Update HISTORY and version

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/13572

Reviewed By: moakbari

Differential Revision: D73568773

Pulled By: anand1976

fbshipit-source-id: d61d76cb864e3af111bb05dc1ee51a8b3f1eaf17

.github/actions/windows-build-steps/action.yml

@@ -11,9 +11,9 @@ runs:
       CMAKE_BIN: C:/Program Files/CMake/bin/cmake.exe
       CTEST_BIN: C:/Program Files/CMake/bin/ctest.exe
       JAVA_HOME: C:/Program Files/BellSoft/LibericaJDK-8
-      SNAPPY_HOME: ${{ github.workspace }}/thirdparty/snappy-1.1.8
-      SNAPPY_INCLUDE: ${{ github.workspace }}/thirdparty/snappy-1.1.8;${{ github.workspace }}/thirdparty/snappy-1.1.8/build
-      SNAPPY_LIB_DEBUG: ${{ github.workspace }}/thirdparty/snappy-1.1.8/build/Debug/snappy.lib
+      SNAPPY_HOME: ${{ github.workspace }}/thirdparty/snappy-1.2.2
+      SNAPPY_INCLUDE: ${{ github.workspace }}/thirdparty/snappy-1.2.2;${{ github.workspace }}/thirdparty/snappy-1.2.2/build
+      SNAPPY_LIB_DEBUG: ${{ github.workspace }}/thirdparty/snappy-1.2.2/build/Debug/snappy.lib
     run: |-
       # NOTE: if ... Exit $LASTEXITCODE lines needed to exit and report failure
       echo ===================== Install Dependencies =====================
@@ -22,14 +22,14 @@ runs:
       mkdir $Env:THIRDPARTY_HOME
       cd $Env:THIRDPARTY_HOME
       echo "Building Snappy dependency..."
-      curl -Lo snappy-1.1.8.zip https://github.com/google/snappy/archive/refs/tags/1.1.8.zip
+      curl -Lo snappy-1.2.2.zip https://github.com/google/snappy/archive/refs/tags/1.2.2.zip
       if(!$?) { Exit $LASTEXITCODE }
-      unzip -q snappy-1.1.8.zip
+      unzip -q snappy-1.2.2.zip
       if(!$?) { Exit $LASTEXITCODE }
-      cd snappy-1.1.8
+      cd snappy-1.2.2
       mkdir build
       cd build
-      & cmake -G "$Env:CMAKE_GENERATOR" ..
+      & cmake -G "$Env:CMAKE_GENERATOR" .. -DSNAPPY_BUILD_TESTS=OFF -DSNAPPY_BUILD_BENCHMARKS=OFF
       if(!$?) { Exit $LASTEXITCODE }
       msbuild Snappy.sln -maxCpuCount -property:Configuration=Debug -property:Platform=x64
       if(!$?) { Exit $LASTEXITCODE }

HISTORY.md

@@ -1,6 +1,33 @@
 # Rocksdb Change Log
 > NOTE: Entries for next release do not go here. Follow instructions in `unreleased_history/README.txt`
 
+## 10.2.1 (04/24/2025)
+### Bug Fixes
+* Fix improper initialization of ExternalTableOptions
+
+## 10.2.0 (04/21/2025)
+### New Features
+* Provide histogram stats `COMPACTION_PREFETCH_BYTES` to measure number of bytes for RocksDB's prefetching (as opposed to file
+system's prefetch) on SST file during compaction read
+* A new API DB::GetNewestUserDefinedTimestamp is added to return the newest user defined timestamp seen in a column family
+* Introduce API `IngestWriteBatchWithIndex()` for ingesting updates into DB while bypassing memtable writes. This improves performance when writing a large write batch to the DB.
+* Add a new CF option `memtable_op_scan_flush_trigger` that triggers a flush of the memtable if an iterator's Seek()/Next() scans over a certain number of invisible entries from the memtable.
+
+### Public API Changes
+* AdvancedColumnFamilyOptions.max_write_buffer_number_to_maintain is deleted. It's deprecated since introduction of a better option max_write_buffer_size_to_maintain since RocksDB 6.5.0.
+* Deprecated API `DB::MaxMemCompactionLevel()`.
+* Deprecated `ReadOptions::ignore_range_deletions`.
+* Deprecated API `experimental::PromoteL0()`.
+* Added arbitrary string map for additional options to be overriden for remote compactions
+* The fail_if_options_file_error option in DBOptions has been removed. The behavior now is to always return failure in any API that fails to persist the OPTIONS file.
+
+### Behavior Changes
+* Make stats `PREFETCH_BYTES_USEFUL`, `PREFETCH_HITS`, `PREFETCH_BYTES` only account for prefetching during user initiated scan
+
+### Bug Fixes
+* Fix a bug in Posix file system that the FSWritableFile created via `FileSystem::ReopenWritableFile` internally does not track the correct file size.
+* Fix a bug where tail size of remote compaction output is not persisted in primary db's manifest
+
 ## 10.1.0 (03/24/2025)
 ### New Features
 * Added a new `DBOptions.calculate_sst_write_lifetime_hint_set` setting that allows to customize which compaction styles SST write lifetime hint calculation is allowed on. Today RocksDB supports only two modes `kCompactionStyleLevel` and `kCompactionStyleUniversal`.

crash_test.mk

@@ -11,18 +11,29 @@ CRASHTEST_MAKE=$(MAKE) -f crash_test.mk
 CRASHTEST_PY=$(PYTHON) -u tools/db_crashtest.py --stress_cmd=$(DB_STRESS_CMD) --cleanup_cmd='$(DB_CLEANUP_CMD)'
 
 .PHONY: crash_test crash_test_with_atomic_flush crash_test_with_txn \
+	crash_test_with_wc_txn crash_test_with_wp_txn crash_test_with_wup_txn \
 	crash_test_with_best_efforts_recovery crash_test_with_ts \
+	crash_test_with_multiops_wc_txn \
+	crash_test_with_multiops_wp_txn \
+	crash_test_with_multiops_wup_txn \
+	crash_test_with_optimistic_txn \
+	crash_test_with_tiered_storage \
 	blackbox_crash_test blackbox_crash_test_with_atomic_flush \
+	blackbox_crash_test_with_wc_txn blackbox_crash_test_with_wp_txn \
+	blackbox_crash_test_with_wup_txn \
 	blackbox_crash_test_with_txn blackbox_crash_test_with_ts \
 	blackbox_crash_test_with_best_efforts_recovery \
-	whitebox_crash_test whitebox_crash_test_with_atomic_flush \
-	whitebox_crash_test_with_txn whitebox_crash_test_with_ts \
 	blackbox_crash_test_with_multiops_wc_txn \
 	blackbox_crash_test_with_multiops_wp_txn \
-	crash_test_with_tiered_storage blackbox_crash_test_with_tiered_storage \
-	whitebox_crash_test_with_tiered_storage \
-	whitebox_crash_test_with_optimistic_txn \
+	blackbox_crash_test_with_multiops_wup_txn \
 	blackbox_crash_test_with_optimistic_txn \
+	blackbox_crash_test_with_tiered_storage \
+	whitebox_crash_test whitebox_crash_test_with_atomic_flush \
+	whitebox_crash_test_with_wc_txn whitebox_crash_test_with_wp_txn \
+	whitebox_crash_test_with_wup_txn \
+	whitebox_crash_test_with_txn whitebox_crash_test_with_ts \
+	whitebox_crash_test_with_optimistic_txn \
+	whitebox_crash_test_with_tiered_storage \
 
 crash_test: $(DB_STRESS_CMD)
 # Do not parallelize
@@ -34,10 +45,20 @@ crash_test_with_atomic_flush: $(DB_STRESS_CMD)
 	$(CRASHTEST_MAKE) whitebox_crash_test_with_atomic_flush
 	$(CRASHTEST_MAKE) blackbox_crash_test_with_atomic_flush
 
-crash_test_with_txn: $(DB_STRESS_CMD)
+crash_test_with_wc_txn: $(DB_STRESS_CMD)
 # Do not parallelize
-	$(CRASHTEST_MAKE) whitebox_crash_test_with_txn
-	$(CRASHTEST_MAKE) blackbox_crash_test_with_txn
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_wc_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_wc_txn
+
+crash_test_with_wp_txn: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_wp_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_wp_txn
+
+crash_test_with_wup_txn: $(DB_STRESS_CMD)
+# Do not parallelize
+	$(CRASHTEST_MAKE) whitebox_crash_test_with_wup_txn
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_wup_txn
 
 crash_test_with_optimistic_txn: $(DB_STRESS_CMD)
 # Do not parallelize
@@ -62,6 +83,9 @@ crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
 crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
 	$(CRASHTEST_MAKE) blackbox_crash_test_with_multiops_wp_txn
 
+crash_test_with_multiops_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_MAKE) blackbox_crash_test_with_multiops_wup_txn
+
 blackbox_crash_test: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --simple blackbox $(CRASH_TEST_EXT_ARGS)
 	$(CRASHTEST_PY) blackbox $(CRASH_TEST_EXT_ARGS)
@@ -69,8 +93,14 @@ blackbox_crash_test: $(DB_STRESS_CMD)
 blackbox_crash_test_with_atomic_flush: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --cf_consistency blackbox $(CRASH_TEST_EXT_ARGS)
 
-blackbox_crash_test_with_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --txn blackbox $(CRASH_TEST_EXT_ARGS)
+blackbox_crash_test_with_wc_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox --txn_write_policy 0 $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_wp_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox --txn_write_policy 1 $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn blackbox --txn_write_policy 2 $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_best_efforts_recovery: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --test_best_efforts_recovery blackbox $(CRASH_TEST_EXT_ARGS)
@@ -79,10 +109,13 @@ blackbox_crash_test_with_ts: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --enable_ts blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --test_multiops_txn --write_policy write_committed blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) --test_multiops_txn --txn_write_policy 0 blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --test_multiops_txn --write_policy write_prepared blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) --test_multiops_txn --txn_write_policy 1 blackbox $(CRASH_TEST_EXT_ARGS)
+
+blackbox_crash_test_with_multiops_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --test_multiops_txn --txn_write_policy 2 blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_tiered_storage: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --test_tiered_storage blackbox $(CRASH_TEST_EXT_ARGS)
@@ -104,9 +137,17 @@ whitebox_crash_test_with_atomic_flush: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --cf_consistency whitebox  --random_kill_odd \
       $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
 
-whitebox_crash_test_with_txn: $(DB_STRESS_CMD)
-	$(CRASHTEST_PY) --txn whitebox --random_kill_odd \
-      $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+whitebox_crash_test_with_wc_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --txn_write_policy 0 \
+	  --random_kill_odd $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_wp_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --txn_write_policy 1 \
+      --random_kill_odd $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+whitebox_crash_test_with_wup_txn: $(DB_STRESS_CMD)
+	$(CRASHTEST_PY) --txn whitebox --txn_write_policy 2 \
+      --random_kill_odd $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
 
 whitebox_crash_test_with_ts: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --enable_ts whitebox --random_kill_odd \
@@ -119,3 +160,8 @@ whitebox_crash_test_with_tiered_storage: $(DB_STRESS_CMD)
 whitebox_crash_test_with_optimistic_txn: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --optimistic_txn whitebox --random_kill_odd \
       $(CRASH_TEST_KILL_ODD) $(CRASH_TEST_EXT_ARGS)
+
+# Old names DEPRECATED
+crash_test_with_txn: crash_test_with_wc_txn
+whitebox_crash_test_with_txn: whitebox_crash_test_with_wc_txn
+blackbox_crash_test_with_txn: blackbox_crash_test_with_wc_txn

db/arena_wrapped_db_iter.cc

@@ -42,9 +42,9 @@ Status ArenaWrappedDBIter::GetProperty(std::string prop_name,
 void ArenaWrappedDBIter::Init(
     Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
     const MutableCFOptions& mutable_cf_options, const Version* version,
-    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) {
+    const SequenceNumber& sequence, uint64_t version_number,
+    ReadCallback* read_callback, ColumnFamilyHandleImpl* cfh,
+    bool expose_blob_index, bool allow_refresh, ReadOnlyMemTable* active_mem) {
   read_options_ = read_options;
   if (!CheckFSFeatureSupport(env->GetFileSystem().get(),
                              FSSupportedOps::kAsyncIO)) {
@@ -52,15 +52,14 @@ void ArenaWrappedDBIter::Init(
   }
   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);
+  db_iter_ = DBIter::NewIter(
+      env, read_options_, ioptions, mutable_cf_options,
+      ioptions.user_comparator, /*internal_iter=*/nullptr, version, sequence,
+      read_callback, cfh, expose_blob_index, active_mem, &arena_);
 
   sv_number_ = version_number;
   allow_refresh_ = allow_refresh;
+  allow_mark_memtable_for_flush_ = active_mem;
   memtable_range_tombstone_iter_ = nullptr;
 }
 
@@ -166,9 +165,8 @@ void ArenaWrappedDBIter::DoRefresh(const Snapshot* snapshot,
     read_callback_->Refresh(read_seq);
   }
   Init(env, read_options_, cfd->ioptions(), sv->mutable_cf_options, sv->current,
-       read_seq, sv->mutable_cf_options.max_sequential_skip_in_iterations,
-       sv->version_number, read_callback_, cfh_, expose_blob_index_,
-       allow_refresh_);
+       read_seq, sv->version_number, read_callback_, cfh_, expose_blob_index_,
+       allow_refresh_, allow_mark_memtable_for_flush_ ? sv->mem : nullptr);
 
   InternalIterator* internal_iter = db_impl->NewInternalIterator(
       read_options_, cfd, sv, &arena_, read_seq,
@@ -253,20 +251,26 @@ Status ArenaWrappedDBIter::Refresh(const Snapshot* snapshot) {
 }
 
 ArenaWrappedDBIter* NewArenaWrappedDbIterator(
-    Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
-    const MutableCFOptions& mutable_cf_options, const Version* version,
-    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,
-    uint64_t version_number, ReadCallback* read_callback,
-    ColumnFamilyHandleImpl* cfh, bool expose_blob_index, bool allow_refresh) {
-  ArenaWrappedDBIter* iter = new ArenaWrappedDBIter();
-  iter->Init(env, read_options, ioptions, mutable_cf_options, version, sequence,
-             max_sequential_skip_in_iterations, version_number, read_callback,
-             cfh, expose_blob_index, allow_refresh);
+    Env* env, const ReadOptions& read_options, ColumnFamilyHandleImpl* cfh,
+    SuperVersion* sv, const SequenceNumber& sequence,
+    ReadCallback* read_callback, DBImpl* db_impl, bool expose_blob_index,
+    bool allow_refresh, bool allow_mark_memtable_for_flush) {
+  ArenaWrappedDBIter* db_iter = new ArenaWrappedDBIter();
+  db_iter->Init(env, read_options, cfh->cfd()->ioptions(),
+                sv->mutable_cf_options, sv->current, sequence,
+                sv->version_number, read_callback, cfh, expose_blob_index,
+                allow_refresh,
+                allow_mark_memtable_for_flush ? sv->mem : nullptr);
   if (cfh != nullptr && allow_refresh) {
-    iter->StoreRefreshInfo(cfh, read_callback, expose_blob_index);
+    db_iter->StoreRefreshInfo(cfh, read_callback, expose_blob_index);
   }
 
-  return iter;
+  InternalIterator* internal_iter = db_impl->NewInternalIterator(
+      db_iter->GetReadOptions(), cfh->cfd(), sv, db_iter->GetArena(), sequence,
+      /*allow_unprepared_value=*/true, db_iter);
+  db_iter->SetIterUnderDBIter(internal_iter);
+
+  return db_iter;
 }
 
 }  // namespace ROCKSDB_NAMESPACE

db/arena_wrapped_db_iter.h

@@ -19,7 +19,6 @@
 #include "options/cf_options.h"
 #include "rocksdb/db.h"
 #include "rocksdb/iterator.h"
-#include "util/autovector.h"
 
 namespace ROCKSDB_NAMESPACE {
 
@@ -99,13 +98,19 @@ class ArenaWrappedDBIter : public Iterator {
 
   bool PrepareValue() override { return db_iter_->PrepareValue(); }
 
+  void Prepare(const std::vector<ScanOptions>& scan_opts) override {
+    db_iter_->Prepare(scan_opts);
+  }
+
+  // FIXME: we could just pass SV in for mutable cf option, version and version
+  // number, but this is used by SstFileReader which does not have a SV.
   void Init(Env* env, const ReadOptions& read_options,
             const ImmutableOptions& ioptions,
             const MutableCFOptions& mutable_cf_options, const Version* version,
-            const SequenceNumber& sequence,
-            uint64_t max_sequential_skip_in_iterations, uint64_t version_number,
+            const SequenceNumber& sequence, uint64_t version_number,
             ReadCallback* read_callback, ColumnFamilyHandleImpl* cfh,
-            bool expose_blob_index, bool allow_refresh);
+            bool expose_blob_index, bool allow_refresh,
+            ReadOnlyMemTable* active_mem);
 
   // Store some parameters so we can refresh the iterator at a later point
   // with these same params
@@ -128,20 +133,16 @@ class ArenaWrappedDBIter : public Iterator {
   ReadCallback* read_callback_;
   bool expose_blob_index_ = false;
   bool allow_refresh_ = true;
+  bool allow_mark_memtable_for_flush_ = true;
   // If this is nullptr, it means the mutable memtable does not contain range
   // tombstone when added under this DBIter.
   std::unique_ptr<TruncatedRangeDelIterator>* memtable_range_tombstone_iter_ =
       nullptr;
 };
 
-// Generate the arena wrapped iterator class.
-// `cfh` is used for reneweal. If left null, renewal will not
-// be supported.
 ArenaWrappedDBIter* NewArenaWrappedDbIterator(
-    Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
-    const MutableCFOptions& mutable_cf_options, const Version* version,
-    const SequenceNumber& sequence, uint64_t max_sequential_skip_in_iterations,
-    uint64_t version_number, ReadCallback* read_callback,
-    ColumnFamilyHandleImpl* cfh = nullptr, bool expose_blob_index = false,
-    bool allow_refresh = true);
+    Env* env, const ReadOptions& read_options, ColumnFamilyHandleImpl* cfh,
+    SuperVersion* sv, const SequenceNumber& sequence,
+    ReadCallback* read_callback, DBImpl* db_impl, bool expose_blob_index,
+    bool allow_refresh, bool allow_mark_memtable_for_flush);
 }  // namespace ROCKSDB_NAMESPACE

db/c.cc

@@ -3295,6 +3295,16 @@ uint64_t rocksdb_options_get_periodic_compaction_seconds(
   return opt->rep.periodic_compaction_seconds;
 }
 
+void rocksdb_options_set_memtable_op_scan_flush_trigger(rocksdb_options_t* opt,
+                                                        uint32_t n) {
+  opt->rep.memtable_op_scan_flush_trigger = n;
+}
+
+uint32_t rocksdb_options_get_memtable_op_scan_flush_trigger(
+    rocksdb_options_t* opt) {
+  return opt->rep.memtable_op_scan_flush_trigger;
+}
+
 void rocksdb_options_enable_statistics(rocksdb_options_t* opt) {
   opt->rep.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
 }
@@ -3804,16 +3814,6 @@ int rocksdb_options_get_min_write_buffer_number_to_merge(
   return opt->rep.min_write_buffer_number_to_merge;
 }
 
-void rocksdb_options_set_max_write_buffer_number_to_maintain(
-    rocksdb_options_t* opt, int n) {
-  opt->rep.max_write_buffer_number_to_maintain = n;
-}
-
-int rocksdb_options_get_max_write_buffer_number_to_maintain(
-    rocksdb_options_t* opt) {
-  return opt->rep.max_write_buffer_number_to_maintain;
-}
-
 void rocksdb_options_set_max_write_buffer_size_to_maintain(
     rocksdb_options_t* opt, int64_t n) {
   opt->rep.max_write_buffer_size_to_maintain = n;

db/c_test.c

@@ -2129,6 +2129,10 @@ int main(int argc, char** argv) {
     CheckCondition(100000 ==
                    rocksdb_options_get_periodic_compaction_seconds(o));
 
+    rocksdb_options_set_memtable_op_scan_flush_trigger(o, 100);
+    CheckCondition(100 ==
+                   rocksdb_options_get_memtable_op_scan_flush_trigger(o));
+
     rocksdb_options_set_ttl(o, 5000);
     CheckCondition(5000 == rocksdb_options_get_ttl(o));
 
@@ -2146,10 +2150,6 @@ int main(int argc, char** argv) {
     CheckCondition(23 ==
                    rocksdb_options_get_min_write_buffer_number_to_merge(o));
 
-    rocksdb_options_set_max_write_buffer_number_to_maintain(o, 64);
-    CheckCondition(64 ==
-                   rocksdb_options_get_max_write_buffer_number_to_maintain(o));
-
     rocksdb_options_set_max_write_buffer_size_to_maintain(o, 50000);
     CheckCondition(50000 ==
                    rocksdb_options_get_max_write_buffer_size_to_maintain(o));
@@ -2407,8 +2407,6 @@ int main(int argc, char** argv) {
     CheckCondition(97 == rocksdb_options_get_max_write_buffer_number(copy));
     CheckCondition(23 ==
                    rocksdb_options_get_min_write_buffer_number_to_merge(copy));
-    CheckCondition(
-        64 == rocksdb_options_get_max_write_buffer_number_to_maintain(copy));
     CheckCondition(50000 ==
                    rocksdb_options_get_max_write_buffer_size_to_maintain(copy));
     CheckCondition(1 == rocksdb_options_get_enable_pipelined_write(copy));
@@ -2572,6 +2570,12 @@ int main(int argc, char** argv) {
     CheckCondition(100000 ==
                    rocksdb_options_get_periodic_compaction_seconds(o));
 
+    rocksdb_options_set_memtable_op_scan_flush_trigger(copy, 800);
+    CheckCondition(800 ==
+                   rocksdb_options_get_memtable_op_scan_flush_trigger(copy));
+    CheckCondition(100 ==
+                   rocksdb_options_get_memtable_op_scan_flush_trigger(o));
+
     rocksdb_options_set_ttl(copy, 8000);
     CheckCondition(8000 == rocksdb_options_get_ttl(copy));
     CheckCondition(5000 == rocksdb_options_get_ttl(o));
@@ -2596,12 +2600,6 @@ int main(int argc, char** argv) {
     CheckCondition(23 ==
                    rocksdb_options_get_min_write_buffer_number_to_merge(o));
 
