 @@ TEST_F(CompactionPickerTest, FIFOToColdMaxCompactionSize) {
  ASSERT_TRUE(compaction.get() != nullptr);
  ASSERT_EQ(compaction->compaction_reason(),
            CompactionReason::kChangeTemperature);
+  // Compaction picker picks older files first and picks one file at a time.
  ASSERT_EQ(compaction->output_temperature(), Temperature::kCold);
-  ASSERT_EQ(2U, compaction->num_input_files(0));
+  ASSERT_EQ(1U, compaction->num_input_files(0));
  ASSERT_EQ(1U, compaction->input(0, 0)->fd.GetNumber());
-  ASSERT_EQ(2U, compaction->input(0, 1)->fd.GetNumber());
 }

 TEST_F(CompactionPickerTest, FIFOToColdWithExistingCold) {
@@ -1245,10 +1206,10 @@ TEST_F(CompactionPickerTest, FIFOToColdWithExistingCold) {
  ASSERT_TRUE(compaction.get() != nullptr);
  ASSERT_EQ(compaction->compaction_reason(),
            CompactionReason::kChangeTemperature);
+  // Compaction picker picks older files first and picks one file at a time.
  ASSERT_EQ(compaction->output_temperature(), Temperature::kCold);
+  ASSERT_EQ(1U, compaction->num_input_files(0));
  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
-  ASSERT_EQ(2U, compaction->num_input_files(0));
-  ASSERT_EQ(3U, compaction->input(0, 1)->fd.GetNumber());
 }

 TEST_F(CompactionPickerTest, FIFOToColdWithHotBetweenCold) {
@@ -1296,7 +1257,7 @@ TEST_F(CompactionPickerTest, FIFOToColdWithHotBetweenCold) {
  ASSERT_EQ(2U, compaction->input(0, 0)->fd.GetNumber());
 }

-TEST_F(CompactionPickerTest, FIFOToColdAndWarm) {
+TEST_F(CompactionPickerTest, FIFOToHotAndWarm) {
  NewVersionStorage(1, kCompactionStyleFIFO);
  const uint64_t kFileSize = 100000;
  const uint64_t kMaxSize = kFileSize * 100000;
@@ -1341,11 +1302,10 @@ TEST_F(CompactionPickerTest, FIFOToColdAndWarm) {
  ASSERT_TRUE(compaction.get() != nullptr);
  ASSERT_EQ(compaction->compaction_reason(),
            CompactionReason::kChangeTemperature);
-  // Assumes compaction picker picks older files first.
+  // Compaction picker picks older files first and picks one file at a time.
  ASSERT_EQ(compaction->output_temperature(), Temperature::kWarm);
-  ASSERT_EQ(2U, compaction->num_input_files(0));
+  ASSERT_EQ(1U, compaction->num_input_files(0));
  ASSERT_EQ(1U, compaction->input(0, 0)->fd.GetNumber());
-  ASSERT_EQ(2U, compaction->input(0, 1)->fd.GetNumber());
 }

 TEST_F(CompactionPickerTest, CompactionPriMinOverlapping1) {
@@ -4284,27 +4244,28 @@ TEST_F(CompactionPickerTest, IntraL0WhenL0IsSmall) {
    SCOPED_TRACE("lbase_size_multiplier=" +
                 std::to_string(lbase_size_multiplier));
    NewVersionStorage(6, kCompactionStyleLevel);
-    // When L0 size is <= Lbase size / max_bytes_for_level_multiplier,
+    // When L0 size is <= Lbase size / max_bytes_for_level_multiplier / 2,
    // intra-L0 compaction is picked. Otherwise, L0->L1
    // compaction is picked.
+    // compensated_file_size will be used to compute total l0 size.
    Add(/*level=*/0, /*file_number=*/1U, /*smallest=*/"100",
-        /*largest=*/"200", /*file_size=*/1000, /*path_id=*/0,
+        /*largest=*/"200", /*file_size=*/10, /*path_id=*/0,
        /*smallest_seq=*/10, /*largest_seq=*/11,
        /*compensated_file_size=*/1000);
    Add(/*level=*/0, /*file_number=*/2U, /*smallest=*/"100",
-        /*largest=*/"100", /*file_size=*/1000, /*path_id=*/0,
+        /*largest=*/"100", /*file_size=*/10, /*path_id=*/0,
        /*smallest_seq=*/20, /*largest_seq=*/21,
        /*compensated_file_size=*/1000);
    Add(/*level=*/0, /*file_number=*/3U, /*smallest=*/"100",
-        /*largest=*/"200", /*file_size=*/1000, /*path_id=*/0,
+        /*largest=*/"200", /*file_size=*/10, /*path_id=*/0,
        /*smallest_seq=*/30, /*largest_seq=*/31,
        /*compensated_file_size=*/1000);
    Add(/*level=*/0, /*file_number=*/4U, /*smallest=*/"100",
-        /*largest=*/"200", /*file_size=*/1000, /*path_id=*/0,
+        /*largest=*/"200", /*file_size=*/10, /*path_id=*/0,
        /*smallest_seq=*/40, /*largest_seq=*/41,
        /*compensated_file_size=*/1000);
    const uint64_t l0_size = 4000;
-    const uint64_t lbase_size = l0_size * lbase_size_multiplier;
+    const uint64_t lbase_size = l0_size * lbase_size_multiplier * 2;
    Add(/*level=*/1, /*file_number=*/5U, /*smallest=*/"100",
        /*largest=*/"200", /*file_size=*/lbase_size, /*path_id=*/0,
        /*smallest_seq=*/0, /*largest_seq=*/0,
@@ -39,12 +39,8 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
          MakeTableFileName(file->fd.GetNumber()));
    }
  }
-  compaction_input.column_family.name =
-      compaction->column_family_data()->GetName();
-  compaction_input.column_family.options =
-      compaction->column_family_data()->GetLatestCFOptions();
-  compaction_input.db_options =
-      BuildDBOptions(db_options_, mutable_db_options_copy_);
+
+  compaction_input.cf_name = compaction->column_family_data()->GetName();
  compaction_input.snapshots = existing_snapshots_;
  compaction_input.has_begin = sub_compact->start.has_value();
  compaction_input.begin =
@@ -52,6 +48,14 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
  compaction_input.has_end = sub_compact->end.has_value();
  compaction_input.end =
      compaction_input.has_end ? sub_compact->end->ToString() : "";
+  compaction_input.options_file_number =
+      sub_compact->compaction->input_version()
+          ->version_set()
+          ->options_file_number();
+
+  TEST_SYNC_POINT_CALLBACK(
+      "CompactionServiceJob::ProcessKeyValueCompactionWithCompactionService",
+      &compaction_input);

  std::string compaction_input_binary;
  Status s = compaction_input.Write(&compaction_input_binary);
@@ -70,10 +74,13 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
  ROCKS_LOG_INFO(
      db_options_.info_log,
      "[%s] [JOB %d] Starting remote compaction (output level: %d): %s",
-      compaction_input.column_family.name.c_str(), job_id_,
+      compaction->column_family_data()->GetName().c_str(), job_id_,
      compaction_input.output_level, input_files_oss.str().c_str());
-  CompactionServiceJobInfo info(dbname_, db_id_, db_session_id_,
-                                GetCompactionId(sub_compact), thread_pri_);
+  CompactionServiceJobInfo info(
+      dbname_, db_id_, db_session_id_, GetCompactionId(sub_compact),
+      thread_pri_, compaction->compaction_reason(),
+      compaction->is_full_compaction(), compaction->is_manual_compaction(),
+      compaction->bottommost_level());
  CompactionServiceScheduleResponse response =
      db_options_.compaction_service->Schedule(info, compaction_input_binary);
  switch (response.status) {
@@ -84,13 +91,14 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
          "CompactionService failed to schedule a remote compaction job.");
      ROCKS_LOG_WARN(db_options_.info_log,
                     "[%s] [JOB %d] Remote compaction failed to start.",
-                     compaction_input.column_family.name.c_str(), job_id_);
+                     compaction->column_family_data()->GetName().c_str(),
+                     job_id_);
      return response.status;
    case CompactionServiceJobStatus::kUseLocal:
      ROCKS_LOG_INFO(
          db_options_.info_log,
          "[%s] [JOB %d] Remote compaction fallback to local by API (Schedule)",
-          compaction_input.column_family.name.c_str(), job_id_);
+          compaction->column_family_data()->GetName().c_str(), job_id_);
      return response.status;
    default:
      assert(false);  // unknown status
@@ -99,7 +107,7 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(

  ROCKS_LOG_INFO(db_options_.info_log,
                 "[%s] [JOB %d] Waiting for remote compaction...",
-                 compaction_input.column_family.name.c_str(), job_id_);
+                 compaction->column_family_data()->GetName().c_str(), job_id_);
  std::string compaction_result_binary;
  CompactionServiceJobStatus compaction_status =
      db_options_.compaction_service->Wait(response.scheduled_job_id,
@@ -109,7 +117,7 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
    ROCKS_LOG_INFO(
        db_options_.info_log,
        "[%s] [JOB %d] Remote compaction fallback to local by API (Wait)",
-        compaction_input.column_family.name.c_str(), job_id_);
+        compaction->column_family_data()->GetName().c_str(), job_id_);
    return compaction_status;
  }

@@ -134,15 +142,19 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
          "result is returned).");
      compaction_result.status.PermitUncheckedError();
    }
-    ROCKS_LOG_WARN(db_options_.info_log,
-                   "[%s] [JOB %d] Remote compaction failed.",
-                   compaction_input.column_family.name.c_str(), job_id_);
+    ROCKS_LOG_WARN(
+        db_options_.info_log, "[%s] [JOB %d] Remote compaction failed.",
+        compaction->column_family_data()->GetName().c_str(), job_id_);
    return compaction_status;
  }

+  // CompactionServiceJobStatus::kSuccess was returned, but somehow we failed to
+  // read the result. Consider this as an installation failure
  if (!s.ok()) {
    sub_compact->status = s;
    compaction_result.status.PermitUncheckedError();
+    db_options_.compaction_service->OnInstallation(
+        response.scheduled_job_id, CompactionServiceJobStatus::kFailure);
    return CompactionServiceJobStatus::kFailure;
  }
  sub_compact->status = compaction_result.status;
@@ -154,18 +166,14 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
    is_first_one = false;
  }

-  ROCKS_LOG_INFO(db_options_.info_log,
-                 "[%s] [JOB %d] Receive remote compaction result, output path: "
-                 "%s, files: %s",
-                 compaction_input.column_family.name.c_str(), job_id_,
-                 compaction_result.output_path.c_str(),
-                 output_files_oss.str().c_str());
-
-  if (!s.ok()) {
-    sub_compact->status = s;
-    return CompactionServiceJobStatus::kFailure;
-  }
+  ROCKS_LOG_INFO(
+      db_options_.info_log,
+      "[%s] [JOB %d] Received remote compaction result, output path: "
+      "%s, files: %s",
+      compaction->column_family_data()->GetName().c_str(), job_id_,
+      compaction_result.output_path.c_str(), output_files_oss.str().c_str());

+  // Installation Starts
  for (const auto& file : compaction_result.output_files) {
    uint64_t file_num = versions_->NewFileNumber();
    auto src_file = compaction_result.output_path + "/" + file.file_name;
@@ -174,6 +182,8 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
    s = fs_->RenameFile(src_file, tgt_file, IOOptions(), nullptr);
    if (!s.ok()) {
      sub_compact->status = s;
+      db_options_.compaction_service->OnInstallation(
+          response.scheduled_job_id, CompactionServiceJobStatus::kFailure);
      return CompactionServiceJobStatus::kFailure;
    }

@@ -182,6 +192,8 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
    s = fs_->GetFileSize(tgt_file, IOOptions(), &file_size, nullptr);
    if (!s.ok()) {
      sub_compact->status = s;
+      db_options_.compaction_service->OnInstallation(
+          response.scheduled_job_id, CompactionServiceJobStatus::kFailure);
      return CompactionServiceJobStatus::kFailure;
    }
    meta.fd = FileDescriptor(file_num, compaction->output_path_id(), file_size,
@@ -191,6 +203,8 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
    meta.oldest_ancester_time = file.oldest_ancester_time;
    meta.file_creation_time = file.file_creation_time;
    meta.epoch_number = file.epoch_number;
+    meta.file_checksum = file.file_checksum;
+    meta.file_checksum_func_name = file.file_checksum_func_name;
    meta.marked_for_compaction = file.marked_for_compaction;
    meta.unique_id = file.unique_id;

@@ -201,11 +215,15 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
  }
  sub_compact->compaction_job_stats = compaction_result.stats;
  sub_compact->Current().SetNumOutputRecords(
-      compaction_result.num_output_records);
-  sub_compact->Current().SetTotalBytes(compaction_result.total_bytes);
+      compaction_result.stats.num_output_records);
+  sub_compact->Current().SetNumOutputFiles(
+      compaction_result.stats.num_output_files);
+  sub_compact->Current().AddBytesWritten(compaction_result.bytes_written);
  RecordTick(stats_, REMOTE_COMPACT_READ_BYTES, compaction_result.bytes_read);
  RecordTick(stats_, REMOTE_COMPACT_WRITE_BYTES,
             compaction_result.bytes_written);
+  db_options_.compaction_service->OnInstallation(
+      response.scheduled_job_id, CompactionServiceJobStatus::kSuccess);
  return CompactionServiceJobStatus::kSuccess;
 }

@@ -220,6 +238,18 @@ void CompactionServiceCompactionJob::RecordCompactionIOStats() {
  CompactionJob::RecordCompactionIOStats();
 }

+void CompactionServiceCompactionJob::UpdateCompactionJobStats(
+    const InternalStats::CompactionStats& stats) const {
+  compaction_job_stats_->elapsed_micros = stats.micros;
+
+  // output information only in remote compaction
+  compaction_job_stats_->total_output_bytes = stats.bytes_written;
+  compaction_job_stats_->total_output_bytes_blob = stats.bytes_written_blob;
+  compaction_job_stats_->num_output_records = stats.num_output_records;
+  compaction_job_stats_->num_output_files = stats.num_output_files;
+  compaction_job_stats_->num_output_files_blob = stats.num_output_files_blob;
+}
+
 CompactionServiceCompactionJob::CompactionServiceCompactionJob(
    int job_id, Compaction* compaction, const ImmutableDBOptions& db_options,
    const MutableDBOptions& mutable_db_options, const FileOptions& file_options,
@@ -255,11 +285,11 @@ Status CompactionServiceCompactionJob::Run() {

  auto* c = compact_->compaction;
  assert(c->column_family_data() != nullptr);
-  assert(c->column_family_data()->current()->storage_info()->NumLevelFiles(
-             compact_->compaction->level()) > 0);
+  const VersionStorageInfo* storage_info = c->input_version()->storage_info();
+  assert(storage_info);
+  assert(storage_info->NumLevelFiles(compact_->compaction->level()) > 0);
+  write_hint_ = storage_info->CalculateSSTWriteHint(c->output_level());

-  write_hint_ =
-      c->column_family_data()->CalculateSSTWriteHint(c->output_level());
  bottommost_level_ = c->bottommost_level();

  Slice begin = compaction_input_.begin;
@@ -274,7 +304,12 @@ Status CompactionServiceCompactionJob::Run() {

  log_buffer_->FlushBufferToLog();
  LogCompaction();
+
+  compaction_result_->stats.Reset();
+
  const uint64_t start_micros = db_options_.clock->NowMicros();
+  c->GetOrInitInputTableProperties();
+
  // Pick the only sub-compaction we should have
  assert(compact_->sub_compact_states.size() == 1);
  SubcompactionState* sub_compact = compact_->sub_compact_states.data();
@@ -312,20 +347,32 @@ Status CompactionServiceCompactionJob::Run() {
  if (status.ok()) {
    status = io_s;
  }
-  if (status.ok()) {
-    // TODO: Add verify_table()
-  }
-
-  // Finish up all book-keeping to unify the subcompaction results
-  compact_->AggregateCompactionStats(compaction_stats_, *compaction_job_stats_);
-  UpdateCompactionStats();
-  RecordCompactionIOStats();

  LogFlush(db_options_.info_log);
  compact_->status = status;
  compact_->status.PermitUncheckedError();

-  // Build compaction result
+  // Build Compaction Job Stats
+
+  // 1. Aggregate CompactionOutputStats into Internal Compaction Stats
+  // (compaction_stats_) and aggregate Compaction Job Stats
+  // (compaction_job_stats_) from the sub compactions
+  compact_->AggregateCompactionStats(compaction_stats_, *compaction_job_stats_);
+
+  // 2. Update the Output information in the Compaction Job Stats with
+  // aggregated Internal Compaction Stats.
+  UpdateCompactionJobStats(compaction_stats_.stats);
+
+  // 3. Set fields that are not propagated as part of aggregations above
+  compaction_result_->stats.is_manual_compaction = c->is_manual_compaction();
+  compaction_result_->stats.is_full_compaction = c->is_full_compaction();
+  compaction_result_->stats.is_remote_compaction = true;
+
+  // 4. Update IO Stats that are not part of the aggregations above (bytes_read,
+  // bytes_written)
+  RecordCompactionIOStats();
+
+  // Build Output
  compaction_result_->output_level = compact_->compaction->output_level();
  compaction_result_->output_path = output_path_;
  for (const auto& output_file : sub_compact->GetOutputs()) {
@@ -334,16 +381,13 @@ Status CompactionServiceCompactionJob::Run() {
        MakeTableFileName(meta.fd.GetNumber()), meta.fd.smallest_seqno,
        meta.fd.largest_seqno, meta.smallest.Encode().ToString(),
        meta.largest.Encode().ToString(), meta.oldest_ancester_time,
-        meta.file_creation_time, meta.epoch_number,
-        output_file.validator.GetHash(), meta.marked_for_compaction,
-        meta.unique_id);
+        meta.file_creation_time, meta.epoch_number, meta.file_checksum,
+        meta.file_checksum_func_name, output_file.validator.GetHash(),
+        meta.marked_for_compaction, meta.unique_id);
  }
-  InternalStats::CompactionStatsFull compaction_stats;
-  sub_compact->AggregateCompactionStats(compaction_stats);
-  compaction_result_->num_output_records =
-      compaction_stats.stats.num_output_records;
-  compaction_result_->total_bytes = compaction_stats.TotalBytesWritten();

+  TEST_SYNC_POINT_CALLBACK("CompactionServiceCompactionJob::Run:0",
+                           &compaction_result_);
  return status;
 }

@@ -396,42 +440,9 @@ static std::unordered_map<std::string, OptionTypeInfo> cfd_type_info = {
 };

 static std::unordered_map<std::string, OptionTypeInfo> cs_input_type_info = {
-    {"column_family",
-     OptionTypeInfo::Struct(
-         "column_family", &cfd_type_info,
-         offsetof(struct CompactionServiceInput, column_family),
-         OptionVerificationType::kNormal, OptionTypeFlags::kNone)},
-    {"db_options",
-     {offsetof(struct CompactionServiceInput, db_options),
-      OptionType::kConfigurable, OptionVerificationType::kNormal,
-      OptionTypeFlags::kNone,
-      [](const ConfigOptions& opts, const std::string& /*name*/,
-         const std::string& value, void* addr) {
-        auto options = static_cast<DBOptions*>(addr);
-        return GetDBOptionsFromString(opts, DBOptions(), value, options);
-      },
-      [](const ConfigOptions& opts, const std::string& /*name*/,
-         const void* addr, std::string* value) {
-        const auto options = static_cast<const DBOptions*>(addr);
-        std::string result;
-        auto status = GetStringFromDBOptions(opts, *options, &result);
-        *value = "{" + result + "}";
-        return status;
-      },
-      [](const ConfigOptions& opts, const std::string& name, const void* addr1,
-         const void* addr2, std::string* mismatch) {
-        const auto this_one = static_cast<const DBOptions*>(addr1);
-        const auto that_one = static_cast<const DBOptions*>(addr2);
-        auto this_conf = DBOptionsAsConfigurable(*this_one);
-        auto that_conf = DBOptionsAsConfigurable(*that_one);
-        std::string mismatch_opt;
-        bool result =
-            this_conf->AreEquivalent(opts, that_conf.get(), &mismatch_opt);
-        if (!result) {
-          *mismatch = name + "." + mismatch_opt;
-        }
-        return result;
-      }}},
+    {"cf_name",
+     {offsetof(struct CompactionServiceInput, cf_name),
+      OptionType::kEncodedString}},
    {"snapshots", OptionTypeInfo::Vector<uint64_t>(
                      offsetof(struct CompactionServiceInput, snapshots),
                      OptionVerificationType::kNormal, OptionTypeFlags::kNone,
@@ -459,6 +470,10 @@ static std::unordered_map<std::string, OptionTypeInfo> cs_input_type_info = {
    {"end",
     {offsetof(struct CompactionServiceInput, end), OptionType::kEncodedString,
      OptionVerificationType::kNormal, OptionTypeFlags::kNone}},
+    {"options_file_number",
+     {offsetof(struct CompactionServiceInput, options_file_number),
+      OptionType::kUInt64T, OptionVerificationType::kNormal,
+      OptionTypeFlags::kNone}},
 };

 static std::unordered_map<std::string, OptionTypeInfo>
@@ -495,6 +510,14 @@ static std::unordered_map<std::string, OptionTypeInfo>
         {offsetof(struct CompactionServiceOutputFile, epoch_number),
          OptionType::kUInt64T, OptionVerificationType::kNormal,
          OptionTypeFlags::kNone}},
+        {"file_checksum",
+         {offsetof(struct CompactionServiceOutputFile, file_checksum),
+          OptionType::kEncodedString, OptionVerificationType::kNormal,
+          OptionTypeFlags::kNone}},
+        {"file_checksum_func_name",
+         {offsetof(struct CompactionServiceOutputFile, file_checksum_func_name),
+          OptionType::kEncodedString, OptionVerificationType::kNormal,
+          OptionTypeFlags::kNone}},
        {"paranoid_hash",
         {offsetof(struct CompactionServiceOutputFile, paranoid_hash),
          OptionType::kUInt64T, OptionVerificationType::kNormal,
@@ -555,6 +578,10 @@ static std::unordered_map<std::string, OptionTypeInfo>
         {offsetof(struct CompactionJobStats, is_manual_compaction),
          OptionType::kBoolean, OptionVerificationType::kNormal,
          OptionTypeFlags::kNone}},
+        {"is_remote_compaction",
+         {offsetof(struct CompactionJobStats, is_remote_compaction),
+          OptionType::kBoolean, OptionVerificationType::kNormal,
+          OptionTypeFlags::kNone}},
        {"total_input_bytes",
         {offsetof(struct CompactionJobStats, total_input_bytes),
          OptionType::kUInt64T, OptionVerificationType::kNormal,
@@ -723,14 +750,6 @@ static std::unordered_map<std::string, OptionTypeInfo> cs_result_type_info = {
     {offsetof(struct CompactionServiceResult, output_path),
      OptionType::kEncodedString, OptionVerificationType::kNormal,
      OptionTypeFlags::kNone}},
-    {"num_output_records",
-     {offsetof(struct CompactionServiceResult, num_output_records),
-      OptionType::kUInt64T, OptionVerificationType::kNormal,
-      OptionTypeFlags::kNone}},
-    {"total_bytes",
-     {offsetof(struct CompactionServiceResult, total_bytes),
-      OptionType::kUInt64T, OptionVerificationType::kNormal,
-      OptionTypeFlags::kNone}},
    {"bytes_read",
     {offsetof(struct CompactionServiceResult, bytes_read),
      OptionType::kUInt64T, OptionVerificationType::kNormal,
@@ -3,9 +3,9 @@
 //  COPYING file in the root directory) and Apache 2.0 License
 //  (found in the LICENSE.Apache file in the root directory).

-
 #include "db/db_test_util.h"
 #include "port/stack_trace.h"
+#include "rocksdb/utilities/options_util.h"
 #include "table/unique_id_impl.h"

 namespace ROCKSDB_NAMESPACE {
@@ -21,8 +21,10 @@ class MyTestCompactionService : public CompactionService {
      : db_path_(std::move(db_path)),
        options_(options),
        statistics_(statistics),
-        start_info_("na", "na", "na", 0, Env::TOTAL),
-        wait_info_("na", "na", "na", 0, Env::TOTAL),
+        start_info_("na", "na", "na", 0, Env::TOTAL, CompactionReason::kUnknown,
+                    false, false, false),
+        wait_info_("na", "na", "na", 0, Env::TOTAL, CompactionReason::kUnknown,
+                   false, false, false),
        listeners_(listeners),
        table_properties_collector_factories_(
            std::move(table_properties_collector_factories)) {}
@@ -97,8 +99,12 @@ class MyTestCompactionService : public CompactionService {
    Status s =
        DB::OpenAndCompact(options, db_path_, db_path_ + "/" + scheduled_job_id,
                           compaction_input, result, options_override);
-    if (is_override_wait_result_) {
-      *result = override_wait_result_;
+    {
+      InstrumentedMutexLock l(&mutex_);
+      if (is_override_wait_result_) {
+        *result = override_wait_result_;
+      }
+      result_ = *result;
    }
    compaction_num_.fetch_add(1);
    if (s.ok()) {
@@ -108,6 +114,11 @@ class MyTestCompactionService : public CompactionService {
    }
  }

+  void OnInstallation(const std::string& /*scheduled_job_id*/,
+                      CompactionServiceJobStatus status) override {
+    final_updated_status_ = status;
+  }
+
  int GetCompactionNum() { return compaction_num_.load(); }

  CompactionServiceJobInfo GetCompactionInfoForStart() { return start_info_; }
@@ -136,6 +147,14 @@ class MyTestCompactionService : public CompactionService {

  void SetCanceled(bool canceled) { canceled_ = canceled; }

+  void GetResult(CompactionServiceResult* deserialized) {
+    CompactionServiceResult::Read(result_, deserialized).PermitUncheckedError();
+  }
+
+  CompactionServiceJobStatus GetFinalCompactionServiceJobStatus() {
+    return final_updated_status_.load();
+  }
+
 private:
  InstrumentedMutex mutex_;
  std::atomic_int compaction_num_{0};
@@ -153,11 +172,14 @@ class MyTestCompactionService : public CompactionService {
  CompactionServiceJobStatus override_wait_status_ =
      CompactionServiceJobStatus::kFailure;
  bool is_override_wait_result_ = false;
+  std::string result_;
  std::string override_wait_result_;
  std::vector<std::shared_ptr<EventListener>> listeners_;
  std::vector<std::shared_ptr<TablePropertiesCollectorFactory>>
      table_properties_collector_factories_;
  std::atomic_bool canceled_{false};
+  std::atomic<CompactionServiceJobStatus> final_updated_status_{
+      CompactionServiceJobStatus::kUseLocal};
 };

 class CompactionServiceTest : public DBTestBase {
@@ -255,6 +277,8 @@ TEST_F(CompactionServiceTest, BasicCompactions) {

  auto my_cs = GetCompactionService();
  ASSERT_GE(my_cs->GetCompactionNum(), 1);
+  ASSERT_EQ(CompactionServiceJobStatus::kSuccess,
+            my_cs->GetFinalCompactionServiceJobStatus());

  // make sure the compaction statistics is only recorded on the remote side
  ASSERT_GE(compactor_statistics->getTickerCount(COMPACT_WRITE_BYTES), 1);
@@ -318,6 +342,34 @@ TEST_F(CompactionServiceTest, BasicCompactions) {
  ReopenWithColumnFamilies({kDefaultColumnFamilyName, "cf_1", "cf_2", "cf_3"},
                           options);
  ASSERT_GT(verify_passed, 0);
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  if (s.IsAborted()) {
+    ASSERT_NOK(result.status);
+  } else {
+    ASSERT_OK(result.status);
+  }
+  ASSERT_GE(result.stats.elapsed_micros, 1);
+  ASSERT_GE(result.stats.cpu_micros, 1);
+
+  ASSERT_EQ(20, result.stats.num_output_records);
+  ASSERT_EQ(result.output_files.size(), result.stats.num_output_files);
+
+  uint64_t total_size = 0;
+  for (auto output_file : result.output_files) {
+    std::string file_name = result.output_path + "/" + output_file.file_name;
+
+    uint64_t file_size = 0;
+    ASSERT_OK(options.env->GetFileSize(file_name, &file_size));
+    ASSERT_GT(file_size, 0);
+    total_size += file_size;
+  }
+  ASSERT_EQ(total_size, result.stats.total_output_bytes);
+
+  ASSERT_TRUE(result.stats.is_remote_compaction);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_FALSE(result.stats.is_full_compaction);
+
  Close();
 }

@@ -356,6 +408,507 @@ TEST_F(CompactionServiceTest, ManualCompaction) {
  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
  VerifyTestData();
+
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  ASSERT_OK(result.status);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_TRUE(result.stats.is_remote_compaction);
+}
+
+TEST_F(CompactionServiceTest, PreservedOptionsLocalCompaction) {
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = 2;
+  options.disable_auto_compactions = true;
+  DestroyAndReopen(options);
+
+  Random rnd(301);
+  for (auto i = 0; i < 2; ++i) {
+    for (auto j = 0; j < 10; ++j) {
+      ASSERT_OK(
+          Put("foo" + std::to_string(i * 10 + j), rnd.RandomString(1024)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "CompactionJob::ProcessKeyValueCompaction()::Processing", [&](void* arg) {
+        auto compaction = static_cast<Compaction*>(arg);
+        std::string options_file_name = OptionsFileName(
+            dbname_,
+            compaction->input_version()->version_set()->options_file_number());
+
+        // Change option twice to make sure the very first OPTIONS file gets
+        // purged
+        ASSERT_OK(dbfull()->SetOptions(
+            {{"level0_file_num_compaction_trigger", "4"}}));
+        ASSERT_EQ(4, dbfull()->GetOptions().level0_file_num_compaction_trigger);
+        ASSERT_OK(dbfull()->SetOptions(
+            {{"level0_file_num_compaction_trigger", "6"}}));
+        ASSERT_EQ(6, dbfull()->GetOptions().level0_file_num_compaction_trigger);
+        dbfull()->TEST_DeleteObsoleteFiles();
+
+        // For non-remote compactions, OPTIONS file can be deleted while
+        // using option at the start of the compaction
+        Status s = env_->FileExists(options_file_name);
+        ASSERT_NOK(s);
+        ASSERT_TRUE(s.IsNotFound());
+        // Should be old value
+        ASSERT_EQ(2, compaction->mutable_cf_options()
+                         ->level0_file_num_compaction_trigger);
+        ASSERT_TRUE(dbfull()->min_options_file_numbers_.empty());
+      });
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+  Status s = dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+  ASSERT_TRUE(s.ok());
+}
+
+TEST_F(CompactionServiceTest, PreservedOptionsRemoteCompaction) {
+  // For non-remote compaction do not preserve options file
+  Options options = CurrentOptions();
+  options.level0_file_num_compaction_trigger = 2;
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+
+  Random rnd(301);
+  for (auto i = 0; i < 2; ++i) {
+    for (auto j = 0; j < 10; ++j) {
+      ASSERT_OK(
+          Put("foo" + std::to_string(i * 10 + j), rnd.RandomString(1024)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  bool is_primary_called = false;
+  // This will be called twice. One from primary and one from remote.
+  // Try changing the option when called from remote. Otherwise, the new option
+  // will be used
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DBImpl::BackgroundCompaction:NonTrivial:BeforeRun", [&](void* /*arg*/) {
+        if (!is_primary_called) {
+          is_primary_called = true;
+          return;
+        }
+        // Change the option right before the compaction run
+        ASSERT_OK(dbfull()->SetOptions(
+            {{"level0_file_num_compaction_trigger", "4"}}));
+        ASSERT_EQ(4, dbfull()->GetOptions().level0_file_num_compaction_trigger);
+        dbfull()->TEST_DeleteObsoleteFiles();
+      });
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "CompactionServiceJob::ProcessKeyValueCompactionWithCompactionService",
+      [&](void* arg) {
+        auto input = static_cast<CompactionServiceInput*>(arg);
+        std::string options_file_name =
+            OptionsFileName(dbname_, input->options_file_number);
+
+        ASSERT_OK(env_->FileExists(options_file_name));
+        ASSERT_FALSE(dbfull()->min_options_file_numbers_.empty());
+        ASSERT_EQ(dbfull()->min_options_file_numbers_.front(),
+                  input->options_file_number);
+
+        DBOptions db_options;
+        ConfigOptions config_options;
+        std::vector<ColumnFamilyDescriptor> all_column_families;
+        config_options.env = env_;
+        ASSERT_OK(LoadOptionsFromFile(config_options, options_file_name,
+                                      &db_options, &all_column_families));
+        bool has_cf = false;
+        for (auto& cf : all_column_families) {
+          if (cf.name == input->cf_name) {
+            // Should be old value
+            ASSERT_EQ(2, cf.options.level0_file_num_compaction_trigger);
+            has_cf = true;
+          }
+        }
+        ASSERT_TRUE(has_cf);
+      });
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "CompactionJob::ProcessKeyValueCompaction()::Processing", [&](void* arg) {
+        auto compaction = static_cast<Compaction*>(arg);
+        ASSERT_EQ(2, compaction->mutable_cf_options()
+                         ->level0_file_num_compaction_trigger);
+      });
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+  Status s = dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+  ASSERT_TRUE(s.ok());
+
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  ASSERT_OK(result.status);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_TRUE(result.stats.is_remote_compaction);
+}
+
+class EventVerifier : public EventListener {
+ public:
+  explicit EventVerifier(uint64_t expected_num_input_records,
+                         size_t expected_num_input_files,
+                         uint64_t expected_num_output_records,
+                         size_t expected_num_output_files,
+                         const std::string& expected_smallest_output_key_prefix,
+                         const std::string& expected_largest_output_key_prefix,
+                         bool expected_is_remote_compaction_on_begin,
+                         bool expected_is_remote_compaction_on_complete)
+      : expected_num_input_records_(expected_num_input_records),
+        expected_num_input_files_(expected_num_input_files),
+        expected_num_output_records_(expected_num_output_records),
+        expected_num_output_files_(expected_num_output_files),
+        expected_smallest_output_key_prefix_(
+            expected_smallest_output_key_prefix),
+        expected_largest_output_key_prefix_(expected_largest_output_key_prefix),
+        expected_is_remote_compaction_on_begin_(
+            expected_is_remote_compaction_on_begin),
+        expected_is_remote_compaction_on_complete_(
+            expected_is_remote_compaction_on_complete) {}
+  void OnCompactionBegin(DB* /*db*/, const CompactionJobInfo& ci) override {
+    ASSERT_EQ(expected_num_input_files_, ci.input_files.size());
+    ASSERT_EQ(expected_num_input_files_, ci.input_file_infos.size());
+    ASSERT_EQ(expected_is_remote_compaction_on_begin_,
+              ci.stats.is_remote_compaction);
+    ASSERT_TRUE(ci.stats.is_manual_compaction);
+    ASSERT_FALSE(ci.stats.is_full_compaction);
+  }
+  void OnCompactionCompleted(DB* /*db*/, const CompactionJobInfo& ci) override {
+    ASSERT_GT(ci.stats.elapsed_micros, 0);
+    ASSERT_GT(ci.stats.cpu_micros, 0);
+    ASSERT_EQ(expected_num_input_records_, ci.stats.num_input_records);
+    ASSERT_EQ(expected_num_input_files_, ci.stats.num_input_files);
+    ASSERT_EQ(expected_num_output_records_, ci.stats.num_output_records);
+    ASSERT_EQ(expected_num_output_files_, ci.stats.num_output_files);
+    ASSERT_EQ(expected_smallest_output_key_prefix_,
+              ci.stats.smallest_output_key_prefix);
+    ASSERT_EQ(expected_largest_output_key_prefix_,
+              ci.stats.largest_output_key_prefix);
+    ASSERT_GT(ci.stats.total_input_bytes, 0);
+    ASSERT_GT(ci.stats.total_output_bytes, 0);
+    ASSERT_EQ(ci.stats.num_input_records,
+              ci.stats.num_output_records + ci.stats.num_records_replaced);
+    ASSERT_EQ(expected_is_remote_compaction_on_complete_,
+              ci.stats.is_remote_compaction);
+    ASSERT_TRUE(ci.stats.is_manual_compaction);
+    ASSERT_FALSE(ci.stats.is_full_compaction);
+  }
+
+ private:
+  uint64_t expected_num_input_records_;
+  size_t expected_num_input_files_;
+  uint64_t expected_num_output_records_;
+  size_t expected_num_output_files_;
+  std::string expected_smallest_output_key_prefix_;
+  std::string expected_largest_output_key_prefix_;
+  bool expected_is_remote_compaction_on_begin_;
+  bool expected_is_remote_compaction_on_complete_;
+};
+
+TEST_F(CompactionServiceTest, VerifyStats) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  auto event_verifier = std::make_shared<EventVerifier>(
+      30 /* expected_num_input_records */, 3 /* expected_num_input_files */,
+      20 /* expected_num_output_records */, 1 /* expected_num_output_files */,
+      "key00000" /* expected_smallest_output_key_prefix */,
+      "key00001" /* expected_largest_output_key_prefix */,
+      true /* expected_is_remote_compaction_on_begin */,
+      true /* expected_is_remote_compaction_on_complete */);
+  options.listeners.push_back(event_verifier);
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+
+  std::string start_str = Key(0);
+  std::string end_str = Key(1);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, &end));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+  VerifyTestData();
+
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  ASSERT_OK(result.status);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_TRUE(result.stats.is_remote_compaction);
+}
+
+TEST_F(CompactionServiceTest, VerifyStatsLocalFallback) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  auto event_verifier = std::make_shared<EventVerifier>(
+      30 /* expected_num_input_records */, 3 /* expected_num_input_files */,
+      20 /* expected_num_output_records */, 1 /* expected_num_output_files */,
+      "key00000" /* expected_smallest_output_key_prefix */,
+      "key00001" /* expected_largest_output_key_prefix */,
+      true /* expected_is_remote_compaction_on_begin */,
+      false /* expected_is_remote_compaction_on_complete */);
+  options.listeners.push_back(event_verifier);
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+  my_cs->OverrideStartStatus(CompactionServiceJobStatus::kUseLocal);
+
+  std::string start_str = Key(0);
+  std::string end_str = Key(1);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, &end));
+  // Remote Compaction did not happen
+  ASSERT_EQ(my_cs->GetCompactionNum(), comp_num);
+  VerifyTestData();
+}
+
+TEST_F(CompactionServiceTest, CorruptedOutput) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "CompactionServiceCompactionJob::Run:0", [&](void* arg) {
+        CompactionServiceResult* compaction_result =
+            *(static_cast<CompactionServiceResult**>(arg));
+        ASSERT_TRUE(compaction_result != nullptr &&
+                    !compaction_result->output_files.empty());
+        // Corrupt files here
+        for (const auto& output_file : compaction_result->output_files) {
+          std::string file_name =
+              compaction_result->output_path + "/" + output_file.file_name;
+
+          uint64_t file_size = 0;
+          Status s = options.env->GetFileSize(file_name, &file_size);
+          ASSERT_OK(s);
+          ASSERT_GT(file_size, 0);
+
+          ASSERT_OK(test::CorruptFile(env_, file_name, 0,
+                                      static_cast<int>(file_size),
+                                      true /* verifyChecksum */));
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  // CompactRange() should fail
+  Status s = db_->CompactRange(CompactRangeOptions(), &start, &end);
+  ASSERT_NOK(s);
+  ASSERT_TRUE(s.IsCorruption());
+
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  // On the worker side, the compaction is considered success
+  // Verification is done on the primary side
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  ASSERT_OK(result.status);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_TRUE(result.stats.is_remote_compaction);
+}
+
+TEST_F(CompactionServiceTest, CorruptedOutputParanoidFileCheck) {
+  for (bool paranoid_file_check_enabled : {false, true}) {
+    SCOPED_TRACE("paranoid_file_check_enabled=" +
+                 std::to_string(paranoid_file_check_enabled));
+
+    Options options = CurrentOptions();
+    Destroy(options);
+    options.disable_auto_compactions = true;
+    options.paranoid_file_checks = paranoid_file_check_enabled;
+    ReopenWithCompactionService(&options);
+    GenerateTestData();
+
+    auto my_cs = GetCompactionService();
+
+    std::string start_str = Key(15);
+    std::string end_str = Key(45);
+    Slice start(start_str);
+    Slice end(end_str);
+    uint64_t comp_num = my_cs->GetCompactionNum();
+
+    ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+        "CompactionServiceCompactionJob::Run:0", [&](void* arg) {
+          CompactionServiceResult* compaction_result =
+              *(static_cast<CompactionServiceResult**>(arg));
+          ASSERT_TRUE(compaction_result != nullptr &&
+                      !compaction_result->output_files.empty());
+          // Corrupt files here
+          for (const auto& output_file : compaction_result->output_files) {
+            std::string file_name =
+                compaction_result->output_path + "/" + output_file.file_name;
+
+            // Corrupt very small range of bytes. This corruption is so small
+            // that this isn't caught by default light-weight check
+            ASSERT_OK(test::CorruptFile(env_, file_name, 0, 1,
+                                        false /* verifyChecksum */));
+          }
+        });
+    SyncPoint::GetInstance()->EnableProcessing();
+
+    Status s = db_->CompactRange(CompactRangeOptions(), &start, &end);
+    if (paranoid_file_check_enabled) {
+      ASSERT_NOK(s);
+      ASSERT_EQ(Status::Corruption("Paranoid checksums do not match"), s);
+    } else {
+      // CompactRange() goes through if paranoid file check is not enabled
+      ASSERT_OK(s);
+    }
+
+    ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+
+    SyncPoint::GetInstance()->DisableProcessing();
+    SyncPoint::GetInstance()->ClearAllCallBacks();
+
+    // On the worker side, the compaction is considered success
+    // Verification is done on the primary side
+    CompactionServiceResult result;
+    my_cs->GetResult(&result);
+    ASSERT_OK(result.status);
+    ASSERT_TRUE(result.stats.is_manual_compaction);
+    ASSERT_TRUE(result.stats.is_remote_compaction);
+  }
+}
+
+TEST_F(CompactionServiceTest, TruncatedOutput) {
+  Options options = CurrentOptions();
+  options.disable_auto_compactions = true;
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "CompactionServiceCompactionJob::Run:0", [&](void* arg) {
+        CompactionServiceResult* compaction_result =
+            *(static_cast<CompactionServiceResult**>(arg));
+        ASSERT_TRUE(compaction_result != nullptr &&
+                    !compaction_result->output_files.empty());
+        // Truncate files here
+        for (const auto& output_file : compaction_result->output_files) {
+          std::string file_name =
+              compaction_result->output_path + "/" + output_file.file_name;
+
+          uint64_t file_size = 0;
+          Status s = options.env->GetFileSize(file_name, &file_size);
+          ASSERT_OK(s);
+          ASSERT_GT(file_size, 0);
+
+          ASSERT_OK(test::TruncateFile(env_, file_name, file_size / 2));
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  // CompactRange() should fail
+  Status s = db_->CompactRange(CompactRangeOptions(), &start, &end);
+  ASSERT_NOK(s);
+  ASSERT_TRUE(s.IsCorruption());
+
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  // On the worker side, the compaction is considered success
+  // Verification is done on the primary side
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  ASSERT_OK(result.status);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_TRUE(result.stats.is_remote_compaction);
+}
+
+TEST_F(CompactionServiceTest, CustomFileChecksum) {
+  Options options = CurrentOptions();
+  options.file_checksum_gen_factory = GetFileChecksumGenCrc32cFactory();
+  ReopenWithCompactionService(&options);
+  GenerateTestData();
+
+  auto my_cs = GetCompactionService();
+
+  std::string start_str = Key(15);
+  std::string end_str = Key(45);
+  Slice start(start_str);
+  Slice end(end_str);
+  uint64_t comp_num = my_cs->GetCompactionNum();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "CompactionServiceCompactionJob::Run:0", [&](void* arg) {
+        CompactionServiceResult* compaction_result =
+            *(static_cast<CompactionServiceResult**>(arg));
+        ASSERT_TRUE(compaction_result != nullptr &&
+                    !compaction_result->output_files.empty());
+        // Validate Checksum files here
+        for (const auto& output_file : compaction_result->output_files) {
+          std::string file_name =
+              compaction_result->output_path + "/" + output_file.file_name;
+
+          FileChecksumGenContext gen_context;
+          gen_context.file_name = file_name;
+          std::unique_ptr<FileChecksumGenerator> file_checksum_gen =
+              options.file_checksum_gen_factory->CreateFileChecksumGenerator(
+                  gen_context);
+
+          std::unique_ptr<SequentialFile> file_reader;
+          uint64_t file_size = 0;
+          Status s = options.env->GetFileSize(file_name, &file_size);
+          ASSERT_OK(s);
+          ASSERT_GT(file_size, 0);
+
+          s = options.env->NewSequentialFile(file_name, &file_reader,
+                                             EnvOptions());
+          ASSERT_OK(s);
+
+          Slice result;
+          std::unique_ptr<char[]> scratch(new char[file_size]);
+          s = file_reader->Read(file_size, &result, scratch.get());
+          ASSERT_OK(s);
+
+          file_checksum_gen->Update(scratch.get(), result.size());
+          file_checksum_gen->Finalize();
+
+          // Verify actual checksum and the func name
+          ASSERT_EQ(file_checksum_gen->Name(),
+                    output_file.file_checksum_func_name);
+          ASSERT_EQ(file_checksum_gen->GetChecksum(),
+                    output_file.file_checksum);
+        }
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &start, &end));
+  ASSERT_GE(my_cs->GetCompactionNum(), comp_num + 1);
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+
+  CompactionServiceResult result;
+  my_cs->GetResult(&result);
+  ASSERT_OK(result.status);
+  ASSERT_TRUE(result.stats.is_manual_compaction);
+  ASSERT_TRUE(result.stats.is_remote_compaction);
 }