-    rocksdb_options_set_max_write_buffer_number_to_maintain(copy, 128);
-    CheckCondition(
-        128 == rocksdb_options_get_max_write_buffer_number_to_maintain(copy));
-    CheckCondition(64 ==
-                   rocksdb_options_get_max_write_buffer_number_to_maintain(o));
-
     rocksdb_options_set_max_write_buffer_size_to_maintain(copy, 9000);
     CheckCondition(9000 ==
                    rocksdb_options_get_max_write_buffer_size_to_maintain(copy));

db/column_family.cc

@@ -262,15 +262,10 @@ ColumnFamilyOptions SanitizeCfOptions(const ImmutableDBOptions& db_options,
   if (result.max_write_buffer_number < 2) {
     result.max_write_buffer_number = 2;
   }
-  // fall back max_write_buffer_number_to_maintain if
-  // max_write_buffer_size_to_maintain is not set
   if (result.max_write_buffer_size_to_maintain < 0) {
     result.max_write_buffer_size_to_maintain =
         result.max_write_buffer_number *
         static_cast<int64_t>(result.write_buffer_size);
-  } else if (result.max_write_buffer_size_to_maintain == 0 &&
-             result.max_write_buffer_number_to_maintain < 0) {
-    result.max_write_buffer_number_to_maintain = result.max_write_buffer_number;
   }
   // bloom filter size shouldn't exceed 1/4 of memtable size.
   if (result.memtable_prefix_bloom_size_ratio > 0.25) {
@@ -453,6 +448,13 @@ ColumnFamilyOptions SanitizeCfOptions(const ImmutableDBOptions& db_options,
     result.preclude_last_level_data_seconds = 0;
   }
 
+  if (read_only && result.memtable_op_scan_flush_trigger != 0) {
+    ROCKS_LOG_WARN(db_options.info_log.get(),
+                   "option memtable_op_scan_flush_trigger is sanitized to "
+                   "0(disabled) for read only DB.");
+    result.memtable_op_scan_flush_trigger = 0;
+  }
+
   return result;
 }
 
@@ -577,7 +579,6 @@ ColumnFamilyData::ColumnFamilyData(
       write_buffer_manager_(write_buffer_manager),
       mem_(nullptr),
       imm_(ioptions_.min_write_buffer_number_to_merge,
-           ioptions_.max_write_buffer_number_to_maintain,
            ioptions_.max_write_buffer_size_to_maintain),
       super_version_(nullptr),
       super_version_number_(0),

db/column_family.h

@@ -537,6 +537,12 @@ class ColumnFamilyData {
     assert(!ts_low.empty());
     const Comparator* ucmp = user_comparator();
     assert(ucmp);
+    // Guard against resurrected full_history_ts_low persisted in MANIFEST
+    // from previous DB sessions. This could happen if UDT was enabled and then
+    // disabled.
+    if (ucmp->timestamp_size() == 0) {
+      return;
+    }
     if (full_history_ts_low_.empty() ||
         ucmp->CompareTimestamp(ts_low, full_history_ts_low_) > 0) {
       full_history_ts_low_ = std::move(ts_low);
@@ -544,6 +550,11 @@ class ColumnFamilyData {
   }
 
   const std::string& GetFullHistoryTsLow() const {
+    const Comparator* ucmp = user_comparator();
+    assert(ucmp);
+    if (ucmp->timestamp_size() == 0) {
+      assert(full_history_ts_low_.empty());
+    }
     return full_history_ts_low_;
   }
 

db/column_family_test.cc

@@ -72,7 +72,6 @@ class ColumnFamilyTestBase : public testing::Test {
     env_->skip_fsync_ = true;
     dbname_ = test::PerThreadDBPath("column_family_test");
     db_options_.create_if_missing = true;
-    db_options_.fail_if_options_file_error = true;
     db_options_.env = env_;
   }
 
@@ -2176,7 +2175,7 @@ TEST_P(ColumnFamilyTest, FlushStaleColumnFamilies) {
   ASSERT_TRUE(has_cf2_sst);
 
   ASSERT_OK(Flush(0));
-  ASSERT_EQ(0, dbfull()->TEST_total_log_size());
+  ASSERT_EQ(0, dbfull()->TEST_wals_total_size());
   Close();
 }
 

db/compaction/compaction_service_job.cc

@@ -77,7 +77,9 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
       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());
+      compaction->bottommost_level(), compaction->start_level(),
+      compaction->output_level());
+
   CompactionServiceScheduleResponse response =
       db_options_.compaction_service->Schedule(info, compaction_input_binary);
   switch (response.status) {
@@ -240,7 +242,8 @@ CompactionJob::ProcessKeyValueCompactionWithCompactionService(
     meta.marked_for_compaction = file.marked_for_compaction;
     meta.unique_id = file.unique_id;
     meta.temperature = file.file_temperature;
-
+    meta.tail_size =
+        FileMetaData::CalculateTailSize(file_size, file.table_properties);
     auto cfd = compaction->column_family_data();
     CompactionOutputs* compaction_outputs =
         sub_compact->Outputs(file.is_proximal_level_output);

db/compaction/compaction_service_test.cc

@@ -22,9 +22,9 @@ class MyTestCompactionService : public CompactionService {
         options_(options),
         statistics_(statistics),
         start_info_("na", "na", "na", 0, Env::TOTAL, CompactionReason::kUnknown,
-                    false, false, false),
+                    false, false, false, -1, -1),
         wait_info_("na", "na", "na", 0, Env::TOTAL, CompactionReason::kUnknown,
-                   false, false, false),
+                   false, false, false, -1, -1),
         listeners_(listeners),
         table_properties_collector_factories_(
             std::move(table_properties_collector_factories)) {}
@@ -84,6 +84,7 @@ class MyTestCompactionService : public CompactionService {
     options_override.table_factory = options_.table_factory;
     options_override.sst_partitioner_factory = options_.sst_partitioner_factory;
     options_override.statistics = statistics_;
+    options_override.info_log = options_.info_log;
     if (!listeners_.empty()) {
       options_override.listeners = listeners_;
     }
@@ -277,8 +278,17 @@ TEST_F(CompactionServiceTest, BasicCompactions) {
   Statistics* primary_statistics = GetPrimaryStatistics();
   Statistics* compactor_statistics = GetCompactorStatistics();
 
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "BlockBasedTable::PrefetchTail::TaiSizeNotRecorded",
+      [&](void* /* arg */) {
+        // Trigger assertion to verify precise tail prefetch size calculation
+        assert(false);
+      });
+
+  SyncPoint::GetInstance()->EnableProcessing();
   GenerateTestData();
   ASSERT_OK(dbfull()->TEST_WaitForCompact());
+  SyncPoint::GetInstance()->DisableProcessing();
   VerifyTestData();
 
   auto my_cs = GetCompactionService();
@@ -380,6 +390,7 @@ TEST_F(CompactionServiceTest, BasicCompactions) {
   ASSERT_FALSE(result.stats.is_full_compaction);
 
   Close();
+  SyncPoint::GetInstance()->DisableProcessing();
 }
 
 TEST_F(CompactionServiceTest, ManualCompaction) {
@@ -890,6 +901,12 @@ TEST_F(CompactionServiceTest, TruncatedOutput) {
   Slice end(end_str);
   uint64_t comp_num = my_cs->GetCompactionNum();
 
+  // Skip calculating tail size to avoid crashing due to truncated file size
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "FileMetaData::CalculateTailSize", [&](void* arg) {
+        bool* skip = static_cast<bool*>(arg);
+        *skip = true;
+      });
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
       "CompactionServiceCompactionJob::Run:0", [&](void* arg) {
         CompactionServiceResult* compaction_result =
@@ -906,7 +923,7 @@ TEST_F(CompactionServiceTest, TruncatedOutput) {
           ASSERT_OK(s);
           ASSERT_GT(file_size, 0);
 
-          ASSERT_OK(test::TruncateFile(env_, file_name, file_size / 2));
+          ASSERT_OK(test::TruncateFile(env_, file_name, file_size / 4));
         }
       });
   SyncPoint::GetInstance()->EnableProcessing();
@@ -1250,17 +1267,31 @@ TEST_F(CompactionServiceTest, PrecludeLastLevel) {
 
   // Verify Output Stats
   auto my_cs = GetCompactionService();
-  CompactionServiceResult result;
-  my_cs->GetResult(&result);
-  ASSERT_OK(result.status);
-  ASSERT_GT(result.internal_stats.output_level_stats.cpu_micros, 0);
-  ASSERT_GT(result.internal_stats.output_level_stats.micros, 0);
-  ASSERT_EQ(result.internal_stats.output_level_stats.num_output_records +
-                result.internal_stats.proximal_level_stats.num_output_records,
-            kNumTrigger * kNumKeys);
-  ASSERT_EQ(result.internal_stats.output_level_stats.num_output_files +
-                result.internal_stats.proximal_level_stats.num_output_files,
-            2);
+  {
+    CompactionServiceResult result;
+    my_cs->GetResult(&result);
+    ASSERT_OK(result.status);
+    ASSERT_GT(result.internal_stats.output_level_stats.cpu_micros, 0);
+    ASSERT_GT(result.internal_stats.output_level_stats.micros, 0);
+    ASSERT_EQ(result.internal_stats.output_level_stats.num_output_records +
+                  result.internal_stats.proximal_level_stats.num_output_records,
+              kNumTrigger * kNumKeys);
+    ASSERT_EQ(result.internal_stats.output_level_stats.num_output_files +
+                  result.internal_stats.proximal_level_stats.num_output_files,
+              2);
+
+    CompactionServiceJobInfo info = my_cs->GetCompactionInfoForStart();
+    ASSERT_EQ(0, info.base_input_level);
+    ASSERT_EQ(kNumLevels - 1, info.output_level);
+  }
+  SyncPoint::GetInstance()->DisableProcessing();
+  // Disable Preclude feature and run full compaction to the bottommost level
+  {
+    ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+    CompactionServiceJobInfo info = my_cs->GetCompactionInfoForStart();
+    ASSERT_EQ(kNumLevels - 2, info.base_input_level);
+    ASSERT_EQ(kNumLevels - 1, info.output_level);
+  }
 }
 
 TEST_F(CompactionServiceTest, ConcurrentCompaction) {
@@ -1330,12 +1361,16 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
   ASSERT_EQ(true, info.is_manual_compaction);
   ASSERT_EQ(false, info.is_full_compaction);
   ASSERT_EQ(true, info.bottommost_level);
+  ASSERT_EQ(1, info.base_input_level);
+  ASSERT_EQ(2, info.output_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);
+  ASSERT_EQ(1, info.base_input_level);
+  ASSERT_EQ(2, info.output_level);
 
   // Test priority BOTTOM
   env_->SetBackgroundThreads(1, Env::BOTTOM);
@@ -1367,18 +1402,24 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
   ASSERT_EQ(false, info.is_full_compaction);
   ASSERT_EQ(true, info.bottommost_level);
   ASSERT_EQ(Env::BOTTOM, info.priority);
+  ASSERT_EQ(0, info.base_input_level);
+  ASSERT_EQ(db_->NumberLevels() - 1, info.output_level);
   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);
+  ASSERT_EQ(0, info.base_input_level);
+  ASSERT_EQ(db_->NumberLevels() - 1, info.output_level);
 
   // Test Non-Bottommost Level
   options.num_levels = 4;
   ReopenWithCompactionService(&options);
   my_cs =
       static_cast_with_check<MyTestCompactionService>(GetCompactionService());
+  int compaction_num = my_cs->GetCompactionNum();
+  ASSERT_EQ(0, compaction_num);
 
   for (int i = 0; i < options.level0_file_num_compaction_trigger; i++) {
     for (int j = 0; j < 10; j++) {
@@ -1387,16 +1428,22 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
     }
     ASSERT_OK(Flush());
   }
-
   ASSERT_OK(dbfull()->TEST_WaitForCompact());
+
+  // This is trivial move. Done locally.
+  ASSERT_EQ(0, my_cs->GetCompactionNum());
   info = my_cs->GetCompactionInfoForStart();
   ASSERT_EQ(false, info.is_manual_compaction);
   ASSERT_EQ(false, info.is_full_compaction);
   ASSERT_EQ(false, info.bottommost_level);
+  ASSERT_EQ(-1, info.base_input_level);
+  ASSERT_EQ(-1, info.output_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);
+  ASSERT_EQ(-1, info.base_input_level);
+  ASSERT_EQ(-1, info.output_level);
 
   // Test Full Compaction + Bottommost Level
   options.num_levels = 6;
@@ -1411,7 +1458,10 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
     }
     ASSERT_OK(Flush());
   }
+  MoveFilesToLevel(options.num_levels - 1);
 
+  // Force final level compaction
+  // base_input_level == output_level == last_level
   CompactRangeOptions cro;
   cro.bottommost_level_compaction = BottommostLevelCompaction::kForce;
   ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));
@@ -1423,10 +1473,15 @@ TEST_F(CompactionServiceTest, CompactionInfo) {
   ASSERT_EQ(true, info.bottommost_level);
   ASSERT_EQ(CompactionReason::kManualCompaction, info.compaction_reason);
   info = my_cs->GetCompactionInfoForWait();
+  ASSERT_EQ(options.num_levels - 1, info.base_input_level);
+  ASSERT_EQ(options.num_levels - 1, info.output_level);
   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);
+  ASSERT_EQ(options.num_levels - 1, info.base_input_level);
+  ASSERT_EQ(options.num_levels - 1, info.output_level);
+  ASSERT_EQ("0,0,0,0,0,1", FilesPerLevel());
 }
 
 TEST_F(CompactionServiceTest, FallbackLocalAuto) {

db/db_filesnapshot.cc

@@ -75,11 +75,9 @@ Status DBImpl::GetLiveFiles(std::vector<std::string>& ret,
 
   ret.emplace_back(CurrentFileName(""));
   ret.emplace_back(DescriptorFileName("", versions_->manifest_file_number()));
-  // The OPTIONS file number is zero in read-write mode when OPTIONS file
-  // writing failed and the DB was configured with
-  // `fail_if_options_file_error == false`. In read-only mode the OPTIONS file
-  // number is zero when no OPTIONS file exist at all. In those cases we do not
-  // record any OPTIONS file in the live file list.
+  // In read-only mode the OPTIONS file number is zero when no OPTIONS file
+  // exist at all. In this cases we do not record any OPTIONS file in the live
+  // file list.
   if (versions_->options_file_number() != 0) {
     ret.emplace_back(OptionsFileName("", versions_->options_file_number()));
   }
@@ -185,14 +183,14 @@ Status DBImpl::GetSortedWalFilesImpl(VectorWalPtr& files, bool need_seqnos) {
   return s;
 }
 
-Status DBImpl::GetCurrentWalFile(std::unique_ptr<WalFile>* current_log_file) {
+Status DBImpl::GetCurrentWalFile(std::unique_ptr<WalFile>* current_wal_file) {
   uint64_t current_logfile_number;
   {
     InstrumentedMutexLock l(&mutex_);
-    current_logfile_number = logfile_number_;
+    current_logfile_number = cur_wal_number_;
   }
 
-  return wal_manager_.GetLiveWalFile(current_logfile_number, current_log_file);
+  return wal_manager_.GetLiveWalFile(current_logfile_number, current_wal_file);
 }
 
 Status DBImpl::GetLiveFilesStorageInfo(
@@ -332,7 +330,7 @@ Status DBImpl::GetLiveFilesStorageInfo(
   const uint64_t options_size = versions_->options_file_size_;
   const uint64_t min_log_num = MinLogNumberToKeep();
   // Ensure consistency with manifest for track_and_verify_wals_in_manifest
-  const uint64_t max_log_num = logfile_number_;
+  const uint64_t max_log_num = cur_wal_number_;
 
   mutex_.Unlock();
 
@@ -369,11 +367,9 @@ Status DBImpl::GetLiveFilesStorageInfo(
     }
   }
 
-  // The OPTIONS file number is zero in read-write mode when OPTIONS file
-  // writing failed and the DB was configured with
-  // `fail_if_options_file_error == false`. In read-only mode the OPTIONS file
-  // number is zero when no OPTIONS file exist at all. In those cases we do not
-  // record any OPTIONS file in the live file list.
+  // In read-only mode the OPTIONS file number is zero when no OPTIONS file
+  // exist at all. In this cases we do not record any OPTIONS file in the live
+  // file list.
   if (options_number != 0) {
     results.emplace_back();
     LiveFileStorageInfo& info = results.back();

db/db_impl/db_impl.cc

@@ -74,6 +74,7 @@
 #include "options/cf_options.h"
 #include "options/options_helper.h"
 #include "options/options_parser.h"
+#include "util/udt_util.h"
 #ifdef ROCKSDB_JEMALLOC
 #include "port/jemalloc_helper.h"
 #endif
@@ -169,7 +170,6 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
                bool read_only)
     : dbname_(dbname),
       own_info_log_(options.info_log == nullptr),
-      init_logger_creation_s_(),
       initial_db_options_(SanitizeOptions(dbname, options, read_only,
                                           &init_logger_creation_s_)),
       env_(initial_db_options_.env),
@@ -185,7 +185,6 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
       mutex_(stats_, immutable_db_options_.clock, DB_MUTEX_WAIT_MICROS,
              immutable_db_options_.use_adaptive_mutex),
 #endif  // COERCE_CONTEXT_SWITCH
-      default_cf_handle_(nullptr),
       error_handler_(this, immutable_db_options_, &mutex_),
       event_logger_(immutable_db_options_.info_log.get()),
       max_total_in_memory_state_(0),
@@ -194,45 +193,15 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
           file_options_, immutable_db_options_)),
       seq_per_batch_(seq_per_batch),
       batch_per_txn_(batch_per_txn),
-      next_job_id_(1),
-      shutting_down_(false),
-      reject_new_background_jobs_(false),
-      db_lock_(nullptr),
-      manual_compaction_paused_(false),
       bg_cv_(&mutex_),
-      logfile_number_(0),
-      log_dir_synced_(false),
-      log_empty_(true),
-      persist_stats_cf_handle_(nullptr),
-      log_sync_cv_(&log_write_mutex_),
-      total_log_size_(0),
-      is_snapshot_supported_(true),
+      wal_sync_cv_(&wal_write_mutex_),
       write_buffer_manager_(immutable_db_options_.write_buffer_manager.get()),
       write_thread_(immutable_db_options_),
       nonmem_write_thread_(immutable_db_options_),
       write_controller_(mutable_db_options_.delayed_write_rate),
-      last_batch_group_size_(0),
-      unscheduled_flushes_(0),
-      unscheduled_compactions_(0),
-      bg_bottom_compaction_scheduled_(0),
-      bg_compaction_scheduled_(0),
-      num_running_compactions_(0),
-      bg_flush_scheduled_(0),
-      num_running_flushes_(0),
-      bg_purge_scheduled_(0),
-      disable_delete_obsolete_files_(0),
-      pending_purge_obsolete_files_(0),
       delete_obsolete_files_last_run_(immutable_db_options_.clock->NowMicros()),
-      has_unpersisted_data_(false),
-      unable_to_release_oldest_log_(false),
-      num_running_ingest_file_(0),
       wal_manager_(immutable_db_options_, file_options_, io_tracer_,
                    seq_per_batch),
-      bg_work_paused_(0),
-      bg_compaction_paused_(0),
-      refitting_level_(false),
-      opened_successfully_(false),
-      periodic_task_scheduler_(),
       two_write_queues_(options.two_write_queues),
       manual_wal_flush_(options.manual_wal_flush),
       // last_sequencee_ is always maintained by the main queue that also writes
@@ -250,14 +219,11 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname,
       // requires a custom gc for compaction, we use that to set use_custom_gc_
       // as well.
       use_custom_gc_(seq_per_batch),
-      shutdown_initiated_(false),
       own_sfm_(options.sst_file_manager == nullptr),
-      closed_(false),
       atomic_flush_install_cv_(&mutex_),
       blob_callback_(immutable_db_options_.sst_file_manager.get(), &mutex_,
                      &error_handler_, &event_logger_,
-                     immutable_db_options_.listeners, dbname_),
-      lock_wal_count_(0) {
+                     immutable_db_options_.listeners, dbname_) {
   // !batch_per_trx_ implies seq_per_batch_ because it is only unset for
   // WriteUnprepared, which should use seq_per_batch_.
   assert(batch_per_txn_ || seq_per_batch_);
@@ -636,8 +602,8 @@ Status DBImpl::CloseHelper() {
     mutex_.Lock();
   }
   {
-    InstrumentedMutexLock lock(&log_write_mutex_);
-    for (auto l : logs_to_free_) {
+    InstrumentedMutexLock lock(&wal_write_mutex_);
+    for (auto l : wals_to_free_) {
       delete l;
     }
     for (auto& log : logs_) {
@@ -1180,11 +1146,11 @@ Status DBImpl::TablesRangeTombstoneSummary(ColumnFamilyHandle* column_family,
 
 void DBImpl::ScheduleBgLogWriterClose(JobContext* job_context) {
   mutex_.AssertHeld();
-  if (!job_context->logs_to_free.empty()) {
-    for (auto l : job_context->logs_to_free) {
+  if (!job_context->wals_to_free.empty()) {
+    for (auto l : job_context->wals_to_free) {
       AddToLogsToFreeQueue(l);
     }
-    job_context->logs_to_free.clear();
+    job_context->wals_to_free.clear();
   }
 }
 
@@ -1443,7 +1409,7 @@ Status DBImpl::SetDBOptions(
         WriteThread::Writer w;
         write_thread_.EnterUnbatched(&w, &mutex_);
         if (wal_other_option_changed ||
-            total_log_size_ > GetMaxTotalWalSize()) {
+            wals_total_size_.LoadRelaxed() > GetMaxTotalWalSize()) {
           Status purge_wal_status = SwitchWAL(&write_context);
           if (!purge_wal_status.ok()) {
             ROCKS_LOG_WARN(immutable_db_options_.info_log,
@@ -1470,14 +1436,9 @@ Status DBImpl::SetDBOptions(
     ROCKS_LOG_INFO(immutable_db_options_.info_log, "SetDBOptions() succeeded");
     new_options.Dump(immutable_db_options_.info_log.get());
     if (!persist_options_status.ok()) {
-      if (immutable_db_options_.fail_if_options_file_error) {
-        s = Status::IOError(
-            "SetDBOptions() succeeded, but unable to persist options",
-            persist_options_status.ToString());
-      }
-      ROCKS_LOG_WARN(immutable_db_options_.info_log,
-                     "Unable to persist options in SetDBOptions() -- %s",
-                     persist_options_status.ToString().c_str());
+      s = Status::IOError(
+          "SetDBOptions() succeeded, but unable to persist options",
+          persist_options_status.ToString());
     }
   } else {
     ROCKS_LOG_WARN(immutable_db_options_.info_log, "SetDBOptions failed");
@@ -1512,8 +1473,8 @@ Status DBImpl::FlushWAL(const WriteOptions& write_options, bool sync) {
   if (manual_wal_flush_) {
     IOStatus io_s;
     {
-      // We need to lock log_write_mutex_ since logs_ might change concurrently
-      InstrumentedMutexLock wl(&log_write_mutex_);
+      // We need to lock wal_write_mutex_ since logs_ might change concurrently
+      InstrumentedMutexLock wl(&wal_write_mutex_);
       log::Writer* cur_log_writer = logs_.back().writer;
       io_s = cur_log_writer->WriteBuffer(write_options);
     }
@@ -1540,7 +1501,7 @@ Status DBImpl::FlushWAL(const WriteOptions& write_options, bool sync) {
 }
 
 bool DBImpl::WALBufferIsEmpty() {
-  InstrumentedMutexLock l(&log_write_mutex_);
+  InstrumentedMutexLock l(&wal_write_mutex_);
   log::Writer* cur_log_writer = logs_.back().writer;
   auto res = cur_log_writer->BufferIsEmpty();
   return res;
@@ -1548,7 +1509,7 @@ bool DBImpl::WALBufferIsEmpty() {
 