 TEST_F(CompactionServiceTest, CancelCompactionOnRemoteSide) {
@@ -437,6 +990,8 @@ TEST_F(CompactionServiceTest, InvalidResult) {
  Slice end(end_str);
  Status s = db_->CompactRange(CompactRangeOptions(), &start, &end);
  ASSERT_FALSE(s.ok());
+  ASSERT_EQ(CompactionServiceJobStatus::kFailure,
+            my_cs->GetFinalCompactionServiceJobStatus());
 }

 TEST_F(CompactionServiceTest, SubCompaction) {
@@ -586,11 +1141,20 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
                              {file.db_path + "/" + file.name}, 2));
  info = my_cs->GetCompactionInfoForStart();
  ASSERT_EQ(Env::USER, info.priority);
+  ASSERT_EQ(CompactionReason::kManualCompaction, info.compaction_reason);
+  ASSERT_EQ(true, info.is_manual_compaction);
+  ASSERT_EQ(false, info.is_full_compaction);
+  ASSERT_EQ(true, info.bottommost_level);
  info = my_cs->GetCompactionInfoForWait();
  ASSERT_EQ(Env::USER, info.priority);
+  ASSERT_EQ(CompactionReason::kManualCompaction, info.compaction_reason);
+  ASSERT_EQ(true, info.is_manual_compaction);
+  ASSERT_EQ(false, info.is_full_compaction);
+  ASSERT_EQ(true, info.bottommost_level);

  // Test priority BOTTOM
  env_->SetBackgroundThreads(1, Env::BOTTOM);
+  // This will set bottommost_level = true but is_full_compaction = false
  options.num_levels = 2;
  ReopenWithCompactionService(&options);
  my_cs =
@@ -613,9 +1177,71 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
  }
  ASSERT_OK(dbfull()->TEST_WaitForCompact());
  info = my_cs->GetCompactionInfoForStart();
+  ASSERT_EQ(CompactionReason::kLevelL0FilesNum, info.compaction_reason);
+  ASSERT_EQ(false, info.is_manual_compaction);
+  ASSERT_EQ(false, info.is_full_compaction);
+  ASSERT_EQ(true, info.bottommost_level);
  ASSERT_EQ(Env::BOTTOM, info.priority);
  info = my_cs->GetCompactionInfoForWait();
  ASSERT_EQ(Env::BOTTOM, info.priority);
+  ASSERT_EQ(CompactionReason::kLevelL0FilesNum, info.compaction_reason);
+  ASSERT_EQ(false, info.is_manual_compaction);
+  ASSERT_EQ(false, info.is_full_compaction);
+  ASSERT_EQ(true, info.bottommost_level);
+
+  // Test Non-Bottommost Level
+  options.num_levels = 4;
+  ReopenWithCompactionService(&options);
+  my_cs =
+      static_cast_with_check<MyTestCompactionService>(GetCompactionService());
+
+  for (int i = 0; i < options.level0_file_num_compaction_trigger; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value_new_new" + std::to_string(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  info = my_cs->GetCompactionInfoForStart();
+  ASSERT_EQ(false, info.is_manual_compaction);
+  ASSERT_EQ(false, info.is_full_compaction);
+  ASSERT_EQ(false, info.bottommost_level);
+  info = my_cs->GetCompactionInfoForWait();
+  ASSERT_EQ(false, info.is_manual_compaction);
+  ASSERT_EQ(false, info.is_full_compaction);
+  ASSERT_EQ(false, info.bottommost_level);
+
+  // Test Full Compaction + Bottommost Level
+  options.num_levels = 6;
+  ReopenWithCompactionService(&options);
+  my_cs =
+      static_cast_with_check<MyTestCompactionService>(GetCompactionService());
+
+  for (int i = 0; i < 20; i++) {
+    for (int j = 0; j < 10; j++) {
+      int key_id = i * 10 + j;
+      ASSERT_OK(Put(Key(key_id), "value_new_new" + std::to_string(key_id)));
+    }
+    ASSERT_OK(Flush());
+  }
+
+  CompactRangeOptions cro;
+  cro.bottommost_level_compaction = BottommostLevelCompaction::kForce;
+  ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));
+
+  ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  info = my_cs->GetCompactionInfoForStart();
+  ASSERT_EQ(true, info.is_manual_compaction);
+  ASSERT_EQ(true, info.is_full_compaction);
+  ASSERT_EQ(true, info.bottommost_level);
+  ASSERT_EQ(CompactionReason::kManualCompaction, info.compaction_reason);
+  info = my_cs->GetCompactionInfoForWait();
+  ASSERT_EQ(true, info.is_manual_compaction);
+  ASSERT_EQ(true, info.is_full_compaction);
+  ASSERT_EQ(true, info.bottommost_level);
+  ASSERT_EQ(CompactionReason::kManualCompaction, info.compaction_reason);
 }

 TEST_F(CompactionServiceTest, FallbackLocalAuto) {
@@ -39,7 +39,7 @@ void CompactionState::AggregateCompactionStats(
    InternalStats::CompactionStatsFull& compaction_stats,
    CompactionJobStats& compaction_job_stats) {
  for (const auto& sc : sub_compact_states) {
-    sc.AggregateCompactionStats(compaction_stats);
+    sc.AggregateCompactionOutputStats(compaction_stats);
    compaction_job_stats.Add(sc.compaction_job_stats);
  }
 }
@@ -13,7 +13,7 @@
 #include "rocksdb/sst_partitioner.h"

 namespace ROCKSDB_NAMESPACE {
-void SubcompactionState::AggregateCompactionStats(
+void SubcompactionState::AggregateCompactionOutputStats(
    InternalStats::CompactionStatsFull& compaction_stats) const {
  compaction_stats.stats.Add(compaction_outputs_.stats_);
  if (HasPenultimateLevelOutputs()) {
@@ -179,7 +179,7 @@ class SubcompactionState {

  void Cleanup(Cache* cache);

-  void AggregateCompactionStats(
+  void AggregateCompactionOutputStats(
      InternalStats::CompactionStatsFull& compaction_stats) const;

  CompactionOutputs& Current() const {
@@ -2512,6 +2512,7 @@ TEST_P(IteratorWriteTimeTest, ReadFromMemtables) {
                              start_time + kSecondsPerRecording * (i + 1));
      }
    }
+    ASSERT_EQ(kNumKeys, i);
    ASSERT_OK(iter->status());
  }

@@ -2531,12 +2532,13 @@ TEST_P(IteratorWriteTimeTest, ReadFromMemtables) {
      }
    }
    ASSERT_OK(iter->status());
+    ASSERT_EQ(-1, i);
  }

  // Reopen the DB and disable the seqno to time recording, data with user
  // specified write time can still get a write time before it's flushed.
  options.preserve_internal_time_seconds = 0;
-  DestroyAndReopen(options);
+  Reopen(options);
  ASSERT_OK(TimedPut(Key(kKeyWithWriteTime), rnd.RandomString(100),
                     kUserSpecifiedWriteTime));
  {
@@ -2613,6 +2615,7 @@ TEST_P(IteratorWriteTimeTest, ReadFromSstFile) {
      }
    }
    ASSERT_OK(iter->status());
+    ASSERT_EQ(kNumKeys, i);
  }

  // Backward iteration
@@ -2632,12 +2635,13 @@ TEST_P(IteratorWriteTimeTest, ReadFromSstFile) {
      }
    }
    ASSERT_OK(iter->status());
+    ASSERT_EQ(-1, i);
  }

  // Reopen the DB and disable the seqno to time recording. Data retrieved from
  // SST files still have write time available.
  options.preserve_internal_time_seconds = 0;
-  DestroyAndReopen(options);
+  Reopen(options);

  dbfull()->TEST_WaitForPeriodicTaskRun(
      [&] { mock_clock_->MockSleepForSeconds(kSecondsPerRecording); });
@@ -2663,6 +2667,7 @@ TEST_P(IteratorWriteTimeTest, ReadFromSstFile) {
                              start_time + kSecondsPerRecording * (i + 1));
      }
    }
+    ASSERT_EQ(kNumKeys, i);
    ASSERT_OK(iter->status());
  }

@@ -2686,6 +2691,7 @@ TEST_P(IteratorWriteTimeTest, ReadFromSstFile) {
      VerifyKeyAndWriteTime(iter.get(), Key(i), 0);
    }
    ASSERT_OK(iter->status());
+    ASSERT_EQ(kNumKeys, i);
  }
  Close();
 }
@@ -688,76 +688,100 @@ TEST_F(DBBasicTest, IdentityAcrossRestarts) {
  constexpr size_t kMinIdSize = 10;
  do {
    for (bool with_manifest : {false, true}) {
-      std::string idfilename = IdentityFileName(dbname_);
-      std::string id1, tmp;
-      ASSERT_OK(db_->GetDbIdentity(id1));
-      ASSERT_GE(id1.size(), kMinIdSize);
+      for (bool write_file : {false, true}) {
+        std::string idfilename = IdentityFileName(dbname_);
+        std::string id1, tmp;
+        ASSERT_OK(db_->GetDbIdentity(id1));
+        ASSERT_GE(id1.size(), kMinIdSize);

-      Options options = CurrentOptions();
-      options.write_dbid_to_manifest = with_manifest;
-      Reopen(options);
-      std::string id2;
-      ASSERT_OK(db_->GetDbIdentity(id2));
-      // id2 should match id1 because identity was not regenerated
-      ASSERT_EQ(id1, id2);
-      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
-      ASSERT_EQ(tmp, id2);
+        Options options = CurrentOptions();
+        options.write_dbid_to_manifest = with_manifest;
+        options.write_identity_file = true;  // initially
+        Reopen(options);
+        std::string id2;
+        ASSERT_OK(db_->GetDbIdentity(id2));
+        // id2 should match id1 because identity was not regenerated
+        ASSERT_EQ(id1, id2);
+        ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+        ASSERT_EQ(tmp, id2);

-      // Recover from deleted/missing IDENTITY
-      ASSERT_OK(env_->DeleteFile(idfilename));
-      Reopen(options);
-      std::string id3;
-      ASSERT_OK(db_->GetDbIdentity(id3));
-      if (with_manifest) {
-        // id3 should match id1 because identity was restored from manifest
-        ASSERT_EQ(id1, id3);
-      } else {
-        // id3 should NOT match id1 because identity was regenerated
-        ASSERT_NE(id1, id3);
-        ASSERT_GE(id3.size(), kMinIdSize);
-      }
-      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
-      ASSERT_EQ(tmp, id3);
+        if (write_file) {
+          // Recover from deleted/missing IDENTITY
+          ASSERT_OK(env_->DeleteFile(idfilename));
+        } else {
+          // Transition to no IDENTITY file
+          options.write_identity_file = false;
+          if (!with_manifest) {
+            // Incompatible options, should fail
+            ASSERT_NOK(TryReopen(options));
+            // Back to a usable config and continue
+            options.write_identity_file = true;
+            Reopen(options);
+            continue;
+          }
+        }
+        Reopen(options);
+        std::string id3;
+        ASSERT_OK(db_->GetDbIdentity(id3));
+        if (with_manifest) {
+          // id3 should match id1 because identity was restored from manifest
+          ASSERT_EQ(id1, id3);
+        } else {
+          // id3 should NOT match id1 because identity was regenerated
+          ASSERT_NE(id1, id3);
+          ASSERT_GE(id3.size(), kMinIdSize);
+        }
+        if (write_file) {
+          ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+          ASSERT_EQ(tmp, id3);

-      // Recover from truncated IDENTITY
-      {
-        std::unique_ptr<WritableFile> w;
-        ASSERT_OK(env_->NewWritableFile(idfilename, &w, EnvOptions()));
-        ASSERT_OK(w->Close());
-      }
-      Reopen(options);
-      std::string id4;
-      ASSERT_OK(db_->GetDbIdentity(id4));
-      if (with_manifest) {
-        // id4 should match id1 because identity was restored from manifest
-        ASSERT_EQ(id1, id4);
-      } else {
-        // id4 should NOT match id1 because identity was regenerated
-        ASSERT_NE(id1, id4);
-        ASSERT_GE(id4.size(), kMinIdSize);
-      }
-      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
-      ASSERT_EQ(tmp, id4);
+          // Recover from truncated IDENTITY
+          std::unique_ptr<WritableFile> w;
+          ASSERT_OK(env_->NewWritableFile(idfilename, &w, EnvOptions()));
+          ASSERT_OK(w->Close());
+        } else {
+          ASSERT_TRUE(env_->FileExists(idfilename).IsNotFound());
+        }
+        Reopen(options);
+        std::string id4;
+        ASSERT_OK(db_->GetDbIdentity(id4));
+        if (with_manifest) {
+          // id4 should match id1 because identity was restored from manifest
+          ASSERT_EQ(id1, id4);
+        } else {
+          // id4 should NOT match id1 because identity was regenerated
+          ASSERT_NE(id1, id4);
+          ASSERT_GE(id4.size(), kMinIdSize);
+        }
+        std::string silly_id = "asdf123456789";
+        if (write_file) {
+          ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+          ASSERT_EQ(tmp, id4);

-      // Recover from overwritten IDENTITY
-      std::string silly_id = "asdf123456789";
-      {
-        std::unique_ptr<WritableFile> w;
-        ASSERT_OK(env_->NewWritableFile(idfilename, &w, EnvOptions()));
-        ASSERT_OK(w->Append(silly_id));
-        ASSERT_OK(w->Close());
+          // Recover from overwritten IDENTITY
+          std::unique_ptr<WritableFile> w;
+          ASSERT_OK(env_->NewWritableFile(idfilename, &w, EnvOptions()));
+          ASSERT_OK(w->Append(silly_id));
+          ASSERT_OK(w->Close());
+        } else {
+          ASSERT_TRUE(env_->FileExists(idfilename).IsNotFound());
+        }
+        Reopen(options);
+        std::string id5;
+        ASSERT_OK(db_->GetDbIdentity(id5));
+        if (with_manifest) {
+          // id4 should match id1 because identity was restored from manifest
+          ASSERT_EQ(id1, id5);
+        } else {
+          ASSERT_EQ(id5, silly_id);
+        }
+        if (write_file) {
+          ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
+          ASSERT_EQ(tmp, id5);
+        } else {
+          ASSERT_TRUE(env_->FileExists(idfilename).IsNotFound());
+        }
      }
-      Reopen(options);
-      std::string id5;
-      ASSERT_OK(db_->GetDbIdentity(id5));
-      if (with_manifest) {
-        // id4 should match id1 because identity was restored from manifest
-        ASSERT_EQ(id1, id5);
-      } else {
-        ASSERT_EQ(id5, silly_id);
-      }
-      ASSERT_OK(ReadFileToString(env_, idfilename, &tmp));
-      ASSERT_EQ(tmp, id5);
    }
  } while (ChangeCompactOptions());
 }
@@ -3407,6 +3431,46 @@ class TableFileListener : public EventListener {
  InstrumentedMutex mutex_;
  std::unordered_map<std::string, std::vector<std::string>> cf_to_paths_;
 };
+
+class FlushTableFileListener : public EventListener {
+ public:
+  void OnTableFileCreated(const TableFileCreationInfo& info) override {
+    InstrumentedMutexLock lock(&mutex_);
+    if (info.reason != TableFileCreationReason::kFlush) {
+      return;
+    }
+    cf_to_flushed_files_[info.cf_name].push_back(info.file_path);
+  }
+  std::vector<std::string>& GetFlushedFiles(const std::string& cf_name) {
+    InstrumentedMutexLock lock(&mutex_);
+    return cf_to_flushed_files_[cf_name];
+  }
+
+ private:
+  InstrumentedMutex mutex_;
+  std::unordered_map<std::string, std::vector<std::string>>
+      cf_to_flushed_files_;
+};
+
+class FlushBlobFileListener : public EventListener {
+ public:
+  void OnBlobFileCreated(const BlobFileCreationInfo& info) override {
+    InstrumentedMutexLock lock(&mutex_);
+    if (info.reason != BlobFileCreationReason::kFlush) {
+      return;
+    }
+    cf_to_flushed_blobs_files_[info.cf_name].push_back(info.file_path);
+  }
+  std::vector<std::string>& GetFlushedBlobFiles(const std::string& cf_name) {
+    InstrumentedMutexLock lock(&mutex_);
+    return cf_to_flushed_blobs_files_[cf_name];
+  }
+
+ private:
+  InstrumentedMutex mutex_;
+  std::unordered_map<std::string, std::vector<std::string>>
+      cf_to_flushed_blobs_files_;
+};
 }  // anonymous namespace

 TEST_F(DBBasicTest, LastSstFileNotInManifest) {
@@ -3512,6 +3576,121 @@ TEST_F(DBBasicTest, RecoverWithMissingFiles) {
  }
 }

+// Param 0: whether to enable blob DB.
+// Param 1: when blob DB is enabled, whether to also delete the missing L0
+// file's associated blob file.
+class BestEffortsRecoverIncompleteVersionTest
+    : public DBTestBase,
+      public testing::WithParamInterface<std::tuple<bool, bool>> {
+ public:
+  BestEffortsRecoverIncompleteVersionTest()
+      : DBTestBase("best_efforts_recover_incomplete_version_test",
+                   /*env_do_fsync=*/false) {}
+};
+
+TEST_P(BestEffortsRecoverIncompleteVersionTest, Basic) {
+  Options options = CurrentOptions();
+  options.enable_blob_files = std::get<0>(GetParam());
+  bool delete_blob_file_too = std::get<1>(GetParam());
+  DestroyAndReopen(options);
+  FlushTableFileListener* flush_table_listener = new FlushTableFileListener();
+  FlushBlobFileListener* flush_blob_listener = new FlushBlobFileListener();
+  // Disable auto compaction to simplify SST file name tracking.
+  options.disable_auto_compactions = true;
+  options.listeners.emplace_back(flush_table_listener);
+  options.listeners.emplace_back(flush_blob_listener);
+  CreateAndReopenWithCF({"pikachu", "eevee"}, options);
+  std::vector<std::string> all_cf_names = {kDefaultColumnFamilyName, "pikachu",
+                                           "eevee"};
+  int num_cfs = static_cast<int>(handles_.size());
+  ASSERT_EQ(3, num_cfs);
+  std::string start = "a";
+  Slice start_slice = start;
+  std::string end = "d";
+  Slice end_slice = end;
+  for (int cf = 0; cf != num_cfs; ++cf) {
+    ASSERT_OK(Put(cf, "a", "a_value"));
+    ASSERT_OK(Flush(cf));
+    // Compact file to L1 to avoid trivial file move in the next compaction
+    ASSERT_OK(db_->CompactRange(CompactRangeOptions(), handles_[cf],
+                                &start_slice, &end_slice));
+    ASSERT_OK(Put(cf, "a", "a_value_new"));
+    ASSERT_OK(Flush(cf));
+    ASSERT_OK(Put(cf, "b", "b_value"));
+    ASSERT_OK(Flush(cf));
+    ASSERT_OK(Put(cf, "f", "f_value"));
+    ASSERT_OK(Flush(cf));
+    ASSERT_OK(db_->CompactRange(CompactRangeOptions(), handles_[cf],
+                                &start_slice, &end_slice));
+  }
+
+  dbfull()->TEST_DeleteObsoleteFiles();
+
+  // Delete the most recent L0 file which is before a compaction.
+  for (int i = 0; i < num_cfs; ++i) {
+    std::vector<std::string>& files =
+        flush_table_listener->GetFlushedFiles(all_cf_names[i]);
+    ASSERT_EQ(4, files.size());
+    ASSERT_OK(env_->DeleteFile(files[files.size() - 1]));
+    if (options.enable_blob_files) {
+      std::vector<std::string>& blob_files =
+          flush_blob_listener->GetFlushedBlobFiles(all_cf_names[i]);
+      ASSERT_EQ(4, blob_files.size());
+      if (delete_blob_file_too) {
+        ASSERT_OK(env_->DeleteFile(blob_files[files.size() - 1]));
+      }
+    }
+  }
+  options.best_efforts_recovery = true;
+  ReopenWithColumnFamilies(all_cf_names, options);
+
+  for (int i = 0; i < num_cfs; ++i) {
+    auto cfh = static_cast<ColumnFamilyHandleImpl*>(handles_[i]);
+    ColumnFamilyData* cfd = cfh->cfd();
+    VersionStorageInfo* vstorage = cfd->current()->storage_info();
+    // The L0 file flushed right before the last compaction is missing.
+    ASSERT_EQ(0, vstorage->LevelFiles(0).size());
+    // Only the output of the last compaction is available.
+    ASSERT_EQ(1, vstorage->LevelFiles(1).size());
+  }
+  // Verify data
+  ReadOptions read_opts;
+  read_opts.total_order_seek = true;
+  for (int i = 0; i < num_cfs; ++i) {
+    std::unique_ptr<Iterator> iter(db_->NewIterator(read_opts, handles_[i]));
+    iter->SeekToFirst();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_OK(iter->status());
+    ASSERT_EQ("a", iter->key());
+    ASSERT_EQ("a_value_new", iter->value());
+    iter->Next();
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_OK(iter->status());
+    ASSERT_EQ("b", iter->key());
+    ASSERT_EQ("b_value", iter->value());
+    iter->Next();
+    ASSERT_FALSE(iter->Valid());
+    ASSERT_OK(iter->status());
+  }
+
+  // Write more data.
+  for (int cf = 0; cf < num_cfs; ++cf) {
+    ASSERT_OK(Put(cf, "g", "g_value"));
+    ASSERT_OK(Flush(cf));
+    ASSERT_OK(db_->CompactRange(CompactRangeOptions(), handles_[cf], nullptr,
+                                nullptr));
+    std::string value;
+    ASSERT_OK(db_->Get(ReadOptions(), handles_[cf], "g", &value));
+    ASSERT_EQ("g_value", value);
+  }
+}
+
+INSTANTIATE_TEST_CASE_P(BestEffortsRecoverIncompleteVersionTest,
+                        BestEffortsRecoverIncompleteVersionTest,
+                        testing::Values(std::make_tuple(false, false),
+                                        std::make_tuple(true, false),
+                                        std::make_tuple(true, true)));
+
 TEST_F(DBBasicTest, BestEffortsRecoveryTryMultipleManifests) {
  Options options = CurrentOptions();
  options.env = env_;
@@ -6146,7 +6146,7 @@ TEST_F(DBCompactionTest, CompactionLimiter) {

  std::vector<std::string> pending_compaction_cfs;
  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
-      "SchedulePendingCompaction::cfd", [&](void* arg) {
+      "EnqueuePendingCompaction::cfd", [&](void* arg) {
        const std::string& cf_name =
            static_cast<ColumnFamilyData*>(arg)->GetName();
        pending_compaction_cfs.emplace_back(cf_name);
@@ -9357,12 +9357,13 @@ TEST_F(DBCompactionTest, FIFOChangeTemperature) {
    ASSERT_OK(Flush());

    ASSERT_OK(Put(Key(0), "value1"));
-    env_->MockSleepForSeconds(800);
    ASSERT_OK(Put(Key(2), "value2"));
    ASSERT_OK(Flush());

+    // First two L0 files both become eligible for temperature change compaction
+    // They should be compacted one-by-one.
    ASSERT_OK(Put(Key(0), "value1"));
-    env_->MockSleepForSeconds(800);
+    env_->MockSleepForSeconds(1200);
    ASSERT_OK(Put(Key(2), "value2"));
    ASSERT_OK(Flush());
    ASSERT_OK(dbfull()->TEST_WaitForCompact());
@@ -21,6 +21,7 @@
 #include "rocksdb/db.h"
 #include "rocksdb/env.h"
 #include "rocksdb/metadata.h"
+#include "rocksdb/transaction_log.h"
 #include "rocksdb/types.h"
 #include "test_util/sync_point.h"
 #include "util/file_checksum_helper.h"
@@ -92,6 +93,11 @@ Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
 }

 Status DBImpl::GetSortedWalFiles(VectorWalPtr& files) {
+  return GetSortedWalFilesImpl(files,
+                               /*need_seqnos*/ true);
+}
+
+Status DBImpl::GetSortedWalFilesImpl(VectorWalPtr& files, bool need_seqnos) {
  // Record tracked WALs as a (minimum) cross-check for directory scan
  std::vector<uint64_t> required_by_manifest;

@@ -117,7 +123,10 @@ Status DBImpl::GetSortedWalFiles(VectorWalPtr& files) {
    }
  }

-  Status s = wal_manager_.GetSortedWalFiles(files);
+  // NOTE: need to include archived WALs because needed WALs might have been
+  // archived since getting required_by_manifest set
+  Status s = wal_manager_.GetSortedWalFiles(files, need_seqnos,
+                                            /*include_archived*/ true);

  // DisableFileDeletions / EnableFileDeletions not supported in read-only DB
  if (deletions_disabled.ok()) {
@@ -206,7 +215,12 @@ Status DBImpl::GetLiveFilesStorageInfo(
    } else if (opts.wal_size_for_flush > 0) {
      // FIXME: avoid querying the filesystem for current WAL state
      // If the outstanding WAL files are small, we skip the flush.
-      s = GetSortedWalFiles(live_wal_files);
+      // Don't take archived log size into account when calculating wal
+      // size for flush, and don't need to verify consistency with manifest
+      // here & now.
+      s = wal_manager_.GetSortedWalFiles(live_wal_files,
+                                         /* need_seqnos */ false,
+                                         /*include_archived*/ false);

      if (!s.ok()) {
        return s;
@@ -217,6 +231,7 @@ Status DBImpl::GetLiveFilesStorageInfo(
      // We may be able to cover 2PC case too.
      uint64_t total_wal_size = 0;
      for (auto& wal : live_wal_files) {
+        assert(wal->Type() == kAliveLogFile);
        total_wal_size += wal->SizeFileBytes();
      }
      if (total_wal_size < opts.wal_size_for_flush) {
@@ -428,7 +443,8 @@ Status DBImpl::GetLiveFilesStorageInfo(
  // WAL files.
  if (s.ok()) {
    // FIXME: avoid querying the filesystem for current WAL state
-    s = GetSortedWalFiles(live_wal_files);
+    s = GetSortedWalFilesImpl(live_wal_files,
+                              /* need_seqnos */ false);
  }
  if (!s.ok()) {
    return s;
@@ -289,10 +289,12 @@ TEST_F(DBFollowerTest, RetryCatchup) {
      {"DBImplFollower::TryCatchupWithLeader:Begin1", "Leader::Start"},
      {"DBImpl::BackgroundCompaction:Start",
       "DBImplFollower::TryCatchupWithLeader:Begin2"},
-      {"VersionEditHandlerPointInTime::MaybeCreateVersion:Begin1",
+      {"VersionEditHandlerPointInTime::MaybeCreateVersionBeforeApplyEdit:"
+       "Begin1",
       "DBImpl::BackgroundCompaction:BeforeCompaction"},
      {"DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles",
-       "VersionEditHandlerPointInTime::MaybeCreateVersion:Begin2"},
+       "VersionEditHandlerPointInTime::MaybeCreateVersionBeforeApplyEdit:"
+       "Begin2"},
      {"DBImplFollower::TryCatchupWithLeader:End", "Follower::WaitForCatchup"},
  });
  SyncPoint::GetInstance()->EnableProcessing();
@@ -335,10 +337,12 @@ TEST_F(DBFollowerTest, RetryCatchupManifestRollover) {
  SyncPoint::GetInstance()->LoadDependency({
      {"DBImplFollower::TryCatchupWithLeader:Begin1", "Leader::Start"},
      {"Leader::Flushed", "DBImplFollower::TryCatchupWithLeader:Begin2"},
-      {"VersionEditHandlerPointInTime::MaybeCreateVersion:Begin1",
+      {"VersionEditHandlerPointInTime::MaybeCreateVersionBeforeApplyEdit:"
+       "Begin1",
       "Leader::Done"},
      {"DBImpl::BackgroundCallCompaction:PurgedObsoleteFiles",
-       "VersionEditHandlerPointInTime::MaybeCreateVersion:Begin2"},
+       "VersionEditHandlerPointInTime::MaybeCreateVersionBeforeApplyEdit:"
+       "Begin2"},
      {"DBImplFollower::TryCatchupWithLeader:End",
       "Follower::WaitForCatchup:1"},
  });
@@ -17,6 +17,7 @@
 #include <cstdio>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <sstream>
 #include <stdexcept>
@@ -391,8 +392,8 @@ Status DBImpl::ResumeImpl(DBRecoverContext context) {
      if (!s.ok()) {
        io_s = versions_->io_status();
        if (!io_s.ok()) {
-          s = error_handler_.SetBGError(io_s,
-                                        BackgroundErrorReason::kManifestWrite);
+          error_handler_.SetBGError(io_s,
+                                    BackgroundErrorReason::kManifestWrite);
        }
      }
    }
@@ -472,7 +473,7 @@ Status DBImpl::ResumeImpl(DBRecoverContext context) {

  if (s.ok()) {
    for (auto cfd : *versions_->GetColumnFamilySet()) {
-      SchedulePendingCompaction(cfd);
+      EnqueuePendingCompaction(cfd);
    }
    MaybeScheduleFlushOrCompaction();
  }
@@ -529,6 +530,11 @@ Status DBImpl::MaybeReleaseTimestampedSnapshotsAndCheck() {
  return Status::OK();
 }

+void DBImpl::UntrackDataFiles() {
+  TrackOrUntrackFiles(/*existing_data_files=*/{},
+                      /*track=*/false);
+}
+
 Status DBImpl::CloseHelper() {
  // Guarantee that there is no background error recovery in progress before
  // continuing with the shutdown
@@ -653,8 +659,9 @@ Status DBImpl::CloseHelper() {
  // We need to release them before the block cache is destroyed. The block
  // cache may be destroyed inside versions_.reset(), when column family data
  // list is destroyed, so leaving handles in table cache after
-  // versions_.reset() may cause issues.
-  // Here we clean all unreferenced handles in table cache.
+  // versions_.reset() may cause issues. Here we clean all unreferenced handles
+  // in table cache, and (for certain builds/conditions) assert that no obsolete
+  // files are hanging around unreferenced (leak) in the table/blob file cache.
  // Now we assume all user queries have finished, so only version set itself
  // can possibly hold the blocks from block cache. After releasing unreferenced
  // handles here, only handles held by version set left and inside
@@ -662,12 +669,22 @@ Status DBImpl::CloseHelper() {
  // time a handle is released, we erase it from the cache too. By doing that,
  // we can guarantee that after versions_.reset(), table cache is empty
  // so the cache can be safely destroyed.
+#ifndef NDEBUG
+  TEST_VerifyNoObsoleteFilesCached(/*db_mutex_already_held=*/true);
+#endif  // !NDEBUG
  table_cache_->EraseUnRefEntries();

  for (auto& txn_entry : recovered_transactions_) {
    delete txn_entry.second;
  }

+  // Return an unowned SstFileManager to a consistent state
+  if (immutable_db_options_.sst_file_manager && !own_sfm_) {
+    mutex_.Unlock();
+    UntrackDataFiles();
+    mutex_.Lock();
+  }
+
  // versions need to be destroyed before table_cache since it can hold
  // references to table_cache.
  {
@@ -916,8 +933,8 @@ Status DBImpl::RegisterRecordSeqnoTimeWorker(const ReadOptions& read_options,
            read_options, write_options, &edit, &mutex_,
            directories_.GetDbDir());
        if (!s.ok() && versions_->io_status().IsIOError()) {
-          s = error_handler_.SetBGError(versions_->io_status(),
-                                        BackgroundErrorReason::kManifestWrite);
+          error_handler_.SetBGError(versions_->io_status(),
+                                    BackgroundErrorReason::kManifestWrite);
        }
      }

@@ -1525,7 +1542,7 @@ Status DBImpl::FlushWAL(const WriteOptions& write_options, bool sync) {
                      io_s.ToString().c_str());
      // In case there is a fs error we should set it globally to prevent the
      // future writes
-      IOStatusCheck(io_s);
+      WALIOStatusCheck(io_s);
      // whether sync or not, we should abort the rest of function upon error
      return static_cast<Status>(io_s);
    }
@@ -1682,7 +1699,7 @@ IOStatus DBImpl::SyncWalImpl(bool include_current_wal,
                    io_s.ToString().c_str());
    // In case there is a fs error we should set it globally to prevent the
    // future writes
-    IOStatusCheck(io_s);
+    WALIOStatusCheck(io_s);
  }
  if (io_s.ok() && need_wal_dir_sync) {
    io_s = directories_.GetWalDir()->FsyncWithDirOptions(
@@ -1724,8 +1741,8 @@ Status DBImpl::ApplyWALToManifest(const ReadOptions& read_options,
      read_options, write_options, synced_wals, &mutex_,
      directories_.GetDbDir());
  if (!status.ok() && versions_->io_status().IsIOError()) {
-    status = error_handler_.SetBGError(versions_->io_status(),
-                                       BackgroundErrorReason::kManifestWrite);
+    error_handler_.SetBGError(versions_->io_status(),
+                              BackgroundErrorReason::kManifestWrite);
  }
  return status;
 }
@@ -2053,30 +2070,34 @@ InternalIterator* DBImpl::NewInternalIterator(
    bool allow_unprepared_value, ArenaWrappedDBIter* db_iter) {
  InternalIterator* internal_iter;
  assert(arena != nullptr);
+  auto prefix_extractor =
+      super_version->mutable_cf_options.prefix_extractor.get();
  // Need to create internal iterator from the arena.
  MergeIteratorBuilder merge_iter_builder(
      &cfd->internal_comparator(), arena,
-      !read_options.total_order_seek &&
-          super_version->mutable_cf_options.prefix_extractor != nullptr,
+      // FIXME? It's not clear what interpretation of prefix seek is needed
+      // here, and no unit test cares about the value provided here.
+      !read_options.total_order_seek && prefix_extractor != nullptr,
      read_options.iterate_upper_bound);
  // Collect iterator for mutable memtable
  auto mem_iter = super_version->mem->NewIterator(
-      read_options, super_version->GetSeqnoToTimeMapping(), arena);
+      read_options, super_version->GetSeqnoToTimeMapping(), arena,
+      super_version->mutable_cf_options.prefix_extractor.get());
  Status s;
  if (!read_options.ignore_range_deletions) {
-    TruncatedRangeDelIterator* mem_tombstone_iter = nullptr;
+    std::unique_ptr<TruncatedRangeDelIterator> mem_tombstone_iter;
    auto range_del_iter = super_version->mem->NewRangeTombstoneIterator(
        read_options, sequence, false /* immutable_memtable */);
    if (range_del_iter == nullptr || range_del_iter->empty()) {
      delete range_del_iter;
    } else {
-      mem_tombstone_iter = new TruncatedRangeDelIterator(
+      mem_tombstone_iter = std::make_unique<TruncatedRangeDelIterator>(
          std::unique_ptr<FragmentedRangeTombstoneIterator>(range_del_iter),
          &cfd->ioptions()->internal_comparator, nullptr /* smallest */,
          nullptr /* largest */);
    }
-    merge_iter_builder.AddPointAndTombstoneIterator(mem_iter,
-                                                    mem_tombstone_iter);
+    merge_iter_builder.AddPointAndTombstoneIterator(
+        mem_iter, std::move(mem_tombstone_iter));
  } else {
    merge_iter_builder.AddIterator(mem_iter);
  }
@@ -2085,6 +2106,7 @@ InternalIterator* DBImpl::NewInternalIterator(
  if (s.ok()) {
    super_version->imm->AddIterators(
        read_options, super_version->GetSeqnoToTimeMapping(),
+        super_version->mutable_cf_options.prefix_extractor.get(),
        &merge_iter_builder, !read_options.ignore_range_deletions);
  }
  TEST_SYNC_POINT_CALLBACK("DBImpl::NewInternalIterator:StatusCallback", &s);
@@ -2475,7 +2497,8 @@ Status DBImpl::GetImpl(const ReadOptions& read_options, const Slice& key,
        RecordTick(stats_, MEMTABLE_HIT);
      }
    }
-    if (!done && !s.ok() && !s.IsMergeInProgress()) {
+    if (!s.ok() && !s.IsMergeInProgress() && !s.IsNotFound()) {
+      assert(done);
      ReturnAndCleanupSuperVersion(cfd, sv);
      return s;
    }
@@ -3141,10 +3164,11 @@ Status DBImpl::MultiGetImpl(
  StopWatch sw(immutable_db_options_.clock, stats_, DB_MULTIGET);

  assert(sorted_keys);
+  assert(start_key + num_keys <= sorted_keys->size());
  // Clear the timestamps for returning results so that we can distinguish
  // between tombstone or key that has never been written
-  for (auto* kctx : *sorted_keys) {
-    assert(kctx);
+  for (size_t i = start_key; i < start_key + num_keys; ++i) {
+    KeyContext* kctx = (*sorted_keys)[i];
    if (kctx->timestamp) {
      kctx->timestamp->clear();
    }
@@ -3207,6 +3231,8 @@ Status DBImpl::MultiGetImpl(
      s = Status::Aborted();
      break;
    }
+    // This could be a long-running operation
+    ROCKSDB_THREAD_YIELD_HOOK();
  }

  // Post processing (decrement reference counts and record statistics)
@@ -3828,6 +3854,9 @@ Iterator* DBImpl::NewIterator(const ReadOptions& _read_options,
    }
  }
  if (read_options.tailing) {
+    read_options.total_order_seek |=
+        immutable_db_options_.prefix_seek_opt_in_only;
+
    auto iter = new ForwardIterator(this, read_options, cfd, sv,
                                    /* allow_unprepared_value */ true);
    result = NewDBIterator(
@@ -4029,6 +4058,9 @@ Status DBImpl::NewIterators(

  assert(cf_sv_pairs.size() == column_families.size());
  if (read_options.tailing) {
+    read_options.total_order_seek |=
+        immutable_db_options_.prefix_seek_opt_in_only;
+
    for (const auto& cf_sv_pair : cf_sv_pairs) {
      auto iter = new ForwardIterator(this, read_options, cf_sv_pair.cfd,
                                      cf_sv_pair.super_version,
@@ -4279,7 +4311,7 @@ void DBImpl::ReleaseSnapshot(const Snapshot* s) {
                   ->storage_info()
                   ->BottommostFilesMarkedForCompaction()
                   .empty()) {
-            SchedulePendingCompaction(cfd);
+            EnqueuePendingCompaction(cfd);
            MaybeScheduleFlushOrCompaction();
            cf_scheduled.push_back(cfd);
          }
@@ -4753,6 +4785,24 @@ void DBImpl::ReleaseFileNumberFromPendingOutputs(
  }
 }

+std::list<uint64_t>::iterator DBImpl::CaptureOptionsFileNumber() {
+  // We need to remember the iterator of our insert, because after the
+  // compaction is done, we need to remove that element from
+  // min_options_file_numbers_.
+  min_options_file_numbers_.push_back(versions_->options_file_number());
+  auto min_options_file_numbers_inserted_elem = min_options_file_numbers_.end();
+  --min_options_file_numbers_inserted_elem;
+  return min_options_file_numbers_inserted_elem;
+}
+
+void DBImpl::ReleaseOptionsFileNumber(
+    std::unique_ptr<std::list<uint64_t>::iterator>& v) {
+  if (v.get() != nullptr) {
+    min_options_file_numbers_.erase(*v.get());
+    v.reset();
+  }
+}
+
 Status DBImpl::GetUpdatesSince(
    SequenceNumber seq, std::unique_ptr<TransactionLogIterator>* iter,
    const TransactionLogIterator::ReadOptions& read_options) {
@@ -5240,6 +5290,14 @@ Status DestroyDB(const std::string& dbname, const Options& options,
  Env* env = soptions.env;
  std::vector<std::string> filenames;
  bool wal_in_db_path = soptions.IsWalDirSameAsDBPath();
+  auto sfm = static_cast_with_check<SstFileManagerImpl>(
+      options.sst_file_manager.get());
+  // Allocate a separate trash bucket to be used by all the to be deleted
+  // files, so we can later wait for this bucket to be empty before return.
+  std::optional<int32_t> bucket;
+  if (sfm) {
+    bucket = sfm->NewTrashBucket();
+  }

  // Reset the logger because it holds a handle to the
  // log file and prevents cleanup and directory removal
@@ -5251,6 +5309,7 @@ Status DestroyDB(const std::string& dbname, const Options& options,
                    /*IODebugContext*=*/nullptr)
      .PermitUncheckedError();

+  std::set<std::string> paths_to_delete;
  FileLock* lock;
  const std::string lockname = LockFileName(dbname);
  Status result = env->LockFile(lockname, &lock);
@@ -5267,10 +5326,9 @@ Status DestroyDB(const std::string& dbname, const Options& options,
          del = DestroyDB(path_to_delete, options);
        } else if (type == kTableFile || type == kWalFile ||
                   type == kBlobFile) {
-          del = DeleteDBFile(
-              &soptions, path_to_delete, dbname,
-              /*force_bg=*/false,
-              /*force_fg=*/(type == kWalFile) ? !wal_in_db_path : false);
+          del = DeleteUnaccountedDBFile(&soptions, path_to_delete, dbname,
+                                        /*force_bg=*/false,
+                                        /*force_fg=*/false, bucket);
        } else {
          del = env->DeleteFile(path_to_delete);
        }
@@ -5279,6 +5337,7 @@ Status DestroyDB(const std::string& dbname, const Options& options,
        }
      }
    }
+    paths_to_delete.insert(dbname);

    std::set<std::string> paths;
    for (const DbPath& db_path : options.db_paths) {
@@ -5300,18 +5359,19 @@ Status DestroyDB(const std::string& dbname, const Options& options,
              (type == kTableFile ||
               type == kBlobFile)) {  // Lock file will be deleted at end
            std::string file_path = path + "/" + fname;
-            Status del = DeleteDBFile(&soptions, file_path, dbname,
-                                      /*force_bg=*/false, /*force_fg=*/false);
+            Status del = DeleteUnaccountedDBFile(&soptions, file_path, dbname,
+                                                 /*force_bg=*/false,
+                                                 /*force_fg=*/false, bucket);
            if (!del.ok() && result.ok()) {
              result = del;
            }
          }
        }
-        // TODO: Should we return an error if we cannot delete the directory?
-        env->DeleteDir(path).PermitUncheckedError();
      }
    }

+    paths_to_delete.merge(paths);
+
    std::vector<std::string> walDirFiles;
    std::string archivedir = ArchivalDirectory(dbname);
    bool wal_dir_exists = false;
@@ -5335,46 +5395,49 @@ Status DestroyDB(const std::string& dbname, const Options& options,
      // Delete archival files.
      for (const auto& file : archiveFiles) {
        if (ParseFileName(file, &number, &type) && type == kWalFile) {
-          Status del =
-              DeleteDBFile(&soptions, archivedir + "/" + file, archivedir,
-                           /*force_bg=*/false, /*force_fg=*/!wal_in_db_path);
+          Status del = DeleteUnaccountedDBFile(
+              &soptions, archivedir + "/" + file, archivedir,
+              /*force_bg=*/false, /*force_fg=*/!wal_in_db_path, bucket);
          if (!del.ok() && result.ok()) {
            result = del;
          }
        }
      }
-      // Ignore error in case dir contains other files
-      env->DeleteDir(archivedir).PermitUncheckedError();
+      paths_to_delete.insert(archivedir);
    }

    // Delete log files in the WAL dir
    if (wal_dir_exists) {
      for (const auto& file : walDirFiles) {
        if (ParseFileName(file, &number, &type) && type == kWalFile) {
-          Status del =
-              DeleteDBFile(&soptions, LogFileName(soptions.wal_dir, number),
-                           soptions.wal_dir, /*force_bg=*/false,
-                           /*force_fg=*/!wal_in_db_path);
+          Status del = DeleteUnaccountedDBFile(
+              &soptions, LogFileName(soptions.wal_dir, number),
+              soptions.wal_dir, /*force_bg=*/false,
+              /*force_fg=*/!wal_in_db_path, bucket);
          if (!del.ok() && result.ok()) {
            result = del;
          }
        }
      }
-      // Ignore error in case dir contains other files
-      env->DeleteDir(soptions.wal_dir).PermitUncheckedError();
+      paths_to_delete.insert(soptions.wal_dir);
    }

    // Ignore error since state is already gone
    env->UnlockFile(lock).PermitUncheckedError();
    env->DeleteFile(lockname).PermitUncheckedError();

+    // Make sure trash files are all cleared before return.
+    if (sfm && bucket.has_value()) {
+      sfm->WaitForEmptyTrashBucket(bucket.value());
+    }
    // sst_file_manager holds a ref to the logger. Make sure the logger is
    // gone before trying to remove the directory.
    soptions.sst_file_manager.reset();

    // Ignore error in case dir contains other files
-    env->DeleteDir(dbname).PermitUncheckedError();
-    ;
+    for (const auto& path_to_delete : paths_to_delete) {
+      env->DeleteDir(path_to_delete).PermitUncheckedError();
+    }
  }
  return result;
 }
@@ -5814,6 +5877,17 @@ Status DBImpl::IngestExternalFiles(
            "timestamps enabled doesn't support ingest behind.");
      }
    }
+    if (ingest_opts.allow_db_generated_files) {
+      if (ingest_opts.write_global_seqno) {
+        return Status::NotSupported(
+            "write_global_seqno is deprecated and does not work with "
+            "allow_db_generated_files.");
+      }
+    }
+    if (ingest_opts.move_files && ingest_opts.link_files) {
+      return Status::InvalidArgument(
+          "`move_files` and `link_files` can not both be true.");
+    }
  }

  // TODO (yanqin) maybe handle the case in which column_families have
@@ -6720,6 +6794,62 @@ void DBImpl::RecordSeqnoToTimeMapping(uint64_t populate_historical_seconds) {
  }
 }

+void DBImpl::TrackOrUntrackFiles(
+    const std::vector<std::string>& existing_data_files, bool track) {
+  auto sfm = static_cast_with_check<SstFileManagerImpl>(
+      immutable_db_options_.sst_file_manager.get());
+  assert(sfm);
+  std::vector<ColumnFamilyMetaData> metadata;
+  GetAllColumnFamilyMetaData(&metadata);
+  auto action = [&](const std::string& file_path,
+                    std::optional<uint64_t> size) {
+    if (track) {
+      if (size) {
+        sfm->OnAddFile(file_path, *size).PermitUncheckedError();
+      } else {
+        sfm->OnAddFile(file_path).PermitUncheckedError();
+      }
+    } else {
+      sfm->OnUntrackFile(file_path).PermitUncheckedError();
+    }
+  };
+
+  std::unordered_set<std::string> referenced_files;
+  for (const auto& md : metadata) {
+    for (const auto& lmd : md.levels) {
+      for (const auto& fmd : lmd.files) {
+        // We're assuming that each sst file name exists in at most one of
+        // the paths.
+        std::string file_path =
+            fmd.directory + kFilePathSeparator + fmd.relative_filename;
+        action(file_path, fmd.size);
+        referenced_files.insert(file_path);
+      }
+    }
+    for (const auto& bmd : md.blob_files) {
+      std::string name = bmd.blob_file_name;
+      // The BlobMetaData.blob_file_name may start with "/".
+      if (!name.empty() && name[0] == kFilePathSeparator) {
+        name = name.substr(1);
+      }
+      // We're assuming that each blob file name exists in at most one of
+      // the paths.
+      std::string file_path = bmd.blob_file_path + kFilePathSeparator + name;
+      action(file_path, bmd.blob_file_size);
+      referenced_files.insert(file_path);
+    }
+  }
+
+  for (const auto& file_path : existing_data_files) {
+    if (referenced_files.find(file_path) != referenced_files.end()) {
+      continue;
+    }
+    // There shouldn't be any duplicated files. In case there is, SstFileManager
+    // will take care of deduping it.
+    action(file_path, /*size=*/std::nullopt);
+  }
+}
+
 void DBImpl::InstallSeqnoToTimeMappingInSV(
    std::vector<SuperVersionContext>* sv_contexts) {
  mutex_.AssertHeld();
@@ -508,6 +508,8 @@ class DBImpl : public DB {
  Status GetLiveFiles(std::vector<std::string>&, uint64_t* manifest_file_size,
                      bool flush_memtable = true) override;
  Status GetSortedWalFiles(VectorWalPtr& files) override;
+  Status GetSortedWalFilesImpl(VectorWalPtr& files, bool need_seqnos);
+
  // Get the known flushed sizes of WALs that might still be written to
  // or have pending sync.
  // NOTE: unlike alive_log_files_, this function includes WALs that might
@@ -851,6 +853,8 @@ class DBImpl : public DB {

  uint64_t GetObsoleteSstFilesSize();

+  uint64_t MinOptionsFileNumberToKeep();
+
  // Returns the list of live files in 'live' and the list
  // of all files in the filesystem in 'candidate_files'.
  // If force == false and the last call was less than
@@ -1149,6 +1153,8 @@ class DBImpl : public DB {
  // Get the background error status
  Status TEST_GetBGError();

+  bool TEST_IsRecoveryInProgress();
+
  // Return the maximum overlapping data (in bytes) at next level for any
  // file at a level >= 1.
  uint64_t TEST_MaxNextLevelOverlappingBytes(
@@ -1224,6 +1230,8 @@ class DBImpl : public DB {
    return logs_.back().number;
  }

+  void TEST_DeleteObsoleteFiles();
+
  const std::unordered_set<uint64_t>& TEST_GetFilesGrabbedForPurge() const {
    return files_grabbed_for_purge_;
  }
@@ -1233,9 +1241,14 @@ class DBImpl : public DB {
  static Status TEST_ValidateOptions(const DBOptions& db_options) {
    return ValidateOptions(db_options);
  }
-
 #endif  // NDEBUG

+  // In certain configurations, verify that the table/blob file cache only
+  // contains entries for live files, to check for effective leaks of open
+  // files. This can only be called when purging of obsolete files has
+  // "settled," such as during parts of DB Close().
+  void TEST_VerifyNoObsoleteFilesCached(bool db_mutex_already_held) const;
+
  // persist stats to column family "_persistent_stats"
  void PersistStats();

@@ -1578,11 +1591,12 @@ class DBImpl : public DB {

  virtual bool OwnTablesAndLogs() const { return true; }

-  // Setup DB identity file, and write DB ID to manifest if necessary.
+  // Read/create DB identity file (as appropriate), and write DB ID to
+  // version_edit if provided.
  Status SetupDBId(const WriteOptions& write_options, bool read_only,
-                   RecoveryContext* recovery_ctx);
-  // Assign db_id_ and write DB ID to manifest if necessary.
-  void SetDBId(std::string&& id, bool read_only, RecoveryContext* recovery_ctx);
+                   bool is_new_db, VersionEdit* version_edit);
+  // Assign db_id_ and write DB ID to version_edit if provided.
+  void SetDBId(std::string&& id, bool read_only, VersionEdit* version_edit);

  // Collect a deduplicated collection of paths used by this DB, including
  // dbname_, DBOptions.db_paths, ColumnFamilyOptions.cf_paths.
@@ -1612,9 +1626,15 @@ class DBImpl : public DB {
  // vast majority of all files), since it already has the file size
  // on record, we don't need to query the file system. Otherwise, we query the
  // file system for the size of an unreferenced file.
+  // REQUIRES: mutex unlocked
  void TrackExistingDataFiles(
      const std::vector<std::string>& existing_data_files);

+  // Untrack data files in sst manager. This is only called during DB::Close on
+  // an unowned SstFileManager, to return it to a consistent state.
+  // REQUIRES: mutex unlocked
+  void UntrackDataFiles();
+
  // SetDbSessionId() should be called in the constuctor DBImpl()
  // to ensure that db_session_id_ gets updated every time the DB is opened
  void SetDbSessionId();
@@ -1681,6 +1701,8 @@ class DBImpl : public DB {
  friend class XFTransactionWriteHandler;
  friend class DBBlobIndexTest;
  friend class WriteUnpreparedTransactionTest_RecoveryTest_Test;
+  friend class CompactionServiceTest_PreservedOptionsLocalCompaction_Test;
+  friend class CompactionServiceTest_PreservedOptionsRemoteCompaction_Test;
 #endif

  struct CompactionState;
@@ -1886,6 +1908,10 @@ class DBImpl : public DB {
    Env::Priority compaction_pri_;
  };

+  static bool IsRecoveryFlush(FlushReason flush_reason) {
+    return flush_reason == FlushReason::kErrorRecoveryRetryFlush ||
+           flush_reason == FlushReason::kErrorRecovery;
+  }
  // Initialize the built-in column family for persistent stats. Depending on
  // whether on-disk persistent stats have been enabled before, it may either
  // create a new column family and column family handle or just a column family
@@ -1948,6 +1974,13 @@ class DBImpl : public DB {
  void ReleaseFileNumberFromPendingOutputs(
      std::unique_ptr<std::list<uint64_t>::iterator>& v);

+  // Similar to pending_outputs, preserve OPTIONS file. Used for remote
+  // compaction.
+  std::list<uint64_t>::iterator CaptureOptionsFileNumber();
+  void ReleaseOptionsFileNumber(
+      std::unique_ptr<std::list<uint64_t>::iterator>& v);
+
+  // Sets bg error if there is an error writing to WAL.
  IOStatus SyncClosedWals(const WriteOptions& write_options,
                          JobContext* job_context, VersionEdit* synced_wals,
                          bool error_recovery_in_prog);
@@ -2030,7 +2063,8 @@ class DBImpl : public DB {
  // REQUIRES: mutex held
  void SelectColumnFamiliesForAtomicFlush(
      autovector<ColumnFamilyData*>* selected_cfds,
-      const autovector<ColumnFamilyData*>& provided_candidate_cfds = {});
+      const autovector<ColumnFamilyData*>& provided_candidate_cfds = {},
+      FlushReason flush_reason = FlushReason::kOthers);

  // Force current memtable contents to be flushed.
  Status FlushMemTable(ColumnFamilyData* cfd, const FlushOptions& options,
@@ -2165,7 +2199,7 @@ class DBImpl : public DB {

  // Used by WriteImpl to update bg_error_ when IO error happens, e.g., write
  // WAL, sync WAL fails, if paranoid check is enabled.
-  void IOStatusCheck(const IOStatus& status);
+  void WALIOStatusCheck(const IOStatus& status);

  // Used by WriteImpl to update bg_error_ in case of memtable insert error.
  void MemTableInsertStatusCheck(const Status& memtable_insert_status);
@@ -2178,6 +2212,10 @@ class DBImpl : public DB {
                          JobContext* job_context, LogBuffer* log_buffer,
                          CompactionJobInfo* compaction_job_info);

+  // REQUIRES: mutex unlocked
+  void TrackOrUntrackFiles(const std::vector<std::string>& existing_data_files,
+                           bool track);
+
  ColumnFamilyData* GetColumnFamilyDataByName(const std::string& cf_name);

  void MaybeScheduleFlushOrCompaction();
@@ -2207,10 +2245,27 @@ class DBImpl : public DB {
  void GenerateFlushRequest(const autovector<ColumnFamilyData*>& cfds,
                            FlushReason flush_reason, FlushRequest* req);

-  // Returns true if `req` is successfully enqueued.
-  bool SchedulePendingFlush(const FlushRequest& req);
+  // Below functions are for executing flush, compaction in the background. A
+  // dequeue is the communication channel between threads that asks for the work
+  // to be done and the available threads in the thread pool that pick it up to
+  // execute it. We use these terminologies to describe the state of the work
+  // and its transitions:
+  // 1) It becomes pending once it's successfully enqueued into the
+  //    corresponding dequeue, a work in this state is also called unscheduled.
+  //    Counter `unscheduled_*_` counts work in this state.
+  // 2) When `MaybeScheduleFlushOrCompaction` schedule a thread to run `BGWork*`
+  //    for the work, it becomes scheduled
+  //    Counter `bg_*_scheduled_` counts work in this state.
+  // 3) Once the thread start to execute `BGWork*`, the work is popped from the
+  //    dequeue, it is now in running state
+  //    Counter `num_running_*_` counts work in this state.
+  // 4) Eventually, the work is finished. We don't need to specifically track
+  //    finished work.

-  void SchedulePendingCompaction(ColumnFamilyData* cfd);
+  // Returns true if `req` is successfully enqueued.
+  bool EnqueuePendingFlush(const FlushRequest& req);
+
+  void EnqueuePendingCompaction(ColumnFamilyData* cfd);
  void SchedulePendingPurge(std::string fname, std::string dir_to_sync,
                            FileType type, uint64_t number, int job_id);
  static void BGWorkCompaction(void* arg);
@@ -2346,6 +2401,9 @@ class DBImpl : public DB {
  bool HaveManualCompaction(ColumnFamilyData* cfd);
  bool MCOverlap(ManualCompactionState* m, ManualCompactionState* m1);
  void UpdateDeletionCompactionStats(const std::unique_ptr<Compaction>& c);
+
+  // May open and read table files for table property.
+  // Should not be called while holding mutex_.
  void BuildCompactionJobInfo(const ColumnFamilyData* cfd, Compaction* c,
                              const Status& st,
                              const CompactionJobStats& compaction_job_stats,
@@ -2712,6 +2770,11 @@ class DBImpl : public DB {
  // State is protected with db mutex.
  std::list<uint64_t> pending_outputs_;

+  // Similar to pending_outputs_, FindObsoleteFiles()/PurgeObsoleteFiles() never
+  // deletes any OPTIONS file that has number bigger than any of the file number
+  // in min_options_file_numbers_.
+  std::list<uint64_t> min_options_file_numbers_;
+
  // flush_queue_ and compaction_queue_ hold column families that we need to
  // flush and compact, respectively.
  // A column family is inserted into flush_queue_ when it satisfies condition
@@ -2934,6 +2997,14 @@ DBOptions SanitizeOptions(const std::string& db, const DBOptions& src,
 CompressionType GetCompressionFlush(const ImmutableCFOptions& ioptions,
                                    const MutableCFOptions& mutable_cf_options);

+// Return a VersionEdit for the DB's recovery when the `memtables` of the
+// specified column family are obsolete. Specifically, the min log number to
+// keep, and the WAL files that can be deleted.
+VersionEdit GetDBRecoveryEditForObsoletingMemTables(
+    VersionSet* vset, const ColumnFamilyData& cfd,
+    const autovector<VersionEdit*>& edit_list,
+    const autovector<MemTable*>& memtables, LogsWithPrepTracker* prep_tracker);
+
 // Return the earliest log file to keep after the memtable flush is
 // finalized.
 // `cfd_to_flush` is the column family whose memtable (specified in
@@ -1561,6 +1561,12 @@ Status DBImpl::CompactFilesImpl(

  compaction_job.Prepare();

+  std::unique_ptr<std::list<uint64_t>::iterator> min_options_file_number_elem;
+  if (immutable_db_options().compaction_service != nullptr) {
+    min_options_file_number_elem.reset(
+        new std::list<uint64_t>::iterator(CaptureOptionsFileNumber()));
+  }
+
  mutex_.Unlock();
  TEST_SYNC_POINT("CompactFilesImpl:0");
  TEST_SYNC_POINT("CompactFilesImpl:1");
@@ -1570,6 +1576,10 @@ Status DBImpl::CompactFilesImpl(
  TEST_SYNC_POINT("CompactFilesImpl:3");
  mutex_.Lock();

+  if (immutable_db_options().compaction_service != nullptr) {
+    ReleaseOptionsFileNumber(min_options_file_number_elem);
+  }
+
  bool compaction_released = false;
  Status status =
      compaction_job.Install(*c->mutable_cf_options(), &compaction_released);
@@ -1595,10 +1605,12 @@ Status DBImpl::CompactFilesImpl(

  ReleaseFileNumberFromPendingOutputs(pending_outputs_inserted_elem);

+  mutex_.Unlock();
  if (compaction_job_info != nullptr) {
    BuildCompactionJobInfo(cfd, c.get(), s, compaction_job_stats,
                           job_context->job_id, compaction_job_info);
  }
+  mutex_.Lock();

  if (status.ok()) {
    // Done
@@ -1878,7 +1890,7 @@ Status DBImpl::ReFitLevel(ColumnFamilyData* cfd, int level, int target_level) {
    Status status = versions_->LogAndApply(cfd, mutable_cf_options,
                                           read_options, write_options, &edit,
                                           &mutex_, directories_.GetDbDir());
-
+    c->MarkFilesBeingCompacted(false);
    cfd->compaction_picker()->UnregisterCompaction(c.get());
    c.reset();

@@ -2304,13 +2316,15 @@ Status DBImpl::FlushMemTable(ColumnFamilyData* cfd,
    }
    WaitForPendingWrites();

-    if (!cfd->mem()->IsEmpty() || !cached_recoverable_state_empty_.load()) {
+    if (!cfd->mem()->IsEmpty() || !cached_recoverable_state_empty_.load() ||
+        IsRecoveryFlush(flush_reason)) {
      s = SwitchMemtable(cfd, &context);
    }
    const uint64_t flush_memtable_id = std::numeric_limits<uint64_t>::max();
    if (s.ok()) {
      if (cfd->imm()->NumNotFlushed() != 0 || !cfd->mem()->IsEmpty() ||
-          !cached_recoverable_state_empty_.load()) {
+          !cached_recoverable_state_empty_.load() ||
+          IsRecoveryFlush(flush_reason)) {
        FlushRequest req{flush_reason, {{cfd, flush_memtable_id}}};
        flush_reqs.emplace_back(std::move(req));
        memtable_ids_to_wait.emplace_back(
@@ -2373,7 +2387,7 @@ Status DBImpl::FlushMemTable(ColumnFamilyData* cfd,
        ColumnFamilyData* loop_cfd =
            req.cfd_to_max_mem_id_to_persist.begin()->first;
        bool already_queued_for_flush = loop_cfd->queued_for_flush();
-        bool flush_req_enqueued = SchedulePendingFlush(req);
+        bool flush_req_enqueued = EnqueuePendingFlush(req);
        if (already_queued_for_flush || flush_req_enqueued) {
          loop_cfd->SetFlushSkipReschedule();
        }
@@ -2487,7 +2501,7 @@ Status DBImpl::AtomicFlushMemTables(
    }
    WaitForPendingWrites();

-    SelectColumnFamiliesForAtomicFlush(&cfds, candidate_cfds);
+    SelectColumnFamiliesForAtomicFlush(&cfds, candidate_cfds, flush_reason);

    // Unref the newly generated candidate cfds (when not provided) in
    // `candidate_cfds`
@@ -2498,7 +2512,8 @@ Status DBImpl::AtomicFlushMemTables(
    }

    for (auto cfd : cfds) {
-      if (cfd->mem()->IsEmpty() && cached_recoverable_state_empty_.load()) {
+      if (cfd->mem()->IsEmpty() && cached_recoverable_state_empty_.load() &&
+          !IsRecoveryFlush(flush_reason)) {
        continue;
      }
      cfd->Ref();
@@ -2523,7 +2538,7 @@ Status DBImpl::AtomicFlushMemTables(
        }
      }
      GenerateFlushRequest(cfds, flush_reason, &flush_req);
-      SchedulePendingFlush(flush_req);
+      EnqueuePendingFlush(flush_req);
      MaybeScheduleFlushOrCompaction();
    }

@@ -2578,7 +2593,7 @@ Status DBImpl::RetryFlushesForErrorRecovery(FlushReason flush_reason,
  if (immutable_db_options_.atomic_flush) {
    FlushRequest flush_req;
    GenerateFlushRequest(cfds, flush_reason, &flush_req);
-    SchedulePendingFlush(flush_req);
+    EnqueuePendingFlush(flush_req);
    for (auto& iter : flush_req.cfd_to_max_mem_id_to_persist) {
      flush_memtable_ids.push_back(iter.second);
    }
@@ -2592,7 +2607,7 @@ Status DBImpl::RetryFlushesForErrorRecovery(FlushReason flush_reason,
          flush_reason,
          {{cfd,
            std::numeric_limits<uint64_t>::max() /* max_mem_id_to_persist */}}};
-      if (SchedulePendingFlush(flush_req)) {
+      if (EnqueuePendingFlush(flush_req)) {
        cfd->SetFlushSkipReschedule();
      };
    }
@@ -2945,6 +2960,7 @@ void DBImpl::AddToCompactionQueue(ColumnFamilyData* cfd) {
  cfd->Ref();
  compaction_queue_.push_back(cfd);
  cfd->set_queued_for_compaction(true);
+  ++unscheduled_compactions_;
 }

 ColumnFamilyData* DBImpl::PopFirstFromCompactionQueue() {
@@ -3000,7 +3016,7 @@ ColumnFamilyData* DBImpl::PickCompactionFromQueue(
  return cfd;
 }

-bool DBImpl::SchedulePendingFlush(const FlushRequest& flush_req) {
+bool DBImpl::EnqueuePendingFlush(const FlushRequest& flush_req) {
  mutex_.AssertHeld();
  bool enqueued = false;
  if (reject_new_background_jobs_) {
@@ -3036,16 +3052,15 @@ bool DBImpl::SchedulePendingFlush(const FlushRequest& flush_req) {
  return enqueued;
 }

-void DBImpl::SchedulePendingCompaction(ColumnFamilyData* cfd) {
+void DBImpl::EnqueuePendingCompaction(ColumnFamilyData* cfd) {
  mutex_.AssertHeld();
  if (reject_new_background_jobs_) {
    return;
  }
  if (!cfd->queued_for_compaction() && cfd->NeedsCompaction()) {
-    TEST_SYNC_POINT_CALLBACK("SchedulePendingCompaction::cfd",
+    TEST_SYNC_POINT_CALLBACK("EnqueuePendingCompaction::cfd",
                             static_cast<void*>(cfd));
    AddToCompactionQueue(cfd);
-    ++unscheduled_compactions_;
  }
 }

@@ -3213,7 +3228,7 @@ Status DBImpl::BackgroundFlush(bool* made_progress, JobContext* job_context,
 #ifndef NDEBUG
      flush_req.reschedule_count += 1;
 #endif /* !NDEBUG */
-      SchedulePendingFlush(flush_req);
+      EnqueuePendingFlush(flush_req);
      *reason = flush_reason;
      *flush_rescheduled_to_retain_udt = true;
      return Status::TryAgain();
@@ -3536,6 +3551,14 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
      is_manual && manual_compaction->disallow_trivial_move;

  CompactionJobStats compaction_job_stats;
+  // Set is_remote_compaction to true on CompactionBegin Event if
+  // compaction_service is set except for trivial moves. We do not know whether
+  // remote compaction will actually be successfully scheduled, or fall back to
+  // local at this time. CompactionCompleted event will tell the truth where
+  // the compaction actually happened.
+  compaction_job_stats.is_remote_compaction =
+      immutable_db_options().compaction_service != nullptr;
+
  Status status;
  if (!error_handler_.IsBGWorkStopped()) {
    if (shutting_down_.load(std::memory_order_acquire)) {
@@ -3673,7 +3696,6 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
              ->ComputeCompactionScore(*(c->immutable_options()),
                                       *(c->mutable_cf_options()));
          AddToCompactionQueue(cfd);
-          ++unscheduled_compactions_;

          c.reset();
          // Don't need to sleep here, because BackgroundCallCompaction
@@ -3702,7 +3724,6 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
          if (cfd->NeedsCompaction()) {
            // Yes, we need more compactions!
            AddToCompactionQueue(cfd);
-            ++unscheduled_compactions_;
            MaybeScheduleFlushOrCompaction();
          }
        }
@@ -3763,6 +3784,8 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    ThreadStatusUtil::SetThreadOperation(ThreadStatus::OP_COMPACTION);

    compaction_job_stats.num_input_files = c->num_input_files(0);
+    // Trivial moves do not get compacted remotely
+    compaction_job_stats.is_remote_compaction = false;

    NotifyOnCompactionBegin(c->column_family_data(), c.get(), status,
                            compaction_job_stats, job_context->job_id);
@@ -3898,6 +3921,12 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
        &bg_bottom_compaction_scheduled_);
    compaction_job.Prepare();

+    std::unique_ptr<std::list<uint64_t>::iterator> min_options_file_number_elem;
+    if (immutable_db_options().compaction_service != nullptr) {
+      min_options_file_number_elem.reset(
+          new std::list<uint64_t>::iterator(CaptureOptionsFileNumber()));
+    }
+
    NotifyOnCompactionBegin(c->column_family_data(), c.get(), status,
                            compaction_job_stats, job_context->job_id);
    mutex_.Unlock();
@@ -3907,6 +3936,11 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
    compaction_job.Run().PermitUncheckedError();
    TEST_SYNC_POINT("DBImpl::BackgroundCompaction:NonTrivial:AfterRun");
    mutex_.Lock();
+
+    if (immutable_db_options().compaction_service != nullptr) {
+      ReleaseOptionsFileNumber(min_options_file_number_elem);
+    }
+
    status =
        compaction_job.Install(*c->mutable_cf_options(), &compaction_released);
    io_s = compaction_job.io_status();
@@ -3992,7 +4026,6 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
                                   *(c->mutable_cf_options()));
      if (!cfd->queued_for_compaction()) {
        AddToCompactionQueue(cfd);
-        ++unscheduled_compactions_;
      }
    }
  }
@@ -4161,7 +4194,7 @@ void DBImpl::BuildCompactionJobInfo(
  compaction_job_info->base_input_level = c->start_level();
  compaction_job_info->output_level = c->output_level();
  compaction_job_info->stats = compaction_job_stats;
-  const auto& input_table_properties = c->GetInputTableProperties();
+  const auto& input_table_properties = c->GetOrInitInputTableProperties();
  const auto& output_table_properties = c->GetOutputTableProperties();
  compaction_job_info->table_properties.insert(input_table_properties.begin(),
                                               input_table_properties.end());
@@ -4264,7 +4297,7 @@ void DBImpl::InstallSuperVersionAndScheduleWork(

  // Whenever we install new SuperVersion, we might need to issue new flushes or
  // compactions.
-  SchedulePendingCompaction(cfd);
+  EnqueuePendingCompaction(cfd);
  MaybeScheduleFlushOrCompaction();

  // Update max_total_in_memory_state_
@@ -9,6 +9,7 @@

 #ifndef NDEBUG

+#include "db/blob/blob_file_cache.h"
 #include "db/column_family.h"
 #include "db/db_impl/db_impl.h"
 #include "db/error_handler.h"
@@ -199,6 +200,11 @@ Status DBImpl::TEST_GetBGError() {
  return error_handler_.GetBGError();
 }

+bool DBImpl::TEST_IsRecoveryInProgress() {
+  InstrumentedMutexLock l(&mutex_);
+  return error_handler_.IsRecoveryInProgress();
+}
+
 void DBImpl::TEST_LockMutex() { mutex_.Lock(); }

 void DBImpl::TEST_UnlockMutex() { mutex_.Unlock(); }
@@ -314,9 +320,58 @@ const autovector<uint64_t>& DBImpl::TEST_GetFilesToQuarantine() const {
  return error_handler_.GetFilesToQuarantine();
 }

+void DBImpl::TEST_DeleteObsoleteFiles() {
+  InstrumentedMutexLock l(&mutex_);
+  DeleteObsoleteFiles();
+}
+
 size_t DBImpl::TEST_EstimateInMemoryStatsHistorySize() const {
  InstrumentedMutexLock l(&const_cast<DBImpl*>(this)->stats_history_mutex_);
  return EstimateInMemoryStatsHistorySize();
 }
+
+void DBImpl::TEST_VerifyNoObsoleteFilesCached(
+    bool db_mutex_already_held) const {
+  // This check is somewhat expensive and obscure to make a part of every
+  // unit test in every build variety. Thus, we only enable it for ASAN builds.
+  if (!kMustFreeHeapAllocations) {
+    return;
+  }
+
+  std::optional<InstrumentedMutexLock> l;
+  if (db_mutex_already_held) {
+    mutex_.AssertHeld();
+  } else {
+    l.emplace(&mutex_);
+  }
+
+  std::vector<uint64_t> live_files;
+  for (auto cfd : *versions_->GetColumnFamilySet()) {
+    if (cfd->IsDropped()) {
+      continue;
+    }
+    // Sneakily add both SST and blob files to the same list
+    cfd->current()->AddLiveFiles(&live_files, &live_files);
+  }
+  std::sort(live_files.begin(), live_files.end());
+
+  auto fn = [&live_files](const Slice& key, Cache::ObjectPtr, size_t,
+                          const Cache::CacheItemHelper* helper) {
+    if (helper != BlobFileCache::GetHelper()) {
+      // Skip non-blob files for now
+      // FIXME: diagnose and fix the leaks of obsolete SST files revealed in
+      // unit tests.
+      return;
+    }
+    // See TableCache and BlobFileCache
+    assert(key.size() == sizeof(uint64_t));
+    uint64_t file_number;
+    GetUnaligned(reinterpret_cast<const uint64_t*>(key.data()), &file_number);
+    // Assert file is in sorted live_files
+    assert(
+        std::binary_search(live_files.begin(), live_files.end(), file_number));
+  };
+  table_cache_->ApplyToAllEntries(fn, {});
+}
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // NDEBUG
@@ -47,7 +47,7 @@ Status DBImpl::SuggestCompactRange(ColumnFamilyHandle* column_family,
    // compaction score
    vstorage->ComputeCompactionScore(*cfd->ioptions(),
                                     *cfd->GetLatestMutableCFOptions());
-    SchedulePendingCompaction(cfd);
+    EnqueuePendingCompaction(cfd);
    MaybeScheduleFlushOrCompaction();
  }
  return Status::OK();
@@ -43,6 +43,14 @@ uint64_t DBImpl::GetObsoleteSstFilesSize() {
  return versions_->GetObsoleteSstFilesSize();
 }

+uint64_t DBImpl::MinOptionsFileNumberToKeep() {
+  mutex_.AssertHeld();
+  if (!min_options_file_numbers_.empty()) {
+    return *min_options_file_numbers_.begin();
+  }
+  return std::numeric_limits<uint64_t>::max();
+}
+
 Status DBImpl::DisableFileDeletions() {
  Status s;
  int my_disable_delete_obsolete_files;
@@ -147,6 +155,7 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
  // here but later find newer generated unfinalized files while scanning.
  job_context->min_pending_output = MinObsoleteSstNumberToKeep();
  job_context->files_to_quarantine = error_handler_.GetFilesToQuarantine();
+  job_context->min_options_file_number = MinOptionsFileNumberToKeep();

  // Get obsolete files.  This function will also update the list of
  // pending files in VersionSet().
@@ -498,7 +507,7 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
                                dbname_);

  // File numbers of most recent two OPTIONS file in candidate_files (found in
-  // previos FindObsoleteFiles(full_scan=true))
+  // previous FindObsoleteFiles(full_scan=true))
  // At this point, there must not be any duplicate file numbers in
  // candidate_files.
  uint64_t optsfile_num1 = std::numeric_limits<uint64_t>::min();
@@ -519,6 +528,11 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
    }
  }

+  // For remote compactions, we need to keep OPTIONS file that may get
+  // referenced by the remote worker
+
+  optsfile_num2 = std::min(optsfile_num2, state.min_options_file_number);
+
  // Close WALs before trying to delete them.
  for (const auto w : state.logs_to_free) {
    // TODO: maybe check the return value of Close.
@@ -722,6 +736,38 @@ void DBImpl::DeleteObsoleteFiles() {
  mutex_.Lock();
 }

+VersionEdit GetDBRecoveryEditForObsoletingMemTables(
+    VersionSet* vset, const ColumnFamilyData& cfd,
+    const autovector<VersionEdit*>& edit_list,
+    const autovector<MemTable*>& memtables, LogsWithPrepTracker* prep_tracker) {
+  VersionEdit wal_deletion_edit;
+  uint64_t min_wal_number_to_keep = 0;
+  assert(edit_list.size() > 0);
+  if (vset->db_options()->allow_2pc) {
+    // Note that if mempurge is successful, the edit_list will
+    // not be applicable (contains info of new min_log number to keep,
+    // and level 0 file path of SST file created during normal flush,
+    // so both pieces of information are irrelevant after a successful
+    // mempurge operation).
+    min_wal_number_to_keep = PrecomputeMinLogNumberToKeep2PC(
+        vset, cfd, edit_list, memtables, prep_tracker);
+
+    // We piggyback the information of earliest log file to keep in the
+    // manifest entry for the last file flushed.
+  } else {
+    min_wal_number_to_keep =
+        PrecomputeMinLogNumberToKeepNon2PC(vset, cfd, edit_list);
+  }
+
+  wal_deletion_edit.SetMinLogNumberToKeep(min_wal_number_to_keep);
+  if (vset->db_options()->track_and_verify_wals_in_manifest) {
+    if (min_wal_number_to_keep > vset->GetWalSet().GetMinWalNumberToKeep()) {
+      wal_deletion_edit.DeleteWalsBefore(min_wal_number_to_keep);
+    }
+  }
+  return wal_deletion_edit;
+}
+
 uint64_t FindMinPrepLogReferencedByMemTable(
    VersionSet* vset, const autovector<MemTable*>& memtables_to_flush) {
  uint64_t min_log = 0;
@@ -921,57 +967,60 @@ uint64_t PrecomputeMinLogNumberToKeep2PC(
 }

 void DBImpl::SetDBId(std::string&& id, bool read_only,
-                     RecoveryContext* recovery_ctx) {
+                     VersionEdit* version_edit) {
  assert(db_id_.empty());
  assert(!id.empty());
  db_id_ = std::move(id);
-  if (!read_only && immutable_db_options_.write_dbid_to_manifest) {
-    assert(recovery_ctx != nullptr);
+  if (!read_only && version_edit) {
+    assert(version_edit != nullptr);
    assert(versions_->GetColumnFamilySet() != nullptr);
-    VersionEdit edit;
-    edit.SetDBId(db_id_);
+    version_edit->SetDBId(db_id_);
    versions_->db_id_ = db_id_;
-    recovery_ctx->UpdateVersionEdits(
-        versions_->GetColumnFamilySet()->GetDefault(), edit);
  }
 }

 Status DBImpl::SetupDBId(const WriteOptions& write_options, bool read_only,
-                         RecoveryContext* recovery_ctx) {
+                         bool is_new_db, VersionEdit* version_edit) {
  Status s;
-  // Check for the IDENTITY file and create it if not there or
-  // broken or not matching manifest
-  std::string db_id_in_file;
-  s = fs_->FileExists(IdentityFileName(dbname_), IOOptions(), nullptr);
-  if (s.ok()) {
-    s = GetDbIdentityFromIdentityFile(&db_id_in_file);
-    if (s.ok() && !db_id_in_file.empty()) {
-      if (db_id_.empty()) {
-        // Loaded from file and wasn't already known from manifest
-        SetDBId(std::move(db_id_in_file), read_only, recovery_ctx);
-        return s;
-      } else if (db_id_ == db_id_in_file) {
-        // Loaded from file and matches manifest
-        return s;
+  if (!is_new_db) {
+    // Check for the IDENTITY file and create it if not there or
+    // broken or not matching manifest
+    std::string db_id_in_file;
+    s = fs_->FileExists(IdentityFileName(dbname_), IOOptions(), nullptr);
+    if (s.ok()) {
+      s = GetDbIdentityFromIdentityFile(&db_id_in_file);
+      if (s.ok() && !db_id_in_file.empty()) {
+        if (db_id_.empty()) {
+          // Loaded from file and wasn't already known from manifest
+          SetDBId(std::move(db_id_in_file), read_only, version_edit);
+          return s;
+        } else if (db_id_ == db_id_in_file) {
+          // Loaded from file and matches manifest
+          return s;
+        }
      }
    }
-  }
-  if (s.IsNotFound()) {
-    s = Status::OK();
-  }
-  if (!s.ok()) {
-    assert(s.IsIOError());
-    return s;
+    if (s.IsNotFound()) {
+      s = Status::OK();
+    }
+    if (!s.ok()) {
+      assert(s.IsIOError());
+      return s;
+    }
  }
  // Otherwise IDENTITY file is missing or no good.
  // Generate new id if needed
  if (db_id_.empty()) {
-    SetDBId(env_->GenerateUniqueId(), read_only, recovery_ctx);
+    SetDBId(env_->GenerateUniqueId(), read_only, version_edit);
  }
  // Persist it to IDENTITY file if allowed
-  if (!read_only) {
-    s = SetIdentityFile(write_options, env_, dbname_, db_id_);
+  if (!read_only && immutable_db_options_.write_identity_file) {
+    s = SetIdentityFile(write_options, env_, dbname_,
+                        immutable_db_options_.metadata_write_temperature,
+                        db_id_);
  }
+  // NOTE: an obsolete IDENTITY file with write_identity_file=false is handled
+  // elsewhere, so that it's only deleted after successful recovery
  return s;
 }

@@ -289,27 +289,25 @@ Status DBImpl::ValidateOptions(const DBOptions& db_options) {
          "start_time and end_time cannot be the same");
    }
  }
+
+  if (!db_options.write_dbid_to_manifest && !db_options.write_identity_file) {
+    return Status::InvalidArgument(
+        "write_dbid_to_manifest and write_identity_file cannot both be false");
+  }
  return Status::OK();
 }

 Status DBImpl::NewDB(std::vector<std::string>* new_filenames) {
-  VersionEdit new_db;
+  VersionEdit new_db_edit;
  const WriteOptions write_options(Env::IOActivity::kDBOpen);
-  Status s = SetIdentityFile(write_options, env_, dbname_);
+  Status s = SetupDBId(write_options, /*read_only=*/false, /*is_new_db=*/true,
+                       &new_db_edit);
  if (!s.ok()) {
    return s;
  }
-  if (immutable_db_options_.write_dbid_to_manifest) {
-    std::string temp_db_id;
-    s = GetDbIdentityFromIdentityFile(&temp_db_id);
-    if (!s.ok()) {
-      return s;
-    }
-    new_db.SetDBId(temp_db_id);
-  }
-  new_db.SetLogNumber(0);
-  new_db.SetNextFile(2);
-  new_db.SetLastSequence(0);
+  new_db_edit.SetLogNumber(0);
+  new_db_edit.SetNextFile(2);
+  new_db_edit.SetLastSequence(0);