 Status DBImpl::GetOpenWalSizes(std::map<uint64_t, uint64_t>& number_to_size) {
   assert(number_to_size.empty());
-  InstrumentedMutexLock l(&log_write_mutex_);
+  InstrumentedMutexLock l(&wal_write_mutex_);
   for (auto& log : logs_) {
     auto* open_file = log.writer->file();
     if (open_file) {
@@ -1590,15 +1551,15 @@ IOStatus DBImpl::SyncWalImpl(bool include_current_wal,
   uint64_t up_to_number;
 
   {
-    InstrumentedMutexLock l(&log_write_mutex_);
+    InstrumentedMutexLock l(&wal_write_mutex_);
     assert(!logs_.empty());
 
-    maybe_active_number = logfile_number_;
+    maybe_active_number = cur_wal_number_;
     up_to_number =
         include_current_wal ? maybe_active_number : maybe_active_number - 1;
 
     while (logs_.front().number <= up_to_number && logs_.front().IsSyncing()) {
-      log_sync_cv_.Wait();
+      wal_sync_cv_.Wait();
     }
     // First check that logs are safe to sync in background.
     if (include_current_wal &&
@@ -1622,7 +1583,7 @@ IOStatus DBImpl::SyncWalImpl(bool include_current_wal,
       }
     }
 
-    need_wal_dir_sync = !log_dir_synced_;
+    need_wal_dir_sync = !wal_dir_synced_;
   }
 
   if (include_current_wal) {
@@ -1695,7 +1656,7 @@ IOStatus DBImpl::SyncWalImpl(bool include_current_wal,
                              /*arg=*/nullptr);
   }
   {
-    InstrumentedMutexLock l(&log_write_mutex_);
+    InstrumentedMutexLock l(&wal_write_mutex_);
     for (auto* wal : wals_internally_closed) {
       // We can only modify the state of log::Writer under the mutex
       bool was_closed = wal->PublishIfClosed();
@@ -1812,9 +1773,9 @@ Status DBImpl::UnlockWAL() {
 
 void DBImpl::MarkLogsSynced(uint64_t up_to, bool synced_dir,
                             VersionEdit* synced_wals) {
-  log_write_mutex_.AssertHeld();
-  if (synced_dir && logfile_number_ == up_to) {
-    log_dir_synced_ = true;
+  wal_write_mutex_.AssertHeld();
+  if (synced_dir && cur_wal_number_ == up_to) {
+    wal_dir_synced_ = true;
   }
   for (auto it = logs_.begin(); it != logs_.end() && it->number <= up_to;) {
     auto& wal = *it;
@@ -1836,7 +1797,7 @@ void DBImpl::MarkLogsSynced(uint64_t up_to, bool synced_dir,
           (immutable_db_options_.background_close_inactive_wals &&
            wal.GetPreSyncSize() == wal.writer->file()->GetFlushedSize())) {
         // Fully synced
-        logs_to_free_.push_back(wal.ReleaseWriter());
+        wals_to_free_.push_back(wal.ReleaseWriter());
         it = logs_.erase(it);
       } else {
         wal.FinishSync();
@@ -1849,17 +1810,17 @@ void DBImpl::MarkLogsSynced(uint64_t up_to, bool synced_dir,
       ++it;
     }
   }
-  log_sync_cv_.SignalAll();
+  wal_sync_cv_.SignalAll();
 }
 
 void DBImpl::MarkLogsNotSynced(uint64_t up_to) {
-  log_write_mutex_.AssertHeld();
+  wal_write_mutex_.AssertHeld();
   for (auto it = logs_.begin(); it != logs_.end() && it->number <= up_to;
        ++it) {
     auto& wal = *it;
     wal.FinishSync();
   }
-  log_sync_cv_.SignalAll();
+  wal_sync_cv_.SignalAll();
 }
 
 SequenceNumber DBImpl::GetLatestSequenceNumber() const {
@@ -1895,6 +1856,69 @@ Status DBImpl::GetFullHistoryTsLow(ColumnFamilyHandle* column_family,
   return Status::OK();
 }
 
+Status DBImpl::GetNewestUserDefinedTimestamp(ColumnFamilyHandle* column_family,
+                                             std::string* newest_timestamp) {
+  if (newest_timestamp == nullptr) {
+    return Status::InvalidArgument("newest_timestamp is nullptr");
+  }
+  ColumnFamilyData* cfd = nullptr;
+  if (column_family == nullptr) {
+    cfd = default_cf_handle_->cfd();
+  } else {
+    auto cfh = static_cast_with_check<ColumnFamilyHandleImpl>(column_family);
+    assert(cfh != nullptr);
+    cfd = cfh->cfd();
+  }
+  assert(cfd != nullptr && cfd->user_comparator() != nullptr);
+  if (cfd->user_comparator()->timestamp_size() == 0) {
+    return Status::InvalidArgument(
+        "Timestamp is not enabled in this column family");
+  }
+  if (cfd->ioptions().persist_user_defined_timestamps) {
+    return Status::NotSupported(
+        "GetNewestUserDefinedTimestamp doesn't support the case when user"
+        "defined timestamps are persisted.");
+  }
+
+  Status status;
+  // Acquire SuperVersion
+  SuperVersion* sv = GetAndRefSuperVersion(cfd);
+  {
+    InstrumentedMutexLock l(&mutex_);
+    bool enter_write_thread = sv->mem == cfd->mem();
+    WriteThread::Writer w;
+    // Enter write thread to read the mutable memtable to avoid racing access
+    // with concurrent writes. No need to enter nonmem_write_thread_ since this
+    // call only care about memtable writes, not WAL writes.
+    if (enter_write_thread) {
+      write_thread_.EnterUnbatched(&w, &mutex_);
+      WaitForPendingWrites();
+    }
+    *newest_timestamp = sv->mem->GetNewestUDT().ToString();
+    assert(!newest_timestamp->empty() || sv->mem->IsEmpty());
+    if (enter_write_thread) {
+      write_thread_.ExitUnbatched(&w);
+    }
+  }
+  // Read from immutable memtables if nothing found in mutable memtable.
+  if (newest_timestamp->empty()) {
+    *newest_timestamp = sv->imm->GetNewestUDT().ToString();
+  }
+  // Read from SST files if no result can be found in memtables.
+  if (newest_timestamp->empty() && sv->current->GetSstFilesSize() != 0) {
+    // full_history_ts_low is used to track the exclusive upperbound of
+    // flushed user defined timestamp. So we can use it to deduce the newest
+    // timestamp in the SST files that the column family has seen.
+    Slice full_history_ts_low = sv->full_history_ts_low;
+    if (!full_history_ts_low.empty()) {
+      GetU64CutoffTsFromFullHistoryTsLow(&full_history_ts_low,
+                                         newest_timestamp);
+    }
+  }
+  ReturnAndCleanupSuperVersion(cfd, sv);
+  return status;
+}
+
 InternalIterator* DBImpl::NewInternalIterator(const ReadOptions& read_options,
                                               Arena* arena,
                                               SequenceNumber sequence,
@@ -1928,10 +1952,10 @@ void DBImpl::BackgroundCallPurge() {
   TEST_SYNC_POINT("DBImpl::BackgroundCallPurge:beforeMutexLock");
   mutex_.Lock();
 
-  while (!logs_to_free_queue_.empty()) {
-    assert(!logs_to_free_queue_.empty());
-    log::Writer* log_writer = *(logs_to_free_queue_.begin());
-    logs_to_free_queue_.pop_front();
+  while (!wals_to_free_queue_.empty()) {
+    assert(!wals_to_free_queue_.empty());
+    log::Writer* log_writer = *(wals_to_free_queue_.begin());
+    wals_to_free_queue_.pop_front();
     mutex_.Unlock();
     delete log_writer;
     mutex_.Lock();
@@ -3597,7 +3621,7 @@ Status DBImpl::CreateColumnFamilyImpl(const ReadOptions& read_options,
     edit.AddColumnFamily(column_family_name);
     uint32_t new_id = versions_->GetColumnFamilySet()->GetNextColumnFamilyID();
     edit.SetColumnFamily(new_id);
-    edit.SetLogNumber(logfile_number_);
+    edit.SetLogNumber(cur_wal_number_);
     edit.SetComparatorName(cf_options.comparator->Name());
     edit.SetPersistUserDefinedTimestamps(
         cf_options.persist_user_defined_timestamps);
@@ -3796,6 +3820,16 @@ bool DBImpl::KeyMayExist(const ReadOptions& read_options,
   return s.ok() || s.IsIncomplete();
 }
 
+std::unique_ptr<MultiScan> DBImpl::NewMultiScan(
+    const ReadOptions& _read_options, ColumnFamilyHandle* column_family,
+    const std::vector<ScanOptions>& scan_opts) {
+  std::unique_ptr<Iterator> iter(NewIterator(_read_options, column_family));
+  iter->Prepare(scan_opts);
+  std::unique_ptr<MultiScan> ms_iter =
+      std::make_unique<MultiScan>(scan_opts, std::move(iter));
+  return ms_iter;
+}
+
 Iterator* DBImpl::NewIterator(const ReadOptions& _read_options,
                               ColumnFamilyHandle* column_family) {
   if (_read_options.io_activity != Env::IOActivity::kUnknown &&
@@ -3852,11 +3886,12 @@ Iterator* DBImpl::NewIterator(const ReadOptions& _read_options,
 
     auto iter = new ForwardIterator(this, read_options, cfd, sv,
                                     /* allow_unprepared_value */ true);
-    result = NewDBIterator(
-        env_, read_options, cfd->ioptions(), sv->mutable_cf_options,
-        cfd->user_comparator(), iter, sv->current, kMaxSequenceNumber,
-        sv->mutable_cf_options.max_sequential_skip_in_iterations,
-        nullptr /* read_callback */, cfh);
+    result = DBIter::NewIter(env_, read_options, cfd->ioptions(),
+                             sv->mutable_cf_options, cfd->user_comparator(),
+                             iter, sv->current, kMaxSequenceNumber,
+                             /*read_callback=*/nullptr, cfh,
+                             /*expose_blob_index=*/false,
+                             /*active_mem=*/sv->mem);
   } else {
     // Note: no need to consider the special case of
     // last_seq_same_as_publish_seq_==false since NewIterator is overridden in
@@ -3934,18 +3969,9 @@ ArenaWrappedDBIter* DBImpl::NewIteratorImpl(
   // Laying out the iterators in the order of being accessed makes it more
   // likely that any iterator pointer is close to the iterator it points to so
   // that they are likely to be in the same cache line and/or page.
-  ArenaWrappedDBIter* db_iter = NewArenaWrappedDbIterator(
-      env_, read_options, cfh->cfd()->ioptions(), sv->mutable_cf_options,
-      sv->current, snapshot,
-      sv->mutable_cf_options.max_sequential_skip_in_iterations,
-      sv->version_number, read_callback, cfh, expose_blob_index, allow_refresh);
-
-  InternalIterator* internal_iter = NewInternalIterator(
-      db_iter->GetReadOptions(), cfh->cfd(), sv, db_iter->GetArena(), snapshot,
-      /* allow_unprepared_value */ true, db_iter);
-  db_iter->SetIterUnderDBIter(internal_iter);
-
-  return db_iter;
+  return NewArenaWrappedDbIterator(
+      env_, read_options, cfh, sv, snapshot, read_callback, this,
+      expose_blob_index, allow_refresh, /*allow_mark_memtable_for_flush=*/true);
 }
 
 std::unique_ptr<Iterator> DBImpl::NewCoalescingIterator(
@@ -4070,13 +4096,11 @@ Status DBImpl::NewIterators(
                                       cf_sv_pair.super_version,
                                       /* allow_unprepared_value */ true);
       iterators->push_back(
-          NewDBIterator(env_, read_options, cf_sv_pair.cfd->ioptions(),
-                        cf_sv_pair.super_version->mutable_cf_options,
-                        cf_sv_pair.cfd->user_comparator(), iter,
-                        cf_sv_pair.super_version->current, kMaxSequenceNumber,
-                        cf_sv_pair.super_version->mutable_cf_options
-                            .max_sequential_skip_in_iterations,
-                        nullptr /*read_callback*/, cf_sv_pair.cfh));
+          DBIter::NewIter(env_, read_options, cf_sv_pair.cfd->ioptions(),
+                          cf_sv_pair.super_version->mutable_cf_options,
+                          cf_sv_pair.cfd->user_comparator(), iter,
+                          cf_sv_pair.super_version->current, kMaxSequenceNumber,
+                          nullptr /*read_callback*/, cf_sv_pair.cfh));
     }
   } else {
     for (const auto& cf_sv_pair : cf_sv_pairs) {
@@ -5435,12 +5459,7 @@ Status DBImpl::WriteOptionsFile(const WriteOptions& write_options,
   if (!s.ok()) {
     ROCKS_LOG_WARN(immutable_db_options_.info_log,
                    "Unnable to persist options -- %s", s.ToString().c_str());
-    if (immutable_db_options_.fail_if_options_file_error) {
-      s = Status::IOError("Unable to persist options.", s.ToString().c_str());
-    } else {
-      // Ignore error
-      s = Status::OK();
-    }
+    s = Status::IOError("Unable to persist options.", s.ToString().c_str());
   }
 
   // Restore lock if appropriate

db/db_impl/db_impl.h

@@ -173,10 +173,10 @@ struct DBOpenLogRecordReadReporter : public log::Reader::Reporter {
 
   void OldLogRecord(size_t bytes) override;
 
-  uint64_t GetCorruptedLogNumber() const { return corrupted_log_number_; }
+  uint64_t GetCorruptedLogNumber() const { return corrupted_wal_number_; }
 
  private:
-  uint64_t corrupted_log_number_ = kMaxSequenceNumber;
+  uint64_t corrupted_wal_number_ = kMaxSequenceNumber;
 };
 
 // While DB is the public interface of RocksDB, and DBImpl is the actual
@@ -256,6 +256,10 @@ class DBImpl : public DB {
   Status WriteWithCallback(const WriteOptions& options, WriteBatch* updates,
                            UserWriteCallback* user_write_cb) override;
 
+  Status IngestWriteBatchWithIndex(
+      const WriteOptions& options,
+      std::shared_ptr<WriteBatchWithIndex> wbwi) override;
+
   using DB::Get;
   Status Get(const ReadOptions& _read_options,
              ColumnFamilyHandle* column_family, const Slice& key,
@@ -379,6 +383,11 @@ class DBImpl : public DB {
                       const std::vector<ColumnFamilyHandle*>& column_families,
                       std::vector<Iterator*>* iterators) override;
 
+  using DB::NewMultiScan;
+  std::unique_ptr<MultiScan> NewMultiScan(
+      const ReadOptions& _read_options, ColumnFamilyHandle* column_family,
+      const std::vector<ScanOptions>& scan_opts) override;
+
   const Snapshot* GetSnapshot() override;
   void ReleaseSnapshot(const Snapshot* snapshot) override;
 
@@ -497,6 +506,9 @@ class DBImpl : public DB {
   Status GetFullHistoryTsLow(ColumnFamilyHandle* column_family,
                              std::string* ts_low) override;
 
+  Status GetNewestUserDefinedTimestamp(ColumnFamilyHandle* column_family,
+                                       std::string* newest_timestamp) override;
+
   Status GetDbIdentity(std::string& identity) const override;
 
   virtual Status GetDbIdentityFromIdentityFile(const IOOptions& opts,
@@ -530,11 +542,11 @@ class DBImpl : public DB {
 
   // 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
+  // NOTE: unlike alive_wal_files_, this function includes WALs that might
   // be obsolete (but not obsolete to a pending Checkpoint) and not yet fully
   // synced.
   Status GetOpenWalSizes(std::map<uint64_t, uint64_t>& number_to_size);
-  Status GetCurrentWalFile(std::unique_ptr<WalFile>* current_log_file) override;
+  Status GetCurrentWalFile(std::unique_ptr<WalFile>* current_wal_file) override;
   Status GetCreationTimeOfOldestFile(uint64_t* creation_time) override;
 
   Status GetUpdatesSince(
@@ -1068,7 +1080,7 @@ class DBImpl : public DB {
 
   void AddToLogsToFreeQueue(log::Writer* log_writer) {
     mutex_.AssertHeld();
-    logs_to_free_queue_.push_back(log_writer);
+    wals_to_free_queue_.push_back(log_writer);
   }
 
   void AddSuperVersionsToFreeQueue(SuperVersion* sv) {
@@ -1133,7 +1145,7 @@ class DBImpl : public DB {
   bool TEST_UnableToReleaseOldestLog() { return unable_to_release_oldest_log_; }
 
   bool TEST_IsLogGettingFlushed() {
-    return alive_log_files_.begin()->getting_flushed;
+    return alive_wal_files_.begin()->getting_flushed;
   }
 
   Status TEST_SwitchMemtable(ColumnFamilyData* cfd = nullptr);
@@ -1213,7 +1225,9 @@ class DBImpl : public DB {
 
   uint64_t TEST_LogfileNumber();
 
-  uint64_t TEST_total_log_size() const { return total_log_size_; }
+  uint64_t TEST_wals_total_size() const {
+    return wals_total_size_.LoadRelaxed();
+  }
 
   void TEST_GetAllBlockCaches(std::unordered_set<const Cache*>* cache_set);
 
@@ -1371,16 +1385,16 @@ class DBImpl : public DB {
 
   // State below is protected by mutex_
   // With two_write_queues enabled, some of the variables that accessed during
-  // WriteToWAL need different synchronization: log_empty_, alive_log_files_,
-  // logs_, logfile_number_. Refer to the definition of each variable below for
+  // WriteToWAL need different synchronization: wal_empty_, alive_wal_files_,
+  // logs_, cur_wal_number_. Refer to the definition of each variable below for
   // more description.
   //
   // `mutex_` can be a hot lock in some workloads, so it deserves dedicated
   // cachelines.
   mutable CacheAlignedInstrumentedMutex mutex_;
 
-  ColumnFamilyHandleImpl* default_cf_handle_;
-  InternalStats* default_cf_internal_stats_;
+  ColumnFamilyHandleImpl* default_cf_handle_ = nullptr;
+  InternalStats* default_cf_internal_stats_ = nullptr;
 
   // table_cache_ provides its own synchronization
   std::shared_ptr<Cache> table_cache_;
@@ -1392,7 +1406,7 @@ class DBImpl : public DB {
 
   // only used for dynamically adjusting max_total_wal_size. it is a sum of
   // [write_buffer_size * max_write_buffer_number] over all column families
-  std::atomic<uint64_t> max_total_in_memory_state_;
+  std::atomic<uint64_t> max_total_in_memory_state_ = 0;
 
   // The options to access storage files
   const FileOptions file_options_;
@@ -1419,14 +1433,14 @@ class DBImpl : public DB {
 
   // Each flush or compaction gets its own job id. this counter makes sure
   // they're unique
-  std::atomic<int> next_job_id_;
+  std::atomic<int> next_job_id_ = 1;
 
-  std::atomic<bool> shutting_down_;
+  std::atomic<bool> shutting_down_ = false;
 
   // No new background jobs can be queued if true. This is used to prevent new
   // background jobs from being queued after WaitForCompact() completes waiting
   // all background jobs then attempts to close when close_db_ option is true.
-  bool reject_new_background_jobs_;
+  bool reject_new_background_jobs_ = false;
 
   // RecoveryContext struct stores the context about version edits along
   // with corresponding column_family_data and column_family_options.
@@ -1524,11 +1538,11 @@ class DBImpl : public DB {
   // ingests `wbwi` is done.
   // @param memtable_updated Whether the same write that ingests wbwi has
   // updated memtable. This is useful for determining whether to set bg
-  // error when IngestWBWI fails.
-  Status IngestWBWI(std::shared_ptr<WriteBatchWithIndex> wbwi,
-                    const WBWIMemTable::SeqnoRange& assigned_seqno,
-                    uint64_t min_prep_log, SequenceNumber last_seqno,
-                    bool memtable_updated, bool ignore_missing_cf);
+  // error when IngestWBWIAsMemtable fails.
+  Status IngestWBWIAsMemtable(std::shared_ptr<WriteBatchWithIndex> wbwi,
+                              const WBWIMemTable::SeqnoRange& assigned_seqno,
+                              uint64_t min_prep_log, SequenceNumber last_seqno,
+                              bool memtable_updated, bool ignore_missing_cf);
 
   // If disable_memtable is set the application logic must guarantee that the
   // batch will still be skipped from memtable during the recovery. An excption
@@ -1558,18 +1572,17 @@ class DBImpl : public DB {
   Status WriteImpl(const WriteOptions& options, WriteBatch* updates,
                    WriteCallback* callback = nullptr,
                    UserWriteCallback* user_write_cb = nullptr,
-                   uint64_t* log_used = nullptr, uint64_t log_ref = 0,
+                   uint64_t* wal_used = nullptr, uint64_t log_ref = 0,
                    bool disable_memtable = false, uint64_t* seq_used = nullptr,
                    size_t batch_cnt = 0,
                    PreReleaseCallback* pre_release_callback = nullptr,
                    PostMemTableCallback* post_memtable_callback = nullptr,
-                   std::shared_ptr<WriteBatchWithIndex> wbwi = nullptr,
-                   uint64_t min_prep_log = 0);
+                   std::shared_ptr<WriteBatchWithIndex> wbwi = nullptr);
 
   Status PipelinedWriteImpl(const WriteOptions& options, WriteBatch* updates,
                             WriteCallback* callback = nullptr,
                             UserWriteCallback* user_write_cb = nullptr,
-                            uint64_t* log_used = nullptr, uint64_t log_ref = 0,
+                            uint64_t* wal_used = nullptr, uint64_t log_ref = 0,
                             bool disable_memtable = false,
                             uint64_t* seq_used = nullptr);
 
@@ -1596,7 +1609,7 @@ class DBImpl : public DB {
   Status WriteImplWALOnly(
       WriteThread* write_thread, const WriteOptions& options,
       WriteBatch* updates, WriteCallback* callback,
-      UserWriteCallback* user_write_cb, uint64_t* log_used,
+      UserWriteCallback* user_write_cb, uint64_t* wal_used,
       const uint64_t log_ref, uint64_t* seq_used, const size_t sub_batch_cnt,
       PreReleaseCallback* pre_release_callback, const AssignOrder assign_order,
       const PublishLastSeq publish_last_seq, const bool disable_memtable);
@@ -1757,9 +1770,9 @@ class DBImpl : public DB {
     }
   };
 