  ROCKS_LOG_INFO(immutable_db_options_.info_log, "Creating manifest 1 \n");
  const std::string manifest = DescriptorFileName(dbname_, 1);
@@ -319,6 +317,12 @@ Status DBImpl::NewDB(std::vector<std::string>* new_filenames) {
    }
    std::unique_ptr<FSWritableFile> file;
    FileOptions file_options = fs_->OptimizeForManifestWrite(file_options_);
+    // DB option takes precedence when not kUnknown
+    if (immutable_db_options_.metadata_write_temperature !=
+        Temperature::kUnknown) {
+      file_options.temperature =
+          immutable_db_options_.metadata_write_temperature;
+    }
    s = NewWritableFile(fs_.get(), manifest, &file, file_options);
    if (!s.ok()) {
      return s;
@@ -335,7 +339,7 @@ Status DBImpl::NewDB(std::vector<std::string>* new_filenames) {
        tmp_set.Contains(FileType::kDescriptorFile)));
    log::Writer log(std::move(file_writer), 0, false);
    std::string record;
-    new_db.EncodeTo(&record);
+    new_db_edit.EncodeTo(&record);
    s = log.AddRecord(write_options, record);
    if (s.ok()) {
      s = SyncManifest(&immutable_db_options_, write_options, log.file());
@@ -344,6 +348,7 @@ Status DBImpl::NewDB(std::vector<std::string>* new_filenames) {
  if (s.ok()) {
    // Make "CURRENT" file that points to the new manifest file.
    s = SetCurrentFile(write_options, fs_.get(), dbname_, 1,
+                       immutable_db_options_.metadata_write_temperature,
                       directories_.GetDbDir());
    if (new_filenames) {
      new_filenames->emplace_back(
@@ -520,7 +525,7 @@ Status DBImpl::Recover(
    }
    assert(s.ok());
  }
-  assert(db_id_.empty());
+  assert(is_new_db || db_id_.empty());
  Status s;
  bool missing_table_file = false;
  if (!immutable_db_options_.best_efforts_recovery) {
@@ -530,6 +535,12 @@ Status DBImpl::Recover(
                           /*no_error_if_files_missing=*/false, is_retry,
                           &desc_status);
    desc_status.PermitUncheckedError();
+    if (is_retry) {
+      RecordTick(stats_, FILE_READ_CORRUPTION_RETRY_COUNT);
+      if (desc_status.ok()) {
+        RecordTick(stats_, FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT);
+      }
+    }
    if (can_retry) {
      // If we're opening for the first time and the failure is likely due to
      // a corrupt MANIFEST file (could result in either the log::Reader
@@ -640,7 +651,7 @@ Status DBImpl::Recover(
                           f->fd.smallest_seqno, f->fd.largest_seqno,
                           f->marked_for_compaction,
                           f->temperature,  // this can be different from
-                                            // `last_level_temperature`
+                           // `last_level_temperature`
                           f->oldest_blob_file_number, f->oldest_ancester_time,
                           f->file_creation_time, f->epoch_number,
                           f->file_checksum, f->file_checksum_func_name,
@@ -660,7 +671,17 @@ Status DBImpl::Recover(
      }
    }
  }
-  s = SetupDBId(write_options, read_only, recovery_ctx);
+  if (is_new_db) {
+    // Already set up DB ID in NewDB
+  } else if (immutable_db_options_.write_dbid_to_manifest && recovery_ctx) {
+    VersionEdit edit;
+    s = SetupDBId(write_options, read_only, is_new_db, &edit);
+    recovery_ctx->UpdateVersionEdits(
+        versions_->GetColumnFamilySet()->GetDefault(), edit);
+  } else {
+    s = SetupDBId(write_options, read_only, is_new_db, nullptr);
+  }
+  assert(!s.ok() || !db_id_.empty());
  ROCKS_LOG_INFO(immutable_db_options_.info_log, "DB ID: %s\n", db_id_.c_str());
  if (s.ok() && !read_only) {
    s = MaybeUpdateNextFileNumber(recovery_ctx);
@@ -1648,7 +1669,8 @@ Status DBImpl::WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
  TableProperties table_properties;
  {
    ScopedArenaPtr<InternalIterator> iter(
-        mem->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr, &arena));
+        mem->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr, &arena,
+                         /*prefix_extractor=*/nullptr));
    ROCKS_LOG_DEBUG(immutable_db_options_.info_log,
                    "[%s] [WriteLevel0TableForRecovery]"
                    " Level-0 table #%" PRIu64 ": started",
@@ -1667,7 +1689,8 @@ Status DBImpl::WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
    meta.oldest_ancester_time = current_time;
    meta.epoch_number = cfd->NewEpochNumber();
    {
-      auto write_hint = cfd->CalculateSSTWriteHint(0);
+      auto write_hint =
+          cfd->current()->storage_info()->CalculateSSTWriteHint(/*level=*/0);
      mutex_.Unlock();

      SequenceNumber earliest_write_conflict_snapshot;
@@ -1930,6 +1953,10 @@ IOStatus DBImpl::CreateWAL(const WriteOptions& write_options,
      BuildDBOptions(immutable_db_options_, mutable_db_options_);
  FileOptions opt_file_options =
      fs_->OptimizeForLogWrite(file_options_, db_options);
+  // DB option takes precedence when not kUnknown
+  if (immutable_db_options_.wal_write_temperature != Temperature::kUnknown) {
+    opt_file_options.temperature = immutable_db_options_.wal_write_temperature;
+  }
  std::string wal_dir = immutable_db_options_.GetWalDir();
  std::string log_fname = LogFileName(wal_dir, log_file_num);

@@ -1969,46 +1996,7 @@ IOStatus DBImpl::CreateWAL(const WriteOptions& write_options,

 void DBImpl::TrackExistingDataFiles(
    const std::vector<std::string>& existing_data_files) {
-  auto sfm = static_cast<SstFileManagerImpl*>(
-      immutable_db_options_.sst_file_manager.get());
-  assert(sfm);
-  std::vector<ColumnFamilyMetaData> metadata;
-  GetAllColumnFamilyMetaData(&metadata);
-
-  std::unordered_set<std::string> referenced_files;
-  for (const auto& md : metadata) {
-    for (const auto& lmd : md.levels) {
-      for (const auto& fmd : lmd.files) {
-        // We're assuming that each sst file name exists in at most one of
-        // the paths.
-        std::string file_path =
-            fmd.directory + kFilePathSeparator + fmd.relative_filename;
-        sfm->OnAddFile(file_path, fmd.size).PermitUncheckedError();
-        referenced_files.insert(file_path);
-      }
-    }
-    for (const auto& bmd : md.blob_files) {
-      std::string name = bmd.blob_file_name;
-      // The BlobMetaData.blob_file_name may start with "/".
-      if (!name.empty() && name[0] == kFilePathSeparator) {
-        name = name.substr(1);
-      }
-      // We're assuming that each blob file name exists in at most one of
-      // the paths.
-      std::string file_path = bmd.blob_file_path + kFilePathSeparator + name;
-      sfm->OnAddFile(file_path, bmd.blob_file_size).PermitUncheckedError();
-      referenced_files.insert(file_path);
-    }
-  }
-
-  for (const auto& file_path : existing_data_files) {
-    if (referenced_files.find(file_path) != referenced_files.end()) {
-      continue;
-    }
-    // There shouldn't be any duplicated files. In case there is, SstFileManager
-    // will take care of deduping it.
-    sfm->OnAddFile(file_path).PermitUncheckedError();
-  }
+  TrackOrUntrackFiles(existing_data_files, /*track=*/true);
 }

 Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
@@ -2152,6 +2140,13 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
    s = impl->LogAndApplyForRecovery(recovery_ctx);
  }

+  if (s.ok() && !impl->immutable_db_options_.write_identity_file) {
+    // On successful recovery, delete an obsolete IDENTITY file to avoid DB ID
+    // inconsistency
+    impl->env_->DeleteFile(IdentityFileName(impl->dbname_))
+        .PermitUncheckedError();
+  }
+
  if (s.ok() && impl->immutable_db_options_.persist_stats_to_disk) {
    impl->mutex_.AssertHeld();
    s = impl->InitPersistStatsColumnFamily();
@@ -12,7 +12,8 @@
 #include "logging/auto_roll_logger.h"
 #include "logging/logging.h"
 #include "monitoring/perf_context_imp.h"
-#include "rocksdb/configurable.h"
+#include "rocksdb/convenience.h"
+#include "rocksdb/utilities/options_util.h"
 #include "util/cast_util.h"
 #include "util/write_batch_util.h"

@@ -938,69 +939,101 @@ Status DB::OpenAndCompact(
    const std::string& output_directory, const std::string& input,
    std::string* output,
    const CompactionServiceOptionsOverride& override_options) {
+  // Check for cancellation
  if (options.canceled && options.canceled->load(std::memory_order_acquire)) {
    return Status::Incomplete(Status::SubCode::kManualCompactionPaused);
  }
+
+  // 1. Deserialize Compaction Input
  CompactionServiceInput compaction_input;
  Status s = CompactionServiceInput::Read(input, &compaction_input);
  if (!s.ok()) {
    return s;
  }

-  compaction_input.db_options.max_open_files = -1;
-  compaction_input.db_options.compaction_service = nullptr;
-  if (compaction_input.db_options.statistics) {
-    compaction_input.db_options.statistics.reset();
-  }
-  compaction_input.db_options.env = override_options.env;
-  compaction_input.db_options.file_checksum_gen_factory =
-      override_options.file_checksum_gen_factory;
-  compaction_input.db_options.statistics = override_options.statistics;
-  compaction_input.column_family.options.comparator =
-      override_options.comparator;
-  compaction_input.column_family.options.merge_operator =
-      override_options.merge_operator;
-  compaction_input.column_family.options.compaction_filter =
-      override_options.compaction_filter;
-  compaction_input.column_family.options.compaction_filter_factory =
-      override_options.compaction_filter_factory;
-  compaction_input.column_family.options.prefix_extractor =
-      override_options.prefix_extractor;
-  compaction_input.column_family.options.table_factory =
-      override_options.table_factory;
-  compaction_input.column_family.options.sst_partitioner_factory =
-      override_options.sst_partitioner_factory;
-  compaction_input.column_family.options.table_properties_collector_factories =
-      override_options.table_properties_collector_factories;
-  compaction_input.db_options.listeners = override_options.listeners;
+  // 2. Load the options
+  DBOptions db_options;
+  ConfigOptions config_options;
+  config_options.env = override_options.env;
+  std::vector<ColumnFamilyDescriptor> all_column_families;

-  std::vector<ColumnFamilyDescriptor> column_families;
-  column_families.push_back(compaction_input.column_family);
-  // TODO: we have to open default CF, because of an implementation limitation,
-  // currently we just use the same CF option from input, which is not collect
-  // and open may fail.
-  if (compaction_input.column_family.name != kDefaultColumnFamilyName) {
-    column_families.emplace_back(kDefaultColumnFamilyName,
-                                 compaction_input.column_family.options);
-  }
+  std::string options_file_name =
+      OptionsFileName(name, compaction_input.options_file_number);

-  DB* db;
-  std::vector<ColumnFamilyHandle*> handles;
-
-  s = DB::OpenAsSecondary(compaction_input.db_options, name, output_directory,
-                          column_families, &handles, &db);
+  s = LoadOptionsFromFile(config_options, options_file_name, &db_options,
+                          &all_column_families);
  if (!s.ok()) {
    return s;
  }

+  // 3. Override pointer configurations in DBOptions with
+  // CompactionServiceOptionsOverride
+  db_options.env = override_options.env;
+  db_options.file_checksum_gen_factory =
+      override_options.file_checksum_gen_factory;
+  db_options.statistics = override_options.statistics;
+  db_options.listeners = override_options.listeners;
+  db_options.compaction_service = nullptr;
+  // We will close the DB after the compaction anyway.
+  // Open as many files as needed for the compaction.
+  db_options.max_open_files = -1;
+
+  // 4. Filter CFs that are needed for OpenAndCompact()
+  // We do not need to open all column families for the remote compaction.
+  // Only open default CF + target CF. If target CF == default CF, we will open
+  // just the default CF (Due to current limitation, DB cannot open without the
+  // default CF)
+  std::vector<ColumnFamilyDescriptor> column_families;
+  for (auto& cf : all_column_families) {
+    if (cf.name == compaction_input.cf_name) {
+      cf.options.comparator = override_options.comparator;
+      cf.options.merge_operator = override_options.merge_operator;
+      cf.options.compaction_filter = override_options.compaction_filter;
+      cf.options.compaction_filter_factory =
+          override_options.compaction_filter_factory;
+      cf.options.prefix_extractor = override_options.prefix_extractor;
+      cf.options.table_factory = override_options.table_factory;
+      cf.options.sst_partitioner_factory =
+          override_options.sst_partitioner_factory;
+      cf.options.table_properties_collector_factories =
+          override_options.table_properties_collector_factories;
+      column_families.emplace_back(cf);
+    } else if (cf.name == kDefaultColumnFamilyName) {
+      column_families.emplace_back(cf);
+    }
+  }
+
+  // 5. Open db As Secondary
+  DB* db;
+  std::vector<ColumnFamilyHandle*> handles;
+  s = DB::OpenAsSecondary(db_options, name, output_directory, column_families,
+                          &handles, &db);
+  if (!s.ok()) {
+    return s;
+  }
+  assert(db);
+
+  // 6. Find the handle of the Column Family that this will compact
+  ColumnFamilyHandle* cfh = nullptr;
+  for (auto* handle : handles) {
+    if (compaction_input.cf_name == handle->GetName()) {
+      cfh = handle;
+      break;
+    }
+  }
+  assert(cfh);
+
+  // 7. Run the compaction without installation.
+  // Output will be stored in the directory specified by output_directory
  CompactionServiceResult compaction_result;
  DBImplSecondary* db_secondary = static_cast_with_check<DBImplSecondary>(db);
-  assert(handles.size() > 0);
-  s = db_secondary->CompactWithoutInstallation(
-      options, handles[0], compaction_input, &compaction_result);
+  s = db_secondary->CompactWithoutInstallation(options, cfh, compaction_input,
+                                               &compaction_result);

+  // 8. Serialize the result
  Status serialization_status = compaction_result.Write(output);

+  // 9. Close the db and return
  for (auto& handle : handles) {
    delete handle;
  }
@@ -556,6 +556,35 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
    const SequenceNumber current_sequence = last_sequence + 1;
    last_sequence += seq_inc;

+    if (log_context.need_log_sync) {
+      VersionEdit synced_wals;
+      log_write_mutex_.Lock();
+      if (status.ok()) {
+        MarkLogsSynced(logfile_number_, log_context.need_log_dir_sync,
+                       &synced_wals);
+      } else {
+        MarkLogsNotSynced(logfile_number_);
+      }
+      log_write_mutex_.Unlock();
+      if (status.ok() && synced_wals.IsWalAddition()) {
+        InstrumentedMutexLock l(&mutex_);
+        // TODO: plumb Env::IOActivity, Env::IOPriority
+        const ReadOptions read_options;
+        status = ApplyWALToManifest(read_options, write_options, &synced_wals);
+      }
+
+      // Requesting sync with two_write_queues_ is expected to be very rare. We
+      // hence provide a simple implementation that is not necessarily
+      // efficient.
+      if (status.ok() && two_write_queues_) {
+        if (manual_wal_flush_) {
+          status = FlushWAL(true);
+        } else {
+          status = SyncWAL();
+        }
+      }
+    }
+
    // PreReleaseCallback is called after WAL write and before memtable write
    if (status.ok()) {
      SequenceNumber next_sequence = current_sequence;
@@ -627,7 +656,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,

  if (!io_s.ok()) {
    // Check WriteToWAL status
-    IOStatusCheck(io_s);
+    WALIOStatusCheck(io_s);
  }
  if (!w.CallbackFailed()) {
    if (!io_s.ok()) {
@@ -639,34 +668,6 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
    assert(pre_release_cb_status.ok());
  }

-  if (log_context.need_log_sync) {
-    VersionEdit synced_wals;
-    log_write_mutex_.Lock();
-    if (status.ok()) {
-      MarkLogsSynced(logfile_number_, log_context.need_log_dir_sync,
-                     &synced_wals);
-    } else {
-      MarkLogsNotSynced(logfile_number_);
-    }
-    log_write_mutex_.Unlock();
-    if (status.ok() && synced_wals.IsWalAddition()) {
-      InstrumentedMutexLock l(&mutex_);
-      // TODO: plumb Env::IOActivity, Env::IOPriority
-      const ReadOptions read_options;
-      status = ApplyWALToManifest(read_options, write_options, &synced_wals);
-    }
-
-    // Requesting sync with two_write_queues_ is expected to be very rare. We
-    // hence provide a simple implementation that is not necessarily efficient.
-    if (two_write_queues_) {
-      if (manual_wal_flush_) {
-        status = FlushWAL(true);
-      } else {
-        status = SyncWAL();
-      }
-    }
-  }
-
  bool should_exit_batch_group = true;
  if (in_parallel_group) {
    // CompleteParallelWorker returns true if this thread should
@@ -798,7 +799,7 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,

    if (!io_s.ok()) {
      // Check WriteToWAL status
-      IOStatusCheck(io_s);
+      WALIOStatusCheck(io_s);
    } else if (!w.CallbackFailed()) {
      WriteStatusCheck(w.status);
    }
@@ -968,21 +969,17 @@ Status DBImpl::WriteImplWALOnly(
  assert(w.state == WriteThread::STATE_GROUP_LEADER);

  if (publish_last_seq == kDoPublishLastSeq) {
-    Status status;
-
    // Currently we only use kDoPublishLastSeq in unordered_write
    assert(immutable_db_options_.unordered_write);
-    WriteContext write_context;
-    if (error_handler_.IsDBStopped()) {
-      status = error_handler_.GetBGError();
-    }
+
    // TODO(myabandeh): Make preliminary checks thread-safe so we could do them
    // without paying the cost of obtaining the mutex.
-    if (status.ok()) {
-      LogContext log_context;
-      status = PreprocessWrite(write_options, &log_context, &write_context);
-      WriteStatusCheckOnLocked(status);
-    }
+    LogContext log_context;
+    WriteContext write_context;
+    Status status =
+        PreprocessWrite(write_options, &log_context, &write_context);
+    WriteStatusCheckOnLocked(status);
+
    if (!status.ok()) {
      WriteThread::WriteGroup write_group;
      write_thread->EnterAsBatchGroupLeader(&w, &write_group);
@@ -1080,7 +1077,7 @@ Status DBImpl::WriteImplWALOnly(
    // This error checking and return is moved up to avoid using uninitialized
    // last_sequence.
    if (!io_s.ok()) {
-      IOStatusCheck(io_s);
+      WALIOStatusCheck(io_s);
      write_thread->ExitAsBatchGroupLeader(write_group, status);
      return status;
    }
@@ -1178,7 +1175,7 @@ void DBImpl::WriteStatusCheck(const Status& status) {
  }
 }

-void DBImpl::IOStatusCheck(const IOStatus& io_status) {
+void DBImpl::WALIOStatusCheck(const IOStatus& io_status) {
  // Is setting bg_error_ enough here?  This will at least stop
  // compaction and fail any further writes.
  if ((immutable_db_options_.paranoid_checks && !io_status.ok() &&
@@ -1186,7 +1183,8 @@ void DBImpl::IOStatusCheck(const IOStatus& io_status) {
      io_status.IsIOFenced()) {
    mutex_.Lock();
    // Maybe change the return status to void?
-    error_handler_.SetBGError(io_status, BackgroundErrorReason::kWriteCallback);
+    error_handler_.SetBGError(io_status, BackgroundErrorReason::kWriteCallback,
+                              /*wal_related=*/true);
    mutex_.Unlock();
  } else {
    // Force writable file to be continue writable.
@@ -1204,8 +1202,7 @@ void DBImpl::MemTableInsertStatusCheck(const Status& status) {
    mutex_.Lock();
    assert(!error_handler_.IsBGWorkStopped());
    // Maybe change the return status to void?
-    error_handler_.SetBGError(status, BackgroundErrorReason::kMemTable)
-        .PermitUncheckedError();
+    error_handler_.SetBGError(status, BackgroundErrorReason::kMemTable);
    mutex_.Unlock();
  }
 }
@@ -1411,6 +1408,7 @@ IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
  total_log_size_ += log_entry.size();
  log_file_number_size.AddSize(*log_size);
  log_empty_ = false;
+
  return io_s;
 }

@@ -1483,9 +1481,14 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
        if (!io_s.ok()) {
          break;
        }
-        io_s = log.writer->file()->Sync(opts, immutable_db_options_.use_fsync);
-        if (!io_s.ok()) {
-          break;
+        // If last sync failed on a later WAL, this could be a fully synced
+        // and closed WAL that just needs to be recorded as synced in the
+        // manifest.
+        if (auto* f = log.writer->file()) {
+          io_s = f->Sync(opts, immutable_db_options_.use_fsync);
+          if (!io_s.ok()) {
+            break;
+          }
        }
      }
    }
@@ -1650,7 +1653,8 @@ Status DBImpl::WriteRecoverableState() {

 void DBImpl::SelectColumnFamiliesForAtomicFlush(
    autovector<ColumnFamilyData*>* selected_cfds,
-    const autovector<ColumnFamilyData*>& provided_candidate_cfds) {
+    const autovector<ColumnFamilyData*>& provided_candidate_cfds,
+    FlushReason flush_reason) {
  mutex_.AssertHeld();
  assert(selected_cfds);

@@ -1673,7 +1677,8 @@ void DBImpl::SelectColumnFamiliesForAtomicFlush(
      continue;
    }
    if (cfd->imm()->NumNotFlushed() != 0 || !cfd->mem()->IsEmpty() ||
-        !cached_recoverable_state_empty_.load()) {
+        !cached_recoverable_state_empty_.load() ||
+        IsRecoveryFlush(flush_reason)) {
      selected_cfds->push_back(cfd);
    }
  }
@@ -1785,13 +1790,13 @@ Status DBImpl::SwitchWAL(WriteContext* write_context) {
      if (!immutable_db_options_.atomic_flush) {
        FlushRequest flush_req;
        GenerateFlushRequest({cfd}, FlushReason::kWalFull, &flush_req);
-        SchedulePendingFlush(flush_req);
+        EnqueuePendingFlush(flush_req);
      }
    }
    if (immutable_db_options_.atomic_flush) {
      FlushRequest flush_req;
      GenerateFlushRequest(cfds, FlushReason::kWalFull, &flush_req);
-      SchedulePendingFlush(flush_req);
+      EnqueuePendingFlush(flush_req);
    }
    MaybeScheduleFlushOrCompaction();
  }
@@ -1877,13 +1882,13 @@ Status DBImpl::HandleWriteBufferManagerFlush(WriteContext* write_context) {
        FlushRequest flush_req;
        GenerateFlushRequest({cfd}, FlushReason::kWriteBufferManager,
                             &flush_req);
-        SchedulePendingFlush(flush_req);
+        EnqueuePendingFlush(flush_req);
      }
    }
    if (immutable_db_options_.atomic_flush) {
      FlushRequest flush_req;
      GenerateFlushRequest(cfds, FlushReason::kWriteBufferManager, &flush_req);
-      SchedulePendingFlush(flush_req);
+      EnqueuePendingFlush(flush_req);
    }
    MaybeScheduleFlushOrCompaction();
  }
@@ -2159,12 +2164,12 @@ Status DBImpl::ScheduleFlushes(WriteContext* context) {
      AssignAtomicFlushSeq(cfds);
      FlushRequest flush_req;
      GenerateFlushRequest(cfds, FlushReason::kWriteBufferFull, &flush_req);
-      SchedulePendingFlush(flush_req);
+      EnqueuePendingFlush(flush_req);
    } else {
      for (auto* cfd : cfds) {
        FlushRequest flush_req;
        GenerateFlushRequest({cfd}, FlushReason::kWriteBufferFull, &flush_req);
-        SchedulePendingFlush(flush_req);
+        EnqueuePendingFlush(flush_req);
      }
    }
    MaybeScheduleFlushOrCompaction();
@@ -2322,7 +2327,8 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
    // We may have lost data from the WritableFileBuffer in-memory buffer for
    // the current log, so treat it as a fatal error and set bg_error
    if (!io_s.ok()) {
-      error_handler_.SetBGError(io_s, BackgroundErrorReason::kMemTable);
+      error_handler_.SetBGError(io_s, BackgroundErrorReason::kMemTable,
+                                /*wal_related=*/true);
    } else {
      error_handler_.SetBGError(s, BackgroundErrorReason::kMemTable);
    }
@@ -2363,8 +2369,8 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context) {
          read_options, write_options, &wal_deletion, &mutex_,
          directories_.GetDbDir());
      if (!s.ok() && versions_->io_status().IsIOError()) {
-        s = error_handler_.SetBGError(versions_->io_status(),
-                                      BackgroundErrorReason::kManifestWrite);
+        error_handler_.SetBGError(versions_->io_status(),
+                                  BackgroundErrorReason::kManifestWrite);
      }
      if (!s.ok()) {
        return s;
@@ -705,6 +705,7 @@ class DBIOCorruptionTest
  DBIOCorruptionTest() : DBIOFailureTest() {
    BlockBasedTableOptions bbto;
    options_ = CurrentOptions();
+    options_.statistics = CreateDBStatistics();

    base_env_ = env_;
    EXPECT_NE(base_env_, nullptr);
@@ -727,6 +728,8 @@ class DBIOCorruptionTest

  Status ReopenDB() { return TryReopen(options_); }

+  Statistics* stats() { return options_.statistics.get(); }
+
 protected:
  std::unique_ptr<Env> env_guard_;
  std::shared_ptr<CorruptionFS> fs_;
@@ -749,8 +752,12 @@ TEST_P(DBIOCorruptionTest, GetReadCorruptionRetry) {
  if (std::get<2>(GetParam())) {
    ASSERT_OK(s);
    ASSERT_EQ(val, "val1");
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);
  } else {
    ASSERT_TRUE(s.IsCorruption());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
  }
 }

@@ -773,8 +780,12 @@ TEST_P(DBIOCorruptionTest, IterReadCorruptionRetry) {
  }
  if (std::get<2>(GetParam())) {
    ASSERT_OK(iter->status());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);
  } else {
    ASSERT_TRUE(iter->status().IsCorruption());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
  }
  delete iter;
 }
@@ -799,9 +810,13 @@ TEST_P(DBIOCorruptionTest, MultiGetReadCorruptionRetry) {
  if (std::get<2>(GetParam())) {
    ASSERT_EQ(values[0].ToString(), "val1");
    ASSERT_EQ(values[1].ToString(), "val2");
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);
  } else {
    ASSERT_TRUE(statuses[0].IsCorruption());
    ASSERT_TRUE(statuses[1].IsCorruption());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
  }
 }

@@ -818,6 +833,9 @@ TEST_P(DBIOCorruptionTest, CompactionReadCorruptionRetry) {
  Status s = dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  if (std::get<2>(GetParam())) {
    ASSERT_OK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);

    std::string val;
    ReadOptions ro;
@@ -826,6 +844,7 @@ TEST_P(DBIOCorruptionTest, CompactionReadCorruptionRetry) {
    ASSERT_EQ(val, "val1");
  } else {
    ASSERT_TRUE(s.IsCorruption());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
  }
 }

@@ -838,6 +857,9 @@ TEST_P(DBIOCorruptionTest, FlushReadCorruptionRetry) {
  Status s = Flush();
  if (std::get<2>(GetParam())) {
    ASSERT_OK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);

    std::string val;
    ReadOptions ro;
@@ -846,6 +868,7 @@ TEST_P(DBIOCorruptionTest, FlushReadCorruptionRetry) {
    ASSERT_EQ(val, "val1");
  } else {
    ASSERT_NOK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
  }
 }

@@ -862,12 +885,91 @@ TEST_P(DBIOCorruptionTest, ManifestCorruptionRetry) {

  if (std::get<2>(GetParam())) {
    ASSERT_OK(ReopenDB());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);
  } else {
    ASSERT_EQ(ReopenDB(), Status::Corruption());
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
  }
  SyncPoint::GetInstance()->DisableProcessing();
 }

+TEST_P(DBIOCorruptionTest, FooterReadCorruptionRetry) {
+  Random rnd(300);
+  bool retry = false;
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "ReadFooterFromFileInternal:0", [&](void* arg) {
+        Slice* data = static_cast<Slice*>(arg);
+        if (!retry) {
+          std::memcpy(const_cast<char*>(data->data()),
+                      rnd.RandomString(static_cast<int>(data->size())).c_str(),
+                      data->size());
+          retry = true;
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(Put("key1", "val1"));
+  Status s = Flush();
+  if (std::get<2>(GetParam())) {
+    ASSERT_OK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);
+
+    std::string val;
+    ReadOptions ro;
+    ro.async_io = std::get<1>(GetParam());
+    ASSERT_OK(dbfull()->Get(ro, "key1", &val));
+    ASSERT_EQ(val, "val1");
+  } else {
+    ASSERT_NOK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
+    ASSERT_GT(stats()->getTickerCount(SST_FOOTER_CORRUPTION_COUNT), 0);
+  }
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->ClearAllCallBacks();
+}
+
+TEST_P(DBIOCorruptionTest, TablePropertiesCorruptionRetry) {
+  Random rnd(300);
+  bool retry = false;
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "ReadTablePropertiesHelper:0", [&](void* arg) {
+        Slice* data = static_cast<Slice*>(arg);
+        if (!retry) {
+          std::memcpy(const_cast<char*>(data->data()),
+                      rnd.RandomString(static_cast<int>(data->size())).c_str(),
+                      data->size());
+          retry = true;
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(Put("key1", "val1"));
+  Status s = Flush();
+  if (std::get<2>(GetParam())) {
+    ASSERT_OK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 1);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_SUCCESS_COUNT),
+              1);
+
+    std::string val;
+    ReadOptions ro;
+    ro.async_io = std::get<1>(GetParam());
+    ASSERT_OK(dbfull()->Get(ro, "key1", &val));
+    ASSERT_EQ(val, "val1");
+  } else {
+    ASSERT_NOK(s);
+    ASSERT_EQ(stats()->getTickerCount(FILE_READ_CORRUPTION_RETRY_COUNT), 0);
+  }
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->ClearAllCallBacks();
+}
+
 // The parameters are - 1. Use FS provided buffer, 2. Use async IO ReadOption,
 // 3. Retry with verify_and_reconstruct_read IOOption
 INSTANTIATE_TEST_CASE_P(DBIOCorruptionTest, DBIOCorruptionTest,
@@ -65,9 +65,8 @@ DBIter::DBIter(Env* _env, const ReadOptions& read_options,
      valid_(false),
      current_entry_is_merged_(false),
      is_key_seqnum_zero_(false),
-      prefix_same_as_start_(mutable_cf_options.prefix_extractor
-                                ? read_options.prefix_same_as_start
-                                : false),
+      prefix_same_as_start_(
+          prefix_extractor_ ? read_options.prefix_same_as_start : false),
      pin_thru_lifetime_(read_options.pin_data),
      expect_total_order_inner_iter_(prefix_extractor_ == nullptr ||
                                     read_options.total_order_seek ||
@@ -93,6 +92,9 @@ DBIter::DBIter(Env* _env, const ReadOptions& read_options,
  status_.PermitUncheckedError();
  assert(timestamp_size_ ==
         user_comparator_.user_comparator()->timestamp_size());
+  // prefix_seek_opt_in_only should force total_order_seek whereever the caller
+  // is duplicating the original ReadOptions
+  assert(!ioptions.prefix_seek_opt_in_only || read_options.total_order_seek);
 }

 Status DBIter::GetProperty(std::string prop_name, std::string* prop) {
@@ -538,6 +540,8 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
    } else {
      iter_.Next();
    }
+    // This could be a long-running operation due to tombstones, etc.
+    ROCKSDB_THREAD_YIELD_HOOK();
  } while (iter_.Valid());

  valid_ = false;
@@ -684,13 +684,14 @@ class DbMemtableKVChecksumTest : public DbKvChecksumTest {
  DbMemtableKVChecksumTest() : DbKvChecksumTest() {}

 protected:
+  const size_t kValueLenOffset = 12;
  // Indices in the memtable entry that we will not corrupt.
  // For memtable entry format, see comments in MemTable::Add().
  // We do not corrupt key length and value length fields in this test
  // case since it causes segfault and ASAN will complain.
  // For this test case, key and value are all of length 3, so
  // key length field is at index 0 and value length field is at index 12.
-  const std::set<size_t> index_not_to_corrupt{0, 12};
+  const std::set<size_t> index_not_to_corrupt{0, kValueLenOffset};

  void SkipNotToCorruptEntry() {
    if (index_not_to_corrupt.find(corrupt_byte_offset_) !=
@@ -737,6 +738,8 @@ TEST_P(DbMemtableKVChecksumTest, GetWithCorruptAfterMemtableInsert) {
        buf[corrupt_byte_offset_] += corrupt_byte_addend_;
        ++corrupt_byte_offset_;
      });
+  // Corrupt value only so that MultiGet below can find the key.
+  corrupt_byte_offset_ = kValueLenOffset + 1;
  SyncPoint::GetInstance()->EnableProcessing();
  Options options = CurrentOptions();
  options.memtable_protection_bytes_per_key =
@@ -745,12 +748,17 @@ TEST_P(DbMemtableKVChecksumTest, GetWithCorruptAfterMemtableInsert) {
    options.merge_operator = MergeOperators::CreateStringAppendOperator();
  }

+  std::string key = "key";
  SkipNotToCorruptEntry();
  while (MoreBytesToCorrupt()) {
    Reopen(options);
    ASSERT_OK(ExecuteWrite(nullptr));
    std::string val;
-    ASSERT_TRUE(db_->Get(ReadOptions(), "key", &val).IsCorruption());
+    ASSERT_TRUE(db_->Get(ReadOptions(), key, &val).IsCorruption());
+    std::vector<std::string> vals = {val};
+    std::vector<Status> statuses = db_->MultiGet(
+        ReadOptions(), {db_->DefaultColumnFamily()}, {key}, &vals, nullptr);
+    ASSERT_TRUE(statuses[0].IsCorruption());
    Destroy(options);
    SkipNotToCorruptEntry();
  }
@@ -339,6 +339,91 @@ TEST_F(DBMemTableTest, ColumnFamilyId) {
  }
 }

+TEST_F(DBMemTableTest, IntegrityChecks) {
+  // We insert keys key000000, key000001 and key000002 into skiplist at fixed
+  // height 1 (smallest height). Then we corrupt the second key to aey000001 to
+  // make it smaller. With `paranoid_memory_checks` set to true, if the
+  // skip list sees key000000 and then aey000001, then it will report out of
+  // order keys with corruption status. With `paranoid_memory_checks` set
+  // to false, read/scan may return wrong results.
+  for (bool allow_data_in_error : {false, true}) {
+    Options options = CurrentOptions();
+    options.allow_data_in_errors = allow_data_in_error;
+    options.paranoid_memory_checks = true;
+    DestroyAndReopen(options);
+    SyncPoint::GetInstance()->SetCallBack(
+        "InlineSkipList::RandomHeight::height", [](void* h) {
+          auto height_ptr = static_cast<int*>(h);
+          *height_ptr = 1;
+        });
+    SyncPoint::GetInstance()->EnableProcessing();
+    ASSERT_OK(Put(Key(0), "val0"));
+    ASSERT_OK(Put(Key(2), "val2"));
+    // p will point to the buffer for encoded key000001
+    char* p = nullptr;
+    SyncPoint::GetInstance()->SetCallBack(
+        "MemTable::Add:BeforeReturn:Encoded", [&](void* encoded) {
+          p = const_cast<char*>(static_cast<Slice*>(encoded)->data());
+        });
+    ASSERT_OK(Put(Key(1), "val1"));
+    SyncPoint::GetInstance()->DisableProcessing();
+    SyncPoint::GetInstance()->ClearAllCallBacks();
+    ASSERT_TRUE(p);
+    // Offset 0 is key size, key bytes start at offset 1.
+    // "key000001 -> aey000001"
+    p[1] = 'a';
+
+    ReadOptions rops;
+    std::string val;
+    Status s = db_->Get(rops, Key(1), &val);
+    ASSERT_TRUE(s.IsCorruption());
+    std::string key0 = Slice(Key(0)).ToString(true);
+    ASSERT_EQ(s.ToString().find(key0) != std::string::npos,
+              allow_data_in_error);
+    // Without `paranoid_memory_checks`, NotFound will be returned.
+    // This would fail an assertion in InlineSkipList::FindGreaterOrEqual().
+    // If we remove the assertion, this passes.
+    // ASSERT_TRUE(db_->Get(ReadOptions(), Key(1), &val).IsNotFound());
+
+    std::vector<std::string> vals;
+    std::vector<Status> statuses = db_->MultiGet(
+        rops, {db_->DefaultColumnFamily()}, {Key(1)}, &vals, nullptr);
+    ASSERT_TRUE(statuses[0].IsCorruption());
+    ASSERT_EQ(statuses[0].ToString().find(key0) != std::string::npos,
+              allow_data_in_error);
+
+    std::unique_ptr<Iterator> iter{db_->NewIterator(rops)};
+    ASSERT_OK(iter->status());
+    iter->Seek(Key(1));
+    ASSERT_TRUE(iter->status().IsCorruption());
+    ASSERT_EQ(iter->status().ToString().find(key0) != std::string::npos,
+              allow_data_in_error);
+
+    iter->Seek(Key(0));
+    ASSERT_TRUE(iter->Valid());
+    ASSERT_OK(iter->status());
+    // iterating through skip list at height at 1 should catch out-of-order keys
+    iter->Next();
+    ASSERT_TRUE(iter->status().IsCorruption());
+    ASSERT_EQ(iter->status().ToString().find(key0) != std::string::npos,
+              allow_data_in_error);
+    ASSERT_FALSE(iter->Valid());
+
+    iter->SeekForPrev(Key(2));
+    ASSERT_TRUE(iter->status().IsCorruption());
+    ASSERT_EQ(iter->status().ToString().find(key0) != std::string::npos,
+              allow_data_in_error);
+
+    // Internally DB Iter will iterate backwards (call Prev()) after
+    // SeekToLast() to find the correct internal key with the last user key.
+    // Prev() will do integrity checks and catch corruption.
+    iter->SeekToLast();
+    ASSERT_TRUE(iter->status().IsCorruption());
+    ASSERT_EQ(iter->status().ToString().find(key0) != std::string::npos,
+              allow_data_in_error);
+    ASSERT_FALSE(iter->Valid());
+  }
+}
 }  // namespace ROCKSDB_NAMESPACE

 int main(int argc, char** argv) {
@@ -245,7 +245,13 @@ TEST_P(DBRateLimiterOnReadTest, VerifyChecksum) {
  // In DirectIO, where we support tail prefetching, during table open, we only
  // do 1 read instead of 4 as described above. Actual checksum verification
  // reads stay the same.
+#ifdef OS_WIN
+  // No file system prefetch implemented for OS Win. During table open,
+  // we only do 1 read for BufferedIO.
+  int num_read_per_file = 4;
+#else
  int num_read_per_file = (!use_direct_io_) ? 7 : 4;
+#endif
  int expected = kNumFiles * num_read_per_file;

  ASSERT_EQ(expected, options_.rate_limiter->GetTotalRequests(Env::IO_USER));
@@ -244,7 +244,7 @@ TEST_F(DBSecondaryTest, SimpleInternalCompaction) {
  ASSERT_EQ(largest.user_key().ToString(), "foo");
  ASSERT_EQ(result.output_level, 1);
  ASSERT_EQ(result.output_path, this->secondary_path_);
-  ASSERT_EQ(result.num_output_records, 2);
+  ASSERT_EQ(result.stats.num_output_records, 2);
  ASSERT_GT(result.bytes_written, 0);
  ASSERT_OK(result.status);
 }
@@ -383,12 +383,16 @@ TEST_F(DBSSTTest, DBWithSstFileManager) {
  ASSERT_EQ(files_moved, 0);

  Close();
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
  Reopen(options);
  ASSERT_EQ(sfm->GetTrackedFiles(), files_in_db);
  ASSERT_EQ(sfm->GetTotalSize(), total_files_size);

  // Verify that we track all the files again after the DB is closed and opened
  Close();
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
  sst_file_manager.reset(NewSstFileManager(env_));
  options.sst_file_manager = sst_file_manager;
  sfm = static_cast<SstFileManagerImpl*>(sst_file_manager.get());
@@ -439,6 +443,11 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {

  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
      "SstFileManagerImpl::OnMoveFile", [&](void* /*arg*/) { files_moved++; });
+
+  int64_t untracked_files = 0;
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "SstFileManagerImpl::OnUntrackFile",
+      [&](void* /*arg*/) { ++untracked_files; });
  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();

  Options options = CurrentOptions();
@@ -485,6 +494,10 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {
  }
  ASSERT_EQ(sfm->GetTotalSize(), total_files_size);
  Close();
+  ASSERT_EQ(untracked_files, files_in_db.size());
+  untracked_files = 0;
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";

  Reopen(options);
  ASSERT_EQ(sfm->GetTrackedFiles(), files_in_db);
@@ -492,6 +505,10 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {

  // Verify that we track all the files again after the DB is closed and opened.
  Close();
+  ASSERT_EQ(untracked_files, files_in_db.size());
+  untracked_files = 0;
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";

  sst_file_manager.reset(NewSstFileManager(env_));
  options.sst_file_manager = sst_file_manager;
@@ -507,6 +524,27 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFiles) {
  ASSERT_EQ(files_deleted, 0);
  ASSERT_EQ(files_scheduled_to_delete, 0);
  Close();
+  ASSERT_EQ(untracked_files, files_in_db.size());
+  untracked_files = 0;
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "SstFileManagerImpl::ScheduleUnaccountedFileDeletion", [&](void* arg) {
+        assert(arg);
+        const std::string* const file_path =
+            static_cast<const std::string*>(arg);
+        if (EndsWith(*file_path, ".blob")) {
+          ++files_scheduled_to_delete;
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DeleteScheduler::OnDeleteFile", [&](void* arg) {
+        const std::string* const file_path =
+            static_cast<const std::string*>(arg);
+        if (EndsWith(*file_path, ".blob")) {
+          files_deleted++;
+        }
+      });
  ASSERT_OK(DestroyDB(dbname_, options));
  ASSERT_EQ(files_deleted, blob_files.size());
  ASSERT_EQ(files_scheduled_to_delete, blob_files.size());
@@ -649,6 +687,26 @@ TEST_F(DBSSTTest, DBWithSstFileManagerForBlobFilesWithGC) {
  }