-  struct LogFileNumberSize {
-    explicit LogFileNumberSize(uint64_t _number) : number(_number) {}
-    LogFileNumberSize() {}
+  struct WalFileNumberSize {
+    explicit WalFileNumberSize(uint64_t _number) : number(_number) {}
+    WalFileNumberSize() {}
     void AddSize(uint64_t new_size) { size += new_size; }
     uint64_t number;
     uint64_t size = 0;
@@ -1781,6 +1794,13 @@ class DBImpl : public DB {
       if (writer->file()) {
         // TODO: plumb Env::IOActivity, Env::IOPriority
         s = writer->WriteBuffer(WriteOptions());
+        if (attempt_truncate_size < SIZE_MAX &&
+            attempt_truncate_size < writer->file()->GetFileSize()) {
+          Status s2 = writer->file()->writable_file()->Truncate(
+              attempt_truncate_size, IOOptions{}, nullptr);
+          // This is just a best effort attempt
+          s2.PermitUncheckedError();
+        }
       }
       delete writer;
       writer = nullptr;
@@ -1813,6 +1833,11 @@ class DBImpl : public DB {
       getting_synced = false;
     }
 
+    void SetAttemptTruncateSize(uint64_t size) {
+      assert(attempt_truncate_size == SIZE_MAX);
+      attempt_truncate_size = size;
+    }
+
     uint64_t number;
     // Visual Studio doesn't support deque's member to be noncopyable because
     // of a std::unique_ptr as a member.
@@ -1825,15 +1850,20 @@ class DBImpl : public DB {
     // to be persisted even if appends happen during sync so it can be used for
     // tracking the synced size in MANIFEST.
     uint64_t pre_sync_size = 0;
+    // When < SIZE_MAX, attempt to truncate the WAL to this size on close,
+    // because a bad entry was written to it beyond that point and it likely
+    // won't be recoverable with the bad entry.
+    uint64_t attempt_truncate_size = SIZE_MAX;
   };
 
-  struct LogContext {
-    explicit LogContext(bool need_sync = false)
-        : need_log_sync(need_sync), need_log_dir_sync(need_sync) {}
-    bool need_log_sync = false;
-    bool need_log_dir_sync = false;
+  struct WalContext {
+    explicit WalContext(bool need_sync = false)
+        : need_wal_sync(need_sync), need_wal_dir_sync(need_sync) {}
+    bool need_wal_sync = false;
+    bool need_wal_dir_sync = false;
     log::Writer* writer = nullptr;
-    LogFileNumberSize* log_file_number_size = nullptr;
+    WalFileNumberSize* wal_file_number_size = nullptr;
+    uint64_t prev_size = SIZE_MAX;
   };
 
   // PurgeFileInfo is a structure to hold information of files to be deleted in
@@ -2041,10 +2071,10 @@ class DBImpl : public DB {
       JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri);
 
   // REQUIRES: log_numbers are sorted in ascending order
-  // corrupted_log_found is set to true if we recover from a corrupted log file.
+  // corrupted_wal_found is set to true if we recover from a corrupted log file.
   Status RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
                          SequenceNumber* next_sequence, bool read_only,
-                         bool is_retry, bool* corrupted_log_found,
+                         bool is_retry, bool* corrupted_wal_found,
                          RecoveryContext* recovery_ctx);
 
   void SetupLogFilesRecovery(
@@ -2152,12 +2182,12 @@ class DBImpl : public DB {
   // log file to its actual size, thereby freeing preallocated space.
   // Return success even if truncate fails
   Status GetLogSizeAndMaybeTruncate(uint64_t wal_number, bool truncate,
-                                    LogFileNumberSize* log);
+                                    WalFileNumberSize* log);
 
-  // Restore alive_log_files_ and total_log_size_ after recovery.
+  // Restore alive_wal_files_ and wals_total_size_ after recovery.
   // It needs to run only when there's no flush during recovery
   // (e.g. avoid_flush_during_recovery=true). May also trigger flush
-  // in case total_log_size > max_total_wal_size.
+  // in case wals_total_size > max_total_wal_size.
   Status RestoreAliveLogFiles(const std::vector<uint64_t>& log_numbers);
 
   // num_bytes: for slowdown case, delay time is calculated based on
@@ -2306,7 +2336,7 @@ class DBImpl : public DB {
 
   // REQUIRES: mutex locked
   Status PreprocessWrite(const WriteOptions& write_options,
-                         LogContext* log_context, WriteContext* write_context);
+                         WalContext* log_context, WriteContext* write_context);
 
   // Merge write batches in the write group into merged_batch.
   // Returns OK if merge is successful.
@@ -2317,20 +2347,21 @@ class DBImpl : public DB {
 
   IOStatus WriteToWAL(const WriteBatch& merged_batch,
                       const WriteOptions& write_options,
-                      log::Writer* log_writer, uint64_t* log_used,
+                      log::Writer* log_writer, uint64_t* wal_used,
                       uint64_t* log_size,
-                      LogFileNumberSize& log_file_number_size,
+                      WalFileNumberSize& wal_file_number_size,
                       SequenceNumber sequence);
 
-  IOStatus WriteToWAL(const WriteThread::WriteGroup& write_group,
-                      log::Writer* log_writer, uint64_t* log_used,
-                      bool need_log_sync, bool need_log_dir_sync,
-                      SequenceNumber sequence,
-                      LogFileNumberSize& log_file_number_size);
+  IOStatus WriteGroupToWAL(const WriteThread::WriteGroup& write_group,
+                           log::Writer* log_writer, uint64_t* wal_used,
+                           bool need_wal_sync, bool need_wal_dir_sync,
+                           SequenceNumber sequence,
+                           WalFileNumberSize& wal_file_number_size);
 
-  IOStatus ConcurrentWriteToWAL(const WriteThread::WriteGroup& write_group,
-                                uint64_t* log_used,
-                                SequenceNumber* last_sequence, size_t seq_inc);
+  IOStatus ConcurrentWriteGroupToWAL(const WriteThread::WriteGroup& write_group,
+                                     uint64_t* wal_used,
+                                     SequenceNumber* last_sequence,
+                                     size_t seq_inc);
 
   // Used by WriteImpl to update bg_error_ if paranoid check is enabled.
   // Caller must hold mutex_.
@@ -2344,7 +2375,7 @@ class DBImpl : public DB {
   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);
+  void HandleMemTableInsertFailure(const Status& nonok_memtable_insert_status);
 
   Status CompactFilesImpl(const CompactionOptions& compact_options,
                           ColumnFamilyData* cfd, Version* version,
@@ -2697,7 +2728,7 @@ class DBImpl : public DB {
       ErrorIteratorFuncType error_iterator_func);
 
   // Lock over the persistent DB state.  Non-nullptr iff successfully acquired.
-  FileLock* db_lock_;
+  FileLock* db_lock_ = nullptr;
 
   // Guards changes to DB and CF options to ensure consistency between
   // * In-memory options objects
@@ -2711,20 +2742,20 @@ class DBImpl : public DB {
   // Guards reads and writes to in-memory stats_history_.
   InstrumentedMutex stats_history_mutex_;
 
-  // In addition to mutex_, log_write_mutex_ protects writes to logs_ and
-  // logfile_number_. With two_write_queues it also protects alive_log_files_,
-  // and log_empty_. Refer to the definition of each variable below for more
+  // In addition to mutex_, wal_write_mutex_ protects writes to logs_ and
+  // cur_wal_number_. With two_write_queues it also protects alive_wal_files_,
+  // and wal_empty_. Refer to the definition of each variable below for more
   // details.
-  // Note: to avoid deadlock, if needed to acquire both log_write_mutex_ and
-  // mutex_, the order should be first mutex_ and then log_write_mutex_.
-  InstrumentedMutex log_write_mutex_;
+  // Note: to avoid deadlock, if needed to acquire both wal_write_mutex_ and
+  // mutex_, the order should be first mutex_ and then wal_write_mutex_.
+  InstrumentedMutex wal_write_mutex_;
 
   // If zero, manual compactions are allowed to proceed. If non-zero, manual
   // compactions may still be running, but will quickly fail with
   // `Status::Incomplete`. The value indicates how many threads have paused
   // manual compactions. It is accessed in read mode outside the DB mutex in
   // compaction code paths.
-  std::atomic<int> manual_compaction_paused_;
+  std::atomic<int> manual_compaction_paused_ = false;
 
   // This condition variable is signaled on these conditions:
   // * whenever bg_compaction_scheduled_ goes down to 0
@@ -2740,106 +2771,114 @@ class DBImpl : public DB {
   // * whenever SetOptions successfully updates options.
   // * whenever a column family is dropped.
   InstrumentedCondVar bg_cv_;
-  // Writes are protected by locking both mutex_ and log_write_mutex_, and reads
-  // must be under either mutex_ or log_write_mutex_. Since after ::Open,
-  // logfile_number_ is currently updated only in write_thread_, it can be read
+
+  ColumnFamilyHandleImpl* persist_stats_cf_handle_ = nullptr;
+
+  bool persistent_stats_cfd_exists_ = true;
+
+  // Writes are protected by locking both mutex_ and wal_write_mutex_, and reads
+  // must be under either mutex_ or wal_write_mutex_. Since after ::Open,
+  // cur_wal_number_ is currently updated only in write_thread_, it can be read
   // from the same write_thread_ without any locks.
-  uint64_t logfile_number_;
+  uint64_t cur_wal_number_ = 0;
+
   // Log files that we can recycle. Must be protected by db mutex_.
-  std::deque<uint64_t> log_recycle_files_;
+  std::deque<uint64_t> wal_recycle_files_;
+
   // The minimum log file number taht can be recycled, if log recycling is
   // enabled. This is used to ensure that log files created by previous
   // instances of the database are not recycled, as we cannot be sure they
   // were created in the recyclable format.
-  uint64_t min_log_number_to_recycle_;
-  // Protected by log_write_mutex_.
-  bool log_dir_synced_;
-  // Without two_write_queues, read and writes to log_empty_ are protected by
+  uint64_t min_wal_number_to_recycle_ = 0;
+
+  // Protected by wal_write_mutex_.
+  bool wal_dir_synced_ = false;
+
+  // Without two_write_queues, read and writes to wal_empty_ are protected by
   // mutex_. Since it is currently updated/read only in write_thread_, it can be
   // accessed from the same write_thread_ without any locks. With
   // two_write_queues writes, where it can be updated in different threads,
-  // read and writes are protected by log_write_mutex_ instead. This is to avoid
-  // expensive mutex_ lock during WAL write, which update log_empty_.
-  bool log_empty_;
-
-  ColumnFamilyHandleImpl* persist_stats_cf_handle_;
-
-  bool persistent_stats_cfd_exists_ = true;
+  // read and writes are protected by wal_write_mutex_ instead. This is to avoid
+  // expensive mutex_ lock during WAL write, which update wal_empty_.
+  bool wal_empty_ = true;
 
   // The current WAL file and those that have not been found obsolete from
   // memtable flushes. A WAL not on this list might still be pending writer
-  // flush and/or sync and close and might still be in logs_. alive_log_files_
-  // is protected by mutex_ and log_write_mutex_ with details as follows:
+  // flush and/or sync and close and might still be in logs_. alive_wal_files_
+  // is protected by mutex_ and wal_write_mutex_ with details as follows:
   // 1. read by FindObsoleteFiles() which can be called in either application
-  //    thread or RocksDB bg threads, both mutex_ and log_write_mutex_ are
+  //    thread or RocksDB bg threads, both mutex_ and wal_write_mutex_ are
   //    held.
-  // 2. pop_front() by FindObsoleteFiles(), both mutex_ and log_write_mutex_
+  // 2. pop_front() by FindObsoleteFiles(), both mutex_ and wal_write_mutex_
   //    are held.
   // 3. push_back() by DBImpl::Open() and DBImpl::RestoreAliveLogFiles()
   //    (actually called by Open()), only mutex_ is held because at this point,
   //    the DB::Open() call has not returned success to application, and the
   //    only other thread(s) that can conflict are bg threads calling
-  //    FindObsoleteFiles() which ensure that both mutex_ and log_write_mutex_
-  //    are held when accessing alive_log_files_.
+  //    FindObsoleteFiles() which ensure that both mutex_ and wal_write_mutex_
+  //    are held when accessing alive_wal_files_.
   // 4. read by DBImpl::Open() is protected by mutex_.
-  // 5. push_back() by SwitchMemtable(). Both mutex_ and log_write_mutex_ are
+  // 5. push_back() by SwitchMemtable(). Both mutex_ and wal_write_mutex_ are
   //    held. This is done by the write group leader. Note that in the case of
   //    two-write-queues, another WAL-only write thread can be writing to the
   //    WAL concurrently. See 9.
-  // 6. read by SwitchWAL() with both mutex_ and log_write_mutex_ held. This is
+  // 6. read by SwitchWAL() with both mutex_ and wal_write_mutex_ held. This is
   //    done by write group leader.
   // 7. read by ConcurrentWriteToWAL() by the write group leader in the case of
-  //    two-write-queues. Only log_write_mutex_ is held to protect concurrent
+  //    two-write-queues. Only wal_write_mutex_ is held to protect concurrent
   //    pop_front() by FindObsoleteFiles().
-  // 8. read by PreprocessWrite() by the write group leader. log_write_mutex_
+  // 8. read by PreprocessWrite() by the write group leader. wal_write_mutex_
   //    is held to protect the data structure from concurrent pop_front() by
   //    FindObsoleteFiles().
   // 9. read by ConcurrentWriteToWAL() by a WAL-only write thread in the case
-  //    of two-write-queues. Only log_write_mutex_ is held. This suffices to
+  //    of two-write-queues. Only wal_write_mutex_ is held. This suffices to
   //    protect the data structure from concurrent push_back() by current
   //    write group leader as well as pop_front() by FindObsoleteFiles().
-  std::deque<LogFileNumberSize> alive_log_files_;
+  std::deque<WalFileNumberSize> alive_wal_files_;
+
+  // Total size of all "alive" WALs (for easy access without synchronization)
+  RelaxedAtomic<uint64_t> wals_total_size_{0};
 
   // Log files that aren't fully synced, and the current log file.
   // Synchronization:
   // 1. read by FindObsoleteFiles() which can be called either in application
-  //    thread or RocksDB bg threads. log_write_mutex_ is always held, while
+  //    thread or RocksDB bg threads. wal_write_mutex_ is always held, while
   //    some reads are performed without mutex_.
-  // 2. pop_front() by FindObsoleteFiles() with only log_write_mutex_ held.
-  // 3. read by DBImpl::Open() with both mutex_ and log_write_mutex_.
-  // 4. emplace_back() by DBImpl::Open() with both mutex_ and log_write_mutex.
+  // 2. pop_front() by FindObsoleteFiles() with only wal_write_mutex_ held.
+  // 3. read by DBImpl::Open() with both mutex_ and wal_write_mutex_.
+  // 4. emplace_back() by DBImpl::Open() with both mutex_ and wal_write_mutex.
   //    Note that at this point, DB::Open() has not returned success to
   //    application, thus the only other thread(s) that can conflict are bg
   //    threads calling FindObsoleteFiles(). See 1.
-  // 5. iteration and clear() from CloseHelper() always hold log_write_mutex
+  // 5. iteration and clear() from CloseHelper() always hold wal_write_mutex
   //    and mutex_.
   // 6. back() called by APIs FlushWAL() and LockWAL() are protected by only
-  //    log_write_mutex_. These two can be called by application threads after
+  //    wal_write_mutex_. These two can be called by application threads after
   //    DB::Open() returns success to applications.
-  // 7. read by SyncWAL(), another API, protected by only log_write_mutex_.
+  // 7. read by SyncWAL(), another API, protected by only wal_write_mutex_.
   // 8. read by MarkLogsNotSynced() and MarkLogsSynced() are protected by
-  //    log_write_mutex_.
-  // 9. erase() by MarkLogsSynced() protected by log_write_mutex_.
-  // 10. read by SyncClosedWals() protected by only log_write_mutex_. This can
+  //    wal_write_mutex_.
+  // 9. erase() by MarkLogsSynced() protected by wal_write_mutex_.
+  // 10. read by SyncClosedWals() protected by only wal_write_mutex_. This can
   //     happen in bg flush threads after DB::Open() returns success to
   //     applications.
   // 11. reads, e.g. front(), iteration, and back() called by PreprocessWrite()
-  //     holds only the log_write_mutex_. This is done by the write group
+  //     holds only the wal_write_mutex_. This is done by the write group
   //     leader. A bg thread calling FindObsoleteFiles() or MarkLogsSynced()
-  //     can happen concurrently. This is fine because log_write_mutex_ is used
+  //     can happen concurrently. This is fine because wal_write_mutex_ is used
   //     by all parties. See 2, 5, 9.
   // 12. reads, empty(), back() called by SwitchMemtable() hold both mutex_ and
-  //     log_write_mutex_. This happens in the write group leader.
+  //     wal_write_mutex_. This happens in the write group leader.
   // 13. emplace_back() by SwitchMemtable() hold both mutex_ and
-  //     log_write_mutex_. This happens in the write group leader. Can conflict
+  //     wal_write_mutex_. This happens in the write group leader. Can conflict
   //     with bg threads calling FindObsoleteFiles(), MarkLogsSynced(),
   //     SyncClosedWals(), etc. as well as application threads calling
   //     FlushWAL(), SyncWAL(), LockWAL(). This is fine because all parties
-  //     require at least log_write_mutex_.
+  //     require at least wal_write_mutex_.
   // 14. iteration called in WriteToWAL(write_group) protected by
-  //     log_write_mutex_. This is done by write group leader when
+  //     wal_write_mutex_. This is done by write group leader when
   //     two-write-queues is disabled and write needs to sync logs.
-  // 15. back() called in ConcurrentWriteToWAL() protected by log_write_mutex_.
+  // 15. back() called in ConcurrentWriteToWAL() protected by wal_write_mutex_.
   //     This can be done by the write group leader if two-write-queues is
   //     enabled. It can also be done by another WAL-only write thread.
   //
@@ -2856,23 +2895,22 @@ class DBImpl : public DB {
   std::deque<LogWriterNumber> logs_;
 
   // Signaled when getting_synced becomes false for some of the logs_.
-  InstrumentedCondVar log_sync_cv_;
+  InstrumentedCondVar wal_sync_cv_;
   // This is the app-level state that is written to the WAL but will be used
   // only during recovery. Using this feature enables not writing the state to
   // memtable on normal writes and hence improving the throughput. Each new
   // write of the state will replace the previous state entirely even if the
   // keys in the two consecutive states do not overlap.
-  // It is protected by log_write_mutex_ when two_write_queues_ is enabled.
+  // It is protected by wal_write_mutex_ when two_write_queues_ is enabled.
   // Otherwise only the heaad of write_thread_ can access it.
   WriteBatch cached_recoverable_state_;
   std::atomic<bool> cached_recoverable_state_empty_ = {true};
-  std::atomic<uint64_t> total_log_size_;
 
   // If this is non-empty, we need to delete these log files in background
-  // threads. Protected by log_write_mutex_.
-  autovector<log::Writer*> logs_to_free_;
+  // threads. Protected by wal_write_mutex_.
+  autovector<log::Writer*> wals_to_free_;
 
-  bool is_snapshot_supported_;
+  bool is_snapshot_supported_ = true;
 
   std::map<uint64_t, std::map<std::string, uint64_t>> stats_history_;
 
@@ -2896,7 +2934,7 @@ class DBImpl : public DB {
   // sleep if it uses up the quota.
   // Note: This is to protect memtable and compaction. If the batch only writes
   // to the WAL its size need not to be included in this.
-  uint64_t last_batch_group_size_;
+  uint64_t last_batch_group_size_ = 0;
 
   FlushScheduler flush_scheduler_;
 
@@ -2955,32 +2993,32 @@ class DBImpl : public DB {
   std::unordered_set<uint64_t> files_grabbed_for_purge_;
 
   // A queue to store log writers to close. Protected by db mutex_.
-  std::deque<log::Writer*> logs_to_free_queue_;
+  std::deque<log::Writer*> wals_to_free_queue_;
 
   std::deque<SuperVersion*> superversions_to_free_queue_;
 
-  int unscheduled_flushes_;
+  int unscheduled_flushes_ = 0;
 
-  int unscheduled_compactions_;
+  int unscheduled_compactions_ = 0;
 
   // count how many background compactions are running or have been scheduled in
   // the BOTTOM pool
-  int bg_bottom_compaction_scheduled_;
+  int bg_bottom_compaction_scheduled_ = 0;
 
   // count how many background compactions are running or have been scheduled
-  int bg_compaction_scheduled_;
+  int bg_compaction_scheduled_ = 0;
 
   // stores the number of compactions are currently running
-  int num_running_compactions_;
+  int num_running_compactions_ = 0;
 
   // number of background memtable flush jobs, submitted to the HIGH pool
-  int bg_flush_scheduled_;
+  int bg_flush_scheduled_ = 0;
 
   // stores the number of flushes are currently running
-  int num_running_flushes_;
+  int num_running_flushes_ = 0;
 
   // number of background obsolete file purge jobs, submitted to the HIGH pool
-  int bg_purge_scheduled_;
+  int bg_purge_scheduled_ = 0;
 
   std::deque<ManualCompactionState*> manual_compaction_dequeue_;
 
@@ -2990,11 +3028,11 @@ class DBImpl : public DB {
   // This enables two different threads to call
   // EnableFileDeletions() and DisableFileDeletions()
   // without any synchronization
-  int disable_delete_obsolete_files_;
+  int disable_delete_obsolete_files_ = 0;
 
   // Number of times FindObsoleteFiles has found deletable files and the
   // corresponding call to PurgeObsoleteFiles has not yet finished.
-  int pending_purge_obsolete_files_;
+  int pending_purge_obsolete_files_ = 0;
 
   // last time when DeleteObsoleteFiles with full scan was executed. Originally
   // initialized with startup time.
@@ -3006,12 +3044,12 @@ class DBImpl : public DB {
   // The mutex used by switch_cv_. mutex_ should be acquired beforehand.
   std::mutex switch_mutex_;
   // Number of threads intending to write to memtable
-  std::atomic<size_t> pending_memtable_writes_ = {};
+  std::atomic<size_t> pending_memtable_writes_{0};
 
   // A flag indicating whether the current rocksdb database has any
   // data that is not yet persisted into either WAL or SST file.
   // Used when disableWAL is true.
-  std::atomic<bool> has_unpersisted_data_;
+  std::atomic<bool> has_unpersisted_data_{false};
 
   // if an attempt was made to flush all column families that
   // the oldest log depends on but uncommitted data in the oldest
@@ -3019,26 +3057,26 @@ class DBImpl : public DB {
   // We must attempt to free the dependent memtables again
   // at a later time after the transaction in the oldest
   // log is fully commited.
-  bool unable_to_release_oldest_log_;
+  bool unable_to_release_oldest_log_{false};
 
   // Number of running IngestExternalFile() or CreateColumnFamilyWithImport()
   // calls.
   // REQUIRES: mutex held
-  int num_running_ingest_file_;
+  int num_running_ingest_file_ = 0;
 
   WalManager wal_manager_;
 
   // A value of > 0 temporarily disables scheduling of background work
-  int bg_work_paused_;
+  int bg_work_paused_ = 0;
 
   // A value of > 0 temporarily disables scheduling of background compaction
-  int bg_compaction_paused_;
+  int bg_compaction_paused_ = 0;
 
   // Guard against multiple concurrent refitting
-  bool refitting_level_;
+  bool refitting_level_ = false;
 
   // Indicate DB was opened successfully
-  bool opened_successfully_;
+  bool opened_successfully_ = false;
 