  Close();
+  ASSERT_EQ(sfm->GetTrackedFiles().size(), 0) << "sfm should be empty";
+  ASSERT_EQ(sfm->GetTotalSize(), 0) << "sfm should be empty";
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "SstFileManagerImpl::ScheduleUnaccountedFileDeletion", [&](void* arg) {
+        assert(arg);
+        const std::string* const file_path =
+            static_cast<const std::string*>(arg);
+        if (EndsWith(*file_path, ".blob")) {
+          ++files_scheduled_to_delete;
+        }
+      });
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DeleteScheduler::OnDeleteFile", [&](void* arg) {
+        const std::string* const file_path =
+            static_cast<const std::string*>(arg);
+        if (EndsWith(*file_path, ".blob")) {
+          files_deleted++;
+        }
+      });
  ASSERT_OK(DestroyDB(dbname_, options));
  sfm->WaitForEmptyTrash();
  ASSERT_EQ(files_deleted, 5);
@@ -883,8 +941,9 @@ TEST_P(DBWALTestWithParam, WALTrashCleanupOnOpen) {
  // Create 4 files in L0
  for (char v = 'a'; v <= 'd'; v++) {
    if (v == 'c') {
-      // Maximize the change that the last log file will be preserved in trash
-      // before restarting the DB.
+      // Maximize the chance that the last log file will be preserved in trash
+      // before restarting the DB. (Enable slow deletion but at a very slow
+      // deletion rate)
      // We have to set this on the 2nd to last file for it to delay deletion
      // on the last file. (Quirk of DeleteScheduler::BackgroundEmptyTrash())
      options.sst_file_manager->SetDeleteRateBytesPerSecond(1);
@@ -1902,6 +1961,24 @@ TEST_F(DBSSTTest, DBWithSFMForBlobFilesAtomicFlush) {
  ASSERT_EQ(files_deleted, 1);

  Close();
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "SstFileManagerImpl::ScheduleUnaccountedFileDeletion", [&](void* arg) {
+        assert(arg);
+        const std::string* const file_path =
+            static_cast<const std::string*>(arg);
+        if (EndsWith(*file_path, ".blob")) {
+          ++files_scheduled_to_delete;
+        }
+      });
+
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DeleteScheduler::OnDeleteFile", [&](void* arg) {
+        const std::string* const file_path =
+            static_cast<const std::string*>(arg);
+        if (EndsWith(*file_path, ".blob")) {
+          files_deleted++;
+        }
+      });
  ASSERT_OK(DestroyDB(dbname_, options));

  ASSERT_EQ(files_scheduled_to_delete, 4);
@@ -10,6 +10,7 @@
 #include <atomic>
 #include <cstdlib>
 #include <functional>
+#include <iostream>
 #include <memory>

 #include "db/db_test_util.h"
@@ -26,6 +27,7 @@
 #include "rocksdb/utilities/replayer.h"
 #include "rocksdb/wal_filter.h"
 #include "test_util/testutil.h"
+#include "util/defer.h"
 #include "util/random.h"
 #include "utilities/fault_injection_env.h"

@@ -5595,32 +5597,45 @@ TEST_F(DBTest2, PrefixBloomFilteredOut) {
  bbto.filter_policy.reset(NewBloomFilterPolicy(10, false));
  bbto.whole_key_filtering = false;
  options.table_factory.reset(NewBlockBasedTableFactory(bbto));
-  DestroyAndReopen(options);

-  // Construct two L1 files with keys:
-  // f1:[aaa1 ccc1] f2:[ddd0]
-  ASSERT_OK(Put("aaa1", ""));
-  ASSERT_OK(Put("ccc1", ""));
-  ASSERT_OK(Flush());
-  ASSERT_OK(Put("ddd0", ""));
-  ASSERT_OK(Flush());
-  CompactRangeOptions cro;
-  cro.bottommost_level_compaction = BottommostLevelCompaction::kSkip;
-  ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));
+  // This test is also the primary test for prefix_seek_opt_in_only
+  for (bool opt_in : {false, true}) {
+    options.prefix_seek_opt_in_only = opt_in;
+    DestroyAndReopen(options);

-  Iterator* iter = db_->NewIterator(ReadOptions());
-  ASSERT_OK(iter->status());
+    // Construct two L1 files with keys:
+    // f1:[aaa1 ccc1] f2:[ddd0]
+    ASSERT_OK(Put("aaa1", ""));
+    ASSERT_OK(Put("ccc1", ""));
+    ASSERT_OK(Flush());
+    ASSERT_OK(Put("ddd0", ""));
+    ASSERT_OK(Flush());
+    CompactRangeOptions cro;
+    cro.bottommost_level_compaction = BottommostLevelCompaction::kSkip;
+    ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));

-  // Bloom filter is filterd out by f1.
-  // This is just one of several valid position following the contract.
-  // Postioning to ccc1 or ddd0 is also valid. This is just to validate
-  // the behavior of the current implementation. If underlying implementation
-  // changes, the test might fail here.
-  iter->Seek("bbb1");
-  ASSERT_OK(iter->status());
-  ASSERT_FALSE(iter->Valid());
+    ReadOptions ropts;
+    for (bool same : {false, true}) {
+      ropts.prefix_same_as_start = same;
+      std::unique_ptr<Iterator> iter(db_->NewIterator(ropts));
+      ASSERT_OK(iter->status());

-  delete iter;
+      iter->Seek("bbb1");
+      ASSERT_OK(iter->status());
+      if (opt_in && !same) {
+        // Unbounded total order seek
+        ASSERT_TRUE(iter->Valid());
+        ASSERT_EQ(iter->key(), "ccc1");
+      } else {
+        // Bloom filter is filterd out by f1. When same == false, this is just
+        // one valid position following the contract. Postioning to ccc1 or ddd0
+        // is also valid. This is just to validate the behavior of the current
+        // implementation. If underlying implementation changes, the test might
+        // fail here.
+        ASSERT_FALSE(iter->Valid());
+      }
+    }
+  }
 }

 TEST_F(DBTest2, RowCacheSnapshot) {
@@ -5985,6 +6000,7 @@ TEST_F(DBTest2, ChangePrefixExtractor) {
    // create a DB with block prefix index
    BlockBasedTableOptions table_options;
    Options options = CurrentOptions();
+    options.prefix_seek_opt_in_only = false;  // Use legacy prefix seek

    // Sometimes filter is checked based on upper bound. Assert counters
    // for that case. Otherwise, only check data correctness.
@@ -6544,6 +6560,235 @@ TEST_P(RenameCurrentTest, Compaction) {
  ASSERT_EQ("d_value", Get("d"));
 }

+TEST_F(DBTest2, VariousFileTemperatures) {
+  constexpr size_t kNumberFileTypes = static_cast<size_t>(kBlobFile) + 1U;
+
+  struct MyTestFS : public FileTemperatureTestFS {
+    explicit MyTestFS(const std::shared_ptr<FileSystem>& fs)
+        : FileTemperatureTestFS(fs) {
+      Reset();
+    }
+
+    IOStatus NewWritableFile(const std::string& fname, const FileOptions& opts,
+                             std::unique_ptr<FSWritableFile>* result,
+                             IODebugContext* dbg) override {
+      IOStatus ios =
+          FileTemperatureTestFS::NewWritableFile(fname, opts, result, dbg);
+      if (ios.ok()) {
+        uint64_t number;
+        FileType type;
+        if (ParseFileName(GetFileName(fname), &number, "LOG", &type)) {
+          if (type == kTableFile) {
+            // Not checked here
+          } else if (type == kWalFile) {
+            if (opts.temperature != expected_wal_temperature) {
+              std::cerr << "Attempt to open " << fname << " with temperature "
+                        << temperature_to_string[opts.temperature]
+                        << " rather than "
+                        << temperature_to_string[expected_wal_temperature]
+                        << std::endl;
+              assert(false);
+            }
+          } else if (type == kDescriptorFile) {
+            if (opts.temperature != expected_manifest_temperature) {
+              std::cerr << "Attempt to open " << fname << " with temperature "
+                        << temperature_to_string[opts.temperature]
+                        << " rather than "
+                        << temperature_to_string[expected_wal_temperature]
+                        << std::endl;
+              assert(false);
+            }
+          } else if (opts.temperature != expected_other_metadata_temperature) {
+            std::cerr << "Attempt to open " << fname << " with temperature "
+                      << temperature_to_string[opts.temperature]
+                      << " rather than "
+                      << temperature_to_string[expected_wal_temperature]
+                      << std::endl;
+            assert(false);
+          }
+          UpdateCount(type, 1);
+        }
+      }
+      return ios;
+    }
+
+    IOStatus RenameFile(const std::string& src, const std::string& dst,
+                        const IOOptions& options,
+                        IODebugContext* dbg) override {
+      IOStatus ios = FileTemperatureTestFS::RenameFile(src, dst, options, dbg);
+      if (ios.ok()) {
+        uint64_t number;
+        FileType src_type;
+        FileType dst_type;
+        assert(ParseFileName(GetFileName(src), &number, "LOG", &src_type));
+        assert(ParseFileName(GetFileName(dst), &number, "LOG", &dst_type));
+
+        UpdateCount(src_type, -1);
+        UpdateCount(dst_type, 1);
+      }
+      return ios;
+    }
+
+    void UpdateCount(FileType type, int delta) {
+      size_t i = static_cast<size_t>(type);
+      assert(i < kNumberFileTypes);
+      counts[i].FetchAddRelaxed(delta);
+    }
+
+    std::map<FileType, size_t> PopCounts() {
+      std::map<FileType, size_t> ret;
+      for (size_t i = 0; i < kNumberFileTypes; ++i) {
+        int c = counts[i].ExchangeRelaxed(0);
+        if (c > 0) {
+          ret[static_cast<FileType>(i)] = c;
+        }
+      }
+      return ret;
+    }
+
+    FileOptions OptimizeForLogWrite(
+        const FileOptions& file_options,
+        const DBOptions& /*db_options*/) const override {
+      FileOptions opts = file_options;
+      if (optimize_wal_temperature != Temperature::kUnknown) {
+        opts.temperature = optimize_wal_temperature;
+      }
+      return opts;
+    }
+
+    FileOptions OptimizeForManifestWrite(
+        const FileOptions& file_options) const override {
+      FileOptions opts = file_options;
+      if (optimize_manifest_temperature != Temperature::kUnknown) {
+        opts.temperature = optimize_manifest_temperature;
+      }
+      return opts;
+    }
+
+    void Reset() {
+      optimize_manifest_temperature = Temperature::kUnknown;
+      optimize_wal_temperature = Temperature::kUnknown;
+      expected_manifest_temperature = Temperature::kUnknown;
+      expected_other_metadata_temperature = Temperature::kUnknown;
+      expected_wal_temperature = Temperature::kUnknown;
+      for (auto& c : counts) {
+        c.StoreRelaxed(0);
+      }
+    }
+
+    Temperature optimize_manifest_temperature;
+    Temperature optimize_wal_temperature;
+    Temperature expected_manifest_temperature;
+    Temperature expected_other_metadata_temperature;
+    Temperature expected_wal_temperature;
+    std::array<RelaxedAtomic<int>, kNumberFileTypes> counts;
+  };
+
+  // We don't have enough non-unknown temps to confidently distinguish that
+  // a specific setting caused a specific outcome, in a single run. This is a
+  // reasonable work-around without blowing up test time. Only returns
+  // non-unknown temperatures.
+  auto RandomTemp = [] {
+    static std::vector<Temperature> temps = {
+        Temperature::kHot, Temperature::kWarm, Temperature::kCold};
+    return temps[Random::GetTLSInstance()->Uniform(
+        static_cast<int>(temps.size()))];
+  };
+
+  auto test_fs = std::make_shared<MyTestFS>(env_->GetFileSystem());
+  std::unique_ptr<Env> env(new CompositeEnvWrapper(env_, test_fs));
+  for (bool use_optimize : {false, true}) {
+    std::cerr << "use_optimize: " << std::to_string(use_optimize) << std::endl;
+    for (bool use_temp_options : {false, true}) {
+      std::cerr << "use_temp_options: " << std::to_string(use_temp_options)
+                << std::endl;
+
+      Options options = CurrentOptions();
+      // Currently require for last level temperature
+      options.compaction_style = kCompactionStyleUniversal;
+      options.env = env.get();
+      test_fs->Reset();
+      if (use_optimize) {
+        test_fs->optimize_manifest_temperature = RandomTemp();
+        test_fs->expected_manifest_temperature =
+            test_fs->optimize_manifest_temperature;
+        test_fs->optimize_wal_temperature = RandomTemp();
+        test_fs->expected_wal_temperature = test_fs->optimize_wal_temperature;
+      }
+      if (use_temp_options) {
+        options.metadata_write_temperature = RandomTemp();
+        test_fs->expected_manifest_temperature =
+            options.metadata_write_temperature;
+        test_fs->expected_other_metadata_temperature =
+            options.metadata_write_temperature;
+        options.wal_write_temperature = RandomTemp();
+        test_fs->expected_wal_temperature = options.wal_write_temperature;
+        options.last_level_temperature = RandomTemp();
+        options.default_write_temperature = RandomTemp();
+      }
+
+      DestroyAndReopen(options);
+      Defer closer([&] { Close(); });
+
+      using FTC = std::map<FileType, size_t>;
+      // Files on DB startup
+      ASSERT_EQ(test_fs->PopCounts(), FTC({{kWalFile, 1},
+                                           {kDescriptorFile, 2},
+                                           {kCurrentFile, 2},
+                                           {kIdentityFile, 1},
+                                           {kOptionsFile, 1}}));
+
+      // Temperature count map
+      using TCM = std::map<Temperature, size_t>;
+      ASSERT_EQ(test_fs->CountCurrentSstFilesByTemp(), TCM({}));
+
+      ASSERT_OK(Put("foo", "1"));
+      ASSERT_OK(Put("bar", "1"));
+      ASSERT_OK(Flush());
+      ASSERT_OK(Put("foo", "2"));
+      ASSERT_OK(Put("bar", "2"));
+      ASSERT_OK(Flush());
+
+      ASSERT_EQ(test_fs->CountCurrentSstFilesByTemp(),
+                TCM({{options.default_write_temperature, 2}}));
+
+      ASSERT_OK(db_->CompactRange({}, nullptr, nullptr));
+      ASSERT_OK(dbfull()->TEST_WaitForBackgroundWork());
+
+      ASSERT_EQ(test_fs->CountCurrentSstFilesByTemp(),
+                TCM({{options.last_level_temperature, 1}}));
+
+      ASSERT_OK(Put("foo", "3"));
+      ASSERT_OK(Put("bar", "3"));
+      ASSERT_OK(Flush());
+
+      // Just in memtable/WAL
+      ASSERT_OK(Put("dog", "3"));
+
+      {
+        TCM expected;
+        expected[options.default_write_temperature] += 1;
+        expected[options.last_level_temperature] += 1;
+        ASSERT_EQ(test_fs->CountCurrentSstFilesByTemp(), expected);
+      }
+
+      // New files during operation
+      ASSERT_EQ(test_fs->PopCounts(), FTC({{kWalFile, 3}, {kTableFile, 4}}));
+
+      Reopen(options);
+
+      // New files during re-open/recovery
+      ASSERT_EQ(test_fs->PopCounts(), FTC({{kWalFile, 1},
+                                           {kTableFile, 1},
+                                           {kDescriptorFile, 1},
+                                           {kCurrentFile, 1},
+                                           {kOptionsFile, 1}}));
+
+      Destroy(options);
+    }
+  }
+}
+
 TEST_F(DBTest2, LastLevelTemperature) {
  class TestListener : public EventListener {
   public:
@@ -366,6 +366,11 @@ Options DBTestBase::GetOptions(
    table_options.block_cache = NewLRUCache(/* too small */ 1);
  }

+  // Test anticipated new default as much as reasonably possible (and remove
+  // this code when obsolete)
+  assert(!table_options.decouple_partitioned_filters);
+  table_options.decouple_partitioned_filters = true;
+
  bool can_allow_mmap = IsMemoryMappedAccessSupported();
  switch (option_config) {
    case kHashSkipList:
@@ -565,6 +570,11 @@ Options DBTestBase::GetOptions(
      options.unordered_write = false;
      break;
    }
+    case kBlockBasedTableWithBinarySearchWithFirstKeyIndex: {
+      table_options.index_type =
+          BlockBasedTableOptions::kBinarySearchWithFirstKey;
+      break;
+    }

    default:
      break;
@@ -831,6 +831,15 @@ class FileTemperatureTestFS : public FileSystemWrapper {
    return count;
  }

+  std::map<Temperature, size_t> CountCurrentSstFilesByTemp() {
+    MutexLock lock(&mu_);
+    std::map<Temperature, size_t> ret;
+    for (const auto& e : current_sst_file_temperatures_) {
+      ret[e.second]++;
+    }
+    return ret;
+  }
+
  void OverrideSstFileTemperature(uint64_t number, Temperature temp) {
    MutexLock lock(&mu_);
    current_sst_file_temperatures_[number] = temp;
@@ -842,7 +851,7 @@ class FileTemperatureTestFS : public FileSystemWrapper {
      requested_sst_file_temperatures_;
  std::map<uint64_t, Temperature> current_sst_file_temperatures_;

-  std::string GetFileName(const std::string& fname) {
+  static std::string GetFileName(const std::string& fname) {
    auto filename = fname.substr(fname.find_last_of(kFilePathSeparator) + 1);
    // workaround only for Windows that the file path could contain both Windows
    // FilePathSeparator and '/'
@@ -1041,6 +1050,7 @@ class DBTestBase : public testing::Test {
    kPartitionedFilterWithNewTableReaderForCompactions,
    kUniversalSubcompactions,
    kUnorderedWrite,
+    kBlockBasedTableWithBinarySearchWithFirstKeyIndex,
    // This must be the last line
    kEnd,
  };
@@ -213,7 +213,6 @@ TEST_P(DBTestUniversalCompaction, UniversalCompactionTrigger) {
  options.num_levels = num_levels_;
  options.write_buffer_size = 105 << 10;  // 105KB
  options.arena_block_size = 4 << 10;
-  options.target_file_size_base = 32 << 10;  // 32KB
  // trigger compaction if there are >= 4 files
  options.level0_file_num_compaction_trigger = 4;
  KeepFilterFactory* filter = new KeepFilterFactory(true);
@@ -1472,6 +1472,126 @@ TEST_F(DBWALTest, SyncMultipleLogs) {
  ASSERT_OK(dbfull()->SyncWAL());
 }

+TEST_F(DBWALTest, DISABLED_RecycleMultipleWalsCrash) {
+  Options options = CurrentOptions();
+  options.max_write_buffer_number = 5;
+  options.track_and_verify_wals_in_manifest = true;
+  options.max_bgerror_resume_count = 0;  // manual resume
+  options.recycle_log_file_num = 3;
+  options.wal_recovery_mode = WALRecoveryMode::kPointInTimeRecovery;
+
+  // Disable truncating recycled WALs to new size in posix env
+  // (approximating a crash)
+  SyncPoint::GetInstance()->SetCallBack(
+      "PosixWritableFile::Close",
+      [](void* arg) { *(static_cast<size_t*>(arg)) = 0; });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  // Re-open with desired options
+  DestroyAndReopen(options);
+  Defer closer([this]() { Close(); });
+
+  // Ensure WAL recycling wasn't sanitized away
+  ASSERT_EQ(db_->GetOptions().recycle_log_file_num,
+            options.recycle_log_file_num);
+
+  // Prepare external files for later ingestion
+  std::string sst_files_dir = dbname_ + "/sst_files/";
+  ASSERT_OK(DestroyDir(env_, sst_files_dir));
+  ASSERT_OK(env_->CreateDir(sst_files_dir));
+  std::string external_file1 = sst_files_dir + "file1.sst";
+  {
+    SstFileWriter sst_file_writer(EnvOptions(), options);
+    ASSERT_OK(sst_file_writer.Open(external_file1));
+    ASSERT_OK(sst_file_writer.Put("external1", "ex1"));
+    ExternalSstFileInfo file_info;
+    ASSERT_OK(sst_file_writer.Finish(&file_info));
+  }
+  std::string external_file2 = sst_files_dir + "file2.sst";
+  {
+    SstFileWriter sst_file_writer(EnvOptions(), options);
+    ASSERT_OK(sst_file_writer.Open(external_file2));
+    ASSERT_OK(sst_file_writer.Put("external2", "ex2"));
+    ExternalSstFileInfo file_info;
+    ASSERT_OK(sst_file_writer.Finish(&file_info));
+  }
+
+  // Populate some WALs to be recycled such that there will be extra data
+  // from an old incarnation of the WAL on recovery
+  ASSERT_OK(db_->PauseBackgroundWork());
+  ASSERT_OK(Put("ignore1", Random::GetTLSInstance()->RandomString(500)));
+  ASSERT_OK(static_cast_with_check<DBImpl>(db_)->TEST_SwitchMemtable());
+  ASSERT_OK(Put("ignore2", Random::GetTLSInstance()->RandomString(500)));
+  ASSERT_OK(static_cast_with_check<DBImpl>(db_)->TEST_SwitchMemtable());
+  ASSERT_OK(db_->ContinueBackgroundWork());
+  ASSERT_OK(Flush());
+  ASSERT_OK(Put("ignore3", Random::GetTLSInstance()->RandomString(500)));
+  ASSERT_OK(Flush());
+
+  // Verify expected log files (still there for recycling)
+  std::vector<FileAttributes> files;
+  int log_count = 0;
+  ASSERT_OK(options.env->GetChildrenFileAttributes(dbname_, &files));
+  for (const auto& f : files) {
+    if (EndsWith(f.name, ".log")) {
+      EXPECT_GT(f.size_bytes, 500);
+      ++log_count;
+    }
+  }
+  EXPECT_EQ(log_count, 3);
+
+  // (Re-used recipe) Generate two inactive WALs and one active WAL, with a
+  // gap in sequence numbers to interfere with recovery
+  ASSERT_OK(db_->PauseBackgroundWork());
+  ASSERT_OK(Put("key1", "val1"));
+  ASSERT_OK(static_cast_with_check<DBImpl>(db_)->TEST_SwitchMemtable());
+  ASSERT_OK(Put("key2", "val2"));
+  ASSERT_OK(static_cast_with_check<DBImpl>(db_)->TEST_SwitchMemtable());
+  // Need a gap in sequence numbers, so e.g. ingest external file
+  // with an open snapshot
+  {
+    ManagedSnapshot snapshot(db_);
+    ASSERT_OK(
+        db_->IngestExternalFile({external_file1}, IngestExternalFileOptions()));
+  }
+  ASSERT_OK(Put("key3", "val3"));
+  ASSERT_OK(db_->SyncWAL());
+  // Need an SST file that is logically after that WAL, so that dropping WAL
+  // data is not a valid point in time.
+  {
+    ManagedSnapshot snapshot(db_);
+    ASSERT_OK(
+        db_->IngestExternalFile({external_file2}, IngestExternalFileOptions()));
+  }
+
+  // Approximate a crash, with respect to recycled WAL data extending past
+  // the end of the current WAL data (see SyncPoint callback above)
+  Close();
+
+  // Verify recycled log files haven't been truncated
+  files.clear();
+  log_count = 0;
+  ASSERT_OK(options.env->GetChildrenFileAttributes(dbname_, &files));
+  for (const auto& f : files) {
+    if (EndsWith(f.name, ".log")) {
+      EXPECT_GT(f.size_bytes, 500);
+      ++log_count;
+    }
+  }
+  EXPECT_EQ(log_count, 3);
+
+  // Verify no data loss after reopen.
+  Reopen(options);
+  EXPECT_EQ("val1", Get("key1"));
+  EXPECT_EQ("val2", Get("key2"));  // Passes because of adjacent seqnos
+  EXPECT_EQ("ex1", Get("external1"));
+  EXPECT_EQ("val3", Get("key3"));  // <- ONLY FAILURE! (Not a point in time)
+  EXPECT_EQ("ex2", Get("external2"));
+
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+}
+
 TEST_F(DBWALTest, SyncWalPartialFailure) {
  class MyTestFileSystem : public FileSystemWrapper {
   public:
@@ -1532,7 +1652,7 @@ TEST_F(DBWALTest, SyncWalPartialFailure) {
  // * one inactive WAL, not synced, and
  // * one active WAL, not synced
  // with a single thread, to exercise as much logic as we reasonably can.
-  ASSERT_OK(static_cast_with_check<DBImpl>(db_)->PauseBackgroundWork());
+  ASSERT_OK(db_->PauseBackgroundWork());
  ASSERT_OK(Put("key1", "val1"));
  ASSERT_OK(static_cast_with_check<DBImpl>(db_)->TEST_SwitchMemtable());
  ASSERT_OK(db_->SyncWAL());
@@ -2757,6 +2877,83 @@ TEST_F(DBWALTest, EmptyWalReopenTest) {
  }
 }

+TEST_F(DBWALTest, RecoveryFlushSwitchWALOnEmptyMemtable) {
+  Options options = CurrentOptions();
+  auto fault_fs = std::make_shared<FaultInjectionTestFS>(FileSystem::Default());
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  options.env = fault_fs_env.get();
+  options.avoid_flush_during_shutdown = true;
+  DestroyAndReopen(options);
+
+  // Make sure the memtable switch in recovery flush happened after test checks
+  // the memtable is empty.
+  SyncPoint::GetInstance()->LoadDependency(
+      {{"DBWALTest.RecoveryFlushSwitchWALOnEmptyMemtable:"
+        "AfterCheckMemtableEmpty",
+        "RecoverFromRetryableBGIOError:BeforeStart"}});
+  SyncPoint::GetInstance()->EnableProcessing();
+  fault_fs->SetThreadLocalErrorContext(
+      FaultInjectionIOType::kMetadataWrite, 7 /* seed*/, 1 /* one_in */,
+      true /* retryable */, false /* has_data_loss*/);
+  fault_fs->EnableThreadLocalErrorInjection(
+      FaultInjectionIOType::kMetadataWrite);
+
+  WriteOptions wo;
+  wo.sync = true;
+  Status s = Put("k", "old_v", wo);
+  ASSERT_TRUE(s.IsIOError());
+  // To verify the key is not in memtable nor SST
+  ASSERT_TRUE(static_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())
+                  ->cfd()
+                  ->mem()
+                  ->IsEmpty());
+  ASSERT_EQ("NOT_FOUND", Get("k"));
+  TEST_SYNC_POINT(
+      "DBWALTest.RecoveryFlushSwitchWALOnEmptyMemtable:"
+      "AfterCheckMemtableEmpty");
+  SyncPoint::GetInstance()->DisableProcessing();
+
+  fault_fs->DisableThreadLocalErrorInjection(
+      FaultInjectionIOType::kMetadataWrite);
+
+  // Keep trying write until recovery of the previous IO error finishes
+  while (!s.ok()) {
+    options.env->SleepForMicroseconds(1000);
+    s = Put("k", "new_v");
+  }
+
+  // If recovery flush didn't switch WAL, we will end up having two duplicate
+  // WAL entries with same seqno and same key that violate assertion during WAL
+  // recovery and fail DB reopen
+  options.avoid_flush_during_recovery = false;
+  Reopen(options);
+
+  ASSERT_EQ("new_v", Get("k"));
+  Destroy(options);
+}
+
+TEST_F(DBWALTest, WALWriteErrorNoRecovery) {
+  Options options = CurrentOptions();
+  auto fault_fs = std::make_shared<FaultInjectionTestFS>(FileSystem::Default());
+  std::unique_ptr<Env> fault_fs_env(NewCompositeEnv(fault_fs));
+  options.env = fault_fs_env.get();
+  options.manual_wal_flush = true;
+  DestroyAndReopen(options);
+  fault_fs->SetThreadLocalErrorContext(
+      FaultInjectionIOType::kWrite, 7 /* seed*/, 1 /* one_in */,
+      true /* retryable */, false /* has_data_loss*/);
+  fault_fs->EnableThreadLocalErrorInjection(FaultInjectionIOType::kWrite);
+
+  ASSERT_OK(Put("k", "v"));
+  Status s;
+  s = db_->FlushWAL(false);
+  ASSERT_TRUE(s.IsIOError());
+  s = dbfull()->TEST_GetBGError();
+  ASSERT_EQ(s.severity(), Status::Severity::kFatalError);
+  ASSERT_FALSE(dbfull()->TEST_IsRecoveryInProgress());
+  fault_fs->DisableThreadLocalErrorInjection(FaultInjectionIOType::kWrite);
+  Destroy(options);
+}
 }  // namespace ROCKSDB_NAMESPACE

 int main(int argc, char** argv) {
@@ -172,6 +172,70 @@ TEST_F(DBBasicTestWithTimestamp, MixedCfs) {
  Close();
 }

+TEST_F(DBBasicTestWithTimestamp, MultiGetMultipleCfs) {
+  const size_t kTimestampSize = Timestamp(0, 0).size();
+  TestComparator test_cmp(kTimestampSize);
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.create_if_missing = true;
+  options.avoid_flush_during_shutdown = true;
+  options.comparator = &test_cmp;
+  DestroyAndReopen(options);
+
+  Options options1 = CurrentOptions();
+  options1.env = env_;
+  options1.comparator = &test_cmp;
+  ColumnFamilyHandle* handle = nullptr;
+  Status s = db_->CreateColumnFamily(options1, "data", &handle);
+  ASSERT_OK(s);
+
+  std::string ts = Timestamp(1, 0);
+  WriteBatch wb(0, 0, 0, kTimestampSize);
+  ASSERT_OK(wb.Put("a", "value"));
+  ASSERT_OK(wb.Put(handle, "a", "value"));
+  const auto ts_sz_func = [kTimestampSize](uint32_t /*cf_id*/) {
+    return kTimestampSize;
+  };
+  ASSERT_OK(wb.UpdateTimestamps(ts, ts_sz_func));
+  ASSERT_OK(db_->Write(WriteOptions(), &wb));
+
+  int num_keys = 2;
+  std::vector<Slice> keys;
+  std::vector<std::string> expected_values;
+  for (int i = 0; i < num_keys; i++) {
+    keys.push_back("a");
+    expected_values.push_back("value");
+  }
+  std::vector<ColumnFamilyHandle*> handles;
+  handles.push_back(db_->DefaultColumnFamily());
+  handles.push_back(handle);
+
+  {
+    Slice read_ts_slice(ts);
+    ReadOptions read_opts;
+    read_opts.timestamp = &read_ts_slice;
+
+    std::vector<PinnableSlice> values;
+    values.resize(num_keys);
+    std::vector<Status> statuses;
+    statuses.resize(num_keys);
+    std::vector<std::string> timestamps;
+    timestamps.resize(num_keys);
+
+    db_->MultiGet(read_opts, num_keys, handles.data(), keys.data(),
+                  values.data(), timestamps.data(), statuses.data());
+
+    for (int i = 0; i < num_keys; i++) {
+      ASSERT_OK(statuses[i]);
+      ASSERT_EQ(expected_values[i], values[i].ToString());
+      ASSERT_EQ(ts, timestamps[i]);
+    }
+  }
+
+  delete handle;
+  Close();
+}
+
 TEST_F(DBBasicTestWithTimestamp, CompactRangeWithSpecifiedRange) {
  Options options = CurrentOptions();
  options.env = env_;
@@ -768,6 +832,7 @@ TEST_P(DBBasicTestWithTimestampTableOptions, GetAndMultiGet) {

 TEST_P(DBBasicTestWithTimestampTableOptions, SeekWithPrefixLessThanKey) {
  Options options = CurrentOptions();
+  options.prefix_seek_opt_in_only = false;  // Use legacy prefix seek
  options.env = env_;
  options.create_if_missing = true;
  options.prefix_extractor.reset(NewFixedPrefixTransform(3));
@@ -945,6 +1010,7 @@ TEST_F(DBBasicTestWithTimestamp, ChangeIterationDirection) {
  TestComparator test_cmp(kTimestampSize);
  options.comparator = &test_cmp;
  options.prefix_extractor.reset(NewFixedPrefixTransform(1));
+  options.prefix_seek_opt_in_only = false;  // Use legacy prefix seek
  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
  DestroyAndReopen(options);
  const std::vector<std::string> timestamps = {Timestamp(1, 1), Timestamp(0, 2),
@@ -330,17 +330,16 @@ inline Slice ExtractUserKey(const Slice& internal_key) {
 // output              : <user_provided_key>
 inline Slice ExtractUserKeyAndStripTimestamp(const Slice& internal_key,
                                             size_t ts_sz) {
-  Slice ret = internal_key;
-  ret.remove_suffix(kNumInternalBytes + ts_sz);
-  return ret;
+  assert(internal_key.size() >= kNumInternalBytes + ts_sz);
+  return Slice(internal_key.data(),
+               internal_key.size() - (kNumInternalBytes + ts_sz));
 }

 // input [user key]: <user_provided_key | ts>
 // output:           <user_provided_key>
 inline Slice StripTimestampFromUserKey(const Slice& user_key, size_t ts_sz) {
-  Slice ret = user_key;
-  ret.remove_suffix(ts_sz);
-  return ret;
+  assert(user_key.size() >= ts_sz);
+  return Slice(user_key.data(), user_key.size() - ts_sz);
 }

 // input [user key]: <user_provided_key | ts>
@@ -23,17 +23,17 @@ static std::string IKey(const std::string& user_key, uint64_t seq,
 }

 static std::string Shorten(const std::string& s, const std::string& l) {
-  std::string result = s;
-  ShortenedIndexBuilder::FindShortestInternalKeySeparator(*BytewiseComparator(),
-                                                          &result, l);
-  return result;
+  std::string scratch;
+  return ShortenedIndexBuilder::FindShortestInternalKeySeparator(
+             *BytewiseComparator(), s, l, &scratch)
+      .ToString();
 }

 static std::string ShortSuccessor(const std::string& s) {
-  std::string result = s;
-  ShortenedIndexBuilder::FindShortInternalKeySuccessor(*BytewiseComparator(),
-                                                       &result);
-  return result;
+  std::string scratch;
+  return ShortenedIndexBuilder::FindShortInternalKeySuccessor(
+             *BytewiseComparator(), s, &scratch)
+      .ToString();
 }

 static void TestKey(const std::string& key, uint64_t seq, ValueType vt) {
@@ -250,8 +250,6 @@ void ErrorHandler::CancelErrorRecovery() {
  EndAutoRecovery();
 }

-STATIC_AVOID_DESTRUCTION(const Status, kOkStatus){Status::OK()};
-
 // This is the main function for looking at an error during a background
 // operation and deciding the severity, and error recovery strategy. The high
 // level algorithm is as follows -
@@ -270,11 +268,11 @@ STATIC_AVOID_DESTRUCTION(const Status, kOkStatus){Status::OK()};
 // This can also get called as part of a recovery operation. In that case, we
 // also track the error separately in recovery_error_ so we can tell in the
 // end whether recovery succeeded or not
-const Status& ErrorHandler::HandleKnownErrors(const Status& bg_err,
-                                              BackgroundErrorReason reason) {
+void ErrorHandler::HandleKnownErrors(const Status& bg_err,
+                                     BackgroundErrorReason reason) {
  db_mutex_->AssertHeld();
  if (bg_err.ok()) {
-    return kOkStatus;
+    return;
  }

  ROCKS_LOG_INFO(db_options_.info_log,
@@ -339,7 +337,7 @@ const Status& ErrorHandler::HandleKnownErrors(const Status& bg_err,
    } else {
      // This error is less severe than previously encountered error. Don't
      // take any further action
-      return bg_error_;
+      return;
    }
  }

@@ -356,7 +354,6 @@ const Status& ErrorHandler::HandleKnownErrors(const Status& bg_err,
  if (bg_error_.severity() >= Status::Severity::kHardError) {
    is_db_stopped_.store(true, std::memory_order_release);
  }
-  return bg_error_;
 }

 // This is the main function for looking at IO related error during the
@@ -383,17 +380,17 @@ const Status& ErrorHandler::HandleKnownErrors(const Status& bg_err,
 // 3) for other cases, HandleKnownErrors(const Status& bg_err,
 //    BackgroundErrorReason reason) will be called to handle other error cases
 //    such as delegating to SstFileManager to handle no space error.
-const Status& ErrorHandler::SetBGError(const Status& bg_status,
-                                       BackgroundErrorReason reason) {
+void ErrorHandler::SetBGError(const Status& bg_status,
+                              BackgroundErrorReason reason, bool wal_related) {
  db_mutex_->AssertHeld();
  Status tmp_status = bg_status;
  IOStatus bg_io_err = status_to_io_status(std::move(tmp_status));

  if (bg_io_err.ok()) {
-    return kOkStatus;
+    return;
  }
-  ROCKS_LOG_WARN(db_options_.info_log, "Background IO error %s",
-                 bg_io_err.ToString().c_str());
+  ROCKS_LOG_WARN(db_options_.info_log, "Background IO error %s, reason %d",
+                 bg_io_err.ToString().c_str(), static_cast<int>(reason));

  RecordStats({ERROR_HANDLER_BG_ERROR_COUNT, ERROR_HANDLER_BG_IO_ERROR_COUNT},
              {} /* int_histograms */);
@@ -413,11 +410,36 @@ const Status& ErrorHandler::SetBGError(const Status& bg_status,
    EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason,
                                          &bg_err, db_mutex_, &auto_recovery);
    recover_context_ = context;
-    return bg_error_;
-  } else if (bg_io_err.subcode() != IOStatus::SubCode::kNoSpace &&
-             (bg_io_err.GetScope() ==
-                  IOStatus::IOErrorScope::kIOErrorScopeFile ||
-              bg_io_err.GetRetryable())) {
+    return;
+  }
+  if (wal_related) {
+    assert(reason == BackgroundErrorReason::kWriteCallback ||
+           reason == BackgroundErrorReason::kMemTable ||
+           reason == BackgroundErrorReason::kFlush);
+  }
+  if (db_options_.manual_wal_flush && wal_related && bg_io_err.IsIOError()) {
+    // With manual_wal_flush, a WAL write failure can drop buffered WAL writes.
+    // Memtables and WAL then become inconsistent. A successful memtable flush
+    // on one CF can cause CFs to be inconsistent upon restart. Before we fix
+    // the bug in auto recovery from WAL write failures that can flush one CF
+    // at a time, we set the error severity to fatal to disallow auto recovery.
+    // TODO: remove parameter `wal_related` once we can automatically recover
+    //  from WAL write failures.
+    bool auto_recovery = false;
+    Status bg_err(new_bg_io_err, Status::Severity::kFatalError);
+    CheckAndSetRecoveryAndBGError(bg_err);
+    ROCKS_LOG_WARN(db_options_.info_log,
+                   "ErrorHandler: A potentially WAL error happened, set "
+                   "background IO error as fatal error\n");
+    EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason,
+                                          &bg_err, db_mutex_, &auto_recovery);
+    recover_context_ = context;
+    return;
+  }
+
+  if (bg_io_err.subcode() != IOStatus::SubCode::kNoSpace &&
+      (bg_io_err.GetScope() == IOStatus::IOErrorScope::kIOErrorScopeFile ||
+       bg_io_err.GetRetryable())) {
    // Second, check if the error is a retryable IO error (file scope IO error
    // is also treated as retryable IO error in RocksDB write path). if it is
    // retryable error and its severity is higher than bg_error_, overwrite the
@@ -426,10 +448,6 @@ const Status& ErrorHandler::SetBGError(const Status& bg_status,
    // IO error as hard error. Note that, all the NoSpace error should be
    // handled by the SstFileManager::StartErrorRecovery(). Therefore, no matter
    // it is retryable or file scope, this logic will be bypassed.
-    bool auto_recovery = false;
-    EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason,
-                                          &new_bg_io_err, db_mutex_,
-                                          &auto_recovery);

    RecordStats({ERROR_HANDLER_BG_RETRYABLE_IO_ERROR_COUNT},
                {} /* int_histograms */);
@@ -445,9 +463,13 @@ const Status& ErrorHandler::SetBGError(const Status& bg_status,
      ROCKS_LOG_INFO(
          db_options_.info_log,
          "ErrorHandler: Compaction will schedule by itself to resume\n");
+      bool auto_recovery = false;
+      EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason,
+                                            &new_bg_io_err, db_mutex_,
+                                            &auto_recovery);
      // Not used in this code path.
      new_bg_io_err.PermitUncheckedError();
-      return bg_error_;
+      return;
    }

    Status::Severity severity;
@@ -469,10 +491,14 @@ const Status& ErrorHandler::SetBGError(const Status& bg_status,
    Status bg_err(new_bg_io_err, severity);
    CheckAndSetRecoveryAndBGError(bg_err);
    recover_context_ = context;
-    return StartRecoverFromRetryableBGIOError(bg_io_err);
-  } else {
-    return HandleKnownErrors(new_bg_io_err, reason);
+    bool auto_recovery = db_options_.max_bgerror_resume_count > 0;
+    EventHelpers::NotifyOnBackgroundError(db_options_.listeners, reason,
+                                          &new_bg_io_err, db_mutex_,
+                                          &auto_recovery);
+    StartRecoverFromRetryableBGIOError(bg_io_err);
+    return;
  }
+  HandleKnownErrors(new_bg_io_err, reason);
 }

 void ErrorHandler::AddFilesToQuarantine(
@@ -620,23 +646,23 @@ Status ErrorHandler::RecoverFromBGError(bool is_manual) {
  return s;
 }

-const Status& ErrorHandler::StartRecoverFromRetryableBGIOError(
+void ErrorHandler::StartRecoverFromRetryableBGIOError(
    const IOStatus& io_error) {
  db_mutex_->AssertHeld();
-  if (bg_error_.ok()) {
-    return bg_error_;
-  } else if (io_error.ok()) {
-    return kOkStatus;
-  } else if (db_options_.max_bgerror_resume_count <= 0 || recovery_in_prog_) {
-    // Auto resume BG error is not enabled, directly return bg_error_.
-    return bg_error_;
-  } else if (end_recovery_) {
+  if (bg_error_.ok() || io_error.ok()) {
+    return;
+  }
+  if (db_options_.max_bgerror_resume_count <= 0 || recovery_in_prog_) {
+    // Auto resume BG error is not enabled
+    return;
+  }
+  if (end_recovery_) {
    // Can temporarily release db mutex
    EventHelpers::NotifyOnErrorRecoveryEnd(db_options_.listeners, bg_error_,
                                           Status::ShutdownInProgress(),
                                           db_mutex_);
    db_mutex_->AssertHeld();
-    return bg_error_;
+    return;
  }
  RecordStats({ERROR_HANDLER_AUTORESUME_COUNT}, {} /* int_histograms */);
  ROCKS_LOG_INFO(
@@ -664,12 +690,6 @@ const Status& ErrorHandler::StartRecoverFromRetryableBGIOError(

  recovery_thread_.reset(
      new port::Thread(&ErrorHandler::RecoverFromRetryableBGIOError, this));
-
-  if (recovery_error_.ok()) {
-    return recovery_error_;
-  } else {
-    return bg_error_;
-  }
 }

 // Automatic recover from Retryable BG IO error. Must be called after db
@@ -56,7 +56,8 @@ class ErrorHandler {
  Status::Severity GetErrorSeverity(BackgroundErrorReason reason,
                                    Status::Code code, Status::SubCode subcode);