   // The min threshold to triggere bottommost compaction for removing
   // garbages, among all column families.
@@ -3084,13 +3122,13 @@ class DBImpl : public DB {
   // error recovery from going on in parallel. The latter, shutting_down_,
   // is set a little later during the shutdown after scheduling memtable
   // flushes
-  std::atomic<bool> shutdown_initiated_;
+  std::atomic<bool> shutdown_initiated_{false};
   // Flag to indicate whether sst_file_manager object was allocated in
   // DB::Open() or passed to us
   bool own_sfm_;
 
   // Flag to check whether Close() has been called on this DB
-  bool closed_;
+  bool closed_ = false;
   // save the closing status, for re-calling the close()
   Status closing_status_;
   // mutex for DB::Close()
@@ -3126,7 +3164,7 @@ class DBImpl : public DB {
 
   // The number of LockWAL called without matching UnlockWAL call.
   // See also lock_wal_write_token_
-  uint32_t lock_wal_count_;
+  uint32_t lock_wal_count_ = 0;
 };
 
 class GetWithTimestampReadCallback : public ReadCallback {

db/db_impl/db_impl_compaction_flush.cc

@@ -168,7 +168,7 @@ Status DBImpl::FlushMemTableToOutputFile(
   // had not been committed yet. Make sure we sync them to keep the persisted
   // WAL state at least as new as the persisted SST state.
   const bool needs_to_sync_closed_wals =
-      logfile_number_ > 0 &&
+      cur_wal_number_ > 0 &&
       (versions_->GetColumnFamilySet()->NumberOfColumnFamilies() > 1 ||
        allow_2pc());
 
@@ -224,7 +224,7 @@ Status DBImpl::FlushMemTableToOutputFile(
   bool need_cancel = false;
   IOStatus log_io_s = IOStatus::OK();
   if (needs_to_sync_closed_wals) {
-    // SyncClosedWals() may unlock and re-lock the log_write_mutex multiple
+    // SyncClosedWals() may unlock and re-lock the wal_write_mutex multiple
     // times.
     VersionEdit synced_wals;
     bool error_recovery_in_prog = error_handler_.IsRecoveryInProgress();
@@ -512,7 +512,7 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
                        job_context->job_id, flush_reason);
   }
 
-  if (logfile_number_ > 0) {
+  if (cur_wal_number_ > 0) {
     // TODO (yanqin) investigate whether we should sync the closed logs for
     // single column family case.
     VersionEdit synced_wals;
@@ -528,7 +528,7 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
 
     if (!log_io_s.ok() && !log_io_s.IsShutdownInProgress() &&
         !log_io_s.IsColumnFamilyDropped()) {
-      if (total_log_size_ > 0) {
+      if (wals_total_size_.LoadRelaxed() > 0) {
         error_handler_.SetBGError(log_io_s, BackgroundErrorReason::kFlush);
       } else {
         // If the WAL is empty, we use different error reason

db/db_impl/db_impl_debug.cc

@@ -224,13 +224,13 @@ void DBImpl::TEST_EndWrite(void* w) {
 }
 
 size_t DBImpl::TEST_LogsToFreeSize() {
-  InstrumentedMutexLock l(&log_write_mutex_);
-  return logs_to_free_.size();
+  InstrumentedMutexLock l(&wal_write_mutex_);
+  return wals_to_free_.size();
 }
 
 uint64_t DBImpl::TEST_LogfileNumber() {
   InstrumentedMutexLock l(&mutex_);
-  return logfile_number_;
+  return cur_wal_number_;
 }
 
 void DBImpl::TEST_GetAllBlockCaches(

db/db_impl/db_impl_files.cc

@@ -28,7 +28,7 @@ uint64_t DBImpl::MinLogNumberToKeep() {
   return versions_->min_log_number_to_keep();
 }
 
-uint64_t DBImpl::MinLogNumberToRecycle() { return min_log_number_to_recycle_; }
+uint64_t DBImpl::MinLogNumberToRecycle() { return min_wal_number_to_recycle_; }
 
 uint64_t DBImpl::MinObsoleteSstNumberToKeep() {
   mutex_.AssertHeld();
@@ -272,77 +272,77 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
 
   // logs_ is empty when called during recovery, in which case there can't yet
   // be any tracked obsolete logs
-  log_write_mutex_.Lock();
+  wal_write_mutex_.Lock();
 
-  if (alive_log_files_.empty() || logs_.empty()) {
+  if (alive_wal_files_.empty() || logs_.empty()) {
     mutex_.AssertHeld();
     // We may reach here if the db is DBImplSecondary
-    log_write_mutex_.Unlock();
+    wal_write_mutex_.Unlock();
     return;
   }
 
   bool mutex_unlocked = false;
-  if (!alive_log_files_.empty() && !logs_.empty()) {
+  if (!alive_wal_files_.empty() && !logs_.empty()) {
     uint64_t min_log_number = job_context->log_number;
-    size_t num_alive_log_files = alive_log_files_.size();
+    size_t num_alive_wal_files = alive_wal_files_.size();
     // find newly obsoleted log files
-    while (alive_log_files_.begin()->number < min_log_number) {
-      auto& earliest = *alive_log_files_.begin();
+    while (alive_wal_files_.begin()->number < min_log_number) {
+      auto& earliest = *alive_wal_files_.begin();
       if (immutable_db_options_.recycle_log_file_num >
-              log_recycle_files_.size() &&
+              wal_recycle_files_.size() &&
           earliest.number >= MinLogNumberToRecycle()) {
         ROCKS_LOG_INFO(immutable_db_options_.info_log,
                        "adding log %" PRIu64 " to recycle list\n",
                        earliest.number);
-        log_recycle_files_.push_back(earliest.number);
+        wal_recycle_files_.push_back(earliest.number);
       } else {
         job_context->log_delete_files.push_back(earliest.number);
       }
       if (job_context->size_log_to_delete == 0) {
-        job_context->prev_total_log_size = total_log_size_;
-        job_context->num_alive_log_files = num_alive_log_files;
+        job_context->prev_wals_total_size = wals_total_size_.LoadRelaxed();
+        job_context->num_alive_wal_files = num_alive_wal_files;
       }
       job_context->size_log_to_delete += earliest.size;
-      total_log_size_ -= earliest.size;
-      alive_log_files_.pop_front();
+      wals_total_size_.FetchSubRelaxed(earliest.size);
+      alive_wal_files_.pop_front();
 
       // Current log should always stay alive since it can't have
       // number < MinLogNumber().
-      assert(alive_log_files_.size());
+      assert(alive_wal_files_.size());
     }
-    log_write_mutex_.Unlock();
+    wal_write_mutex_.Unlock();
     mutex_.Unlock();
     mutex_unlocked = true;
     TEST_SYNC_POINT_CALLBACK("FindObsoleteFiles::PostMutexUnlock", nullptr);
-    log_write_mutex_.Lock();
+    wal_write_mutex_.Lock();
     while (!logs_.empty() && logs_.front().number < min_log_number) {
       auto& log = logs_.front();
       if (log.IsSyncing()) {
-        log_sync_cv_.Wait();
+        wal_sync_cv_.Wait();
         // logs_ could have changed while we were waiting.
         continue;
       }
       // This WAL file is not live, so it's OK if we never sync the rest of it.
       // If it's already closed, then it's been fully synced. If
       // !background_close_inactive_wals then we need to Close it before
-      // removing from logs_ but not blocking while holding log_write_mutex_.
+      // removing from logs_ but not blocking while holding wal_write_mutex_.
       if (!immutable_db_options_.background_close_inactive_wals &&
           log.writer->file()) {
         // We are taking ownership of and pinning the front entry, so we can
         // expect it to be the same after releasing and re-acquiring the lock
         log.PrepareForSync();
-        log_write_mutex_.Unlock();
+        wal_write_mutex_.Unlock();
         // TODO: maybe check the return value of Close.
         // TODO: plumb Env::IOActivity, Env::IOPriority
         auto s = log.writer->file()->Close({});
         s.PermitUncheckedError();
-        log_write_mutex_.Lock();
+        wal_write_mutex_.Lock();
         log.writer->PublishIfClosed();
         assert(&log == &logs_.front());
         log.FinishSync();
-        log_sync_cv_.SignalAll();
+        wal_sync_cv_.SignalAll();
       }
-      logs_to_free_.push_back(log.ReleaseWriter());
+      wals_to_free_.push_back(log.ReleaseWriter());
       logs_.pop_front();
     }
     // Current log cannot be obsolete.
@@ -350,16 +350,16 @@ void DBImpl::FindObsoleteFiles(JobContext* job_context, bool force,
   }
 
   // We're just cleaning up for DB::Write().
-  assert(job_context->logs_to_free.empty());
-  job_context->logs_to_free = logs_to_free_;
+  assert(job_context->wals_to_free.empty());
+  job_context->wals_to_free = wals_to_free_;
 
-  logs_to_free_.clear();
-  log_write_mutex_.Unlock();
+  wals_to_free_.clear();
+  wal_write_mutex_.Unlock();
   if (mutex_unlocked) {
     mutex_.Lock();
   }
-  job_context->log_recycle_files.assign(log_recycle_files_.begin(),
-                                        log_recycle_files_.end());
+  job_context->log_recycle_files.assign(wal_recycle_files_.begin(),
+                                        wal_recycle_files_.end());
 }
 
 // Delete obsolete files and log status and information of file deletion
@@ -431,7 +431,7 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
                                             state.sst_live.end());
   std::unordered_set<uint64_t> blob_live_set(state.blob_live.begin(),
                                              state.blob_live.end());
-  std::unordered_set<uint64_t> log_recycle_files_set(
+  std::unordered_set<uint64_t> wal_recycle_files_set(
       state.log_recycle_files.begin(), state.log_recycle_files.end());
   std::unordered_set<uint64_t> quarantine_files_set(
       state.files_to_quarantine.begin(), state.files_to_quarantine.end());
@@ -491,13 +491,13 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
       std::unique(candidate_files.begin(), candidate_files.end()),
       candidate_files.end());
 
-  if (state.prev_total_log_size > 0) {
+  if (state.prev_wals_total_size > 0) {
     ROCKS_LOG_INFO(immutable_db_options_.info_log,
                    "[JOB %d] Try to delete WAL files size %" PRIu64
                    ", prev total WAL file size %" PRIu64
                    ", number of live WAL files %" ROCKSDB_PRIszt ".\n",
                    state.job_id, state.size_log_to_delete,
-                   state.prev_total_log_size, state.num_alive_log_files);
+                   state.prev_wals_total_size, state.num_alive_wal_files);
   }
 
   std::vector<std::string> old_info_log_files;
@@ -532,7 +532,7 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
   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) {
+  for (const auto w : state.wals_to_free) {
     // TODO: maybe check the return value of Close.
     // TODO: plumb Env::IOActivity, Env::IOPriority
     auto s = w->Close({});
@@ -559,8 +559,8 @@ void DBImpl::PurgeObsoleteFiles(JobContext& state, bool schedule_only) {
       case kWalFile:
         keep = ((number >= state.log_number) ||
                 (number == state.prev_log_number) ||
-                (log_recycle_files_set.find(number) !=
-                 log_recycle_files_set.end()));
+                (wal_recycle_files_set.find(number) !=
+                 wal_recycle_files_set.end()));
         break;
       case kDescriptorFile:
         // Keep my manifest file, and any newer incarnations'

db/db_impl/db_impl_open.cc

@@ -1119,7 +1119,7 @@ void DBOpenLogRecordReadReporter::Corruption(size_t bytes, const Status& s,
                  static_cast<int>(bytes), s.ToString().c_str());
   if (status != nullptr && status->ok()) {
     *status = s;
-    corrupted_log_number_ = log_number;
+    corrupted_wal_number_ = log_number;
   }
 }
 
@@ -1902,8 +1902,8 @@ void DBImpl::FinishLogFilesRecovery(int job_id, const Status& status) {
 }
 
 Status DBImpl::GetLogSizeAndMaybeTruncate(uint64_t wal_number, bool truncate,
-                                          LogFileNumberSize* log_ptr) {
-  LogFileNumberSize log(wal_number);
+                                          WalFileNumberSize* log_ptr) {
+  WalFileNumberSize log(wal_number);
   std::string fname =
       LogFileName(immutable_db_options_.GetWalDir(), wal_number);
   Status s;
@@ -1946,27 +1946,27 @@ Status DBImpl::RestoreAliveLogFiles(const std::vector<uint64_t>& wal_numbers) {
   assert(immutable_db_options_.avoid_flush_during_recovery);
   // Mark these as alive so they'll be considered for deletion later by
   // FindObsoleteFiles()
-  total_log_size_ = 0;
-  log_empty_ = false;
+  wals_total_size_.StoreRelaxed(0);
+  wal_empty_ = false;
   uint64_t min_wal_with_unflushed_data =
       versions_->MinLogNumberWithUnflushedData();
   for (auto wal_number : wal_numbers) {
     if (!allow_2pc() && wal_number < min_wal_with_unflushed_data) {
       // In non-2pc mode, the WAL files not backing unflushed data are not
-      // alive, thus should not be added to the alive_log_files_.
+      // alive, thus should not be added to the alive_wal_files_.
       continue;
     }
     // We preallocate space for wals, but then after a crash and restart, those
     // preallocated space are not needed anymore. It is likely only the last
     // log has such preallocated space, so we only truncate for the last log.
-    LogFileNumberSize log;
+    WalFileNumberSize log;
     s = GetLogSizeAndMaybeTruncate(
         wal_number, /*truncate=*/(wal_number == wal_numbers.back()), &log);
     if (!s.ok()) {
       break;
     }
-    total_log_size_ += log.size;
-    alive_log_files_.push_back(log);
+    wals_total_size_.FetchAddRelaxed(log.size);
+    alive_wal_files_.push_back(log);
   }
   return s;
 }
@@ -2449,18 +2449,18 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
     if (s.ok()) {
       // Prevent log files created by previous instance from being recycled.
       // They might be in alive_log_file_, and might get recycled otherwise.
-      impl->min_log_number_to_recycle_ = new_log_number;
+      impl->min_wal_number_to_recycle_ = new_log_number;
     }
     if (s.ok()) {
-      InstrumentedMutexLock wl(&impl->log_write_mutex_);
-      impl->logfile_number_ = new_log_number;
+      InstrumentedMutexLock wl(&impl->wal_write_mutex_);
+      impl->cur_wal_number_ = new_log_number;
       assert(new_log != nullptr);
       assert(impl->logs_.empty());
       impl->logs_.emplace_back(new_log_number, new_log);
     }
 
     if (s.ok()) {
-      impl->alive_log_files_.emplace_back(impl->logfile_number_);
+      impl->alive_wal_files_.emplace_back(impl->cur_wal_number_);
       // In WritePrepared there could be gap in sequence numbers. This breaks
       // the trick we use in kPointInTimeRecovery which assumes the first seq in
       // the log right after the corrupted log is one larger than the last seq
@@ -2473,14 +2473,14 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
       if (recovered_seq != kMaxSequenceNumber) {
         WriteBatch empty_batch;
         WriteBatchInternal::SetSequence(&empty_batch, recovered_seq);
-        uint64_t log_used, log_size;
+        uint64_t wal_used, log_size;
         log::Writer* log_writer = impl->logs_.back().writer;
-        LogFileNumberSize& log_file_number_size = impl->alive_log_files_.back();
+        WalFileNumberSize& wal_file_number_size = impl->alive_wal_files_.back();
 
-        assert(log_writer->get_log_number() == log_file_number_size.number);
+        assert(log_writer->get_log_number() == wal_file_number_size.number);
         impl->mutex_.AssertHeld();
-        s = impl->WriteToWAL(empty_batch, write_options, log_writer, &log_used,
-                             &log_size, log_file_number_size, recovered_seq);
+        s = impl->WriteToWAL(empty_batch, write_options, log_writer, &wal_used,
+                             &log_size, wal_file_number_size, recovered_seq);
         if (s.ok()) {
           // Need to fsync, otherwise it might get lost after a power reset.
           s = impl->FlushWAL(write_options, false);

db/db_impl/db_impl_readonly.cc

@@ -185,16 +185,10 @@ Iterator* DBImplReadOnly::NewIterator(const ReadOptions& _read_options,
           ? static_cast<const SnapshotImpl*>(read_options.snapshot)->number_
           : latest_snapshot;
   ReadCallback* read_callback = nullptr;  // No read callback provided.
-  auto db_iter = NewArenaWrappedDbIterator(
-      env_, read_options, cfd->ioptions(), super_version->mutable_cf_options,
-      super_version->current, read_seq,
-      super_version->mutable_cf_options.max_sequential_skip_in_iterations,
-      super_version->version_number, read_callback);
-  auto internal_iter = NewInternalIterator(
-      db_iter->GetReadOptions(), cfd, super_version, db_iter->GetArena(),
-      read_seq, /* allow_unprepared_value */ true, db_iter);
-  db_iter->SetIterUnderDBIter(internal_iter);
-  return db_iter;
+  return NewArenaWrappedDbIterator(
+      env_, read_options, cfh, super_version, read_seq, read_callback, this,
+      /*expose_blob_index=*/false, /*allow_refresh=*/false,
+      /*allow_mark_memtable_for_flush=*/false);
 }
 
 Status DBImplReadOnly::NewIterators(
@@ -231,36 +225,32 @@ Status DBImplReadOnly::NewIterators(
           ? static_cast<const SnapshotImpl*>(read_options.snapshot)->number_
           : latest_snapshot;
 
-  autovector<std::tuple<ColumnFamilyData*, SuperVersion*>> cfd_to_sv;
+  autovector<std::tuple<ColumnFamilyHandleImpl*, SuperVersion*>> cfh_to_sv;
 
   const bool check_read_ts =
       read_options.timestamp && read_options.timestamp->size() > 0;
   for (auto cfh : column_families) {
     auto* cfd = static_cast_with_check<ColumnFamilyHandleImpl>(cfh)->cfd();
     auto* sv = cfd->GetSuperVersion()->Ref();
-    cfd_to_sv.emplace_back(cfd, sv);
+    cfh_to_sv.emplace_back(static_cast_with_check<ColumnFamilyHandleImpl>(cfh),
+                           sv);
     if (check_read_ts) {
       const Status s =
           FailIfReadCollapsedHistory(cfd, sv, *(read_options.timestamp));
       if (!s.ok()) {
-        for (auto prev_entry : cfd_to_sv) {
+        for (auto prev_entry : cfh_to_sv) {
           std::get<1>(prev_entry)->Unref();
         }
         return s;
       }
     }
   }
-  assert(cfd_to_sv.size() == column_families.size());
-  for (auto [cfd, sv] : cfd_to_sv) {
+  assert(cfh_to_sv.size() == column_families.size());
+  for (auto [cfh, sv] : cfh_to_sv) {
     auto* db_iter = NewArenaWrappedDbIterator(
-        env_, read_options, cfd->ioptions(), sv->mutable_cf_options,
-        sv->current, read_seq,
-        sv->mutable_cf_options.max_sequential_skip_in_iterations,
-        sv->version_number, read_callback);
-    auto* internal_iter = NewInternalIterator(
-        db_iter->GetReadOptions(), cfd, sv, db_iter->GetArena(), read_seq,
-        /* allow_unprepared_value */ true, db_iter);
-    db_iter->SetIterUnderDBIter(internal_iter);
+        env_, read_options, cfh, sv, read_seq, read_callback, this,
+        /*expose_blob_index=*/false, /*allow_refresh=*/false,
+        /*allow_mark_memtable_for_flush=*/false);
     iterators->push_back(db_iter);
   }
 

db/db_impl/db_impl_secondary.cc

@@ -566,17 +566,10 @@ ArenaWrappedDBIter* DBImplSecondary::NewIteratorImpl(
   assert(snapshot == kMaxSequenceNumber);
   snapshot = versions_->LastSequence();
   assert(snapshot != kMaxSequenceNumber);
-  auto db_iter = NewArenaWrappedDbIterator(
-      env_, read_options, cfh->cfd()->ioptions(),
-      super_version->mutable_cf_options, super_version->current, snapshot,
-      super_version->mutable_cf_options.max_sequential_skip_in_iterations,
-      super_version->version_number, read_callback, cfh, expose_blob_index,
-      allow_refresh);
-  auto internal_iter = NewInternalIterator(
-      db_iter->GetReadOptions(), cfh->cfd(), super_version, db_iter->GetArena(),
-      snapshot, /* allow_unprepared_value */ true, db_iter);
-  db_iter->SetIterUnderDBIter(internal_iter);
-  return db_iter;
+  return NewArenaWrappedDbIterator(env_, read_options, cfh, super_version,
+                                   snapshot, read_callback, this,
+                                   expose_blob_index, allow_refresh,
+                                   /*allow_mark_memtable_for_flush=*/false);
 }
 
 Status DBImplSecondary::NewIterators(
@@ -705,13 +698,13 @@ Status DBImplSecondary::CheckConsistency() {
 
 Status DBImplSecondary::TryCatchUpWithPrimary() {
   assert(versions_.get() != nullptr);
-  assert(manifest_reader_.get() != nullptr);
   Status s;
   // read the manifest and apply new changes to the secondary instance
   std::unordered_set<ColumnFamilyData*> cfds_changed;
   JobContext job_context(0, true /*create_superversion*/);
   {
     InstrumentedMutexLock lock_guard(&mutex_);
+    assert(manifest_reader_.get() != nullptr);
     s = static_cast_with_check<ReactiveVersionSet>(versions_.get())
             ->ReadAndApply(&mutex_, &manifest_reader_,
                            manifest_reader_status_.get(), &cfds_changed,
@@ -991,7 +984,7 @@ Status DB::OpenAndCompact(
   }
 
   // 2. Load the options
-  DBOptions db_options;
+  DBOptions base_db_options;
   ConfigOptions config_options;
   config_options.env = override_options.env;
   config_options.ignore_unknown_options = true;
@@ -1004,13 +997,22 @@ Status DB::OpenAndCompact(
   std::string options_file_name =
       OptionsFileName(name, compaction_input.options_file_number);
 
-  s = LoadOptionsFromFile(config_options, options_file_name, &db_options,
+  s = LoadOptionsFromFile(config_options, options_file_name, &base_db_options,
                           &all_column_families);
   if (!s.ok()) {
     return s;
   }
 
-  // 3. Override pointer configurations in DBOptions with
+  // 3. Options to Override
+  // Override serializable configurations from override_options.options_map
+  DBOptions db_options;
+  s = GetDBOptionsFromMap(config_options, base_db_options,
+                          override_options.options_map, &db_options);
+  if (!s.ok()) {
+    return s;
+  }
+
+  // Override options that are directly set as shared ptrs in
   // CompactionServiceOptionsOverride
   db_options.env = override_options.env;
   db_options.file_checksum_gen_factory =
@@ -1021,6 +1023,7 @@ Status DB::OpenAndCompact(
   // We will close the DB after the compaction anyway.
   // Open as many files as needed for the compaction.
   db_options.max_open_files = -1;
+  db_options.info_log = override_options.info_log;
 
   // 4. Filter CFs that are needed for OpenAndCompact()
   // We do not need to open all column families for the remote compaction.
@@ -1030,6 +1033,18 @@ Status DB::OpenAndCompact(
   std::vector<ColumnFamilyDescriptor> column_families;
   for (auto& cf : all_column_families) {
     if (cf.name == compaction_input.cf_name) {
+      ColumnFamilyOptions cf_options;
+      // Override serializable configurations from override_options.options_map
+      s = GetColumnFamilyOptionsFromMap(config_options, cf.options,
+                                        override_options.options_map,
+                                        &cf_options);
+      if (!s.ok()) {
+        return s;
+      }
+      cf.options = std::move(cf_options);
+
+      // Override options that are directly set as shared ptrs in
+      // CompactionServiceOptionsOverride
       cf.options.comparator = override_options.comparator;
       cf.options.merge_operator = override_options.merge_operator;
       cf.options.compaction_filter = override_options.compaction_filter;
@@ -1041,6 +1056,7 @@ Status DB::OpenAndCompact(
           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);
@@ -1057,6 +1073,9 @@ Status DB::OpenAndCompact(
   }
   assert(db);
 
+  TEST_SYNC_POINT_CALLBACK(
+      "DBImplSecondary::OpenAndCompact::AfterOpenAsSecondary:0", db);
+
   // 6. Find the handle of the Column Family that this will compact
   ColumnFamilyHandle* cfh = nullptr;
   for (auto* handle : handles) {

db/db_impl/db_impl_write.cc

@@ -157,7 +157,7 @@ Status DBImpl::Write(const WriteOptions& write_options, WriteBatch* my_batch) {
   if (s.ok()) {
     s = WriteImpl(write_options, my_batch, /*callback=*/nullptr,
                   /*user_write_cb=*/nullptr,
-                  /*log_used=*/nullptr);
+                  /*wal_used=*/nullptr);
   }
   return s;
 }
@@ -190,11 +190,38 @@ Status DBImpl::WriteWithCallback(const WriteOptions& write_options,
   return s;
 }
 
-Status DBImpl::IngestWBWI(std::shared_ptr<WriteBatchWithIndex> wbwi,
-                          const WBWIMemTable::SeqnoRange& assigned_seqno,
-                          uint64_t prep_log,
-                          SequenceNumber last_seqno_after_ingest,
-                          bool memtable_updated, bool ignore_missing_cf) {
+Status DBImpl::IngestWriteBatchWithIndex(
+    const WriteOptions& write_options,
+    std::shared_ptr<WriteBatchWithIndex> wbwi) {
+  if (!wbwi) {
+    return Status::InvalidArgument("Batch is nullptr!");
+  }
+  if (!write_options.disableWAL) {
+    return Status::NotSupported(
+        "IngestWriteBatchWithIndex does not support disableWAL=true");
+  }
+  Status s;
+  if (write_options.protection_bytes_per_key > 0) {
+    s = WriteBatchInternal::UpdateProtectionInfo(
+        wbwi->GetWriteBatch(), write_options.protection_bytes_per_key);
+  }
+  if (s.ok()) {
+    WriteBatch dummy_empty_batch;
+    s = WriteImpl(
+        write_options, /*updates=*/&dummy_empty_batch, /*callback=*/nullptr,
+        /*user_write_cb=*/nullptr, /*log_used=*/nullptr, /*log_ref=*/0,
+        /*disable_memtable=*/false, /*seq_used=*/nullptr,
+        /*batch_cnt=*/0, /*pre_release_callback=*/nullptr,
+        /*post_memtable_callback=*/nullptr, /*wbwi=*/wbwi);
+  }
+  return s;
+}
+
+Status DBImpl::IngestWBWIAsMemtable(
+    std::shared_ptr<WriteBatchWithIndex> wbwi,
+    const WBWIMemTable::SeqnoRange& assigned_seqno, uint64_t min_prep_log,
+    SequenceNumber last_seqno_after_ingest, bool memtable_updated,
+    bool ignore_missing_cf) {
   // Keys in new memtable have seqno > last_seqno_after_ingest >= keys in wbwi.
   assert(assigned_seqno.upper_bound <= last_seqno_after_ingest);
   // Keys in the current memtable have seqno <= LastSequence() < keys in wbwi.
@@ -238,12 +265,30 @@ Status DBImpl::IngestWBWI(std::shared_ptr<WriteBatchWithIndex> wbwi,
     wbwi_memtable->AssignSequenceNumbers(assigned_seqno);
     // This is needed to keep the WAL that contains Prepare alive until
     // committed data in this memtable is persisted.
-    wbwi_memtable->SetMinPrepLog(prep_log);
+    wbwi_memtable->SetMinPrepLog(min_prep_log);
     memtables.push_back(wbwi_memtable);
     cfd->Ref();
     cfds.push_back(cfd);
   }
 
+  autovector<ColumnFamilyData*> cfds_for_atomic_flush;
+  if (immutable_db_options_.atomic_flush) {
+    SelectColumnFamiliesForAtomicFlush(&cfds_for_atomic_flush);
+    for (auto cfd : cfds_for_atomic_flush) {
+      bool found = false;
+      for (auto existing_cfd : cfds) {
+        if (existing_cfd == cfd) {
+          found = true;
+          break;
+        }
+      }
+      if (!found) {
+        cfd->Ref();
+        cfds.push_back(cfd);
+      }
+    }
+  }
+
   // Stop writes to the DB by entering both write threads
   WriteThread::Writer nonmem_w;
   if (two_write_queues_) {
@@ -253,15 +298,16 @@ Status DBImpl::IngestWBWI(std::shared_ptr<WriteBatchWithIndex> wbwi,
 
   // Switch memtable and add WBWIMemTables
   Status s;
-  for (size_t i = 0; i < memtables.size(); ++i) {
-    assert(!immutable_db_options_.atomic_flush);
-    // NOTE: to support atomic flush, need to call
-    // SelectColumnFamiliesForAtomicFlush()
+  for (size_t i = 0; i < cfds.size(); ++i) {
     WriteContext write_context;
     // TODO: not switch on empty memtable, may need to update metadata
     //   like NextLogNumber(), earliest_seqno and memtable id.
-    s = SwitchMemtable(cfds[i], &write_context, memtables[i],
-                       last_seqno_after_ingest);
+    if (i < memtables.size()) {
+      s = SwitchMemtable(cfds[i], &write_context, memtables[i],
+                         last_seqno_after_ingest);
+    } else {
+      s = SwitchMemtable(cfds[i], &write_context);
+    }
     if (!s.ok()) {
       // SwitchMemtable() can only fail if a new WAL is to be created, this
       // should only happen for the first call to SwitchMemtable(). log will
@@ -301,9 +347,18 @@ Status DBImpl::IngestWBWI(std::shared_ptr<WriteBatchWithIndex> wbwi,
         continue;
       }
       cfd->imm()->FlushRequested();
+      if (!immutable_db_options_.atomic_flush) {
+        FlushRequest flush_req;
+        // TODO: a new flush reason for ingesting memtable
+        GenerateFlushRequest({cfd}, FlushReason::kExternalFileIngestion,
+                             &flush_req);
+        EnqueuePendingFlush(flush_req);
+      }
+    }
+    if (immutable_db_options_.atomic_flush) {
+      AssignAtomicFlushSeq(cfds);
       FlushRequest flush_req;
-      // TODO: a new flush reason for ingesting memtable
-      GenerateFlushRequest({cfd}, FlushReason::kExternalFileIngestion,
+      GenerateFlushRequest(cfds, FlushReason::kExternalFileIngestion,
                            &flush_req);
       EnqueuePendingFlush(flush_req);
     }
@@ -314,13 +369,12 @@ Status DBImpl::IngestWBWI(std::shared_ptr<WriteBatchWithIndex> wbwi,
 
 Status DBImpl::WriteImpl(const WriteOptions& write_options,
                          WriteBatch* my_batch, WriteCallback* callback,
-                         UserWriteCallback* user_write_cb, uint64_t* log_used,
+                         UserWriteCallback* user_write_cb, uint64_t* wal_used,
                          uint64_t log_ref, bool disable_memtable,
                          uint64_t* seq_used, size_t batch_cnt,
                          PreReleaseCallback* pre_release_callback,
                          PostMemTableCallback* post_memtable_callback,
-                         std::shared_ptr<WriteBatchWithIndex> wbwi,
-                         uint64_t prep_log) {
+                         std::shared_ptr<WriteBatchWithIndex> wbwi) {
   assert(!seq_per_batch_ || batch_cnt != 0);
   assert(my_batch == nullptr || my_batch->Count() == 0 ||
          write_options.protection_bytes_per_key == 0 ||
@@ -409,9 +463,17 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     return Status::NotSupported(
         "DeleteRange is not compatible with row cache.");
   }
+  // Whether the WBWI is from transaction commit or a direct write
+  // (IngestWriteBatchWithIndex())
+  bool ingest_wbwi_for_commit = false;
   if (wbwi) {
-    assert(prep_log > 0);
-    // Used only in WriteCommittedTxn::CommitInternal() with no `callback`.
+    if (my_batch->HasCommit()) {
+      ingest_wbwi_for_commit = true;
+      assert(log_ref);
+    } else {
+      // Only supports disableWAL for directly ingesting WBWI for now.
+      assert(write_options.disableWAL);
+    }
     assert(!callback);
     if (immutable_db_options_.unordered_write) {
       return Status::NotSupported(
@@ -421,9 +483,9 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
       return Status::NotSupported(
           "Ingesting WriteBatch does not support pipelined_write");
     }
-    if (immutable_db_options_.atomic_flush) {
+    if (!wbwi->GetOverwriteKey()) {
       return Status::NotSupported(
-          "Ingesting WriteBatch does not support atomic_flush");
+          "WriteBatchWithIndex ingestion requires overwrite_key=true");
     }
   }
   // Otherwise IsLatestPersistentState optimization does not make sense
@@ -444,7 +506,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     // they don't consume sequence.
     return WriteImplWALOnly(
         &nonmem_write_thread_, write_options, my_batch, callback, user_write_cb,
-        log_used, log_ref, seq_used, batch_cnt, pre_release_callback,
+        wal_used, log_ref, seq_used, batch_cnt, pre_release_callback,
         assign_order, kDontPublishLastSeq, disable_memtable);
   }
 
@@ -458,7 +520,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     // sequence in in increasing order, iii) call pre_release_callback serially
     Status status = WriteImplWALOnly(
         &write_thread_, write_options, my_batch, callback, user_write_cb,
-        log_used, log_ref, &seq, sub_batch_cnt, pre_release_callback,
+        wal_used, log_ref, &seq, sub_batch_cnt, pre_release_callback,
         kDoAssignOrder, kDoPublishLastSeq, disable_memtable);
     TEST_SYNC_POINT("DBImpl::WriteImpl:UnorderedWriteAfterWriteWAL");
     if (!status.ok()) {
@@ -477,7 +539,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
 
   if (immutable_db_options_.enable_pipelined_write) {
     return PipelinedWriteImpl(write_options, my_batch, callback, user_write_cb,
-                              log_used, log_ref, disable_memtable, seq_used);
+                              wal_used, log_ref, disable_memtable, seq_used);
   }
 
   PERF_TIMER_GUARD(write_pre_and_post_process_time);
@@ -524,16 +586,19 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
           assert(tmp_s.ok());
         }
       }
-      versions_->SetLastSequence(last_sequence);
-      MemTableInsertStatusCheck(w.status);
+      if (w.status.ok()) {  // Don't publish a partial batch write
+        versions_->SetLastSequence(last_sequence);
+      } else {
+        HandleMemTableInsertFailure(w.status);
+      }
       write_thread_.ExitAsBatchGroupFollower(&w);
     }
     assert(w.state == WriteThread::STATE_COMPLETED);
     // STATE_COMPLETED conditional below handles exit
   }
   if (w.state == WriteThread::STATE_COMPLETED) {
-    if (log_used != nullptr) {
-      *log_used = w.log_used;
+    if (wal_used != nullptr) {
+      *wal_used = w.wal_used;
     }
     if (seq_used != nullptr) {
       *seq_used = w.sequence;
@@ -549,7 +614,8 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
   // when it finds suitable, and finish them in the same write batch.
   // This is how a write job could be done by the other writer.
   WriteContext write_context;
-  LogContext log_context(write_options.sync);
+  // FIXME: also check disableWAL like others?
+  WalContext wal_context(write_options.sync);
   WriteThread::WriteGroup write_group;
   bool in_parallel_group = false;
   uint64_t last_sequence = kMaxSequenceNumber;
@@ -563,7 +629,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     // PreprocessWrite does its own perf timing.
     PERF_TIMER_STOP(write_pre_and_post_process_time);
 
-    status = PreprocessWrite(write_options, &log_context, &write_context);
+    status = PreprocessWrite(write_options, &wal_context, &write_context);
     if (!two_write_queues_) {
       // Assign it after ::PreprocessWrite since the sequence might advance
       // inside it by WriteRecoverableState
@@ -631,7 +697,13 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
             continue;
           }
           // TODO: maybe handle the tracing status?
-          tracer_->Write(writer->batch).PermitUncheckedError();
+          if (wbwi && !ingest_wbwi_for_commit) {
+            // for transaction write, tracer only needs the commit marker which
+            // is in writer->batch
+            tracer_->Write(wbwi->GetWriteBatch()).PermitUncheckedError();
+          } else {
+            tracer_->Write(writer->batch).PermitUncheckedError();
+          }
         }
       }
     }
@@ -689,22 +761,21 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
 
     if (!two_write_queues_) {
       if (status.ok() && !write_options.disableWAL) {
-        assert(log_context.log_file_number_size);
-        LogFileNumberSize& log_file_number_size =
-            *(log_context.log_file_number_size);
+        assert(wal_context.wal_file_number_size);
+        wal_context.prev_size = wal_context.writer->file()->GetFileSize();
         PERF_TIMER_GUARD(write_wal_time);
-        io_s =
-            WriteToWAL(write_group, log_context.writer, log_used,
-                       log_context.need_log_sync, log_context.need_log_dir_sync,
-                       last_sequence + 1, log_file_number_size);
+        io_s = WriteGroupToWAL(write_group, wal_context.writer, wal_used,
+                               wal_context.need_wal_sync,
+                               wal_context.need_wal_dir_sync, last_sequence + 1,
+                               *wal_context.wal_file_number_size);
       }
     } else {
       if (status.ok() && !write_options.disableWAL) {
         PERF_TIMER_GUARD(write_wal_time);
         // LastAllocatedSequence is increased inside WriteToWAL under
         // wal_write_mutex_ to ensure ordered events in WAL
-        io_s = ConcurrentWriteToWAL(write_group, log_used, &last_sequence,
-                                    seq_inc);
+        io_s = ConcurrentWriteGroupToWAL(write_group, wal_used, &last_sequence,
+                                         seq_inc);
       } else {
         // Otherwise we inc seq number for memtable writes
         last_sequence = versions_->FetchAddLastAllocatedSequence(seq_inc);
@@ -716,16 +787,16 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     last_sequence += seq_inc;
     // Seqno assigned to this write are [current_sequence, last_sequence]
 
-    if (log_context.need_log_sync) {
+    if (wal_context.need_wal_sync) {
       VersionEdit synced_wals;
-      log_write_mutex_.Lock();
+      wal_write_mutex_.Lock();
       if (status.ok()) {
-        MarkLogsSynced(logfile_number_, log_context.need_log_dir_sync,
+        MarkLogsSynced(cur_wal_number_, wal_context.need_wal_dir_sync,
                        &synced_wals);
       } else {
-        MarkLogsNotSynced(logfile_number_);
+        MarkLogsNotSynced(cur_wal_number_);
       }
-      log_write_mutex_.Unlock();
+      wal_write_mutex_.Unlock();
       if (status.ok() && synced_wals.IsWalAddition()) {
         InstrumentedMutexLock l(&mutex_);
         // TODO: plumb Env::IOActivity, Env::IOPriority
@@ -760,7 +831,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
         writer->sequence = next_sequence;
         if (writer->pre_release_callback) {
           Status ws = writer->pre_release_callback->Callback(
-              writer->sequence, disable_memtable, writer->log_used, index++,
+              writer->sequence, disable_memtable, writer->wal_used, index++,
               pre_release_callback_cnt);
           if (!ws.ok()) {
             status = pre_release_cb_status = ws;
@@ -834,12 +905,13 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     // handle exit, false means somebody else did
     should_exit_batch_group = write_thread_.CompleteParallelMemTableWriter(&w);
   }
-  if (wbwi) {
-    if (status.ok() && w.status.ok()) {
+  if (wbwi && status.ok() && w.status.ok()) {
+    uint32_t wbwi_count = wbwi->GetWriteBatch()->Count();
+    // skip empty batch case
+    if (wbwi_count) {
       // w.batch contains (potentially empty) commit time batch updates,
       // only ingest wbwi if w.batch is applied to memtable successfully
       uint32_t memtable_update_count = w.batch->Count();
-      uint32_t wbwi_count = wbwi->GetWriteBatch()->Count();
       // Seqno assigned to this write are [last_seq + 1 - seq_inc, last_seq].
       // seq_inc includes w.batch (memtable updates) and wbwi
       // w.batch gets first `memtable_update_count` sequence numbers.
@@ -852,10 +924,11 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
       if (two_write_queues_) {
         assert(ub <= versions_->LastAllocatedSequence());
       }
-      status = IngestWBWI(wbwi, {/*lower_bound=*/lb, /*upper_bound=*/ub},
-                          prep_log, last_sequence,
-                          /*memtable_updated=*/memtable_update_count > 0,
-                          write_options.ignore_missing_column_families);
+      status =
+          IngestWBWIAsMemtable(wbwi, {/*lower_bound=*/lb, /*upper_bound=*/ub},
+                               /*min_prep_log=*/log_ref, last_sequence,
+                               /*memtable_updated=*/memtable_update_count > 0,
+                               write_options.ignore_missing_column_families);
     }
   }
 
@@ -873,9 +946,19 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
       }
       // Note: if we are to resume after non-OK statuses we need to revisit how
       // we react to non-OK statuses here.
-      versions_->SetLastSequence(last_sequence);
+      if (w.status.ok()) {  // Don't publish a partial batch write
+        versions_->SetLastSequence(last_sequence);
+      }
+    }
+    if (!w.status.ok()) {
+      if (wal_context.prev_size < SIZE_MAX) {
+        InstrumentedMutexLock l(&wal_write_mutex_);
+        if (logs_.back().number == wal_context.wal_file_number_size->number) {
+          logs_.back().SetAttemptTruncateSize(wal_context.prev_size);
+        }
+      }
+      HandleMemTableInsertFailure(w.status);
     }
-    MemTableInsertStatusCheck(w.status);
     write_thread_.ExitAsBatchGroupLeader(write_group, status);
   }
 
@@ -888,7 +971,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
 Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
                                   WriteBatch* my_batch, WriteCallback* callback,
                                   UserWriteCallback* user_write_cb,
-                                  uint64_t* log_used, uint64_t log_ref,
+                                  uint64_t* wal_used, uint64_t log_ref,
                                   bool disable_memtable, uint64_t* seq_used) {
   PERF_TIMER_GUARD(write_pre_and_post_process_time);
   StopWatch write_sw(immutable_db_options_.clock, stats_, DB_WRITE);
@@ -905,10 +988,10 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
     if (w.callback && !w.callback->AllowWriteBatching()) {
       write_thread_.WaitForMemTableWriters();
     }
-    LogContext log_context(!write_options.disableWAL && write_options.sync);
+    WalContext wal_context(!write_options.disableWAL && write_options.sync);
     // PreprocessWrite does its own perf timing.
     PERF_TIMER_STOP(write_pre_and_post_process_time);
-    w.status = PreprocessWrite(write_options, &log_context, &write_context);
+    w.status = PreprocessWrite(write_options, &wal_context, &write_context);
     PERF_TIMER_START(write_pre_and_post_process_time);
 
     // This can set non-OK status if callback fail.
@@ -977,13 +1060,13 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
                           wal_write_group.size - 1);
         RecordTick(stats_, WRITE_DONE_BY_OTHER, wal_write_group.size - 1);
       }
-      assert(log_context.log_file_number_size);
-      LogFileNumberSize& log_file_number_size =
-          *(log_context.log_file_number_size);
-      io_s =
-          WriteToWAL(wal_write_group, log_context.writer, log_used,
-                     log_context.need_log_sync, log_context.need_log_dir_sync,
-                     current_sequence, log_file_number_size);
+      assert(wal_context.wal_file_number_size);
+      WalFileNumberSize& wal_file_number_size =
+          *(wal_context.wal_file_number_size);
+      io_s = WriteGroupToWAL(wal_write_group, wal_context.writer, wal_used,
+                             wal_context.need_wal_sync,
+                             wal_context.need_wal_dir_sync, current_sequence,
+                             wal_file_number_size);
       w.status = io_s;
     }
 
@@ -995,13 +1078,13 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
     }
 
     VersionEdit synced_wals;
-    if (log_context.need_log_sync) {
-      InstrumentedMutexLock l(&log_write_mutex_);
+    if (wal_context.need_wal_sync) {
+      InstrumentedMutexLock l(&wal_write_mutex_);
       if (w.status.ok()) {
-        MarkLogsSynced(logfile_number_, log_context.need_log_dir_sync,
+        MarkLogsSynced(cur_wal_number_, wal_context.need_wal_dir_sync,
                        &synced_wals);
       } else {
-        MarkLogsNotSynced(logfile_number_);
+        MarkLogsNotSynced(cur_wal_number_);
       }
     }
     if (w.status.ok() && synced_wals.IsWalAddition()) {
@@ -1032,7 +1115,12 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
           &flush_scheduler_, &trim_history_scheduler_,
           write_options.ignore_missing_column_families, 0 /*log_number*/, this,
           false /*concurrent_memtable_writes*/, seq_per_batch_, batch_per_txn_);
-      versions_->SetLastSequence(memtable_write_group.last_sequence);
+      if (memtable_write_group.status
+              .ok()) {  // Don't publish a partial batch write
+        versions_->SetLastSequence(memtable_write_group.last_sequence);
+      } else {
+        HandleMemTableInsertFailure(memtable_write_group.status);
+      }
       write_thread_.ExitAsMemTableWriter(&w, memtable_write_group);
     }
   } else {
@@ -1061,8 +1149,11 @@ Status DBImpl::PipelinedWriteImpl(const WriteOptions& write_options,
     PERF_TIMER_START(write_pre_and_post_process_time);
 
     if (write_thread_.CompleteParallelMemTableWriter(&w)) {
-      MemTableInsertStatusCheck(w.status);
-      versions_->SetLastSequence(w.write_group->last_sequence);
+      if (w.status.ok()) {  // Don't publish a partial batch write
+        versions_->SetLastSequence(w.write_group->last_sequence);
+      } else {
+        HandleMemTableInsertFailure(w.status);
+      }
       write_thread_.ExitAsMemTableWriter(&w, *w.write_group);
     }
   }
@@ -1134,7 +1225,7 @@ Status DBImpl::UnorderedWriteMemtable(const WriteOptions& write_options,
 Status DBImpl::WriteImplWALOnly(
     WriteThread* write_thread, const WriteOptions& write_options,
     WriteBatch* my_batch, WriteCallback* callback,
-    UserWriteCallback* user_write_cb, uint64_t* log_used,
+    UserWriteCallback* user_write_cb, uint64_t* wal_used,
     const uint64_t log_ref, uint64_t* seq_used, const size_t sub_batch_cnt,
     PreReleaseCallback* pre_release_callback, const AssignOrder assign_order,
     const PublishLastSeq publish_last_seq, const bool disable_memtable) {
@@ -1147,8 +1238,8 @@ Status DBImpl::WriteImplWALOnly(
   write_thread->JoinBatchGroup(&w);
   assert(w.state != WriteThread::STATE_PARALLEL_MEMTABLE_WRITER);
   if (w.state == WriteThread::STATE_COMPLETED) {
-    if (log_used != nullptr) {
-      *log_used = w.log_used;
+    if (wal_used != nullptr) {
+      *wal_used = w.wal_used;
     }
     if (seq_used != nullptr) {
       *seq_used = w.sequence;
@@ -1164,10 +1255,10 @@ Status DBImpl::WriteImplWALOnly(
 