-  const Status& SetBGError(const Status& bg_err, BackgroundErrorReason reason);
+  void SetBGError(const Status& bg_err, BackgroundErrorReason reason,
+                  bool wal_related = false);

  Status GetBGError() const { return bg_error_; }

@@ -135,11 +136,10 @@ class ErrorHandler {
  // unsorted.
  autovector<uint64_t> files_to_quarantine_;

-  const Status& HandleKnownErrors(const Status& bg_err,
-                                  BackgroundErrorReason reason);
+  void HandleKnownErrors(const Status& bg_err, BackgroundErrorReason reason);
  Status OverrideNoSpaceError(const Status& bg_error, bool* auto_recovery);
  void RecoverFromNoSpace();
-  const Status& StartRecoverFromRetryableBGIOError(const IOStatus& io_error);
+  void StartRecoverFromRetryableBGIOError(const IOStatus& io_error);
  void RecoverFromRetryableBGIOError();
  // First, if it is in recovery and the recovery_error is ok. Set the
  // recovery_error_ to bg_err. Second, if the severity is higher than the
@@ -851,13 +851,17 @@ TEST_F(DBErrorHandlingFSTest, DoubleManifestWriteError) {
      });
  SyncPoint::GetInstance()->EnableProcessing();
  s = Flush();
-  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+  ASSERT_TRUE(s.IsNoSpace());
+  ASSERT_EQ(dbfull()->TEST_GetBGError().severity(),
+            ROCKSDB_NAMESPACE::Status::Severity::kHardError);
  ASSERT_FALSE(dbfull()->TEST_GetFilesToQuarantine().empty());
  fault_fs_->SetFilesystemActive(true);

  // This Resume() will attempt to create a new manifest file and fail again
  s = dbfull()->Resume();
-  ASSERT_EQ(s.severity(), ROCKSDB_NAMESPACE::Status::Severity::kHardError);
+  ASSERT_TRUE(s.IsNoSpace());
+  ASSERT_EQ(dbfull()->TEST_GetBGError().severity(),
+            ROCKSDB_NAMESPACE::Status::Severity::kHardError);
  ASSERT_FALSE(dbfull()->TEST_GetFilesToQuarantine().empty());
  fault_fs_->SetFilesystemActive(true);
  SyncPoint::GetInstance()->ClearAllCallBacks();
@@ -124,6 +124,7 @@ void EventHelpers::LogAndNotifyTableFileCreationFinished(
              << "comparator" << table_properties.comparator_name
              << "user_defined_timestamps_persisted"
              << table_properties.user_defined_timestamps_persisted
+              << "key_largest_seqno" << table_properties.key_largest_seqno
              << "merge_operator" << table_properties.merge_operator_name
              << "prefix_extractor_name"
              << table_properties.prefix_extractor_name << "property_collectors"
@@ -228,15 +229,18 @@ void EventHelpers::NotifyOnErrorRecoveryEnd(
    InstrumentedMutex* db_mutex) {
  if (!listeners.empty()) {
    db_mutex->AssertHeld();
+    // Make copies before releasing mutex to avoid race.
+    Status old_bg_error_cp = old_bg_error;
+    Status new_bg_error_cp = new_bg_error;
    // release lock while notifying events
    db_mutex->Unlock();
    TEST_SYNC_POINT("NotifyOnErrorRecoveryEnd:MutexUnlocked:1");
    TEST_SYNC_POINT("NotifyOnErrorRecoveryEnd:MutexUnlocked:2");
    for (auto& listener : listeners) {
      BackgroundErrorRecoveryInfo info;
-      info.old_bg_error = old_bg_error;
-      info.new_bg_error = new_bg_error;
-      listener->OnErrorRecoveryCompleted(old_bg_error);
+      info.old_bg_error = old_bg_error_cp;
+      info.new_bg_error = new_bg_error_cp;
+      listener->OnErrorRecoveryCompleted(old_bg_error_cp);
      listener->OnErrorRecoveryEnd(info);
      info.old_bg_error.PermitUncheckedError();
      info.new_bg_error.PermitUncheckedError();
@@ -152,6 +152,85 @@ Status UpdateManifestForFilesState(
 // EXPERIMENTAL new filtering features

 namespace {
+template <size_t N>
+class SemiStaticCappedKeySegmentsExtractor : public KeySegmentsExtractor {
+ public:
+  SemiStaticCappedKeySegmentsExtractor(const uint32_t* byte_widths) {
+    id_ = kName();
+    uint32_t prev_end = 0;
+    if constexpr (N > 0) {  // Suppress a compiler warning
+      for (size_t i = 0; i < N; ++i) {
+        prev_end = prev_end + byte_widths[i];
+        ideal_ends_[i] = prev_end;
+        id_ += std::to_string(byte_widths[i]) + "b";
+      }
+    }
+  }
+
+  static const char* kName() { return "CappedKeySegmentsExtractor"; }
+
+  const char* Name() const override { return kName(); }
+
+  std::string GetId() const override { return id_; }
+
+  void Extract(const Slice& key_or_bound, KeyKind /*kind*/,
+               Result* result) const override {
+    // Optimistic assignment
+    result->segment_ends.assign(ideal_ends_.begin(), ideal_ends_.end());
+    if constexpr (N > 0) {  // Suppress a compiler warning
+      uint32_t key_size = static_cast<uint32_t>(key_or_bound.size());
+      if (key_size < ideal_ends_.back()) {
+        // Need to fix up (should be rare)
+        for (size_t i = 0; i < N; ++i) {
+          result->segment_ends[i] = std::min(key_size, result->segment_ends[i]);
+        }
+      }
+    }
+  }
+
+ private:
+  std::array<uint32_t, N> ideal_ends_;
+  std::string id_;
+};
+
+class DynamicCappedKeySegmentsExtractor : public KeySegmentsExtractor {
+ public:
+  DynamicCappedKeySegmentsExtractor(const std::vector<uint32_t>& byte_widths) {
+    id_ = kName();
+    uint32_t prev_end = 0;
+    for (size_t i = 0; i < byte_widths.size(); ++i) {
+      prev_end = prev_end + byte_widths[i];
+      ideal_ends_[i] = prev_end;
+      id_ += std::to_string(byte_widths[i]) + "b";
+    }
+    final_ideal_end_ = prev_end;
+  }
+
+  static const char* kName() { return "CappedKeySegmentsExtractor"; }
+
+  const char* Name() const override { return kName(); }
+
+  std::string GetId() const override { return id_; }
+
+  void Extract(const Slice& key_or_bound, KeyKind /*kind*/,
+               Result* result) const override {
+    // Optimistic assignment
+    result->segment_ends = ideal_ends_;
+    uint32_t key_size = static_cast<uint32_t>(key_or_bound.size());
+    if (key_size < final_ideal_end_) {
+      // Need to fix up (should be rare)
+      for (size_t i = 0; i < ideal_ends_.size(); ++i) {
+        result->segment_ends[i] = std::min(key_size, result->segment_ends[i]);
+      }
+    }
+  }
+
+ private:
+  std::vector<uint32_t> ideal_ends_;
+  uint32_t final_ideal_end_;
+  std::string id_;
+};
+
 void GetFilterInput(FilterInput select, const Slice& key,
                    const KeySegmentsExtractor::Result& extracted,
                    Slice* out_input, Slice* out_leadup) {
@@ -211,12 +290,6 @@ void GetFilterInput(FilterInput select, const Slice& key,
      assert(false);
      return Slice();
    }
-
-    Slice operator()(SelectValue) {
-      // TODO
-      assert(false);
-      return Slice();
-    }
  };

  Slice input = std::visit(FilterInputGetter(key, extracted), select);
@@ -256,9 +329,6 @@ const char* DeserializeFilterInput(const char* p, const char* limit,
        case 3:
          *out = SelectColumnName{};
          return p;
-        case 4:
-          *out = SelectValue{};
-          return p;
        default:
          // Reserved for future use
          return nullptr;
@@ -315,7 +385,6 @@ void SerializeFilterInput(std::string* out, const FilterInput& select) {
    void operator()(SelectLegacyKeyPrefix) { out->push_back(1); }
    void operator()(SelectUserTimestamp) { out->push_back(2); }
    void operator()(SelectColumnName) { out->push_back(3); }
-    void operator()(SelectValue) { out->push_back(4); }
    void operator()(SelectKeySegment select) {
      // TODO: expand supported cases
      assert(select.segment_index < 16);
@@ -372,6 +441,7 @@ enum BuiltinSstQueryFilters : char {
  // and filtered independently because it might be a special case that is
  // not representative of the minimum in a spread of values.
  kBytewiseMinMaxFilter = 0x10,
+  kRevBytewiseMinMaxFilter = 0x11,
 };

 class SstQueryFilterBuilder {
@@ -459,7 +529,10 @@ class CategoryScopeFilterWrapperBuilder : public SstQueryFilterBuilder {

 class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
 public:
-  using SstQueryFilterConfigImpl::SstQueryFilterConfigImpl;
+  explicit BytewiseMinMaxSstQueryFilterConfig(
+      const FilterInput& input,
+      const KeySegmentsExtractor::KeyCategorySet& categories, bool reverse)
+      : SstQueryFilterConfigImpl(input, categories), reverse_(reverse) {}

  std::unique_ptr<SstQueryFilterBuilder> NewBuilder(
      bool sanity_checks) const override {
@@ -477,11 +550,13 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
      const KeySegmentsExtractor::Result& lower_bound_extracted,
      const Slice& upper_bound_excl,
      const KeySegmentsExtractor::Result& upper_bound_extracted) {
-    assert(!filter.empty() && filter[0] == kBytewiseMinMaxFilter);
+    assert(!filter.empty() && (filter[0] == kBytewiseMinMaxFilter ||
+                               filter[0] == kRevBytewiseMinMaxFilter));
    if (filter.size() <= 4) {
      // Missing some data
      return true;
    }
+    bool reverse = (filter[0] == kRevBytewiseMinMaxFilter);
    bool empty_included = (filter[1] & kEmptySeenFlag) != 0;
    const char* p = filter.data() + 2;
    const char* limit = filter.data() + filter.size();
@@ -528,8 +603,13 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {

    // May match if both the upper bound and lower bound indicate there could
    // be overlap
-    return upper_bound_input.compare(smallest) >= 0 &&
-           lower_bound_input.compare(largest) <= 0;
+    if (reverse) {
+      return upper_bound_input.compare(smallest) <= 0 &&
+             lower_bound_input.compare(largest) >= 0;
+    } else {
+      return upper_bound_input.compare(smallest) >= 0 &&
+             lower_bound_input.compare(largest) <= 0;
+    }
  }

 protected:
@@ -551,19 +631,11 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
                       &prev_leadup);

        int compare = prev_leadup.compare(leadup);
-        if (compare > 0) {
-          status = Status::Corruption(
-              "Ordering invariant violated from 0x" +
-              prev_key->ToString(/*hex=*/true) + " with prefix 0x" +
-              prev_leadup.ToString(/*hex=*/true) + " to 0x" +
-              key.ToString(/*hex=*/true) + " with prefix 0x" +
-              leadup.ToString(/*hex=*/true));
-          return;
-        } else if (compare == 0) {
+        if (compare == 0) {
          // On the same prefix leading up to the segment, the segments must
          // not be out of order.
          compare = prev_input.compare(input);
-          if (compare > 0) {
+          if (parent.reverse_ ? compare < 0 : compare > 0) {
            status = Status::Corruption(
                "Ordering invariant violated from 0x" +
                prev_key->ToString(/*hex=*/true) + " with segment 0x" +
@@ -573,6 +645,9 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
            return;
          }
        }
+        // NOTE: it is not strictly required that the leadup be ordered, just
+        // satisfy the "common segment prefix property" which would be
+        // expensive to check
      }

      // Now actually update state for the filter inputs
@@ -598,7 +673,8 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
        return 0;
      }
      return 2 + GetFilterInputSerializedLength(parent.input_) +
-             VarintLength(smallest.size()) + smallest.size() + largest.size();
+             VarintLength(parent.reverse_ ? largest.size() : smallest.size()) +
+             smallest.size() + largest.size();
    }

    void Finish(std::string& append_to) override {
@@ -610,23 +686,27 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
      }
      size_t old_append_to_size = append_to.size();
      append_to.reserve(old_append_to_size + encoded_length);
-      append_to.push_back(kBytewiseMinMaxFilter);
+      append_to.push_back(parent.reverse_ ? kRevBytewiseMinMaxFilter
+                                          : kBytewiseMinMaxFilter);

      append_to.push_back(empty_seen ? kEmptySeenFlag : 0);

      SerializeFilterInput(&append_to, parent.input_);

-      PutVarint32(&append_to, static_cast<uint32_t>(smallest.size()));
-      append_to.append(smallest);
-      // The end of `largest` is given by the end of the filter
-      append_to.append(largest);
+      auto& minv = parent.reverse_ ? largest : smallest;
+      auto& maxv = parent.reverse_ ? smallest : largest;
+      PutVarint32(&append_to, static_cast<uint32_t>(minv.size()));
+      append_to.append(minv);
+      // The end of `maxv` is given by the end of the filter
+      append_to.append(maxv);
      assert(append_to.size() == old_append_to_size + encoded_length);
    }

    const BytewiseMinMaxSstQueryFilterConfig& parent;
    const bool sanity_checks;
    // Smallest and largest segment seen, excluding the empty segment which
-    // is tracked separately
+    // is tracked separately. "Reverse" from parent is only applied at
+    // serialization time, for efficiency.
    std::string smallest;
    std::string largest;
    bool empty_seen = false;
@@ -635,6 +715,8 @@ class BytewiseMinMaxSstQueryFilterConfig : public SstQueryFilterConfigImpl {
    Status status;
  };

+  bool reverse_;
+
 private:
  static constexpr char kEmptySeenFlag = 0x1;
 };
@@ -711,7 +793,7 @@ class SstQueryFilterConfigsManagerImpl : public SstQueryFilterConfigsManager {
                      uint64_t /*file_size*/) override {
      // FIXME later: `key` might contain user timestamp. That should be
      // exposed properly in a future update to TablePropertiesCollector
-      KeySegmentsExtractor::Result extracted;
+      extracted.Reset();
      if (extractor) {
        extractor->Extract(key, KeySegmentsExtractor::kFullUserKey, &extracted);
        if (UNLIKELY(extracted.category >=
@@ -750,7 +832,7 @@ class SstQueryFilterConfigsManagerImpl : public SstQueryFilterConfigsManager {
        }
      }
      prev_key.assign(key.data(), key.size());
-      prev_extracted = std::move(extracted);
+      std::swap(prev_extracted, extracted);
      first_key = false;
      return Status::OK();
    }
@@ -859,6 +941,7 @@ class SstQueryFilterConfigsManagerImpl : public SstQueryFilterConfigsManager {
    std::vector<std::shared_ptr<SstQueryFilterBuilder>> builders;
    bool first_key = true;
    std::string prev_key;
+    KeySegmentsExtractor::Result extracted;
    KeySegmentsExtractor::Result prev_extracted;
    KeySegmentsExtractor::KeyCategorySet categories_seen;
  };
@@ -1035,6 +1118,7 @@ class SstQueryFilterConfigsManagerImpl : public SstQueryFilterConfigsManager {
            may_match = MayMatch_CategoryScopeFilterWrapper(filter, *state);
            break;
          case kBytewiseMinMaxFilter:
+          case kRevBytewiseMinMaxFilter:
            if (state == nullptr) {
              // TODO? Report problem
              // No filtering
@@ -1188,14 +1272,63 @@ const std::string SstQueryFilterConfigsManagerImpl::kTablePropertyName =
    "rocksdb.sqfc";
 }  // namespace

+std::shared_ptr<const KeySegmentsExtractor>
+MakeSharedCappedKeySegmentsExtractor(const std::vector<size_t>& byte_widths) {
+  std::vector<uint32_t> byte_widths_checked;
+  byte_widths_checked.resize(byte_widths.size());
+  size_t final_end = 0;
+  for (size_t i = 0; i < byte_widths.size(); ++i) {
+    final_end += byte_widths[i];
+    if (byte_widths[i] > UINT32_MAX / 2 || final_end > UINT32_MAX) {
+      // Better to crash than to proceed unsafely
+      return nullptr;
+    }
+    byte_widths_checked[i] = static_cast<uint32_t>(byte_widths[i]);
+  }
+
+  switch (byte_widths_checked.size()) {
+    case 0:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<0>>(
+          byte_widths_checked.data());
+    case 1:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<1>>(
+          byte_widths_checked.data());
+    case 2:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<2>>(
+          byte_widths_checked.data());
+    case 3:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<3>>(
+          byte_widths_checked.data());
+    case 4:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<4>>(
+          byte_widths_checked.data());
+    case 5:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<5>>(
+          byte_widths_checked.data());
+    case 6:
+      return std::make_shared<SemiStaticCappedKeySegmentsExtractor<6>>(
+          byte_widths_checked.data());
+    default:
+      return std::make_shared<DynamicCappedKeySegmentsExtractor>(
+          byte_widths_checked);
+  }
+}
+
 bool SstQueryFilterConfigs::IsEmptyNotFound() const {
  return this == &kEmptyNotFoundSQFC;
 }

 std::shared_ptr<SstQueryFilterConfig> MakeSharedBytewiseMinMaxSQFC(
    FilterInput input, KeySegmentsExtractor::KeyCategorySet categories) {
-  return std::make_shared<BytewiseMinMaxSstQueryFilterConfig>(input,
-                                                              categories);
+  return std::make_shared<BytewiseMinMaxSstQueryFilterConfig>(
+      input, categories,
+      /*reverse=*/false);
+}
+
+std::shared_ptr<SstQueryFilterConfig> MakeSharedReverseBytewiseMinMaxSQFC(
+    FilterInput input, KeySegmentsExtractor::KeyCategorySet categories) {
+  return std::make_shared<BytewiseMinMaxSstQueryFilterConfig>(input, categories,
+                                                              /*reverse=*/true);
 }

 Status SstQueryFilterConfigsManager::MakeShared(
@@ -44,9 +44,12 @@ Status ExternalSstFileIngestionJob::Prepare(
      return status;
    }

+    // Files generated in another DB or CF may have a different column family
+    // ID, so we let it pass here.
    if (file_to_ingest.cf_id !=
            TablePropertiesCollectorFactory::Context::kUnknownColumnFamily &&
-        file_to_ingest.cf_id != cfd_->GetID()) {
+        file_to_ingest.cf_id != cfd_->GetID() &&
+        !ingestion_options_.allow_db_generated_files) {
      return Status::InvalidArgument(
          "External file column family id don't match");
    }
@@ -110,7 +113,7 @@ Status ExternalSstFileIngestionJob::Prepare(
    const std::string path_outside_db = f.external_file_path;
    const std::string path_inside_db = TableFileName(
        cfd_->ioptions()->cf_paths, f.fd.GetNumber(), f.fd.GetPathId());
-    if (ingestion_options_.move_files) {
+    if (ingestion_options_.move_files || ingestion_options_.link_files) {
      status =
          fs_->LinkFile(path_outside_db, path_inside_db, IOOptions(), nullptr);
      if (status.ok()) {
@@ -704,9 +707,16 @@ Status ExternalSstFileIngestionJob::SanityCheckTableProperties(
  // Get table version
  auto version_iter = uprops.find(ExternalSstFilePropertyNames::kVersion);
  if (version_iter == uprops.end()) {
-    return Status::Corruption("External file version not found");
+    if (!ingestion_options_.allow_db_generated_files) {
+      return Status::Corruption("External file version not found");
+    } else {
+      // 0 is special version for when a file from live DB does not have the
+      // version table property
+      file_to_ingest->version = 0;
+    }
+  } else {
+    file_to_ingest->version = DecodeFixed32(version_iter->second.c_str());
  }
-  file_to_ingest->version = DecodeFixed32(version_iter->second.c_str());

  auto seqno_iter = uprops.find(ExternalSstFilePropertyNames::kGlobalSeqno);
  if (file_to_ingest->version == 2) {
@@ -733,8 +743,15 @@ Status ExternalSstFileIngestionJob::SanityCheckTableProperties(
      return Status::InvalidArgument(
          "External SST file V1 does not support global seqno");
    }
+  } else if (file_to_ingest->version == 0) {
+    // allow_db_generated_files is true
+    assert(seqno_iter == uprops.end());
+    file_to_ingest->original_seqno = 0;
+    file_to_ingest->global_seqno_offset = 0;
  } else {
-    return Status::InvalidArgument("External file version is not supported");
+    return Status::InvalidArgument("External file version " +
+                                   std::to_string(file_to_ingest->version) +
+                                   " is not supported");
  }

  file_to_ingest->cf_id = static_cast<uint32_t>(props->column_family_id);
@@ -896,6 +913,34 @@ Status ExternalSstFileIngestionJob::GetIngestedFileInfo(
  } else if (!iter->status().ok()) {
    return iter->status();
  }
+  SequenceNumber largest_seqno =
+      table_reader.get()->GetTableProperties()->key_largest_seqno;
+  // UINT64_MAX means unknown and the file is generated before table property
+  // `key_largest_seqno` is introduced.
+  if (largest_seqno != UINT64_MAX && largest_seqno > 0) {
+    return Status::Corruption(
+        "External file has non zero largest sequence number " +
+        std::to_string(largest_seqno));
+  }
+  if (ingestion_options_.allow_db_generated_files &&
+      largest_seqno == UINT64_MAX) {
+    // Need to verify that all keys have seqno zero.
+    for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+      Status pik_status =
+          ParseInternalKey(iter->key(), &key, allow_data_in_errors);
+      if (!pik_status.ok()) {
+        return Status::Corruption("Corrupted key in external file. ",
+                                  pik_status.getState());
+      }
+      if (key.sequence != 0) {
+        return Status::NotSupported(
+            "External file has a key with non zero sequence number.");
+      }
+    }
+    if (!iter->status().ok()) {
+      return iter->status();
+    }
+  }

  std::unique_ptr<InternalIterator> range_del_iter(
      table_reader->NewRangeTombstoneIterator(ro));
@@ -911,6 +956,11 @@ Status ExternalSstFileIngestionJob::GetIngestedFileInfo(
        return Status::Corruption("Corrupted key in external file. ",
                                  pik_status.getState());
      }
+      if (key.sequence != 0) {
+        return Status::Corruption(
+            "External file has a range deletion with non zero sequence "
+            "number.");
+      }
      RangeTombstone tombstone(key, range_del_iter->value());

      InternalKey start_key = tombstone.SerializeKey();
@@ -1045,11 +1095,18 @@ Status ExternalSstFileIngestionJob::AssignLevelAndSeqnoForIngestedFile(
          "Column family enables user-defined timestamps, please make sure the "
          "key range (without timestamp) of external file does not overlap "
          "with key range (without timestamp) in the db");
+      return status;
    }
    if (*assigned_seqno == 0) {
      *assigned_seqno = last_seqno + 1;
    }
  }
+
+  if (ingestion_options_.allow_db_generated_files && *assigned_seqno != 0) {
+    return Status::InvalidArgument(
+        "An ingested file is assigned to a non-zero sequence number, which is "
+        "incompatible with ingestion option allow_db_generated_files.");
+  }
  return status;
 }

@@ -66,7 +66,7 @@ class ExternalSSTFileTestBase : public DBTestBase {

 class ExternSSTFileLinkFailFallbackTest
    : public ExternalSSTFileTestBase,
-      public ::testing::WithParamInterface<std::tuple<bool, bool>> {
+      public ::testing::WithParamInterface<std::tuple<bool, bool, bool>> {
 public:
  ExternSSTFileLinkFailFallbackTest() {
    fs_ = std::make_shared<ExternalSSTTestFS>(env_->GetFileSystem(), true);
@@ -674,10 +674,8 @@ class SstFileWriterCollector : public TablePropertiesCollector {

  Status Finish(UserCollectedProperties* properties) override {
    std::string count = std::to_string(count_);
-    *properties = UserCollectedProperties{
-        {prefix_ + "_SstFileWriterCollector", "YES"},
-        {prefix_ + "_Count", count},
-    };
+    properties->insert({prefix_ + "_SstFileWriterCollector", "YES"});
+    properties->insert({prefix_ + "_Count", count});
    return Status::OK();
  }

@@ -2212,7 +2210,8 @@ TEST_P(ExternSSTFileLinkFailFallbackTest, LinkFailFallBackExternalSst) {
  DestroyAndReopen(options_);
  const int kNumKeys = 10000;
  IngestExternalFileOptions ifo;
-  ifo.move_files = true;
+  ifo.move_files = std::get<2>(GetParam());
+  ifo.link_files = !ifo.move_files;
  ifo.failed_move_fall_back_to_copy = failed_move_fall_back_to_copy;

  std::string file_path = sst_files_dir_ + "file1.sst";
@@ -2253,6 +2252,13 @@ TEST_P(ExternSSTFileLinkFailFallbackTest, LinkFailFallBackExternalSst) {
    ASSERT_EQ(0, bytes_copied);
    ASSERT_EQ(file_size, bytes_moved);
    ASSERT_FALSE(copyfile);
+
+    Status es = env_->FileExists(file_path);
+    if (ifo.move_files) {
+      ASSERT_TRUE(es.IsNotFound());
+    } else {
+      ASSERT_OK(es);
+    }
  } else {
    // Link operation fails.
    ASSERT_EQ(0, bytes_moved);
@@ -2271,6 +2277,11 @@ TEST_P(ExternSSTFileLinkFailFallbackTest, LinkFailFallBackExternalSst) {
  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }

+INSTANTIATE_TEST_CASE_P(ExternSSTFileLinkFailFallbackTest,
+                        ExternSSTFileLinkFailFallbackTest,
+                        testing::Combine(testing::Bool(), testing::Bool(),
+                                         testing::Bool()));
+
 class TestIngestExternalFileListener : public EventListener {
 public:
  void OnExternalFileIngested(DB* /*db*/,
@@ -3719,17 +3730,343 @@ TEST_F(ExternalSSTFileWithTimestampTest, TimestampsNotPersistedBasic) {
 }

 INSTANTIATE_TEST_CASE_P(ExternalSSTFileTest, ExternalSSTFileTest,
-                        testing::Values(std::make_tuple(false, false),
-                                        std::make_tuple(false, true),
-                                        std::make_tuple(true, false),
-                                        std::make_tuple(true, true)));
+                        testing::Combine(testing::Bool(), testing::Bool()));

-INSTANTIATE_TEST_CASE_P(ExternSSTFileLinkFailFallbackTest,
-                        ExternSSTFileLinkFailFallbackTest,
-                        testing::Values(std::make_tuple(true, false),
-                                        std::make_tuple(true, true),
-                                        std::make_tuple(false, false)));
+class IngestDBGeneratedFileTest
+    : public ExternalSSTFileTestBase,
+      public ::testing::WithParamInterface<std::tuple<bool, bool>> {
+ public:
+  IngestDBGeneratedFileTest() {
+    ingest_opts.allow_db_generated_files = true;
+    ingest_opts.link_files = std::get<0>(GetParam());
+    ingest_opts.verify_checksums_before_ingest = std::get<1>(GetParam());
+    ingest_opts.snapshot_consistency = false;
+  }

+ protected:
+  IngestExternalFileOptions ingest_opts;
+};
+
+INSTANTIATE_TEST_CASE_P(BasicMultiConfig, IngestDBGeneratedFileTest,
+                        testing::Combine(testing::Bool(), testing::Bool()));
+
+TEST_P(IngestDBGeneratedFileTest, FailureCase) {
+  if (encrypted_env_ && ingest_opts.link_files) {
+    // FIXME: should fail ingestion or support this combination.
+    ROCKSDB_GTEST_SKIP(
+        "Encrypted env and link_files do not work together, as we reopen the "
+        "file after linking it which appends an extra encryption prefix.");
+    return;
+  }
+  // Ingesting overlapping data should always fail.
+  do {
+    SCOPED_TRACE("option_config_ = " + std::to_string(option_config_));
+
+    Options options = CurrentOptions();
+    CreateAndReopenWithCF({"toto"}, options);
+    // Fill CFs with overlapping keys. Will try to ingest CF1 into default CF.
+    for (int k = 0; k < 50; ++k) {
+      ASSERT_OK(Put(Key(k), "default_cf_" + Key(k)));
+    }
+    for (int k = 49; k < 100; ++k) {
+      ASSERT_OK(Put(1, Key(k), "cf1_" + Key(k)));
+    }
+    ASSERT_OK(Flush(/*cf=*/1));
+    {
+      // Verify that largest key of the file has non-zero seqno.
+      std::vector<std::vector<FileMetaData>> metadata;
+      dbfull()->TEST_GetFilesMetaData(handles_[1], &metadata, nullptr);
+      const FileMetaData& file = metadata[0][0];
+      ValueType vtype;
+      SequenceNumber seq;
+      UnPackSequenceAndType(ExtractInternalKeyFooter(file.largest.Encode()),
+                            &seq, &vtype);
+      ASSERT_GE(seq, 0);
+    }
+    std::vector<LiveFileMetaData> live_meta;
+    db_->GetLiveFilesMetaData(&live_meta);
+    ASSERT_EQ(live_meta.size(), 1);
+    std::vector<std::string> to_ingest_files;
+    to_ingest_files.emplace_back(live_meta[0].directory + "/" +
+                                 live_meta[0].relative_filename);
+    // Ingesting a file whose boundary key has non-zero seqno.
+    Status s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+    // This error msg is from checking seqno of boundary keys.
+    ASSERT_TRUE(
+        s.ToString().find("External file has non zero sequence number") !=
+        std::string::npos);
+    ASSERT_NOK(s);
+
+    {
+      // Only non-boundary key with non-zero seqno.
+      const Snapshot* snapshot = db_->GetSnapshot();
+      ASSERT_OK(Put(1, Key(70), "cf1_" + Key(70)));
+      ASSERT_OK(Flush(1));
+      CompactRangeOptions cro;
+      cro.bottommost_level_compaction =
+          BottommostLevelCompaction::kForceOptimized;
+      ASSERT_OK(db_->CompactRange(cro, handles_[1], nullptr, nullptr));
+
+      // Verify that only the non-boundary key of the file has non-zero seqno.
+      std::vector<std::vector<FileMetaData>> metadata;
+      // File may be at different level for different options.
+      dbfull()->TEST_GetFilesMetaData(handles_[1], &metadata, nullptr);
+      bool found_file = false;
+      for (const auto& level : metadata) {
+        if (level.empty()) {
+          continue;
+        }
+        ASSERT_FALSE(found_file);
+        found_file = true;
+        ASSERT_EQ(1, level.size());
+        const FileMetaData& file = level[0];
+        ValueType vtype;
+        SequenceNumber seq;
+        UnPackSequenceAndType(ExtractInternalKeyFooter(file.largest.Encode()),
+                              &seq, &vtype);
+        ASSERT_EQ(seq, 0);
+        UnPackSequenceAndType(ExtractInternalKeyFooter(file.smallest.Encode()),
+                              &seq, &vtype);
+        ASSERT_EQ(seq, 0);
+        ASSERT_GT(file.fd.largest_seqno, 0);
+      }
+      ASSERT_TRUE(found_file);
+      live_meta.clear();
+      db_->GetLiveFilesMetaData(&live_meta);
+      ASSERT_EQ(live_meta.size(), 1);
+      to_ingest_files[0] =
+          live_meta[0].directory + "/" + live_meta[0].relative_filename;
+      s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+      ASSERT_NOK(s);
+      // This error msg is from checking largest seqno in table property.
+      ASSERT_TRUE(s.ToString().find("non zero largest sequence number") !=
+                  std::string::npos);
+      db_->ReleaseSnapshot(snapshot);
+    }
+
+    CompactRangeOptions cro;
+    cro.bottommost_level_compaction =
+        BottommostLevelCompaction::kForceOptimized;
+    ASSERT_OK(db_->CompactRange(cro, handles_[1], nullptr, nullptr));
+    live_meta.clear();
+    db_->GetLiveFilesMetaData(&live_meta);
+    ASSERT_EQ(live_meta.size(), 1);
+    ASSERT_EQ(0, live_meta[0].largest_seqno);
+    to_ingest_files[0] =
+        live_meta[0].directory + "/" + live_meta[0].relative_filename;
+
+    ingest_opts.allow_db_generated_files = false;
+    // Ingesting a DB genrate file with allow_db_generated_files = false;
+    s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+    ASSERT_TRUE(s.ToString().find("External file version not found") !=
+                std::string::npos);
+    ASSERT_NOK(s);
+
+    const std::string err =
+        "An ingested file is assigned to a non-zero sequence number, which is "
+        "incompatible with ingestion option allow_db_generated_files";
+    ingest_opts.allow_db_generated_files = true;
+    s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+    ASSERT_TRUE(s.ToString().find(err) != std::string::npos);
+    ASSERT_NOK(s);
+    if (options.compaction_style != kCompactionStyleUniversal) {
+      // FIXME: after fixing ingestion with universal compaction, currently
+      //  will always ingest into L0.
+      ingest_opts.fail_if_not_bottommost_level = true;
+      s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+      ASSERT_NOK(s);
+      ASSERT_TRUE(s.ToString().find("Files cannot be ingested to Lmax") !=
+                  std::string::npos);
+      ingest_opts.fail_if_not_bottommost_level = false;
+    }
+    ingest_opts.write_global_seqno = true;
+    s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+    ASSERT_TRUE(s.ToString().find("write_global_seqno is deprecated and does "
+                                  "not work with allow_db_generated_files") !=
+                std::string::npos);
+    ASSERT_NOK(s);
+    ingest_opts.write_global_seqno = false;
+
+    // Delete the overlapping key.
+    ASSERT_OK(db_->Delete(WriteOptions(), handles_[1], Key(49)));
+    ASSERT_OK(db_->CompactRange(cro, handles_[1], nullptr, nullptr));
+    live_meta.clear();
+    db_->GetLiveFilesMetaData(&live_meta);
+    bool cf1_file_found = false;
+    for (const auto& f : live_meta) {
+      if (f.column_family_name == "toto") {
+        ASSERT_FALSE(cf1_file_found);
+        cf1_file_found = true;
+        ASSERT_EQ(0, f.largest_seqno);
+        to_ingest_files[0] = f.directory + "/" + f.relative_filename;
+      }
+    }
+    ASSERT_TRUE(cf1_file_found);
+
+    const Snapshot* snapshot = db_->GetSnapshot();
+    ingest_opts.snapshot_consistency = true;
+    s = db_->IngestExternalFile(to_ingest_files, ingest_opts);
+    // snapshot_consistency with snapshot will assign a newest sequence number.
+    ASSERT_TRUE(s.ToString().find(err) != std::string::npos);
+    ASSERT_NOK(s);
+
+    ingest_opts.snapshot_consistency = false;
+    ASSERT_OK(db_->IngestExternalFile(to_ingest_files, ingest_opts));
+    db_->ReleaseSnapshot(snapshot);
+
+    // Verify default CF content.
+    std::string val;
+    for (int k = 0; k < 100; ++k) {
+      ASSERT_OK(db_->Get(ReadOptions(), Key(k), &val));
+      if (k < 50) {
+        ASSERT_EQ(val, "default_cf_" + Key(k));
+      } else {
+        ASSERT_EQ(val, "cf1_" + Key(k));
+      }
+    }
+  } while (ChangeOptions(kSkipPlainTable | kSkipFIFOCompaction));
+}
+
+class IngestDBGeneratedFileTest2
+    : public ExternalSSTFileTestBase,
+      public ::testing::WithParamInterface<
+          std::tuple<bool, bool, bool, bool, bool>> {
+ public:
+  IngestDBGeneratedFileTest2() = default;
+};
+
+INSTANTIATE_TEST_CASE_P(VaryingOptions, IngestDBGeneratedFileTest2,
+                        testing::Combine(testing::Bool(), testing::Bool(),
+                                         testing::Bool(), testing::Bool(),
+                                         testing::Bool()));
+
+TEST_P(IngestDBGeneratedFileTest2, NotOverlapWithDB) {
+  // Use a separate column family to sort some data, generate multiple SST
+  // files. Then ingest these files into another column family or DB. The data
+  // to be ingested does not overlap with existing data.
+  IngestExternalFileOptions ingest_opts;
+  ingest_opts.allow_db_generated_files = true;
+  ingest_opts.snapshot_consistency = std::get<0>(GetParam());
+  ingest_opts.allow_global_seqno = std::get<1>(GetParam());
+  ingest_opts.allow_blocking_flush = std::get<2>(GetParam());
+  ingest_opts.fail_if_not_bottommost_level = std::get<3>(GetParam());
+  ingest_opts.link_files = std::get<4>(GetParam());
+
+  do {
+    SCOPED_TRACE("option_config_ = " + std::to_string(option_config_));
+    Options options = CurrentOptions();
+    // vector memtable for temp CF does not support concurrent write
+    options.allow_concurrent_memtable_write = false;
+    CreateAndReopenWithCF({"toto"}, options);
+
+    // non-empty bottommost level
+    WriteOptions wo;
+    for (int k = 0; k < 50; ++k) {
+      ASSERT_OK(db_->Put(wo, handles_[1], Key(k), "base_val_" + Key(k)));
+    }
+    ASSERT_OK(Flush());
+    CompactRangeOptions cro;
+    cro.bottommost_level_compaction =
+        BottommostLevelCompaction::kForceOptimized;
+    ASSERT_OK(db_->CompactRange(cro, handles_[1], nullptr, nullptr));
+    // non-empty memtable
+    for (int k = 50; k < 100; ++k) {
+      ASSERT_OK(db_->Put(wo, handles_[1], Key(k), "base_val_" + Key(k)));
+    }
+
+    // load external data to sort, generate multiple files
+    Options temp_cf_opts;
+    ColumnFamilyHandle* temp_cfh;
+    temp_cf_opts.target_file_size_base = 4 << 10;
+    temp_cf_opts.memtable_factory.reset(new VectorRepFactory());
+    temp_cf_opts.allow_concurrent_memtable_write = false;
+    temp_cf_opts.compaction_style = kCompactionStyleUniversal;
+    ASSERT_OK(db_->CreateColumnFamily(temp_cf_opts, "temp_cf", &temp_cfh));
+
+    Random rnd(301);
+    std::vector<std::string> expected_value;
+    expected_value.resize(100);
+    // Out of order insertion of keys from 100 to 199.
+    for (int k = 99; k >= 0; --k) {
+      expected_value[k] = rnd.RandomString(200);
+      ASSERT_OK(db_->Put(wo, temp_cfh, Key(k + 100), expected_value[k]));
+    }
+    ASSERT_OK(db_->CompactRange(cro, temp_cfh, nullptr, nullptr));
+    std::vector<std::string> sst_file_paths;
+    ColumnFamilyMetaData cf_meta;
+    db_->GetColumnFamilyMetaData(temp_cfh, &cf_meta);
+    ASSERT_GT(cf_meta.file_count, 1);
+    for (const auto& level_meta : cf_meta.levels) {
+      if (level_meta.level + 1 < temp_cf_opts.num_levels) {
+        ASSERT_EQ(0, level_meta.files.size());
+      } else {
+        ASSERT_GT(level_meta.files.size(), 1);
+        for (const auto& meta : level_meta.files) {
+          ASSERT_EQ(0, meta.largest_seqno);
+          sst_file_paths.emplace_back(meta.directory + "/" +
+                                      meta.relative_filename);
+        }
+      }
+    }
+
+    ASSERT_OK(
+        db_->IngestExternalFile(handles_[1], sst_file_paths, ingest_opts));
+    // Verify state of the CF1
+    ReadOptions ro;
+    std::string val;
+    for (int k = 0; k < 100; ++k) {
+      ASSERT_OK(db_->Get(ro, handles_[1], Key(k), &val));
+      ASSERT_EQ(val, "base_val_" + Key(k));
+      ASSERT_OK(db_->Get(ro, handles_[1], Key(100 + k), &val));
+      ASSERT_EQ(val, expected_value[k]);
+    }
+
+    // Ingest into another DB.
+    if (!encrypted_env_) {
+      // Ingestion between encrypted env and non-encrypted env won't work.
+      std::string db2_path = test::PerThreadDBPath("DB2");
+      Options db2_options;
+      db2_options.create_if_missing = true;
+      DB* db2 = nullptr;
+      ASSERT_OK(DB::Open(db2_options, db2_path, &db2));
+      // Write some base data.
+      expected_value.emplace_back(rnd.RandomString(100));
+      ASSERT_OK(db2->Put(WriteOptions(), Key(200), expected_value.back()));
+      ASSERT_OK(db2->CompactRange(cro, nullptr, nullptr));
+      expected_value.emplace_back(rnd.RandomString(100));
+      ASSERT_OK(db2->Put(WriteOptions(), Key(201), expected_value.back()));
+
+      ASSERT_OK(db2->IngestExternalFile({sst_file_paths}, ingest_opts));
+      {
+        std::unique_ptr<Iterator> iter{db2->NewIterator(ReadOptions())};
+        iter->SeekToFirst();
+        // The DB should have keys 100-199 from ingested files, and keys 200 and
+        // 201 from itself.
+        for (int k = 100; k <= 201; ++k, iter->Next()) {
+          ASSERT_TRUE(iter->Valid());
+          ASSERT_EQ(iter->key(), Key(k));
+          ASSERT_EQ(iter->value(), expected_value[k - 100]);
+        }
+        ASSERT_FALSE(iter->Valid());
+        ASSERT_OK(iter->status());
+      }
+
+      // Dropping the original CF should not affect db2, reopening it should not
+      // miss SST files.
+      ASSERT_OK(db_->DropColumnFamily(temp_cfh));
+      ASSERT_OK(db_->DestroyColumnFamilyHandle(temp_cfh));
+      ASSERT_OK(db2->Close());
+      delete db2;
+      ASSERT_OK(DB::Open(db2_options, db2_path, &db2));
+      ASSERT_OK(db2->Close());
+      delete db2;
+      ASSERT_OK(DestroyDB(db2_path, db2_options));
+    } else {
+      ASSERT_OK(db_->DropColumnFamily(temp_cfh));
+      ASSERT_OK(db_->DestroyColumnFamilyHandle(temp_cfh));
+    }
+  } while (ChangeOptions(kSkipPlainTable | kSkipFIFOCompaction));
+}
 }  // namespace ROCKSDB_NAMESPACE

 int main(int argc, char** argv) {
@@ -567,34 +567,44 @@ class FaultInjectionDBTest : public DBTestBase {
 TEST(FaultInjectionFSTest, ReadUnsyncedData) {
  std::shared_ptr<FaultInjectionTestFS> fault_fs =
      std::make_shared<FaultInjectionTestFS>(FileSystem::Default());
+  fault_fs->SetInjectUnsyncedDataLoss(true);
  ASSERT_TRUE(fault_fs->ReadUnsyncedData());
+  ASSERT_TRUE(fault_fs->InjectUnsyncedDataLoss());

-  uint32_t len = Random::GetTLSInstance()->Uniform(10000) + 1;
-  Random rnd(len);
+  // This is a randomized mini-stress test, to reduce the chances of bugs in
+  // FaultInjectionTestFS being caught only in db_stress, where they are
+  // difficult to debug. ~1000 iterations might be needed to debug relevant
+  // code changes. Limiting to 10 for each regular unit test run.
+  auto seed = Random::GetTLSInstance()->Next();
+  for (int i = 0; i < 10; i++, seed++) {
+    Random rnd(seed);
+    uint32_t len = rnd.Uniform(10000) + 1;

-  // Create partially synced file
-  std::string f = test::PerThreadDBPath("read_unsynced.data");
-  std::string data = rnd.RandomString(len);
-  {
+    std::string f =
+        test::PerThreadDBPath("read_unsynced." + std::to_string(seed));
+    std::string data = rnd.RandomString(len);
+
+    // Create partially synced file
    std::unique_ptr<FSWritableFile> w;
    ASSERT_OK(fault_fs->NewWritableFile(f, {}, &w, nullptr));
    uint32_t synced_len = rnd.Uniform(len + 1);
    ASSERT_OK(w->Append(Slice(data.data(), synced_len), {}, nullptr));
-    ASSERT_OK(w->Sync({}, nullptr));
+    if (synced_len > 0) {
+      ASSERT_OK(w->Sync({}, nullptr));
+    }
    ASSERT_OK(w->Append(Slice(data.data() + synced_len, len - synced_len), {},
                        nullptr));
-    // no sync here
-    ASSERT_OK(w->Close({}, nullptr));
-  }
-  // Test file size includes unsynced data
-  {
-    uint64_t file_size;
-    ASSERT_OK(fault_fs->GetFileSize(f, {}, &file_size, nullptr));
-    ASSERT_EQ(len, file_size);
-  }
-  // Test read file contents, with two reads that probably don't
-  // align with the unsynced split.
-  {
+
+    // Test file size includes unsynced data
+    {
+      uint64_t file_size;
+      ASSERT_OK(fault_fs->GetFileSize(f, {}, &file_size, nullptr));
+      ASSERT_EQ(len, file_size);
+    }
+
+    // Test read file contents, with two reads that probably don't
+    // align with the unsynced split. And maybe a sync or write between
+    // the two reads.
    std::unique_ptr<FSSequentialFile> r;
    ASSERT_OK(fault_fs->NewSequentialFile(f, {}, &r, nullptr));
    uint32_t first_read_len = rnd.Uniform(len + 1);
@@ -603,12 +613,36 @@ TEST(FaultInjectionFSTest, ReadUnsyncedData) {
    ASSERT_OK(r->Read(first_read_len, {}, &sl, scratch.get(), nullptr));
    ASSERT_EQ(first_read_len, sl.size());
    ASSERT_EQ(0, sl.compare(Slice(data.data(), first_read_len)));
-    uint32_t second_read_len = len - first_read_len;
+
+    // Maybe a sync and/or write and/or close between the two reads.
+    if (rnd.OneIn(2)) {
+      ASSERT_OK(w->Sync({}, nullptr));
+    }
+    if (rnd.OneIn(2)) {
+      uint32_t more_len = rnd.Uniform(1000) + 1;
+      std::string more_data = rnd.RandomString(more_len);
+      ASSERT_OK(w->Append(more_data, {}, nullptr));
+      data += more_data;
+      len += more_len;
+    }
+    if (rnd.OneIn(2)) {
+      ASSERT_OK(w->Sync({}, nullptr));
+    }
+    if (rnd.OneIn(2)) {
+      ASSERT_OK(w->Close({}, nullptr));
+      w.reset();
+    }
+
+    // Second read some of, all of, or more than rest of file
+    uint32_t second_read_len = rnd.Uniform(len + 1);
    scratch.reset(new char[second_read_len]);
    ASSERT_OK(r->Read(second_read_len, {}, &sl, scratch.get(), nullptr));
-    ASSERT_EQ(second_read_len, sl.size());
-    ASSERT_EQ(0,
-              sl.compare(Slice(data.data() + first_read_len, second_read_len)));
+    if (len - first_read_len < second_read_len) {
+      ASSERT_EQ(len - first_read_len, sl.size());
+    } else {
+      ASSERT_EQ(second_read_len, sl.size());
+    }
+    ASSERT_EQ(0, sl.compare(Slice(data.data() + first_read_len, sl.size())));
  }
 }
 }  // namespace ROCKSDB_NAMESPACE
@@ -235,7 +235,7 @@ Status FlushJob::Run(LogsWithPrepTracker* prep_tracker, FileMetaData* file_meta,

  AutoThreadOperationStageUpdater stage_run(ThreadStatus::STAGE_FLUSH_RUN);
  if (mems_.empty()) {
-    ROCKS_LOG_BUFFER(log_buffer_, "[%s] Nothing in memtable to flush",
+    ROCKS_LOG_BUFFER(log_buffer_, "[%s] No memtable to flush",
                     cfd_->GetName().c_str());
    return Status::OK();
  }
@@ -421,8 +421,8 @@ Status FlushJob::MemPurge() {
  std::vector<std::unique_ptr<FragmentedRangeTombstoneIterator>>
      range_del_iters;
  for (MemTable* m : mems_) {
-    memtables.push_back(
-        m->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr, &arena));
+    memtables.push_back(m->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr,
+                                       &arena, /*prefix_extractor=*/nullptr));
    auto* range_del_iter = m->NewRangeTombstoneIterator(
        ro, kMaxSequenceNumber, true /* immutable_memtable */);
    if (range_del_iter != nullptr) {
@@ -630,7 +630,7 @@ Status FlushJob::MemPurge() {
        new_mem->SetNextLogNumber(mems_[0]->GetNextLogNumber());

        // This addition will not trigger another flush, because
-        // we do not call SchedulePendingFlush().
+        // we do not call EnqueuePendingFlush().
        cfd_->imm()->Add(new_mem, &job_context_->memtables_to_free);
        new_mem->Ref();
        // Piggyback FlushJobInfo on the first flushed memtable.
@@ -861,7 +861,7 @@ Status FlushJob::WriteLevel0Table() {
  std::vector<BlobFileAddition> blob_file_additions;

  {
-    auto write_hint = cfd_->CalculateSSTWriteHint(0);
+    auto write_hint = base_->storage_info()->CalculateSSTWriteHint(/*level=*/0);
    Env::IOPriority io_priority = GetRateLimiterPriority();
    db_mutex_->Unlock();
    if (log_buffer_) {
@@ -893,8 +893,8 @@ Status FlushJob::WriteLevel0Table() {
          db_options_.info_log,
          "[%s] [JOB %d] Flushing memtable with next log file: %" PRIu64 "\n",
          cfd_->GetName().c_str(), job_context_->job_id, m->GetNextLogNumber());
-      memtables.push_back(
-          m->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr, &arena));
+      memtables.push_back(m->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr,
+                                         &arena, /*prefix_extractor=*/nullptr));
      auto* range_del_iter = m->NewRangeTombstoneIterator(
          ro, kMaxSequenceNumber, true /* immutable_memtable */);
      if (range_del_iter != nullptr) {
@@ -1017,10 +1017,15 @@ Status FlushJob::WriteLevel0Table() {
    ROCKS_LOG_BUFFER(log_buffer_,
                     "[%s] [JOB %d] Level-0 flush table #%" PRIu64 ": %" PRIu64
                     " bytes %s"
-                     "%s",
+                     " %s"
+                     " %s",
                     cfd_->GetName().c_str(), job_context_->job_id,
                     meta_.fd.GetNumber(), meta_.fd.GetFileSize(),
                     s.ToString().c_str(),
+                     s.ok() && meta_.fd.GetFileSize() == 0
+                         ? "It's an empty SST file from a successful flush so "
+                           "won't be kept in the DB"
+                         : "",
                     meta_.marked_for_compaction ? " (needs compaction)" : "");

    if (s.ok() && output_file_directory_ != nullptr && sync_output_directory_) {
@@ -1151,6 +1156,11 @@ void FlushJob::GetEffectiveCutoffUDTForPickedMemTables() {
  // Find the newest user-defined timestamps from all the flushed memtables.
  for (MemTable* m : mems_) {
    Slice table_newest_udt = m->GetNewestUDT();
+    // Empty memtables can be legitimately created and flushed, for example
+    // by error recovery flush attempts.
+    if (table_newest_udt.empty()) {
+      continue;
+    }
    if (cutoff_udt_.empty() ||
        ucmp->CompareTimestamp(table_newest_udt, cutoff_udt_) > 0) {
      if (!cutoff_udt_.empty()) {
@@ -68,7 +68,8 @@ class FlushJobTestBase : public testing::Test {
  }

  void NewDB() {
-    ASSERT_OK(SetIdentityFile(WriteOptions(), env_, dbname_));
+    ASSERT_OK(
+        SetIdentityFile(WriteOptions(), env_, dbname_, Temperature::kUnknown));
    VersionEdit new_db;

    new_db.SetLogNumber(0);
@@ -114,7 +115,8 @@ class FlushJobTestBase : public testing::Test {
    }
    ASSERT_OK(s);
    // Make "CURRENT" file that points to the new manifest file.
-    s = SetCurrentFile(WriteOptions(), fs_.get(), dbname_, 1, nullptr);
+    s = SetCurrentFile(WriteOptions(), fs_.get(), dbname_, 1,
+                       Temperature::kUnknown, nullptr);
    ASSERT_OK(s);
  }

@@ -140,12 +142,13 @@ class FlushJobTestBase : public testing::Test {
      column_families.emplace_back(cf_name, cf_options_);
    }

-    versions_.reset(new VersionSet(
-        dbname_, &db_options_, env_options_, table_cache_.get(),
-        &write_buffer_manager_, &write_controller_,
-        /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr,
-        /*db_id=*/"", /*db_session_id=*/"", /*daily_offpeak_time_utc=*/"",
-        /*error_handler=*/nullptr, /*read_only=*/false));
+    versions_.reset(
+        new VersionSet(dbname_, &db_options_, env_options_, table_cache_.get(),
+                       &write_buffer_manager_, &write_controller_,
+                       /*block_cache_tracer=*/nullptr, /*io_tracer=*/nullptr,
+                       test::kUnitTestDbId, /*db_session_id=*/"",
+                       /*daily_offpeak_time_utc=*/"",
+                       /*error_handler=*/nullptr, /*read_only=*/false));
    EXPECT_OK(versions_->Recover(column_families, false));
  }

@@ -167,6 +167,10 @@ class ForwardLevelIterator : public InternalIterator {
    assert(valid_);
    return file_iter_->value();
  }
+  uint64_t write_unix_time() const override {
+    assert(valid_);
+    return file_iter_->write_unix_time();
+  }
  Status status() const override {
    if (!status_.ok()) {
      return status_;
@@ -712,9 +716,11 @@ void ForwardIterator::RebuildIterators(bool refresh_sv) {
  UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping =
      sv_->GetSeqnoToTimeMapping();
  mutable_iter_ =
-      sv_->mem->NewIterator(read_options_, seqno_to_time_mapping, &arena_);
-  sv_->imm->AddIterators(read_options_, seqno_to_time_mapping, &imm_iters_,
-                         &arena_);
+      sv_->mem->NewIterator(read_options_, seqno_to_time_mapping, &arena_,
+                            sv_->mutable_cf_options.prefix_extractor.get());
+  sv_->imm->AddIterators(read_options_, seqno_to_time_mapping,
+                         sv_->mutable_cf_options.prefix_extractor.get(),
+                         &imm_iters_, &arena_);
  if (!read_options_.ignore_range_deletions) {
    std::unique_ptr<FragmentedRangeTombstoneIterator> range_del_iter(
        sv_->mem->NewRangeTombstoneIterator(
@@ -781,9 +787,11 @@ void ForwardIterator::RenewIterators() {
  UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping =
      svnew->GetSeqnoToTimeMapping();
  mutable_iter_ =
-      svnew->mem->NewIterator(read_options_, seqno_to_time_mapping, &arena_);
-  svnew->imm->AddIterators(read_options_, seqno_to_time_mapping, &imm_iters_,
-                           &arena_);
+      svnew->mem->NewIterator(read_options_, seqno_to_time_mapping, &arena_,
+                              svnew->mutable_cf_options.prefix_extractor.get());
+  svnew->imm->AddIterators(read_options_, seqno_to_time_mapping,
+                           svnew->mutable_cf_options.prefix_extractor.get(),
+                           &imm_iters_, &arena_);
  ReadRangeDelAggregator range_del_agg(&cfd_->internal_comparator(),
                                       kMaxSequenceNumber /* upper_bound */);
  if (!read_options_.ignore_range_deletions) {
@@ -202,6 +202,10 @@ struct JobContext {
  // that corresponds to the set of files in 'live'.
  uint64_t manifest_file_number;
  uint64_t pending_manifest_file_number;
+
+  // Used for remote compaction. To prevent OPTIONS files from getting
+  // purged by PurgeObsoleteFiles() of the primary host
+  uint64_t min_options_file_number;
  uint64_t log_number;
  uint64_t prev_log_number;

@@ -354,13 +354,13 @@ TEST_F(EventListenerTest, OnSingleDBFlushTest) {
 }

 TEST_F(EventListenerTest, MultiCF) {
-  Options options;
-  options.env = CurrentOptions().env;
-  options.write_buffer_size = k110KB;
-#ifdef ROCKSDB_USING_THREAD_STATUS
-  options.enable_thread_tracking = true;
-#endif  // ROCKSDB_USING_THREAD_STATUS
  for (auto atomic_flush : {false, true}) {
+    Options options;
+    options.env = CurrentOptions().env;
+    options.write_buffer_size = k110KB;
+#ifdef ROCKSDB_USING_THREAD_STATUS
+    options.enable_thread_tracking = true;
+#endif  // ROCKSDB_USING_THREAD_STATUS
    options.atomic_flush = atomic_flush;
    options.create_if_missing = true;
    DestroyAndReopen(options);
@@ -55,7 +55,10 @@ IOStatus Writer::WriteBuffer(const WriteOptions& write_options) {
  if (dest_->seen_error()) {
 #ifndef NDEBUG
    if (dest_->seen_injected_error()) {
-      return IOStatus::IOError("Seen injected error. Skip writing buffer.");
+      std::stringstream msg;
+      msg << "Seen " << FaultInjectionTestFS::kInjected
+          << " error. Skip writing buffer.";
+      return IOStatus::IOError(msg.str());
    }
 #endif  // NDEBUG
    return IOStatus::IOError("Seen error. Skip writing buffer.");
@@ -93,7 +96,10 @@ IOStatus Writer::AddRecord(const WriteOptions& write_options,
  if (dest_->seen_error()) {
 #ifndef NDEBUG
    if (dest_->seen_injected_error()) {
-      return IOStatus::IOError("Seen injected error. Skip writing buffer.");
+      std::stringstream msg;
+      msg << "Seen " << FaultInjectionTestFS::kInjected
+          << " error. Skip writing buffer.";
+      return IOStatus::IOError(msg.str());
    }
 #endif  // NDEBUG
    return IOStatus::IOError("Seen error. Skip writing buffer.");
@@ -205,7 +211,10 @@ IOStatus Writer::AddCompressionTypeRecord(const WriteOptions& write_options) {
  if (dest_->seen_error()) {
 #ifndef NDEBUG
    if (dest_->seen_injected_error()) {
-      return IOStatus::IOError("Seen injected error. Skip writing buffer.");
+      std::stringstream msg;
+      msg << "Seen " << FaultInjectionTestFS::kInjected
+          << " error. Skip writing buffer.";
+      return IOStatus::IOError(msg.str());
    }
 #endif  // NDEBUG
    return IOStatus::IOError("Seen error. Skip writing buffer.");
@@ -67,9 +67,10 @@ ImmutableMemTableOptions::ImmutableMemTableOptions(
      statistics(ioptions.stats),
      merge_operator(ioptions.merge_operator.get()),
      info_log(ioptions.logger),
-      allow_data_in_errors(ioptions.allow_data_in_errors),
      protection_bytes_per_key(
-          mutable_cf_options.memtable_protection_bytes_per_key) {}
+          mutable_cf_options.memtable_protection_bytes_per_key),
+      allow_data_in_errors(ioptions.allow_data_in_errors),
+      paranoid_memory_checks(mutable_cf_options.paranoid_memory_checks) {}

 MemTable::MemTable(const InternalKeyComparator& cmp,
                   const ImmutableOptions& ioptions,
@@ -364,29 +365,41 @@ const char* EncodeKey(std::string* scratch, const Slice& target) {

 class MemTableIterator : public InternalIterator {
 public:
-  MemTableIterator(const MemTable& mem, const ReadOptions& read_options,
-                   UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping,
-                   Arena* arena, bool use_range_del_table = false)
+  enum Kind { kPointEntries, kRangeDelEntries };
+  MemTableIterator(
+      Kind kind, const MemTable& mem, const ReadOptions& read_options,
+      UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping = nullptr,
+      Arena* arena = nullptr,
+      const SliceTransform* cf_prefix_extractor = nullptr)
      : bloom_(nullptr),
        prefix_extractor_(mem.prefix_extractor_),
        comparator_(mem.comparator_),
-        valid_(false),
        seqno_to_time_mapping_(seqno_to_time_mapping),
-        arena_mode_(arena != nullptr),
-        value_pinned_(
-            !mem.GetImmutableMemTableOptions()->inplace_update_support),
-        protection_bytes_per_key_(mem.moptions_.protection_bytes_per_key),
        status_(Status::OK()),
        logger_(mem.moptions_.info_log),
-        ts_sz_(mem.ts_sz_) {
-    if (use_range_del_table) {
+        ts_sz_(mem.ts_sz_),
+        protection_bytes_per_key_(mem.moptions_.protection_bytes_per_key),
+        valid_(false),
+        value_pinned_(
+            !mem.GetImmutableMemTableOptions()->inplace_update_support),
+        arena_mode_(arena != nullptr),
+        paranoid_memory_checks_(mem.moptions_.paranoid_memory_checks),
+        allow_data_in_error(mem.moptions_.allow_data_in_errors) {
+    if (kind == kRangeDelEntries) {
      iter_ = mem.range_del_table_->GetIterator(arena);
-    } else if (prefix_extractor_ != nullptr && !read_options.total_order_seek &&
-               !read_options.auto_prefix_mode) {
+    } else if (prefix_extractor_ != nullptr &&
+               // NOTE: checking extractor equivalence when not pointer
+               // equivalent is arguably too expensive for memtable
+               prefix_extractor_ == cf_prefix_extractor &&
+               (read_options.prefix_same_as_start ||
+                (!read_options.total_order_seek &&
+                 !read_options.auto_prefix_mode))) {
      // Auto prefix mode is not implemented in memtable yet.
+      assert(kind == kPointEntries);
      bloom_ = mem.bloom_filter_.get();
      iter_ = mem.table_->GetDynamicPrefixIterator(arena);
    } else {
+      assert(kind == kPointEntries);
      iter_ = mem.table_->GetIterator(arena);
    }
    status_.PermitUncheckedError();
@@ -406,6 +419,7 @@ class MemTableIterator : public InternalIterator {
    } else {
      delete iter_;
    }
+    status_.PermitUncheckedError();
  }

 #ifndef NDEBUG
@@ -415,16 +429,22 @@ class MemTableIterator : public InternalIterator {
  PinnedIteratorsManager* pinned_iters_mgr_ = nullptr;
 #endif

-  bool Valid() const override { return valid_ && status_.ok(); }
+  bool Valid() const override {
+    // If inner iter_ is not valid, then this iter should also not be valid.
+    assert(iter_->Valid() || !(valid_ && status_.ok()));
+    return valid_ && status_.ok();
+  }
+
  void Seek(const Slice& k) override {
    PERF_TIMER_GUARD(seek_on_memtable_time);
    PERF_COUNTER_ADD(seek_on_memtable_count, 1);
+    status_ = Status::OK();
    if (bloom_) {
      // iterator should only use prefix bloom filter
      Slice user_k_without_ts(ExtractUserKeyAndStripTimestamp(k, ts_sz_));
      if (prefix_extractor_->InDomain(user_k_without_ts)) {
-        if (!bloom_->MayContain(
-                prefix_extractor_->Transform(user_k_without_ts))) {
+        Slice prefix = prefix_extractor_->Transform(user_k_without_ts);
+        if (!bloom_->MayContain(prefix)) {
          PERF_COUNTER_ADD(bloom_memtable_miss_count, 1);
          valid_ = false;
          return;
@@ -433,13 +453,18 @@ class MemTableIterator : public InternalIterator {
        }
      }
    }
-    iter_->Seek(k, nullptr);
+    if (paranoid_memory_checks_) {
+      status_ = iter_->SeekAndValidate(k, nullptr, allow_data_in_error);
+    } else {
+      iter_->Seek(k, nullptr);
+    }
    valid_ = iter_->Valid();
    VerifyEntryChecksum();
  }
  void SeekForPrev(const Slice& k) override {
    PERF_TIMER_GUARD(seek_on_memtable_time);
    PERF_COUNTER_ADD(seek_on_memtable_count, 1);
+    status_ = Status::OK();
    if (bloom_) {
      Slice user_k_without_ts(ExtractUserKeyAndStripTimestamp(k, ts_sz_));
      if (prefix_extractor_->InDomain(user_k_without_ts)) {
@@ -453,7 +478,11 @@ class MemTableIterator : public InternalIterator {
        }
      }
    }
-    iter_->Seek(k, nullptr);
+    if (paranoid_memory_checks_) {
+      status_ = iter_->SeekAndValidate(k, nullptr, allow_data_in_error);
+    } else {
+      iter_->Seek(k, nullptr);
+    }
    valid_ = iter_->Valid();
    VerifyEntryChecksum();
    if (!Valid() && status().ok()) {
@@ -464,11 +493,13 @@ class MemTableIterator : public InternalIterator {
    }
  }
  void SeekToFirst() override {
+    status_ = Status::OK();
    iter_->SeekToFirst();
    valid_ = iter_->Valid();
    VerifyEntryChecksum();
  }
  void SeekToLast() override {
+    status_ = Status::OK();
    iter_->SeekToLast();
    valid_ = iter_->Valid();
    VerifyEntryChecksum();
@@ -476,8 +507,12 @@ class MemTableIterator : public InternalIterator {
  void Next() override {
    PERF_COUNTER_ADD(next_on_memtable_count, 1);
    assert(Valid());
-    iter_->Next();
-    TEST_SYNC_POINT_CALLBACK("MemTableIterator::Next:0", iter_);
+    if (paranoid_memory_checks_) {
+      status_ = iter_->NextAndValidate(allow_data_in_error);
+    } else {
+      iter_->Next();
+      TEST_SYNC_POINT_CALLBACK("MemTableIterator::Next:0", iter_);
+    }
    valid_ = iter_->Valid();
    VerifyEntryChecksum();
  }
@@ -494,7 +529,11 @@ class MemTableIterator : public InternalIterator {
  void Prev() override {
    PERF_COUNTER_ADD(prev_on_memtable_count, 1);
    assert(Valid());
-    iter_->Prev();
+    if (paranoid_memory_checks_) {
+      status_ = iter_->PrevAndValidate(allow_data_in_error);
+    } else {
+      iter_->Prev();
+    }
    valid_ = iter_->Valid();
    VerifyEntryChecksum();
  }
@@ -540,15 +579,17 @@ class MemTableIterator : public InternalIterator {
  const SliceTransform* const prefix_extractor_;
  const MemTable::KeyComparator comparator_;
  MemTableRep::Iterator* iter_;
-  bool valid_;
  // The seqno to time mapping is owned by the SuperVersion.
  UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping_;
-  bool arena_mode_;
-  bool value_pinned_;
-  uint32_t protection_bytes_per_key_;
  Status status_;
  Logger* logger_;
  size_t ts_sz_;
+  uint32_t protection_bytes_per_key_;
+  bool valid_;
+  bool value_pinned_;
+  bool arena_mode_;
+  const bool paranoid_memory_checks_;
+  const bool allow_data_in_error;

  void VerifyEntryChecksum() {
    if (protection_bytes_per_key_ > 0 && Valid()) {
@@ -563,11 +604,13 @@ class MemTableIterator : public InternalIterator {

 InternalIterator* MemTable::NewIterator(
    const ReadOptions& read_options,
-    UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping, Arena* arena) {
+    UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping, Arena* arena,
+    const SliceTransform* prefix_extractor) {
  assert(arena != nullptr);
  auto mem = arena->AllocateAligned(sizeof(MemTableIterator));
  return new (mem)
-      MemTableIterator(*this, read_options, seqno_to_time_mapping, arena);
+      MemTableIterator(MemTableIterator::kPointEntries, *this, read_options,
+                       seqno_to_time_mapping, arena, prefix_extractor);
 }

 FragmentedRangeTombstoneIterator* MemTable::NewRangeTombstoneIterator(
@@ -602,8 +645,7 @@ FragmentedRangeTombstoneIterator* MemTable::NewRangeTombstoneIteratorInternal(
    cache->reader_mutex.lock();
    if (!cache->tombstones) {
      auto* unfragmented_iter = new MemTableIterator(
-          *this, read_options, nullptr /* seqno_to_time_mapping= */,
-          nullptr /* arena */, true /* use_range_del_table */);
+          MemTableIterator::kRangeDelEntries, *this, read_options);
      cache->tombstones.reset(new FragmentedRangeTombstoneList(
          std::unique_ptr<InternalIterator>(unfragmented_iter),
          comparator_.comparator));
@@ -624,8 +666,7 @@ void MemTable::ConstructFragmentedRangeTombstones() {
  if (!is_range_del_table_empty_.load(std::memory_order_relaxed)) {
    // TODO: plumb Env::IOActivity, Env::IOPriority
    auto* unfragmented_iter = new MemTableIterator(
-        *this, ReadOptions(), nullptr /*seqno_to_time_mapping=*/,
-        nullptr /* arena */, true /* use_range_del_table */);
+        MemTableIterator::kRangeDelEntries, *this, ReadOptions());

    fragmented_range_tombstone_list_ =
        std::make_unique<FragmentedRangeTombstoneList>(
@@ -933,6 +974,8 @@ static bool SaveValue(void* arg, const char* entry) {
  Saver* s = static_cast<Saver*>(arg);
  assert(s != nullptr);
  assert(!s->value || !s->columns);
+  assert(!*(s->found_final_value));
+  assert(s->status->ok() || s->status->IsMergeInProgress());

  MergeContext* merge_context = s->merge_context;
  SequenceNumber max_covering_tombstone_seq = s->max_covering_tombstone_seq;
@@ -966,6 +1009,7 @@ static bool SaveValue(void* arg, const char* entry) {
      *(s->status) = MemTable::VerifyEntryChecksum(
          entry, s->protection_bytes_per_key, s->allow_data_in_errors);
      if (!s->status->ok()) {
+        *(s->found_final_value) = true;
        ROCKS_LOG_ERROR(s->logger, "In SaveValue: %s", s->status->getState());
        // Memtable entry corrupted
        return false;
@@ -1231,6 +1275,7 @@ static bool SaveValue(void* arg, const char* entry) {
                     ". ");
          msg.append("seq: " + std::to_string(seq) + ".");
        }
+        *(s->found_final_value) = true;
        *(s->status) = Status::Corruption(msg.c_str());
        return false;
      }
@@ -1310,8 +1355,12 @@ bool MemTable::Get(const LookupKey& key, std::string* value,

  // No change to value, since we have not yet found a Put/Delete
  // Propagate corruption error
-  if (!found_final_value && merge_in_progress && !s->IsCorruption()) {
-    *s = Status::MergeInProgress();
+  if (!found_final_value && merge_in_progress) {
+    if (s->ok()) {
+      *s = Status::MergeInProgress();
+    } else {
+      assert(s->IsMergeInProgress());
+    }
  }
  PERF_COUNTER_ADD(get_from_memtable_count, 1);
  return found_final_value;
@@ -1347,7 +1396,19 @@ void MemTable::GetFromTable(const LookupKey& key,
  saver.do_merge = do_merge;
  saver.allow_data_in_errors = moptions_.allow_data_in_errors;
  saver.protection_bytes_per_key = moptions_.protection_bytes_per_key;
-  table_->Get(key, &saver, SaveValue);
+
+  if (!moptions_.paranoid_memory_checks) {
+    table_->Get(key, &saver, SaveValue);
+  } else {
+    Status check_s = table_->GetAndValidate(key, &saver, SaveValue,
+                                            moptions_.allow_data_in_errors);
+    if (check_s.IsCorruption()) {
+      *(saver.status) = check_s;
+      // Should stop searching the LSM.
+      *(saver.found_final_value) = true;
+    }
+  }
+  assert(s->ok() || s->IsMergeInProgress() || *found_final_value);
  *seq = saver.seq;
 }

@@ -1421,10 +1482,19 @@ void MemTable::MultiGet(const ReadOptions& read_options, MultiGetRange* range,
                 &found_final_value, &merge_in_progress);

    if (!found_final_value && merge_in_progress) {
-      *(iter->s) = Status::MergeInProgress();
+      if (iter->s->ok()) {
+        *(iter->s) = Status::MergeInProgress();
+      } else {
+        assert(iter->s->IsMergeInProgress());
+      }
    }

-    if (found_final_value) {
+    if (found_final_value ||
+        (!iter->s->ok() && !iter->s->IsMergeInProgress())) {
+      // `found_final_value` should be set if an error/corruption occurs.
+      // The check on iter->s is just there in case GetFromTable() did not
+      // set `found_final_value` properly.
+      assert(found_final_value);
      if (iter->value) {
        iter->value->PinSelf();
        range->AddValueSize(iter->value->size());
@@ -60,8 +60,9 @@ struct ImmutableMemTableOptions {
  Statistics* statistics;
  MergeOperator* merge_operator;
  Logger* info_log;
-  bool allow_data_in_errors;
  uint32_t protection_bytes_per_key;
+  bool allow_data_in_errors;
+  bool paranoid_memory_checks;
 };

 // Batched counters to updated when inserting keys in one write batch.
@@ -209,7 +210,8 @@ class MemTable {
  // data, currently only needed for iterators serving user reads.
  InternalIterator* NewIterator(
      const ReadOptions& read_options,
-      UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping, Arena* arena);
+      UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping, Arena* arena,
+      const SliceTransform* prefix_extractor);

  // Returns an iterator that yields the range tombstones of the memtable.
  // The caller must ensure that the underlying MemTable remains live
@@ -249,12 +251,14 @@ class MemTable {
  // If do_merge = true the default behavior which is Get value for key is
  // executed. Expected behavior is described right below.
  // If memtable contains a value for key, store it in *value and return true.
-  // If memtable contains a deletion for key, store a NotFound() error
-  // in *status and return true.
+  // If memtable contains a deletion for key, store NotFound() in *status and
+  // return true.
  // If memtable contains Merge operation as the most recent entry for a key,
  //   and the merge process does not stop (not reaching a value or delete),
  //   prepend the current merge operand to *operands.
  //   store MergeInProgress in s, and return false.
+  // If an unexpected error or corruption occurs, store Corruption() or other
+  // error in *status and return true.
  // Else, return false.
  // If any operation was found, its most recent sequence number
  // will be stored in *seq on success (regardless of whether true/false is
@@ -264,6 +268,11 @@ class MemTable {
  // If do_merge = false then any Merge Operands encountered for key are simply
  // stored in merge_context.operands_list and never actually merged to get a
  // final value. The raw Merge Operands are eventually returned to the user.
+  // @param value If not null and memtable contains a value for key, `value`
+  // will be set to the result value.
+  // @param column If not null and memtable contains a value/WideColumn for key,
+  // `column` will be set to the result value/WideColumn.
+  // Note: only one of `value` and `column` can be non-nullptr.
  // @param immutable_memtable Whether this memtable is immutable. Used
  // internally by NewRangeTombstoneIterator(). See comment above
  // NewRangeTombstoneIterator() for more detail.
@@ -181,7 +181,8 @@ bool MemTableListVersion::GetFromList(
    }

    if (done) {
-      assert(*seq != kMaxSequenceNumber || s->IsNotFound());
+      assert(*seq != kMaxSequenceNumber ||
+             (!s->ok() && !s->IsMergeInProgress()));
      return true;
    }
    if (!s->ok() && !s->IsMergeInProgress() && !s->IsNotFound()) {
@@ -213,20 +214,23 @@ Status MemTableListVersion::AddRangeTombstoneIterators(
 void MemTableListVersion::AddIterators(
    const ReadOptions& options,
    UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping,
+    const SliceTransform* prefix_extractor,
    std::vector<InternalIterator*>* iterator_list, Arena* arena) {
  for (auto& m : memlist_) {
-    iterator_list->push_back(
-        m->NewIterator(options, seqno_to_time_mapping, arena));
+    iterator_list->push_back(m->NewIterator(options, seqno_to_time_mapping,
+                                            arena, prefix_extractor));
  }
 }

 void MemTableListVersion::AddIterators(
    const ReadOptions& options,
    UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping,
+    const SliceTransform* prefix_extractor,
    MergeIteratorBuilder* merge_iter_builder, bool add_range_tombstone_iter) {
  for (auto& m : memlist_) {
-    auto mem_iter = m->NewIterator(options, seqno_to_time_mapping,
-                                   merge_iter_builder->GetArena());
+    auto mem_iter =
+        m->NewIterator(options, seqno_to_time_mapping,
+                       merge_iter_builder->GetArena(), prefix_extractor);
    if (!add_range_tombstone_iter || options.ignore_range_deletions) {
      merge_iter_builder->AddIterator(mem_iter);
    } else {
@@ -235,19 +239,19 @@ void MemTableListVersion::AddIterators(
      SequenceNumber read_seq = options.snapshot != nullptr
                                    ? options.snapshot->GetSequenceNumber()
                                    : kMaxSequenceNumber;
-      TruncatedRangeDelIterator* mem_tombstone_iter = nullptr;
+      std::unique_ptr<TruncatedRangeDelIterator> mem_tombstone_iter;
      auto range_del_iter = m->NewRangeTombstoneIterator(
          options, read_seq, true /* immutale_memtable */);
      if (range_del_iter == nullptr || range_del_iter->empty()) {
        delete range_del_iter;
      } else {
-        mem_tombstone_iter = new TruncatedRangeDelIterator(
+        mem_tombstone_iter = std::make_unique<TruncatedRangeDelIterator>(
            std::unique_ptr<FragmentedRangeTombstoneIterator>(range_del_iter),
            &m->GetInternalKeyComparator(), nullptr /* smallest */,
            nullptr /* largest */);
      }
-      merge_iter_builder->AddPointAndTombstoneIterator(mem_iter,
-                                                       mem_tombstone_iter);
+      merge_iter_builder->AddPointAndTombstoneIterator(
+          mem_iter, std::move(mem_tombstone_iter));
    }
  }
 }
@@ -558,11 +562,12 @@ Status MemTableList::TryInstallMemtableFlushResults(
        batch_file_number = m->file_number_;
        if (m->edit_.GetBlobFileAdditions().empty()) {
          ROCKS_LOG_BUFFER(log_buffer,
-                           "[%s] Level-0 commit table #%" PRIu64 " started",
+                           "[%s] Level-0 commit flush result of table #%" PRIu64
+                           " started",
                           cfd->GetName().c_str(), m->file_number_);
        } else {
          ROCKS_LOG_BUFFER(log_buffer,
-                           "[%s] Level-0 commit table #%" PRIu64
+                           "[%s] Level-0 commit flush result of table #%" PRIu64
                           " (+%zu blob files) started",
                           cfd->GetName().c_str(), m->file_number_,
                           m->edit_.GetBlobFileAdditions().size());
@@ -580,37 +585,28 @@ Status MemTableList::TryInstallMemtableFlushResults(

    // TODO(myabandeh): Not sure how batch_count could be 0 here.
    if (batch_count > 0) {
-      uint64_t min_wal_number_to_keep = 0;
-      assert(edit_list.size() > 0);
-      if (vset->db_options()->allow_2pc) {
-        // Note that if mempurge is successful, the edit_list will
-        // not be applicable (contains info of new min_log number to keep,
-        // and level 0 file path of SST file created during normal flush,
-        // so both pieces of information are irrelevant after a successful
-        // mempurge operation).
-        min_wal_number_to_keep = PrecomputeMinLogNumberToKeep2PC(
-            vset, *cfd, edit_list, memtables_to_flush, prep_tracker);
-
-        // We piggyback the information of earliest log file to keep in the
-        // manifest entry for the last file flushed.
+      VersionEdit edit;
+#ifdef ROCKSDB_ASSERT_STATUS_CHECKED
+      if (memtables_to_flush.size() == memlist.size()) {
+        // TODO(yuzhangyu): remove this testing code once the
+        // `GetEditForDroppingCurrentVersion` API is used by the atomic data
+        // replacement. This function can get the same edits for wal related
+        // fields, and some duplicated fields as contained already in edit_list
+        // for column family's recovery.
+        edit = GetEditForDroppingCurrentVersion(cfd, vset, prep_tracker);
      } else {
-        min_wal_number_to_keep =
-            PrecomputeMinLogNumberToKeepNon2PC(vset, *cfd, edit_list);
+        edit = GetDBRecoveryEditForObsoletingMemTables(
+            vset, *cfd, edit_list, memtables_to_flush, prep_tracker);
      }
-
-      VersionEdit wal_deletion;
-      wal_deletion.SetMinLogNumberToKeep(min_wal_number_to_keep);
-      if (vset->db_options()->track_and_verify_wals_in_manifest) {
-        if (min_wal_number_to_keep >
-            vset->GetWalSet().GetMinWalNumberToKeep()) {
-          wal_deletion.DeleteWalsBefore(min_wal_number_to_keep);
-        }
-        TEST_SYNC_POINT_CALLBACK(
-            "MemTableList::TryInstallMemtableFlushResults:"
-            "AfterComputeMinWalToKeep",
-            nullptr);
-      }
-      edit_list.push_back(&wal_deletion);
+#else
+      edit = GetDBRecoveryEditForObsoletingMemTables(
+          vset, *cfd, edit_list, memtables_to_flush, prep_tracker);
+#endif  // ROCKSDB_ASSERT_STATUS_CHECKED
+      TEST_SYNC_POINT_CALLBACK(
+          "MemTableList::TryInstallMemtableFlushResults:"
+          "AfterComputeMinWalToKeep",
+          nullptr);
+      edit_list.push_back(&edit);

      const auto manifest_write_cb = [this, cfd, batch_count, log_buffer,
                                      to_delete, mu](const Status& status) {
@@ -757,12 +753,12 @@ void MemTableList::RemoveMemTablesOrRestoreFlags(
      MemTable* m = current_->memlist_.back();
      if (m->edit_.GetBlobFileAdditions().empty()) {
        ROCKS_LOG_BUFFER(log_buffer,
-                         "[%s] Level-0 commit table #%" PRIu64
+                         "[%s] Level-0 commit flush result of table #%" PRIu64
                         ": memtable #%" PRIu64 " done",
                         cfd->GetName().c_str(), m->file_number_, mem_id);
      } else {
        ROCKS_LOG_BUFFER(log_buffer,
-                         "[%s] Level-0 commit table #%" PRIu64
+                         "[%s] Level-0 commit flush result of table #%" PRIu64
                         " (+%zu blob files)"
                         ": memtable #%" PRIu64 " done",
                         cfd->GetName().c_str(), m->file_number_,
@@ -1024,4 +1020,38 @@ void MemTableList::RemoveOldMemTables(uint64_t log_number,
  ResetTrimHistoryNeeded();
 }

+VersionEdit MemTableList::GetEditForDroppingCurrentVersion(
+    const ColumnFamilyData* cfd, VersionSet* vset,
+    LogsWithPrepTracker* prep_tracker) const {
+  assert(cfd);
+  auto& memlist = current_->memlist_;
+  if (memlist.empty()) {
+    return VersionEdit();
+  }
+
+  uint64_t max_next_log_number = 0;
+  autovector<VersionEdit*> edit_list;
+  autovector<MemTable*> memtables_to_drop;
+  for (auto it = memlist.rbegin(); it != memlist.rend(); ++it) {
+    MemTable* m = *it;
+    memtables_to_drop.push_back(m);
+    max_next_log_number = std::max(m->GetNextLogNumber(), max_next_log_number);
+  }
+
+  // Check the obsoleted MemTables' impact on WALs related to DB's recovery (min
+  // log number to keep, a delta of WAL files to delete).
+  VersionEdit edit_with_log_number;
+  edit_with_log_number.SetPrevLogNumber(0);
+  edit_with_log_number.SetLogNumber(max_next_log_number);
+  edit_list.push_back(&edit_with_log_number);
+  VersionEdit edit = GetDBRecoveryEditForObsoletingMemTables(
+      vset, *cfd, edit_list, memtables_to_drop, prep_tracker);
+
+  // Set fields related to the column family's recovery.
+  edit.SetColumnFamily(cfd->GetID());
+  edit.SetPrevLogNumber(0);
+  edit.SetLogNumber(max_next_log_number);
+  return edit;
+}
+
 }  // namespace ROCKSDB_NAMESPACE
@@ -113,11 +113,13 @@ class MemTableListVersion {

  void AddIterators(const ReadOptions& options,
                    UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping,
+                    const SliceTransform* prefix_extractor,
                    std::vector<InternalIterator*>* iterator_list,
                    Arena* arena);

  void AddIterators(const ReadOptions& options,
                    UnownedPtr<const SeqnoToTimeMapping> seqno_to_time_mapping,
+                    const SliceTransform* prefix_extractor,
                    MergeIteratorBuilder* merge_iter_builder,
                    bool add_range_tombstone_iter);

@@ -447,6 +449,12 @@ class MemTableList {
  void RemoveOldMemTables(uint64_t log_number,
                          autovector<MemTable*>* to_delete);

+  // This API is only used by atomic date replacement. To get an edit for
+  // dropping the current `MemTableListVersion`.
+  VersionEdit GetEditForDroppingCurrentVersion(
+      const ColumnFamilyData* cfd, VersionSet* vset,
+      LogsWithPrepTracker* prep_tracker) const;
+
 private:
  friend Status InstallMemtableAtomicFlushResults(
      const autovector<MemTableList*>* imm_lists,
@@ -287,6 +287,7 @@ TEST_F(MemTableListTest, GetTest) {