     // TODO(myabandeh): Make preliminary checks thread-safe so we could do them
     // without paying the cost of obtaining the mutex.
-    LogContext log_context;
+    WalContext wal_context;
     WriteContext write_context;
     Status status =
-        PreprocessWrite(write_options, &log_context, &write_context);
+        PreprocessWrite(write_options, &wal_context, &write_context);
     WriteStatusCheckOnLocked(status);
 
     if (!status.ok()) {
@@ -1264,8 +1355,8 @@ Status DBImpl::WriteImplWALOnly(
   }
   Status status;
   if (!write_options.disableWAL) {
-    IOStatus io_s =
-        ConcurrentWriteToWAL(write_group, log_used, &last_sequence, seq_inc);
+    IOStatus io_s = ConcurrentWriteGroupToWAL(write_group, wal_used,
+                                              &last_sequence, seq_inc);
     status = io_s;
     // last_sequence may not be set if there is an error
     // This error checking and return is moved up to avoid using uninitialized
@@ -1317,7 +1408,7 @@ Status DBImpl::WriteImplWALOnly(
       if (!writer->CallbackFailed() && writer->pre_release_callback) {
         assert(writer->sequence != kMaxSequenceNumber);
         Status ws = writer->pre_release_callback->Callback(
-            writer->sequence, disable_memtable, writer->log_used, index++,
+            writer->sequence, disable_memtable, writer->wal_used, index++,
             pre_release_callback_cnt);
         if (!ws.ok()) {
           status = ws;
@@ -1386,24 +1477,22 @@ void DBImpl::WALIOStatusCheck(const IOStatus& io_status) {
   }
 }
 
-void DBImpl::MemTableInsertStatusCheck(const Status& status) {
-  // A non-OK status here indicates that the state implied by the
-  // WAL has diverged from the in-memory state.  This could be
-  // because of a corrupt write_batch (very bad), or because the
-  // client specified an invalid column family and didn't specify
-  // ignore_missing_column_families.
-  if (!status.ok()) {
-    mutex_.Lock();
-    assert(!error_handler_.IsBGWorkStopped());
-    error_handler_.SetBGError(status, BackgroundErrorReason::kMemTable);
-    mutex_.Unlock();
-  }
+void DBImpl::HandleMemTableInsertFailure(const Status& status) {
+  assert(!status.ok());
+  // A non-OK status on memtable insert indicates that the state implied by the
+  // WAL has diverged from the in-memory state.  This could be because of a
+  // corrupt write_batch (very bad), or because the client specified an invalid
+  // column family and didn't specify ignore_missing_column_families.
+  mutex_.Lock();
+  assert(!error_handler_.IsBGWorkStopped());
+  error_handler_.SetBGError(status, BackgroundErrorReason::kMemTable);
+  mutex_.Unlock();
 }
 
 Status DBImpl::PreprocessWrite(const WriteOptions& write_options,
-                               LogContext* log_context,
+                               WalContext* wal_context,
                                WriteContext* write_context) {
-  assert(write_context != nullptr && log_context != nullptr);
+  assert(write_context != nullptr && wal_context != nullptr);
   Status status;
 
   if (error_handler_.IsDBStopped()) {
@@ -1413,7 +1502,8 @@ Status DBImpl::PreprocessWrite(const WriteOptions& write_options,
 
   PERF_TIMER_GUARD(write_scheduling_flushes_compactions_time);
 
-  if (UNLIKELY(status.ok() && total_log_size_ > GetMaxTotalWalSize())) {
+  if (UNLIKELY(status.ok() &&
+               wals_total_size_.LoadRelaxed() > GetMaxTotalWalSize())) {
     assert(versions_);
     InstrumentedMutexLock l(&mutex_);
     const ColumnFamilySet* const column_families =
@@ -1482,17 +1572,17 @@ Status DBImpl::PreprocessWrite(const WriteOptions& write_options,
       WriteBufferManagerStallWrites();
     }
   }
-  InstrumentedMutexLock l(&log_write_mutex_);
-  if (status.ok() && log_context->need_log_sync) {
+  InstrumentedMutexLock l(&wal_write_mutex_);
+  if (status.ok() && wal_context->need_wal_sync) {
     // Wait until the parallel syncs are finished. Any sync process has to sync
     // the front log too so it is enough to check the status of front()
-    // We do a while loop since log_sync_cv_ is signalled when any sync is
+    // We do a while loop since wal_sync_cv_ is signalled when any sync is
     // finished
     // Note: there does not seem to be a reason to wait for parallel sync at
     // this early step but it is not important since parallel sync (SyncWAL) and
-    // need_log_sync are usually not used together.
+    // need_wal_sync are usually not used together.
     while (logs_.front().IsSyncing()) {
-      log_sync_cv_.Wait();
+      wal_sync_cv_.Wait();
     }
     for (auto& log : logs_) {
       // This is just to prevent the logs to be synced by a parallel SyncWAL
@@ -1503,12 +1593,12 @@ Status DBImpl::PreprocessWrite(const WriteOptions& write_options,
       log.PrepareForSync();
     }
   } else {
-    log_context->need_log_sync = false;
+    wal_context->need_wal_sync = false;
   }
-  log_context->writer = logs_.back().writer;
-  log_context->need_log_dir_sync =
-      log_context->need_log_dir_sync && !log_dir_synced_;
-  log_context->log_file_number_size = std::addressof(alive_log_files_.back());
+  wal_context->writer = logs_.back().writer;
+  wal_context->need_wal_dir_sync =
+      wal_context->need_wal_dir_sync && !wal_dir_synced_;
+  wal_context->wal_file_number_size = std::addressof(alive_wal_files_.back());
 
   return status;
 }
@@ -1559,12 +1649,12 @@ Status DBImpl::MergeBatch(const WriteThread::WriteGroup& write_group,
 }
 
 // When two_write_queues_ is disabled, this function is called from the only
-// write thread. Otherwise this must be called holding log_write_mutex_.
+// write thread. Otherwise this must be called holding wal_write_mutex_.
 IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
                             const WriteOptions& write_options,
-                            log::Writer* log_writer, uint64_t* log_used,
+                            log::Writer* log_writer, uint64_t* wal_used,
                             uint64_t* log_size,
-                            LogFileNumberSize& log_file_number_size,
+                            WalFileNumberSize& wal_file_number_size,
                             SequenceNumber sequence) {
   assert(log_size != nullptr);
 
@@ -1576,7 +1666,7 @@ IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
   }
   *log_size = log_entry.size();
   // When two_write_queues_ WriteToWAL has to be protected from concurretn calls
-  // from the two queues anyway and log_write_mutex_ is already held. Otherwise
+  // from the two queues anyway and wal_write_mutex_ is already held. Otherwise
   // if manual_wal_flush_ is enabled we need to protect log_writer->AddRecord
   // from possible concurrent calls via the FlushWAL by the application.
   const bool needs_locking = manual_wal_flush_ && !two_write_queues_;
@@ -1584,7 +1674,7 @@ IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
   // manual_wal_flush_ feature (by UNLIKELY) instead of the more common case
   // when we do not need any locking.
   if (UNLIKELY(needs_locking)) {
-    log_write_mutex_.Lock();
+    wal_write_mutex_.Lock();
   }
   IOStatus io_s = log_writer->MaybeAddUserDefinedTimestampSizeRecord(
       write_options, versions_->GetColumnFamiliesTimestampSizeForRecord());
@@ -1594,23 +1684,24 @@ IOStatus DBImpl::WriteToWAL(const WriteBatch& merged_batch,
   io_s = log_writer->AddRecord(write_options, log_entry, sequence);
 
   if (UNLIKELY(needs_locking)) {
-    log_write_mutex_.Unlock();
+    wal_write_mutex_.Unlock();
   }
-  if (log_used != nullptr) {
-    *log_used = logfile_number_;
+  if (wal_used != nullptr) {
+    *wal_used = cur_wal_number_;
+    assert(*wal_used == wal_file_number_size.number);
   }
-  total_log_size_ += log_entry.size();
-  log_file_number_size.AddSize(*log_size);
-  log_empty_ = false;
+  wals_total_size_.FetchAddRelaxed(log_entry.size());
+  wal_file_number_size.AddSize(*log_size);
+  wal_empty_ = false;
 
   return io_s;
 }
 
-IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
-                            log::Writer* log_writer, uint64_t* log_used,
-                            bool need_log_sync, bool need_log_dir_sync,
-                            SequenceNumber sequence,
-                            LogFileNumberSize& log_file_number_size) {
+IOStatus DBImpl::WriteGroupToWAL(const WriteThread::WriteGroup& write_group,
+                                 log::Writer* log_writer, uint64_t* wal_used,
+                                 bool need_wal_sync, bool need_wal_dir_sync,
+                                 SequenceNumber sequence,
+                                 WalFileNumberSize& wal_file_number_size) {
   IOStatus io_s;
   assert(!two_write_queues_);
   assert(!write_group.leader->disable_wal);
@@ -1625,10 +1716,10 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
   }
 
   if (merged_batch == write_group.leader->batch) {
-    write_group.leader->log_used = logfile_number_;
+    write_group.leader->wal_used = cur_wal_number_;
   } else if (write_with_wal > 1) {
     for (auto writer : write_group) {
-      writer->log_used = logfile_number_;
+      writer->wal_used = cur_wal_number_;
     }
   }
 
@@ -1640,14 +1731,14 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
   WriteOptions write_options;
   write_options.rate_limiter_priority =
       write_group.leader->rate_limiter_priority;
-  io_s = WriteToWAL(*merged_batch, write_options, log_writer, log_used,
-                    &log_size, log_file_number_size, sequence);
+  io_s = WriteToWAL(*merged_batch, write_options, log_writer, wal_used,
+                    &log_size, wal_file_number_size, sequence);
   if (to_be_cached_state) {
     cached_recoverable_state_ = *to_be_cached_state;
     cached_recoverable_state_empty_ = false;
   }
 
-  if (io_s.ok() && need_log_sync) {
+  if (io_s.ok() && need_wal_sync) {
     StopWatch sw(immutable_db_options_.clock, stats_, WAL_FILE_SYNC_MICROS);
     // It's safe to access logs_ with unlocked mutex_ here because:
     //  - we've set getting_synced=true for all logs,
@@ -1657,15 +1748,15 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
     //  - as long as other threads don't modify it, it's safe to read
     //    from std::deque from multiple threads concurrently.
     //
-    // Sync operation should work with locked log_write_mutex_, because:
+    // Sync operation should work with locked wal_write_mutex_, because:
     //   when DBOptions.manual_wal_flush_ is set,
     //   FlushWAL function will be invoked by another thread.
-    //   if without locked log_write_mutex_, the log file may get data
+    //   if without locked wal_write_mutex_, the log file may get data
     //   corruption
 
     const bool needs_locking = manual_wal_flush_ && !two_write_queues_;
     if (UNLIKELY(needs_locking)) {
-      log_write_mutex_.Lock();
+      wal_write_mutex_.Lock();
     }
 
     if (io_s.ok()) {
@@ -1688,10 +1779,10 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
     }
 
     if (UNLIKELY(needs_locking)) {
-      log_write_mutex_.Unlock();
+      wal_write_mutex_.Unlock();
     }
 
-    if (io_s.ok() && need_log_dir_sync) {
+    if (io_s.ok() && need_wal_dir_sync) {
       // We only sync WAL directory the first time WAL syncing is
       // requested, so that in case users never turn on WAL sync,
       // we can avoid the disk I/O in the write code path.
@@ -1706,7 +1797,7 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
   }
   if (io_s.ok()) {
     auto stats = default_cf_internal_stats_;
-    if (need_log_sync) {
+    if (need_wal_sync) {
       stats->AddDBStats(InternalStats::kIntStatsWalFileSynced, 1);
       RecordTick(stats_, WAL_FILE_SYNCED);
     }
@@ -1723,8 +1814,8 @@ IOStatus DBImpl::WriteToWAL(const WriteThread::WriteGroup& write_group,
   return io_s;
 }
 
-IOStatus DBImpl::ConcurrentWriteToWAL(
-    const WriteThread::WriteGroup& write_group, uint64_t* log_used,
+IOStatus DBImpl::ConcurrentWriteGroupToWAL(
+    const WriteThread::WriteGroup& write_group, uint64_t* wal_used,
     SequenceNumber* last_sequence, size_t seq_inc) {
   IOStatus io_s;
 
@@ -1741,14 +1832,14 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
     return io_s;
   }
 
-  // We need to lock log_write_mutex_ since logs_ and alive_log_files might be
+  // We need to lock wal_write_mutex_ since logs_ and alive_wal_files might be
   // pushed back concurrently
-  log_write_mutex_.Lock();
+  wal_write_mutex_.Lock();
   if (merged_batch == write_group.leader->batch) {
-    write_group.leader->log_used = logfile_number_;
+    write_group.leader->wal_used = cur_wal_number_;
   } else if (write_with_wal > 1) {
     for (auto writer : write_group) {
-      writer->log_used = logfile_number_;
+      writer->wal_used = cur_wal_number_;
     }
   }
   *last_sequence = versions_->FetchAddLastAllocatedSequence(seq_inc);
@@ -1756,9 +1847,9 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
   WriteBatchInternal::SetSequence(merged_batch, sequence);
 
   log::Writer* log_writer = logs_.back().writer;
-  LogFileNumberSize& log_file_number_size = alive_log_files_.back();
+  WalFileNumberSize& wal_file_number_size = alive_wal_files_.back();
 
-  assert(log_writer->get_log_number() == log_file_number_size.number);
+  assert(log_writer->get_log_number() == wal_file_number_size.number);
 
   uint64_t log_size;
 
@@ -1766,13 +1857,13 @@ IOStatus DBImpl::ConcurrentWriteToWAL(
   WriteOptions write_options;
   write_options.rate_limiter_priority =
       write_group.leader->rate_limiter_priority;
-  io_s = WriteToWAL(*merged_batch, write_options, log_writer, log_used,
-                    &log_size, log_file_number_size, sequence);
+  io_s = WriteToWAL(*merged_batch, write_options, log_writer, wal_used,
+                    &log_size, wal_file_number_size, sequence);
   if (to_be_cached_state) {
     cached_recoverable_state_ = *to_be_cached_state;
     cached_recoverable_state_empty_ = false;
   }
-  log_write_mutex_.Unlock();
+  wal_write_mutex_.Unlock();
 
   if (io_s.ok()) {
     const bool concurrent = true;
@@ -1800,7 +1891,7 @@ Status DBImpl::WriteRecoverableState() {
     bool dont_care_bool;
     SequenceNumber next_seq;
     if (two_write_queues_) {
-      log_write_mutex_.Lock();
+      wal_write_mutex_.Lock();
     }
     SequenceNumber seq;
     if (two_write_queues_) {
@@ -1815,13 +1906,17 @@ Status DBImpl::WriteRecoverableState() {
         0 /*recovery_log_number*/, this, false /* concurrent_memtable_writes */,
         &next_seq, &dont_care_bool, seq_per_batch_);
     auto last_seq = next_seq - 1;
-    if (two_write_queues_) {
-      versions_->FetchAddLastAllocatedSequence(last_seq - seq);
-      versions_->SetLastPublishedSequence(last_seq);
+    if (status.ok()) {  // Don't publish a partial batch write
+      if (two_write_queues_) {
+        versions_->FetchAddLastAllocatedSequence(last_seq - seq);
+        versions_->SetLastPublishedSequence(last_seq);
+      }
+      versions_->SetLastSequence(last_seq);
+    } else {
+      HandleMemTableInsertFailure(status);
     }
-    versions_->SetLastSequence(last_seq);
     if (two_write_queues_) {
-      log_write_mutex_.Unlock();
+      wal_write_mutex_.Unlock();
     }
     if (status.ok() && recoverable_state_pre_release_callback_) {
       const bool DISABLE_MEMTABLE = true;
@@ -1893,7 +1988,10 @@ void DBImpl::AssignAtomicFlushSeq(const autovector<ColumnFamilyData*>& cfds) {
   assert(immutable_db_options_.atomic_flush);
   auto seq = versions_->LastSequence();
   for (auto cfd : cfds) {
-    cfd->imm()->AssignAtomicFlushSeq(seq);
+    // cfd can be nullptr, see ScheduleFlushes()
+    if (cfd) {
+      cfd->imm()->AssignAtomicFlushSeq(seq);
+    }
   }
 }
 
@@ -1902,11 +2000,11 @@ Status DBImpl::SwitchWAL(WriteContext* write_context) {
   assert(write_context != nullptr);
   Status status;
 
-  if (alive_log_files_.begin()->getting_flushed) {
+  if (alive_wal_files_.begin()->getting_flushed) {
     return status;
   }
 
-  auto oldest_alive_log = alive_log_files_.begin()->number;
+  auto oldest_alive_log = alive_wal_files_.begin()->number;
   bool flush_wont_release_oldest_log = false;
   if (allow_2pc()) {
     auto oldest_log_with_uncommitted_prep =
@@ -1936,14 +2034,14 @@ Status DBImpl::SwitchWAL(WriteContext* write_context) {
     // transactions then we cannot flush this log until those transactions are
     // commited.
     unable_to_release_oldest_log_ = false;
-    alive_log_files_.begin()->getting_flushed = true;
+    alive_wal_files_.begin()->getting_flushed = true;
   }
 
   ROCKS_LOG_INFO(
       immutable_db_options_.info_log,
       "Flushing all column families with data in WAL number %" PRIu64
       ". Total log size is %" PRIu64 " while max_total_wal_size is %" PRIu64,
-      oldest_alive_log, total_log_size_.load(), GetMaxTotalWalSize());
+      oldest_alive_log, wals_total_size_.LoadRelaxed(), GetMaxTotalWalSize());
   // no need to refcount because drop is happening in write thread, so can't
   // happen while we're in the write thread
   autovector<ColumnFamilyData*> cfds;
@@ -2413,21 +2511,21 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
   // Do this without holding the dbmutex lock.
   assert(versions_->prev_log_number() == 0);
   if (two_write_queues_) {
-    log_write_mutex_.Lock();
+    wal_write_mutex_.Lock();
   }
-  bool creating_new_log = !log_empty_;
+  bool creating_new_log = !wal_empty_;
   if (two_write_queues_) {
-    log_write_mutex_.Unlock();
+    wal_write_mutex_.Unlock();
   }
   uint64_t recycle_log_number = 0;
   // If file deletion is disabled, don't recycle logs since it'll result in
   // the file getting renamed
   if (creating_new_log && immutable_db_options_.recycle_log_file_num &&
-      !log_recycle_files_.empty() && IsFileDeletionsEnabled()) {
-    recycle_log_number = log_recycle_files_.front();
+      !wal_recycle_files_.empty() && IsFileDeletionsEnabled()) {
+    recycle_log_number = wal_recycle_files_.front();
   }
   uint64_t new_log_number =
-      creating_new_log ? versions_->NewFileNumber() : logfile_number_;
+      creating_new_log ? versions_->NewFileNumber() : cur_wal_number_;
   // For use outside of holding DB mutex
   const MutableCFOptions mutable_cf_options_copy =
       cfd->GetLatestMutableCFOptions();
@@ -2453,14 +2551,14 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
   mutex_.Unlock();
   if (creating_new_log) {
     PredecessorWALInfo info;
-    log_write_mutex_.Lock();
+    wal_write_mutex_.Lock();
     if (!logs_.empty()) {
       log::Writer* cur_log_writer = logs_.back().writer;
       info = PredecessorWALInfo(cur_log_writer->get_log_number(),
                                 cur_log_writer->file()->GetFileSize(),
                                 cur_log_writer->GetLastSeqnoRecorded());
     }
-    log_write_mutex_.Unlock();
+    wal_write_mutex_.Unlock();
     // TODO: Write buffer size passed in should be max of all CF's instead
     // of mutable_cf_options.write_buffer_size.
     io_s = CreateWAL(write_options, new_log_number, recycle_log_number,
@@ -2501,11 +2599,11 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
     // concurrent full purges don't delete the file while we're recycling it.
     // To achieve that we hold the old log number in the recyclable list until
     // after it has been renamed.
-    assert(log_recycle_files_.front() == recycle_log_number);
-    log_recycle_files_.pop_front();
+    assert(wal_recycle_files_.front() == recycle_log_number);
+    wal_recycle_files_.pop_front();
   }
   if (s.ok() && creating_new_log) {
-    InstrumentedMutexLock l(&log_write_mutex_);
+    InstrumentedMutexLock l(&wal_write_mutex_);
     assert(new_log != nullptr);
     if (!logs_.empty()) {
       // Alway flush the buffer of the last log before switching to a new one
@@ -2527,11 +2625,11 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
       }
     }
     if (s.ok()) {
-      logfile_number_ = new_log_number;
-      log_empty_ = true;
-      log_dir_synced_ = false;
-      logs_.emplace_back(logfile_number_, new_log);
-      alive_log_files_.emplace_back(logfile_number_);
+      cur_wal_number_ = new_log_number;
+      wal_empty_ = true;
+      wal_dir_synced_ = false;
+      logs_.emplace_back(cur_wal_number_, new_log);
+      alive_wal_files_.emplace_back(cur_wal_number_);
     }
   }
 
@@ -2562,7 +2660,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
     // obsolete. So we should track the WAL obsoletion event before actually
     // updating the empty CF's log number.
     uint64_t min_wal_number_to_keep =
-        versions_->PreComputeMinLogNumberWithUnflushedData(logfile_number_);
+        versions_->PreComputeMinLogNumberWithUnflushedData(cur_wal_number_);
     if (min_wal_number_to_keep >
         versions_->GetWalSet().GetMinWalNumberToKeep()) {
       // TODO: plumb Env::IOActivity, Env::IOPriority
@@ -2597,7 +2695,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
 
       for (auto cf : empty_cfs) {
         if (cf->IsEmpty()) {
-          cf->SetLogNumber(logfile_number_);
+          cf->SetLogNumber(cur_wal_number_);
           // MEMPURGE: No need to change this, because new adds
           // should still receive new sequence numbers.
           cf->mem()->SetCreationSeq(versions_->LastSequence());
@@ -2614,14 +2712,14 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
       // advance the log number. no need to persist this in the manifest
       if (cf->IsEmpty()) {
         if (creating_new_log) {
-          cf->SetLogNumber(logfile_number_);
+          cf->SetLogNumber(cur_wal_number_);
         }
         cf->mem()->SetCreationSeq(versions_->LastSequence());
       }
     }
   }
 