  // Fetch the newly written keys
  merge_context.Clear();
+  s = Status::OK();
  found = mem->Get(LookupKey("key1", seq), &value, /*columns*/ nullptr,
                   /*timestamp*/ nullptr, &s, &merge_context,
                   &max_covering_tombstone_seq, ReadOptions(),
@@ -295,6 +296,7 @@ TEST_F(MemTableListTest, GetTest) {
  ASSERT_EQ(value, "value1");

  merge_context.Clear();
+  s = Status::OK();
  found = mem->Get(LookupKey("key1", 2), &value, /*columns*/ nullptr,
                   /*timestamp*/ nullptr, &s, &merge_context,
                   &max_covering_tombstone_seq, ReadOptions(),
@@ -303,6 +305,7 @@ TEST_F(MemTableListTest, GetTest) {
  ASSERT_TRUE(found && s.IsNotFound());

  merge_context.Clear();
+  s = Status::OK();
  found = mem->Get(LookupKey("key2", seq), &value, /*columns*/ nullptr,
                   /*timestamp*/ nullptr, &s, &merge_context,
                   &max_covering_tombstone_seq, ReadOptions(),
@@ -311,6 +314,7 @@ TEST_F(MemTableListTest, GetTest) {
  ASSERT_EQ(value, "value2.2");

  merge_context.Clear();
+  s = Status::OK();
  found = mem->Get(LookupKey("key3", seq), &value, /*columns*/ nullptr,
                   /*timestamp*/ nullptr, &s, &merge_context,
                   &max_covering_tombstone_seq, ReadOptions(),
@@ -350,6 +354,7 @@ TEST_F(MemTableListTest, GetTest) {

  // Fetch keys via MemTableList
  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key1", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -357,6 +362,7 @@ TEST_F(MemTableListTest, GetTest) {
  ASSERT_TRUE(found && s.IsNotFound());

  merge_context.Clear();
+  s = Status::OK();
  found = list.current()->Get(LookupKey("key1", saved_seq), &value,
                              /*columns=*/nullptr, /*timestamp=*/nullptr, &s,
                              &merge_context, &max_covering_tombstone_seq,
@@ -365,6 +371,7 @@ TEST_F(MemTableListTest, GetTest) {
  ASSERT_EQ("value1", value);

  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key2", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -373,12 +380,14 @@ TEST_F(MemTableListTest, GetTest) {
  ASSERT_EQ(value, "value2.3");

  merge_context.Clear();
+  s = Status::OK();
  found = list.current()->Get(LookupKey("key2", 1), &value, /*columns=*/nullptr,
                              /*timestamp=*/nullptr, &s, &merge_context,
                              &max_covering_tombstone_seq, ReadOptions());
  ASSERT_FALSE(found);

  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key3", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -438,6 +447,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {

  // Fetch the newly written keys
  merge_context.Clear();
+  s = Status::OK();
  found = mem->Get(LookupKey("key1", seq), &value, /*columns*/ nullptr,
                   /*timestamp*/ nullptr, &s, &merge_context,
                   &max_covering_tombstone_seq, ReadOptions(),
@@ -446,6 +456,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
  ASSERT_TRUE(found && s.IsNotFound());

  merge_context.Clear();
+  s = Status::OK();
  found = mem->Get(LookupKey("key2", seq), &value, /*columns*/ nullptr,
                   /*timestamp*/ nullptr, &s, &merge_context,
                   &max_covering_tombstone_seq, ReadOptions(),
@@ -462,6 +473,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {

  // Fetch keys via MemTableList
  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key1", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -469,6 +481,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
  ASSERT_TRUE(found && s.IsNotFound());

  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key2", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -508,6 +521,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {

  // Verify keys are present in history
  merge_context.Clear();
+  s = Status::OK();
  found = list.current()->GetFromHistory(
      LookupKey("key1", seq), &value, /*columns=*/nullptr,
      /*timestamp=*/nullptr, &s, &merge_context, &max_covering_tombstone_seq,
@@ -515,6 +529,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
  ASSERT_TRUE(found && s.IsNotFound());

  merge_context.Clear();
+  s = Status::OK();
  found = list.current()->GetFromHistory(
      LookupKey("key2", seq), &value, /*columns=*/nullptr,
      /*timestamp=*/nullptr, &s, &merge_context, &max_covering_tombstone_seq,
@@ -568,6 +583,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {

  // Verify keys are no longer in MemTableList
  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key1", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -575,6 +591,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
  ASSERT_FALSE(found);

  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key2", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -582,6 +599,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
  ASSERT_FALSE(found);

  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key3", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -590,6 +608,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {

  // Verify that the second memtable's keys are in the history
  merge_context.Clear();
+  s = Status::OK();
  found = list.current()->GetFromHistory(
      LookupKey("key1", seq), &value, /*columns=*/nullptr,
      /*timestamp=*/nullptr, &s, &merge_context, &max_covering_tombstone_seq,
@@ -597,6 +616,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {
  ASSERT_TRUE(found && s.IsNotFound());

  merge_context.Clear();
+  s = Status::OK();
  found = list.current()->GetFromHistory(
      LookupKey("key3", seq), &value, /*columns=*/nullptr,
      /*timestamp=*/nullptr, &s, &merge_context, &max_covering_tombstone_seq,
@@ -606,6 +626,7 @@ TEST_F(MemTableListTest, GetFromHistoryTest) {

  // Verify that key2 from the first memtable is no longer in the history
  merge_context.Clear();
+  s = Status::OK();
  found =
      list.current()->Get(LookupKey("key2", seq), &value, /*columns=*/nullptr,
                          /*timestamp=*/nullptr, &s, &merge_context,
@@ -443,7 +443,8 @@ class Repairer {
      ro.total_order_seek = true;
      Arena arena;
      ScopedArenaPtr<InternalIterator> iter(
-          mem->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr, &arena));
+          mem->NewIterator(ro, /*seqno_to_time_mapping=*/nullptr, &arena,
+                           /*prefix_extractor=*/nullptr));
      int64_t _current_time = 0;
      immutable_db_options_.clock->GetCurrentTime(&_current_time)
          .PermitUncheckedError();  // ignore error
@@ -451,7 +452,8 @@ class Repairer {
      meta.file_creation_time = current_time;
      SnapshotChecker* snapshot_checker = DisableGCSnapshotChecker::Instance();

-      auto write_hint = cfd->CalculateSSTWriteHint(0);
+      auto write_hint =
+          cfd->current()->storage_info()->CalculateSSTWriteHint(/*level=*/0);
      std::vector<std::unique_ptr<FragmentedRangeTombstoneIterator>>
          range_del_iters;
      auto range_del_iter = mem->NewRangeTombstoneIterator(
@@ -164,6 +164,7 @@ Status TableCache::GetTableReader(
 }

 Cache::Handle* TableCache::Lookup(Cache* cache, uint64_t file_number) {
+  // NOTE: sharing same Cache with BlobFileCache
  Slice key = GetSliceForFileNumber(&file_number);
  return cache->Lookup(key);
 }
@@ -179,6 +180,7 @@ Status TableCache::FindTable(
    size_t max_file_size_for_l0_meta_pin, Temperature file_temperature) {
  PERF_TIMER_GUARD_WITH_CLOCK(find_table_nanos, ioptions_.clock);
  uint64_t number = file_meta.fd.GetNumber();
+  // NOTE: sharing same Cache with BlobFileCache
  Slice key = GetSliceForFileNumber(&number);
  *handle = cache_.Lookup(key);
  TEST_SYNC_POINT_CALLBACK("TableCache::FindTable:0",
@@ -230,7 +232,7 @@ InternalIterator* TableCache::NewIterator(
    const InternalKey* smallest_compaction_key,
    const InternalKey* largest_compaction_key, bool allow_unprepared_value,
    uint8_t block_protection_bytes_per_key, const SequenceNumber* read_seqno,
-    TruncatedRangeDelIterator** range_del_iter) {
+    std::unique_ptr<TruncatedRangeDelIterator>* range_del_iter) {
  PERF_TIMER_GUARD(new_table_iterator_nanos);

  Status s;
@@ -285,7 +287,7 @@ InternalIterator* TableCache::NewIterator(
        delete new_range_del_iter;
        *range_del_iter = nullptr;
      } else {
-        *range_del_iter = new TruncatedRangeDelIterator(
+        *range_del_iter = std::make_unique<TruncatedRangeDelIterator>(
            std::unique_ptr<FragmentedRangeTombstoneIterator>(
                new_range_del_iter),
            &icomparator, &file_meta.smallest, &file_meta.largest);
@@ -100,7 +100,7 @@ class TableCache {
      const InternalKey* largest_compaction_key, bool allow_unprepared_value,
      uint8_t protection_bytes_per_key,
      const SequenceNumber* range_del_read_seqno = nullptr,
-      TruncatedRangeDelIterator** range_del_iter = nullptr);
+      std::unique_ptr<TruncatedRangeDelIterator>* range_del_iter = nullptr);

  // If a seek to internal key "k" in specified file finds an entry,
  // call get_context->SaveValue() repeatedly until
@@ -24,11 +24,13 @@
 #include <vector>

 #include "cache/cache_reservation_manager.h"
+#include "db/blob/blob_file_cache.h"
 #include "db/blob/blob_file_meta.h"
 #include "db/dbformat.h"
 #include "db/internal_stats.h"
 #include "db/table_cache.h"
 #include "db/version_edit.h"
+#include "db/version_edit_handler.h"
 #include "db/version_set.h"
 #include "port/port.h"
 #include "table/table_reader.h"
@@ -37,6 +39,25 @@
 namespace ROCKSDB_NAMESPACE {

 class VersionBuilder::Rep {
+  class NewestFirstBySeqNo {
+   public:
+    bool operator()(const FileMetaData* lhs, const FileMetaData* rhs) const {
+      assert(lhs);
+      assert(rhs);
+
+      if (lhs->fd.largest_seqno != rhs->fd.largest_seqno) {
+        return lhs->fd.largest_seqno > rhs->fd.largest_seqno;
+      }
+
+      if (lhs->fd.smallest_seqno != rhs->fd.smallest_seqno) {
+        return lhs->fd.smallest_seqno > rhs->fd.smallest_seqno;
+      }
+
+      // Break ties by file number
+      return lhs->fd.GetNumber() > rhs->fd.GetNumber();
+    }
+  };
+
  class NewestFirstByEpochNumber {
   private:
    inline static const NewestFirstBySeqNo seqno_cmp;
@@ -249,9 +270,10 @@ class VersionBuilder::Rep {
  std::unordered_map<uint64_t, int> table_file_levels_;
  // Current compact cursors that should be changed after the last compaction
  std::unordered_map<int, InternalKey> updated_compact_cursors_;
-  NewestFirstByEpochNumber level_zero_cmp_by_epochno_;
-  NewestFirstBySeqNo level_zero_cmp_by_seqno_;
-  BySmallestKey level_nonzero_cmp_;
+  const std::shared_ptr<const NewestFirstByEpochNumber>
+      level_zero_cmp_by_epochno_;
+  const std::shared_ptr<const NewestFirstBySeqNo> level_zero_cmp_by_seqno_;
+  const std::shared_ptr<const BySmallestKey> level_nonzero_cmp_;

  // Mutable metadata objects for all blob files affected by the series of
  // version edits.
@@ -259,11 +281,56 @@ class VersionBuilder::Rep {

  std::shared_ptr<CacheReservationManager> file_metadata_cache_res_mgr_;

+  ColumnFamilyData* cfd_;
+  VersionEditHandler* version_edit_handler_;
+  bool track_found_and_missing_files_;
+  // If false, only a complete Version with all files consisting it found is
+  // considered valid. If true, besides complete Version, if the Version is
+  // never edited in an atomic group, an incomplete Version with only a suffix
+  // of L0 files missing is also considered valid.
+  bool allow_incomplete_valid_version_;
+
+  // These are only tracked if `track_found_and_missing_files_` is enabled.
+
+  // The SST files that are found (blob files not included yet).
+  std::unordered_set<uint64_t> found_files_;
+  // Missing SST files for L0
+  std::unordered_set<uint64_t> l0_missing_files_;
+  // Missing SST files for non L0 levels
+  std::unordered_set<uint64_t> non_l0_missing_files_;
+  // Intermediate SST files (blob files not included yet)
+  std::vector<std::string> intermediate_files_;
+  // The highest file number for all the missing blob files, useful to check
+  // if a complete Version is available.
+  uint64_t missing_blob_files_high_ = kInvalidBlobFileNumber;
+  // Missing blob files, useful to check if only the missing L0 files'
+  // associated blob files are missing.
+  std::unordered_set<uint64_t> missing_blob_files_;
+  // True if all files consisting the Version can be found. Or if
+  // `allow_incomplete_valid_version_` is true and the version history is not
+  // ever edited in an atomic group, this will be true if only a
+  // suffix of L0 SST files and their associated blob files are missing.
+  bool valid_version_available_;
+  // True if version is ever edited in an atomic group.
+  bool edited_in_atomic_group_;
+
+  // Flag to indicate if the Version is updated since last validity check. If no
+  // `Apply` call is made between a `Rep`'s construction and a
+  // `ValidVersionAvailable` check or between two `ValidVersionAvailable` calls.
+  // This flag will be true to indicate the cached validity value can be
+  // directly used without a recheck.
+  bool version_updated_since_last_check_;
+
+  // End of fields that are only tracked when `track_found_and_missing_files_`
+  // is enabled.
+
 public:
  Rep(const FileOptions& file_options, const ImmutableCFOptions* ioptions,
      TableCache* table_cache, VersionStorageInfo* base_vstorage,
      VersionSet* version_set,
-      std::shared_ptr<CacheReservationManager> file_metadata_cache_res_mgr)
+      std::shared_ptr<CacheReservationManager> file_metadata_cache_res_mgr,
+      ColumnFamilyData* cfd, VersionEditHandler* version_edit_handler,
+      bool track_found_and_missing_files, bool allow_incomplete_valid_version)
      : file_options_(file_options),
        ioptions_(ioptions),
        table_cache_(table_cache),
@@ -271,11 +338,76 @@ class VersionBuilder::Rep {
        version_set_(version_set),
        num_levels_(base_vstorage->num_levels()),
        has_invalid_levels_(false),
-        level_nonzero_cmp_(base_vstorage_->InternalComparator()),
-        file_metadata_cache_res_mgr_(file_metadata_cache_res_mgr) {
+        level_zero_cmp_by_epochno_(
+            std::make_shared<NewestFirstByEpochNumber>()),
+        level_zero_cmp_by_seqno_(std::make_shared<NewestFirstBySeqNo>()),
+        level_nonzero_cmp_(std::make_shared<BySmallestKey>(
+            base_vstorage_->InternalComparator())),
+        file_metadata_cache_res_mgr_(file_metadata_cache_res_mgr),
+        cfd_(cfd),
+        version_edit_handler_(version_edit_handler),
+        track_found_and_missing_files_(track_found_and_missing_files),
+        allow_incomplete_valid_version_(allow_incomplete_valid_version) {
    assert(ioptions_);

    levels_ = new LevelState[num_levels_];
+    if (track_found_and_missing_files_) {
+      assert(cfd_);
+      assert(version_edit_handler_);
+      // `track_found_and_missing_files_` mode used by VersionEditHandlerPIT
+      // assumes the initial base version is valid. For best efforts recovery,
+      // base will be empty. For manifest tailing usage like secondary instance,
+      // they do not allow incomplete version, so the base version in subsequent
+      // catch up attempts should be valid too.
+      valid_version_available_ = true;
+      edited_in_atomic_group_ = false;
+      version_updated_since_last_check_ = false;
+    }
+  }
+
+  Rep(const Rep& other)
+      : file_options_(other.file_options_),
+        ioptions_(other.ioptions_),
+        table_cache_(other.table_cache_),
+        base_vstorage_(other.base_vstorage_),
+        version_set_(other.version_set_),
+        num_levels_(other.num_levels_),
+        invalid_level_sizes_(other.invalid_level_sizes_),
+        has_invalid_levels_(other.has_invalid_levels_),
+        table_file_levels_(other.table_file_levels_),
+        updated_compact_cursors_(other.updated_compact_cursors_),
+        level_zero_cmp_by_epochno_(other.level_zero_cmp_by_epochno_),
+        level_zero_cmp_by_seqno_(other.level_zero_cmp_by_seqno_),
+        level_nonzero_cmp_(other.level_nonzero_cmp_),
+        mutable_blob_file_metas_(other.mutable_blob_file_metas_),
+        file_metadata_cache_res_mgr_(other.file_metadata_cache_res_mgr_),
+        cfd_(other.cfd_),
+        version_edit_handler_(other.version_edit_handler_),
+        track_found_and_missing_files_(other.track_found_and_missing_files_),
+        allow_incomplete_valid_version_(other.allow_incomplete_valid_version_),
+        found_files_(other.found_files_),
+        l0_missing_files_(other.l0_missing_files_),
+        non_l0_missing_files_(other.non_l0_missing_files_),
+        intermediate_files_(other.intermediate_files_),
+        missing_blob_files_high_(other.missing_blob_files_high_),
+        missing_blob_files_(other.missing_blob_files_),
+        valid_version_available_(other.valid_version_available_),
+        edited_in_atomic_group_(other.edited_in_atomic_group_),
+        version_updated_since_last_check_(
+            other.version_updated_since_last_check_) {
+    assert(ioptions_);
+    levels_ = new LevelState[num_levels_];
+    for (int level = 0; level < num_levels_; level++) {
+      levels_[level] = other.levels_[level];
+      const auto& added = levels_[level].added_files;
+      for (auto& pair : added) {
+        RefFile(pair.second);
+      }
+    }
+    if (track_found_and_missing_files_) {
+      assert(cfd_);
+      assert(version_edit_handler_);
+    }
  }

  ~Rep() {
@@ -289,6 +421,12 @@ class VersionBuilder::Rep {
    delete[] levels_;
  }

+  void RefFile(FileMetaData* f) {
+    assert(f);
+    assert(f->refs > 0);
+    f->refs++;
+  }
+
  void UnrefFile(FileMetaData* f) {
    f->refs--;
    if (f->refs <= 0) {
@@ -397,7 +535,7 @@ class VersionBuilder::Rep {

          if (epoch_number_requirement ==
              EpochNumberRequirement::kMightMissing) {
-            if (!level_zero_cmp_by_seqno_(lhs, rhs)) {
+            if (!level_zero_cmp_by_seqno_->operator()(lhs, rhs)) {
              std::ostringstream oss;
              oss << "L0 files are not sorted properly: files #"
                  << lhs->fd.GetNumber() << " with seqnos (largest, smallest) "
@@ -429,7 +567,7 @@ class VersionBuilder::Rep {
              }
            }

-            if (!level_zero_cmp_by_epochno_(lhs, rhs)) {
+            if (!level_zero_cmp_by_epochno_->operator()(lhs, rhs)) {
              std::ostringstream oss;
              oss << "L0 files are not sorted properly: files #"
                  << lhs->fd.GetNumber() << " with epoch number "
@@ -458,7 +596,7 @@ class VersionBuilder::Rep {
          assert(lhs);
          assert(rhs);

-          if (!level_nonzero_cmp_(lhs, rhs)) {
+          if (!level_nonzero_cmp_->operator()(lhs, rhs)) {
            std::ostringstream oss;
            oss << 'L' << level << " files are not sorted properly: files #"
                << lhs->fd.GetNumber() << ", #" << rhs->fd.GetNumber();
@@ -607,12 +745,9 @@ class VersionBuilder::Rep {
      return Status::Corruption("VersionBuilder", oss.str());
    }

-    // Note: we use C++11 for now but in C++14, this could be done in a more
-    // elegant way using generalized lambda capture.
-    VersionSet* const vs = version_set_;
-    const ImmutableCFOptions* const ioptions = ioptions_;
-
-    auto deleter = [vs, ioptions](SharedBlobFileMetaData* shared_meta) {
+    auto deleter = [vs = version_set_, ioptions = ioptions_,
+                    bc = cfd_ ? cfd_->blob_file_cache()
+                              : nullptr](SharedBlobFileMetaData* shared_meta) {
      if (vs) {
        assert(ioptions);
        assert(!ioptions->cf_paths.empty());
@@ -621,6 +756,9 @@ class VersionBuilder::Rep {
        vs->AddObsoleteBlobFile(shared_meta->GetBlobFileNumber(),
                                ioptions->cf_paths.front().path);
      }
+      if (bc) {
+        bc->Evict(shared_meta->GetBlobFileNumber());
+      }

      delete shared_meta;
    };
@@ -629,12 +767,27 @@ class VersionBuilder::Rep {
        blob_file_number, blob_file_addition.GetTotalBlobCount(),
        blob_file_addition.GetTotalBlobBytes(),
        blob_file_addition.GetChecksumMethod(),
-        blob_file_addition.GetChecksumValue(), deleter);
+        blob_file_addition.GetChecksumValue(), std::move(deleter));

    mutable_blob_file_metas_.emplace(
        blob_file_number, MutableBlobFileMetaData(std::move(shared_meta)));

-    return Status::OK();
+    Status s;
+    if (track_found_and_missing_files_) {
+      assert(version_edit_handler_);
+      s = version_edit_handler_->VerifyBlobFile(cfd_, blob_file_number,
+                                                blob_file_addition);
+      if (s.IsPathNotFound() || s.IsNotFound() || s.IsCorruption()) {
+        missing_blob_files_high_ =
+            std::max(missing_blob_files_high_, blob_file_number);
+        missing_blob_files_.insert(blob_file_number);
+        s = Status::OK();
+      } else if (!s.ok()) {
+        return s;
+      }
+    }
+
+    return s;
  }

  Status ApplyBlobFileGarbage(const BlobFileGarbage& blob_file_garbage) {
@@ -752,6 +905,29 @@ class VersionBuilder::Rep {
    table_file_levels_[file_number] =
        VersionStorageInfo::FileLocation::Invalid().GetLevel();

+    if (track_found_and_missing_files_) {
+      assert(version_edit_handler_);
+      if (l0_missing_files_.find(file_number) != l0_missing_files_.end()) {
+        l0_missing_files_.erase(file_number);
+      } else if (non_l0_missing_files_.find(file_number) !=
+                 non_l0_missing_files_.end()) {
+        non_l0_missing_files_.erase(file_number);
+      } else {
+        auto fiter = found_files_.find(file_number);
+        // Only mark new files added during this catchup attempt for deletion.
+        // These files were never installed in VersionStorageInfo.
+        // Already referenced files that are deleted by a VersionEdit will
+        // be added to the VersionStorageInfo's obsolete files when the old
+        // version is dereferenced.
+        if (fiter != found_files_.end()) {
+          assert(!ioptions_->cf_paths.empty());
+          intermediate_files_.emplace_back(
+              MakeTableFileName(ioptions_->cf_paths[0].path, file_number));
+          found_files_.erase(fiter);
+        }
+      }
+    }
+
    return Status::OK();
  }

@@ -824,7 +1000,31 @@ class VersionBuilder::Rep {

    table_file_levels_[file_number] = level;

-    return Status::OK();
+    Status s;
+    if (track_found_and_missing_files_) {
+      assert(version_edit_handler_);
+      assert(!ioptions_->cf_paths.empty());
+      const std::string fpath =
+          MakeTableFileName(ioptions_->cf_paths[0].path, file_number);
+      s = version_edit_handler_->VerifyFile(cfd_, fpath, level, meta);
+      if (s.IsPathNotFound() || s.IsNotFound() || s.IsCorruption()) {
+        if (0 == level) {
+          l0_missing_files_.insert(file_number);
+        } else {
+          non_l0_missing_files_.insert(file_number);
+        }
+        if (s.IsCorruption()) {
+          found_files_.insert(file_number);
+        }
+        s = Status::OK();
+      } else if (!s.ok()) {
+        return s;
+      } else {
+        found_files_.insert(file_number);
+      }
+    }
+
+    return s;
  }

  Status ApplyCompactCursors(int level,
@@ -845,6 +1045,7 @@ class VersionBuilder::Rep {

  // Apply all of the edits in *edit to the current state.
  Status Apply(const VersionEdit* edit) {
+    bool version_updated = false;
    {
      const Status s = CheckConsistency(base_vstorage_);
      if (!s.ok()) {
@@ -862,6 +1063,7 @@ class VersionBuilder::Rep {
      if (!s.ok()) {
        return s;
      }
+      version_updated = true;
    }

    // Increase the amount of garbage for blob files affected by GC
@@ -870,6 +1072,7 @@ class VersionBuilder::Rep {
      if (!s.ok()) {
        return s;
      }
+      version_updated = true;
    }

    // Delete table files
@@ -881,6 +1084,7 @@ class VersionBuilder::Rep {
      if (!s.ok()) {
        return s;
      }
+      version_updated = true;
    }

    // Add new table files
@@ -892,6 +1096,7 @@ class VersionBuilder::Rep {
      if (!s.ok()) {
        return s;
      }
+      version_updated = true;
    }

    // Populate compact cursors for round-robin compaction, leave
@@ -904,6 +1109,13 @@ class VersionBuilder::Rep {
        return s;
      }
    }
+
+    if (track_found_and_missing_files_ && version_updated) {
+      version_updated_since_last_check_ = true;
+      if (!edited_in_atomic_group_ && edit->IsInAtomicGroup()) {
+        edited_in_atomic_group_ = true;
+      }
+    }
    return Status::OK();
  }

@@ -1046,14 +1258,35 @@ class VersionBuilder::Rep {
        mutable_meta.GetGarbageBlobCount(), mutable_meta.GetGarbageBlobBytes());
  }

+  bool OnlyLinkedToMissingL0Files(
+      const std::unordered_set<uint64_t>& linked_ssts) const {
+    return std::all_of(
+        linked_ssts.begin(), linked_ssts.end(), [&](const uint64_t& element) {
+          return l0_missing_files_.find(element) != l0_missing_files_.end();
+        });
+  }
+
  // Add the blob file specified by meta to *vstorage if it is determined to
  // contain valid data (blobs).
  template <typename Meta>
-  static void AddBlobFileIfNeeded(VersionStorageInfo* vstorage, Meta&& meta) {
+  void AddBlobFileIfNeeded(VersionStorageInfo* vstorage, Meta&& meta,
+                           uint64_t blob_file_number) const {
    assert(vstorage);
    assert(meta);

-    if (meta->GetLinkedSsts().empty() &&
+    const auto& linked_ssts = meta->GetLinkedSsts();
+    if (track_found_and_missing_files_) {
+      if (missing_blob_files_.find(blob_file_number) !=
+          missing_blob_files_.end()) {
+        return;
+      }
+      // Leave the empty case for the below blob garbage collection logic.
+      if (!linked_ssts.empty() && OnlyLinkedToMissingL0Files(linked_ssts)) {
+        return;
+      }
+    }
+
+    if (linked_ssts.empty() &&
        meta->GetGarbageBlobCount() >= meta->GetTotalBlobCount()) {
      return;
    }
@@ -1065,6 +1298,7 @@ class VersionBuilder::Rep {
  // applied, and save the result into *vstorage.
  void SaveBlobFilesTo(VersionStorageInfo* vstorage) const {
    assert(vstorage);
+    assert(!track_found_and_missing_files_ || valid_version_available_);

    assert(base_vstorage_);
    vstorage->ReserveBlob(base_vstorage_->GetBlobFiles().size() +
@@ -1080,22 +1314,24 @@ class VersionBuilder::Rep {
    }

    auto process_base =
-        [vstorage](const std::shared_ptr<BlobFileMetaData>& base_meta) {
+        [this, vstorage](const std::shared_ptr<BlobFileMetaData>& base_meta) {
          assert(base_meta);

-          AddBlobFileIfNeeded(vstorage, base_meta);
+          AddBlobFileIfNeeded(vstorage, base_meta,
+                              base_meta->GetBlobFileNumber());

          return true;
        };

    auto process_mutable =
-        [vstorage](const MutableBlobFileMetaData& mutable_meta) {
-          AddBlobFileIfNeeded(vstorage, CreateBlobFileMetaData(mutable_meta));
+        [this, vstorage](const MutableBlobFileMetaData& mutable_meta) {
+          AddBlobFileIfNeeded(vstorage, CreateBlobFileMetaData(mutable_meta),
+                              mutable_meta.GetBlobFileNumber());

          return true;
        };

-    auto process_both = [vstorage](
+    auto process_both = [this, vstorage](
                            const std::shared_ptr<BlobFileMetaData>& base_meta,
                            const MutableBlobFileMetaData& mutable_meta) {
      assert(base_meta);
@@ -1108,12 +1344,14 @@ class VersionBuilder::Rep {
               mutable_meta.GetGarbageBlobBytes());
        assert(base_meta->GetLinkedSsts() == mutable_meta.GetLinkedSsts());

-        AddBlobFileIfNeeded(vstorage, base_meta);
+        AddBlobFileIfNeeded(vstorage, base_meta,
+                            base_meta->GetBlobFileNumber());

        return true;
      }

-      AddBlobFileIfNeeded(vstorage, CreateBlobFileMetaData(mutable_meta));
+      AddBlobFileIfNeeded(vstorage, CreateBlobFileMetaData(mutable_meta),
+                          mutable_meta.GetBlobFileNumber());

      return true;
    };
@@ -1125,6 +1363,10 @@ class VersionBuilder::Rep {
  void MaybeAddFile(VersionStorageInfo* vstorage, int level,
                    FileMetaData* f) const {
    const uint64_t file_number = f->fd.GetNumber();
+    if (track_found_and_missing_files_ && level == 0 &&
+        l0_missing_files_.find(file_number) != l0_missing_files_.end()) {
+      return;
+    }

    const auto& level_state = levels_[level];

@@ -1148,6 +1390,29 @@ class VersionBuilder::Rep {
    }
  }

+  bool ContainsCompleteVersion() const {
+    assert(track_found_and_missing_files_);
+    return l0_missing_files_.empty() && non_l0_missing_files_.empty() &&
+           (missing_blob_files_high_ == kInvalidBlobFileNumber ||
+            missing_blob_files_high_ < GetMinOldestBlobFileNumber());
+  }
+
+  bool HasMissingFiles() const {
+    assert(track_found_and_missing_files_);
+    return !l0_missing_files_.empty() || !non_l0_missing_files_.empty() ||
+           missing_blob_files_high_ != kInvalidBlobFileNumber;
+  }
+
+  std::vector<std::string>& GetAndClearIntermediateFiles() {
+    assert(track_found_and_missing_files_);
+    return intermediate_files_;
+  }
+
+  void ClearFoundFiles() {
+    assert(track_found_and_missing_files_);
+    found_files_.clear();
+  }
+
  template <typename Cmp>
  void SaveSSTFilesTo(VersionStorageInfo* vstorage, int level, Cmp cmp) const {
    // Merge the set of added files with the set of pre-existing files.
@@ -1156,6 +1421,16 @@ class VersionBuilder::Rep {
    const auto& unordered_added_files = levels_[level].added_files;
    vstorage->Reserve(level, base_files.size() + unordered_added_files.size());

+    MergeUnorderdAddedFilesWithBase(
+        base_files, unordered_added_files, cmp,
+        [&](FileMetaData* file) { MaybeAddFile(vstorage, level, file); });
+  }
+
+  template <typename Cmp, typename AddFileFunc>
+  void MergeUnorderdAddedFilesWithBase(
+      const std::vector<FileMetaData*>& base_files,
+      const std::unordered_map<uint64_t, FileMetaData*>& unordered_added_files,
+      Cmp cmp, AddFileFunc add_file_func) const {
    // Sort added files for the level.
    std::vector<FileMetaData*> added_files;
    added_files.reserve(unordered_added_files.size());
@@ -1171,9 +1446,9 @@ class VersionBuilder::Rep {
    while (added_iter != added_end || base_iter != base_end) {
      if (base_iter == base_end ||
          (added_iter != added_end && cmp(*added_iter, *base_iter))) {
-        MaybeAddFile(vstorage, level, *added_iter++);
+        add_file_func(*added_iter++);
      } else {
-        MaybeAddFile(vstorage, level, *base_iter++);
+        add_file_func(*base_iter++);
      }
    }
  }
@@ -1215,13 +1490,13 @@ class VersionBuilder::Rep {
    }

    if (epoch_number_requirement == EpochNumberRequirement::kMightMissing) {
-      SaveSSTFilesTo(vstorage, /* level */ 0, level_zero_cmp_by_seqno_);
+      SaveSSTFilesTo(vstorage, /* level */ 0, *level_zero_cmp_by_seqno_);
    } else {
-      SaveSSTFilesTo(vstorage, /* level */ 0, level_zero_cmp_by_epochno_);
+      SaveSSTFilesTo(vstorage, /* level */ 0, *level_zero_cmp_by_epochno_);
    }

    for (int level = 1; level < num_levels_; ++level) {
-      SaveSSTFilesTo(vstorage, level, level_nonzero_cmp_);
+      SaveSSTFilesTo(vstorage, level, *level_nonzero_cmp_);
    }
  }

@@ -1232,8 +1507,111 @@ class VersionBuilder::Rep {
    }
  }

+  bool ValidVersionAvailable() {
+    assert(track_found_and_missing_files_);
+    if (version_updated_since_last_check_) {
+      valid_version_available_ = ContainsCompleteVersion();
+      if (!valid_version_available_ && !edited_in_atomic_group_ &&
+          allow_incomplete_valid_version_) {
+        valid_version_available_ = OnlyMissingL0Suffix();
+      }
+      version_updated_since_last_check_ = false;
+    }
+    return valid_version_available_;
+  }
+
+  bool OnlyMissingL0Suffix() const {
+    if (!non_l0_missing_files_.empty()) {
+      return false;
+    }
+    assert(!(l0_missing_files_.empty() && missing_blob_files_.empty()));
+
+    if (!l0_missing_files_.empty() && !MissingL0FilesAreL0Suffix()) {
+      return false;
+    }
+    if (!missing_blob_files_.empty() &&
+        !RemainingSstFilesNotMissingBlobFiles()) {
+      return false;
+    }
+    return true;
+  }
+
+  // Check missing L0 files are a suffix of expected sorted L0 files.
+  bool MissingL0FilesAreL0Suffix() const {
+    assert(non_l0_missing_files_.empty());
+    assert(!l0_missing_files_.empty());
+    std::vector<FileMetaData*> expected_sorted_l0_files;
+    const auto& base_files = base_vstorage_->LevelFiles(0);
+    const auto& unordered_added_files = levels_[0].added_files;
+    expected_sorted_l0_files.reserve(base_files.size() +
+                                     unordered_added_files.size());
+    EpochNumberRequirement epoch_number_requirement =
+        base_vstorage_->GetEpochNumberRequirement();
+
+    if (epoch_number_requirement == EpochNumberRequirement::kMightMissing) {
+      MergeUnorderdAddedFilesWithBase(
+          base_files, unordered_added_files, *level_zero_cmp_by_seqno_,
+          [&](FileMetaData* file) {
+            expected_sorted_l0_files.push_back(file);
+          });
+    } else {
+      MergeUnorderdAddedFilesWithBase(
+          base_files, unordered_added_files, *level_zero_cmp_by_epochno_,
+          [&](FileMetaData* file) {
+            expected_sorted_l0_files.push_back(file);
+          });
+    }
+    assert(expected_sorted_l0_files.size() >= l0_missing_files_.size());
+    std::unordered_set<uint64_t> unaddressed_missing_files = l0_missing_files_;
+    for (auto iter = expected_sorted_l0_files.begin();
+         iter != expected_sorted_l0_files.end(); iter++) {
+      uint64_t file_number = (*iter)->fd.GetNumber();
+      if (l0_missing_files_.find(file_number) != l0_missing_files_.end()) {
+        assert(unaddressed_missing_files.find(file_number) !=
+               unaddressed_missing_files.end());
+        unaddressed_missing_files.erase(file_number);
+      } else if (!unaddressed_missing_files.empty()) {
+        return false;
+      } else {
+        break;
+      }
+    }
+    return true;
+  }
+
+  // Check for each of the missing blob file missing, it either is older than
+  // the minimum oldest blob file required by this Version or only linked to
+  // the missing L0 files.
+  bool RemainingSstFilesNotMissingBlobFiles() const {
+    assert(non_l0_missing_files_.empty());
+    assert(!missing_blob_files_.empty());
+    bool no_l0_files_missing = l0_missing_files_.empty();
+    uint64_t min_oldest_blob_file_num = GetMinOldestBlobFileNumber();
+    for (const auto& missing_blob_file : missing_blob_files_) {
+      if (missing_blob_file < min_oldest_blob_file_num) {
+        continue;
+      }
+      auto iter = mutable_blob_file_metas_.find(missing_blob_file);
+      assert(iter != mutable_blob_file_metas_.end());
+      const std::unordered_set<uint64_t>& linked_ssts =
+          iter->second.GetLinkedSsts();
+      // TODO(yuzhangyu): In theory, if no L0 SST files ara missing, and only
+      // blob files exclusively linked to a L0 suffix are missing, we can
+      // recover to a valid point in time too. We don't recover that type of
+      // incomplete Version yet.
+      if (!linked_ssts.empty() && no_l0_files_missing) {
+        return false;
+      }
+      if (!OnlyLinkedToMissingL0Files(linked_ssts)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
  // Save the current state in *vstorage.
  Status SaveTo(VersionStorageInfo* vstorage) const {
+    assert(!track_found_and_missing_files_ || valid_version_available_);
    Status s;

 #ifndef NDEBUG
@@ -1266,6 +1644,7 @@ class VersionBuilder::Rep {
      size_t max_file_size_for_l0_meta_pin, const ReadOptions& read_options,
      uint8_t block_protection_bytes_per_key) {
    assert(table_cache_ != nullptr);
+    assert(!track_found_and_missing_files_ || valid_version_available_);

    size_t table_cache_capacity =
        table_cache_->get_cache().get()->GetCapacity();
@@ -1305,6 +1684,11 @@ class VersionBuilder::Rep {
    for (int level = 0; level < num_levels_; level++) {
      for (auto& file_meta_pair : levels_[level].added_files) {
        auto* file_meta = file_meta_pair.second;
+        uint64_t file_number = file_meta->fd.GetNumber();
+        if (track_found_and_missing_files_ && level == 0 &&
+            l0_missing_files_.find(file_number) != l0_missing_files_.end()) {
+          continue;
+        }
        // If the file has been opened before, just skip it.
        if (!file_meta->table_reader_handle) {
          files_meta.emplace_back(file_meta, level);
@@ -1369,9 +1753,13 @@ VersionBuilder::VersionBuilder(
    const FileOptions& file_options, const ImmutableCFOptions* ioptions,
    TableCache* table_cache, VersionStorageInfo* base_vstorage,
    VersionSet* version_set,
-    std::shared_ptr<CacheReservationManager> file_metadata_cache_res_mgr)
+    std::shared_ptr<CacheReservationManager> file_metadata_cache_res_mgr,
+    ColumnFamilyData* cfd, VersionEditHandler* version_edit_handler,
+    bool track_found_and_missing_files, bool allow_incomplete_valid_version)
    : rep_(new Rep(file_options, ioptions, table_cache, base_vstorage,
-                   version_set, file_metadata_cache_res_mgr)) {}
+                   version_set, file_metadata_cache_res_mgr, cfd,
+                   version_edit_handler, track_found_and_missing_files,
+                   allow_incomplete_valid_version)) {}

 VersionBuilder::~VersionBuilder() = default;

@@ -1399,27 +1787,71 @@ Status VersionBuilder::LoadTableHandlers(
      read_options, block_protection_bytes_per_key);
 }

-uint64_t VersionBuilder::GetMinOldestBlobFileNumber() const {
-  return rep_->GetMinOldestBlobFileNumber();
+void VersionBuilder::CreateOrReplaceSavePoint() {
+  assert(rep_);
+  savepoint_ = std::move(rep_);
+  rep_ = std::make_unique<Rep>(*savepoint_);
 }

+bool VersionBuilder::ValidVersionAvailable() {
+  return rep_->ValidVersionAvailable();
+}
+
+bool VersionBuilder::HasMissingFiles() const { return rep_->HasMissingFiles(); }
+
+std::vector<std::string>& VersionBuilder::GetAndClearIntermediateFiles() {
+  return rep_->GetAndClearIntermediateFiles();
+}
+
+void VersionBuilder::ClearFoundFiles() { return rep_->ClearFoundFiles(); }
+
+Status VersionBuilder::SaveSavePointTo(VersionStorageInfo* vstorage) const {
+  if (!savepoint_ || !savepoint_->ValidVersionAvailable()) {
+    return Status::InvalidArgument();
+  }
+  return savepoint_->SaveTo(vstorage);
+}
+
+Status VersionBuilder::LoadSavePointTableHandlers(
+    InternalStats* internal_stats, int max_threads,
+    bool prefetch_index_and_filter_in_cache, bool is_initial_load,
+    const std::shared_ptr<const SliceTransform>& prefix_extractor,
+    size_t max_file_size_for_l0_meta_pin, const ReadOptions& read_options,
+    uint8_t block_protection_bytes_per_key) {
+  if (!savepoint_ || !savepoint_->ValidVersionAvailable()) {
+    return Status::InvalidArgument();
+  }
+  return savepoint_->LoadTableHandlers(
+      internal_stats, max_threads, prefetch_index_and_filter_in_cache,
+      is_initial_load, prefix_extractor, max_file_size_for_l0_meta_pin,
+      read_options, block_protection_bytes_per_key);
+}
+
+void VersionBuilder::ClearSavePoint() { savepoint_.reset(nullptr); }
+
 BaseReferencedVersionBuilder::BaseReferencedVersionBuilder(
-    ColumnFamilyData* cfd)
+    ColumnFamilyData* cfd, VersionEditHandler* version_edit_handler,
+    bool track_found_and_missing_files, bool allow_incomplete_valid_version)
    : version_builder_(new VersionBuilder(
          cfd->current()->version_set()->file_options(), cfd->ioptions(),
          cfd->table_cache(), cfd->current()->storage_info(),
          cfd->current()->version_set(),
-          cfd->GetFileMetadataCacheReservationManager())),
+          cfd->GetFileMetadataCacheReservationManager(), cfd,
+          version_edit_handler, track_found_and_missing_files,
+          allow_incomplete_valid_version)),
      version_(cfd->current()) {
  version_->Ref();
 }

 BaseReferencedVersionBuilder::BaseReferencedVersionBuilder(
-    ColumnFamilyData* cfd, Version* v)
+    ColumnFamilyData* cfd, Version* v, VersionEditHandler* version_edit_handler,
+    bool track_found_and_missing_files, bool allow_incomplete_valid_version)
    : version_builder_(new VersionBuilder(
          cfd->current()->version_set()->file_options(), cfd->ioptions(),
          cfd->table_cache(), v->storage_info(), v->version_set(),
-          cfd->GetFileMetadataCacheReservationManager())),
+          cfd->GetFileMetadataCacheReservationManager(), cfd,
+          version_edit_handler, track_found_and_missing_files,
+          allow_incomplete_valid_version)),
      version_(v) {
  assert(version_ != cfd->current());
 }