-  cfd->mem()->SetNextLogNumber(logfile_number_);
+  cfd->mem()->SetNextLogNumber(cur_wal_number_);
   assert(new_mem != nullptr);
   cfd->imm()->Add(cfd->mem(), &context->memtables_to_free_);
   if (new_imm) {
@@ -2633,7 +2731,7 @@ Status DBImpl::SwitchMemtable(ColumnFamilyData* cfd, WriteContext* context,
     // we always try to flush all immutable memtable. For atomic flush, these
     // two memtables will be marked eligible for flush in the same call to
     // AssignAtomicFlushSeq().
-    new_imm->SetNextLogNumber(logfile_number_);
+    new_imm->SetNextLogNumber(cur_wal_number_);
     cfd->imm()->Add(new_imm, &context->memtables_to_free_);
   }
   new_mem->Ref();

db/db_iter.cc

@@ -9,7 +9,6 @@
 
 #include "db/db_iter.h"
 
-#include <iostream>
 #include <limits>
 #include <string>
 
@@ -42,9 +41,8 @@ DBIter::DBIter(Env* _env, const ReadOptions& read_options,
                const MutableCFOptions& mutable_cf_options,
                const Comparator* cmp, InternalIterator* iter,
                const Version* version, SequenceNumber s, bool arena_mode,
-               uint64_t max_sequential_skip_in_iterations,
                ReadCallback* read_callback, ColumnFamilyHandleImpl* cfh,
-               bool expose_blob_index)
+               bool expose_blob_index, ReadOnlyMemTable* active_mem)
     : prefix_extractor_(mutable_cf_options.prefix_extractor.get()),
       env_(_env),
       clock_(ioptions.clock),
@@ -58,11 +56,21 @@ DBIter::DBIter(Env* _env, const ReadOptions& read_options,
       read_callback_(read_callback),
       sequence_(s),
       statistics_(ioptions.stats),
-      max_skip_(max_sequential_skip_in_iterations),
+      max_skip_(mutable_cf_options.max_sequential_skip_in_iterations),
       max_skippable_internal_keys_(read_options.max_skippable_internal_keys),
       num_internal_keys_skipped_(0),
       iterate_lower_bound_(read_options.iterate_lower_bound),
       iterate_upper_bound_(read_options.iterate_upper_bound),
+      cfh_(cfh),
+      timestamp_ub_(read_options.timestamp),
+      timestamp_lb_(read_options.iter_start_ts),
+      timestamp_size_(timestamp_ub_ ? timestamp_ub_->size() : 0),
+      active_mem_(active_mem),
+      memtable_seqno_lb_((active_mem_ && !active_mem_->IsEmpty())
+                             ? active_mem_->GetFirstSequenceNumber()
+                             : kMaxSequenceNumber),
+      memtable_op_scan_flush_trigger_(
+          mutable_cf_options.memtable_op_scan_flush_trigger),
       direction_(kForward),
       valid_(false),
       current_entry_is_merged_(false),
@@ -76,11 +84,7 @@ DBIter::DBIter(Env* _env, const ReadOptions& read_options,
       expose_blob_index_(expose_blob_index),
       allow_unprepared_value_(read_options.allow_unprepared_value),
       is_blob_(false),
-      arena_mode_(arena_mode),
-      cfh_(cfh),
-      timestamp_ub_(read_options.timestamp),
-      timestamp_lb_(read_options.iter_start_ts),
-      timestamp_size_(timestamp_ub_ ? timestamp_ub_->size() : 0) {
+      arena_mode_(arena_mode) {
   RecordTick(statistics_, NO_ITERATOR_CREATED);
   if (pin_thru_lifetime_) {
     pinned_iters_mgr_.StartPinning();
@@ -369,6 +373,8 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
   // to one.
   bool reseek_done = false;
 
+  uint64_t mem_ops_scanned = 0;
+  bool marked_for_flush = false;
   do {
     // Will update is_key_seqnum_zero_ as soon as we parsed the current key
     // but we need to save the previous value to be used in the loop.
@@ -425,6 +431,12 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
           CompareKeyForSkip(ikey_.user_key, saved_key_.GetUserKey()) <= 0) {
         num_skipped++;  // skip this entry
         PERF_COUNTER_ADD(internal_key_skipped_count, 1);
+        if (memtable_op_scan_flush_trigger_ && active_mem_ &&
+            ikey_.sequence >= memtable_seqno_lb_ && !marked_for_flush &&
+            ++mem_ops_scanned >= memtable_op_scan_flush_trigger_) {
+          active_mem_->MarkForFlush();
+          marked_for_flush = true;
+        }
       } else {
         assert(!skipping_saved_key ||
                CompareKeyForSkip(ikey_.user_key, saved_key_.GetUserKey()) > 0);
@@ -446,6 +458,12 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
                                       !iter_.iter()->IsKeyPinned() /* copy */);
               skipping_saved_key = true;
               PERF_COUNTER_ADD(internal_delete_skipped_count, 1);
+              if (memtable_op_scan_flush_trigger_ && active_mem_ &&
+                  ikey_.sequence >= memtable_seqno_lb_ && !marked_for_flush &&
+                  ++mem_ops_scanned >= memtable_op_scan_flush_trigger_) {
+                active_mem_->MarkForFlush();
+                marked_for_flush = true;
+              }
             }
             break;
           case kTypeValue:
@@ -1224,6 +1242,8 @@ bool DBIter::FindValueForCurrentKeyUsingSeek() {
 
     if (timestamp_lb_ != nullptr) {
       saved_key_.SetInternalKey(ikey);
+    } else {
+      saved_key_.SetUserKey(ikey.user_key);
     }
 
     valid_ = true;
@@ -1790,21 +1810,4 @@ void DBIter::SeekToLast() {
         StripTimestampFromUserKey(saved_key_.GetUserKey(), timestamp_size_)));
   }
 }
-
-Iterator* NewDBIterator(Env* env, const ReadOptions& read_options,
-                        const ImmutableOptions& ioptions,
-                        const MutableCFOptions& mutable_cf_options,
-                        const Comparator* user_key_comparator,
-                        InternalIterator* internal_iter, const Version* version,
-                        const SequenceNumber& sequence,
-                        uint64_t max_sequential_skip_in_iterations,
-                        ReadCallback* read_callback,
-                        ColumnFamilyHandleImpl* cfh, bool expose_blob_index) {
-  DBIter* db_iter = new DBIter(
-      env, read_options, ioptions, mutable_cf_options, user_key_comparator,
-      internal_iter, version, sequence, false,
-      max_sequential_skip_in_iterations, read_callback, cfh, expose_blob_index);
-  return db_iter;
-}
-
 }  // namespace ROCKSDB_NAMESPACE

db/db_iter.h

@@ -57,6 +57,33 @@ class Version;
 // numbers, deletion markers, overwrites, etc.
 class DBIter final : public Iterator {
  public:
+  // Return a new DBIter that reads from `internal_iter` at the specified
+  // `sequence` number.
+  //
+  // @param active_mem Pointer to the active memtable that `internal_iter`
+  // is reading from. If not null, the memtable can be marked for flush
+  // according to option mutable_cf_options.memtable_op_scan_flush_trigger.
+  // @param arena_mode If true, the DBIter will be allocated from the arena.
+  static DBIter* NewIter(Env* env, const ReadOptions& read_options,
+                         const ImmutableOptions& ioptions,
+                         const MutableCFOptions& mutable_cf_options,
+                         const Comparator* user_key_comparator,
+                         InternalIterator* internal_iter,
+                         const Version* version, const SequenceNumber& sequence,
+                         ReadCallback* read_callback,
+                         ColumnFamilyHandleImpl* cfh = nullptr,
+                         bool expose_blob_index = false,
+                         ReadOnlyMemTable* active_mem = nullptr,
+                         Arena* arena = nullptr) {
+    void* mem = arena ? arena->AllocateAligned(sizeof(DBIter))
+                      : operator new(sizeof(DBIter));
+    DBIter* db_iter = new (mem)
+        DBIter(env, read_options, ioptions, mutable_cf_options,
+               user_key_comparator, internal_iter, version, sequence, arena,
+               read_callback, cfh, expose_blob_index, active_mem);
+    return db_iter;
+  }
+
   // The following is grossly complicated. TODO: clean it up
   // Which direction is the iterator currently moving?
   // (1) When moving forward:
@@ -113,14 +140,6 @@ class DBIter final : public Iterator {
     uint64_t skip_count_;
   };
 
-  DBIter(Env* _env, const ReadOptions& read_options,
-         const ImmutableOptions& ioptions,
-         const MutableCFOptions& mutable_cf_options, const Comparator* cmp,
-         InternalIterator* iter, const Version* version, SequenceNumber s,
-         bool arena_mode, uint64_t max_sequential_skip_in_iterations,
-         ReadCallback* read_callback, ColumnFamilyHandleImpl* cfh,
-         bool expose_blob_index);
-
   // No copying allowed
   DBIter(const DBIter&) = delete;
   void operator=(const DBIter&) = delete;
@@ -220,7 +239,26 @@ class DBIter final : public Iterator {
 
   bool PrepareValue() override;
 
+  void Prepare(const std::vector<ScanOptions>& scan_opts) override {
+    std::optional<std::vector<ScanOptions>> new_scan_opts;
+    new_scan_opts.emplace(scan_opts);
+    scan_opts_.swap(new_scan_opts);
+    if (!scan_opts.empty()) {
+      iter_.Prepare(&scan_opts_.value());
+    } else {
+      iter_.Prepare(nullptr);
+    }
+  }
+
  private:
+  DBIter(Env* _env, const ReadOptions& read_options,
+         const ImmutableOptions& ioptions,
+         const MutableCFOptions& mutable_cf_options, const Comparator* cmp,
+         InternalIterator* iter, const Version* version, SequenceNumber s,
+         bool arena_mode, ReadCallback* read_callback,
+         ColumnFamilyHandleImpl* cfh, bool expose_blob_index,
+         ReadOnlyMemTable* active_mem);
+
   class BlobReader {
    public:
     BlobReader(const Version* version, ReadTier read_tier,
@@ -425,6 +463,21 @@ class DBIter final : public Iterator {
   IterKey prefix_;
 
   Status status_;
+  Slice lazy_blob_index_;
+
+  // List of operands for merge operator.
+  MergeContext merge_context_;
+  LocalStatistics local_stats_;
+  PinnedIteratorsManager pinned_iters_mgr_;
+  ColumnFamilyHandleImpl* cfh_;
+  const Slice* const timestamp_ub_;
+  const Slice* const timestamp_lb_;
+  const size_t timestamp_size_;
+  std::string saved_timestamp_;
+  std::optional<std::vector<ScanOptions>> scan_opts_;
+  ReadOnlyMemTable* active_mem_;
+  SequenceNumber memtable_seqno_lb_;
+  uint32_t memtable_op_scan_flush_trigger_;
   Direction direction_;
   bool valid_;
   bool current_entry_is_merged_;
@@ -443,29 +496,7 @@ class DBIter final : public Iterator {
   // the stacked BlobDB implementation is used, false otherwise.
   bool expose_blob_index_;
   bool allow_unprepared_value_;
-  Slice lazy_blob_index_;
   bool is_blob_;
   bool arena_mode_;
-  // List of operands for merge operator.
-  MergeContext merge_context_;
-  LocalStatistics local_stats_;
-  PinnedIteratorsManager pinned_iters_mgr_;
-  ColumnFamilyHandleImpl* cfh_;
-  const Slice* const timestamp_ub_;
-  const Slice* const timestamp_lb_;
-  const size_t timestamp_size_;
-  std::string saved_timestamp_;
 };
-
-// Return a new iterator that converts internal keys (yielded by
-// "*internal_iter") that were live at the specified `sequence` number
-// into appropriate user keys.
-Iterator* NewDBIterator(
-    Env* env, const ReadOptions& read_options, const ImmutableOptions& ioptions,
-    const MutableCFOptions& mutable_cf_options,
-    const Comparator* user_key_comparator, InternalIterator* internal_iter,
-    const Version* version, const SequenceNumber& sequence,
-    uint64_t max_sequential_skip_in_iterations, ReadCallback* read_callback,
-    ColumnFamilyHandleImpl* cfh = nullptr, bool expose_blob_index = false);
-
 }  // namespace ROCKSDB_NAMESPACE

db/db_iter_stress_test.cc

@@ -528,11 +528,10 @@ TEST_F(DBIteratorStressTest, StressTest) {
                   internal_iter->target_hidden_fraction =
                       target_hidden_fraction;
                   internal_iter->trace = trace;
-                  db_iter.reset(NewDBIterator(
+                  db_iter.reset(DBIter::NewIter(
                       env_, ropt, ImmutableOptions(options),
                       MutableCFOptions(options), BytewiseComparator(),
-                      internal_iter, nullptr /* version */, sequence,
-                      options.max_sequential_skip_in_iterations,
+                      internal_iter, /*version=*/nullptr, sequence,
                       nullptr /*read_callback*/));
                 }
 

db/db_iter_test.cc

@@ -259,10 +259,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     internal_iter->Finish();
 
     ReadOptions ro;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -294,10 +293,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     internal_iter->Finish();
 
     ReadOptions ro;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -322,10 +320,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -356,10 +353,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -393,10 +389,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -425,10 +420,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 7 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     SetPerfLevel(kEnableCount);
@@ -465,10 +459,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 4 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -492,10 +485,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -517,10 +509,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -554,10 +545,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     ReadOptions ro;
     ro.iterate_upper_bound = &prefix;
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 7 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     SetPerfLevel(kEnableCount);
@@ -586,10 +576,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     internal_iter->Finish();
 
     ReadOptions ro;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -631,10 +620,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     internal_iter->Finish();
 
     ReadOptions ro;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 2 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -664,10 +652,9 @@ TEST_F(DBIteratorTest, DBIteratorPrevNext) {
     internal_iter->Finish();
 
     ReadOptions ro;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -696,10 +683,9 @@ TEST_F(DBIteratorTest, DBIteratorEmpty) {
     TestIterator* internal_iter = new TestIterator(BytewiseComparator());
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 0 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(!db_iter->Valid());
@@ -710,10 +696,9 @@ TEST_F(DBIteratorTest, DBIteratorEmpty) {
     TestIterator* internal_iter = new TestIterator(BytewiseComparator());
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 0 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToFirst();
     ASSERT_TRUE(!db_iter->Valid());
@@ -735,11 +720,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkipCountSkips) {
   }
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      2 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      2 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToLast();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "c");
@@ -782,10 +766,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
       internal_iter->Finish();
 
       options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, i + 2 /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
       db_iter->SeekToLast();
       ASSERT_TRUE(db_iter->Valid());
@@ -820,10 +804,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
       internal_iter->AddPut("c", "200");
       internal_iter->Finish();
 
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, i + 2 /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
       db_iter->SeekToLast();
       ASSERT_TRUE(db_iter->Valid());
@@ -851,10 +835,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
       internal_iter->AddPut("c", "200");
       internal_iter->Finish();
 
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, 202 /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
       db_iter->SeekToLast();
       ASSERT_TRUE(db_iter->Valid());
@@ -886,10 +870,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
       }
       internal_iter->AddPut("c", "200");
       internal_iter->Finish();
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, i /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
       db_iter->SeekToLast();
       ASSERT_TRUE(!db_iter->Valid());
@@ -906,10 +890,9 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
     }
     internal_iter->AddPut("c", "200");
     internal_iter->Finish();
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 200 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -944,10 +927,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
       }
       internal_iter->Finish();
 
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, i + 2 /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
       db_iter->SeekToLast();
       ASSERT_TRUE(db_iter->Valid());
@@ -981,10 +964,10 @@ TEST_F(DBIteratorTest, DBIteratorUseSkip) {
       }
       internal_iter->Finish();
 
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, i + 2 /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
       db_iter->SeekToLast();
       ASSERT_TRUE(db_iter->Valid());
@@ -1033,10 +1016,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 0;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -1081,10 +1063,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 2;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -1127,10 +1108,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 2;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -1167,10 +1147,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 2;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -1204,10 +1183,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 2;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToLast();
@@ -1236,10 +1214,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 2;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -1275,10 +1252,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
     internal_iter->Finish();
 
     ro.max_skippable_internal_keys = 2;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
@@ -1314,10 +1290,10 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
       internal_iter->Finish();
 
       ro.max_skippable_internal_keys = i;
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
           env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
           internal_iter, nullptr /* version */, 2 * i + 1 /* sequence */,
-          options.max_sequential_skip_in_iterations,
+
           nullptr /* read_callback */));
 
       db_iter->SeekToFirst();
@@ -1369,10 +1345,9 @@ TEST_F(DBIteratorTest, DBIteratorSkipInternalKeys) {
 
       options.max_sequential_skip_in_iterations = 1000;
       ro.max_skippable_internal_keys = i;
-      std::unique_ptr<Iterator> db_iter(NewDBIterator(
-          env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
+      std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
+          env_, ro, ioptions, MutableCFOptions(options), BytewiseComparator(),
           internal_iter, nullptr /* version */, 2 * i + 1 /* sequence */,
-          options.max_sequential_skip_in_iterations,
           nullptr /* read_callback */));
 
       db_iter->SeekToFirst();
@@ -1412,11 +1387,11 @@ TEST_F(DBIteratorTest, DBIteratorTimedPutBasic) {
   internal_iter->AddTimedPut("d", "3", /*write_unix_time=*/0);
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  options.max_sequential_skip_in_iterations = 1;
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      7 /* sequence */, /*max_sequential_skip_in_iterations*/ 1,
-      nullptr /* read_callback */));
+      7 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToFirst();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1463,11 +1438,10 @@ TEST_F(DBIteratorTest, DBIterator1) {
   internal_iter->AddMerge("b", "2");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      1 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      1 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToFirst();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1493,11 +1467,10 @@ TEST_F(DBIteratorTest, DBIterator2) {
   internal_iter->AddMerge("b", "2");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      0 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      0 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToFirst();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1519,11 +1492,10 @@ TEST_F(DBIteratorTest, DBIterator3) {
   internal_iter->AddMerge("b", "2");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      2 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      2 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToFirst();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1545,11 +1517,10 @@ TEST_F(DBIteratorTest, DBIterator4) {
   internal_iter->AddMerge("b", "2");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      4 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      4 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToFirst();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -1580,10 +1551,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 0 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1605,10 +1575,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 1 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1630,10 +1599,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 2 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1655,10 +1623,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 3 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1680,10 +1647,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 4 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1705,10 +1671,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 5 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1730,10 +1695,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 6 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1753,10 +1717,9 @@ TEST_F(DBIteratorTest, DBIterator5) {
     internal_iter->AddMerge("a", "merge_2");
     internal_iter->AddPut("b", "val_b");
     internal_iter->Finish();
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 10 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->Seek("b");
     ASSERT_TRUE(db_iter->Valid());
@@ -1785,10 +1748,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 0 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1810,10 +1772,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 1 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1835,10 +1796,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 2 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1860,10 +1820,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 3 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(!db_iter->Valid());
@@ -1881,10 +1840,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 4 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1906,10 +1864,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 5 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1931,10 +1888,9 @@ TEST_F(DBIteratorTest, DBIterator6) {
     internal_iter->AddMerge("a", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 6 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -1976,10 +1932,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 0 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2013,10 +1968,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 2 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2056,10 +2010,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 4 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2099,10 +2052,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 5 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2147,10 +2099,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 6 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2196,10 +2147,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 7 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2239,10 +2189,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 9 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2288,10 +2237,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 13 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2338,10 +2286,9 @@ TEST_F(DBIteratorTest, DBIterator7) {
     internal_iter->AddDeletion("c");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ioptions, mutable_cf_options, BytewiseComparator(),
         internal_iter, nullptr /* version */, 14 /* sequence */,
-        options.max_sequential_skip_in_iterations,
         nullptr /* read_callback */));
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2371,11 +2318,10 @@ TEST_F(DBIteratorTest, DBIterator8) {
   internal_iter->AddPut("b", "0");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      10 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      10 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToLast();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "b");
@@ -2403,11 +2349,10 @@ TEST_F(DBIteratorTest, DBIterator9) {
     internal_iter->AddMerge("d", "merge_6");
     internal_iter->Finish();
 
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ImmutableOptions(options), MutableCFOptions(options),
         BytewiseComparator(), internal_iter, nullptr /* version */,
-        10 /* sequence */, options.max_sequential_skip_in_iterations,
-        nullptr /* read_callback */));
+        10 /* sequence */, nullptr /* read_callback */));
 
     db_iter->SeekToLast();
     ASSERT_TRUE(db_iter->Valid());
@@ -2471,11 +2416,10 @@ TEST_F(DBIteratorTest, DBIterator10) {
   internal_iter->AddPut("d", "4");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      10 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      10 /* sequence */, nullptr /* read_callback */));
 
   db_iter->Seek("c");
   ASSERT_TRUE(db_iter->Valid());
@@ -2512,7 +2456,7 @@ TEST_F(DBIteratorTest, SeekToLastOccurrenceSeq0) {
   internal_iter->AddPut("b", "2");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
       10 /* sequence */, 0 /* force seek */, nullptr /* read_callback */));
@@ -2542,11 +2486,10 @@ TEST_F(DBIteratorTest, DBIterator11) {
   internal_iter->AddMerge("b", "2");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      1 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      1 /* sequence */, nullptr /* read_callback */));
   db_iter->SeekToFirst();
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "a");
@@ -2571,7 +2514,7 @@ TEST_F(DBIteratorTest, DBIterator12) {
   internal_iter->AddSingleDeletion("b");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
       10 /* sequence */, 0 /* force seek */, nullptr /* read_callback */));
@@ -2610,11 +2553,11 @@ TEST_F(DBIteratorTest, DBIterator13) {
   internal_iter->AddPut(key, "8");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  options.max_sequential_skip_in_iterations = 3;
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      2 /* sequence */, 3 /* max_sequential_skip_in_iterations */,
-      nullptr /* read_callback */));
+      2 /* sequence */, nullptr /* read_callback */));
   db_iter->Seek("b");
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), key);
@@ -2640,11 +2583,11 @@ TEST_F(DBIteratorTest, DBIterator14) {
   internal_iter->AddPut("c", "9");
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  options.max_sequential_skip_in_iterations = 1;
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      4 /* sequence */, 1 /* max_sequential_skip_in_iterations */,
-      nullptr /* read_callback */));
+      4 /* sequence */, nullptr /* read_callback */));
   db_iter->Seek("b");
   ASSERT_TRUE(db_iter->Valid());
   ASSERT_EQ(db_iter->key().ToString(), "b");
@@ -2680,11 +2623,11 @@ class DBIterWithMergeIterTest : public testing::Test {
     InternalIterator* merge_iter =
         NewMergingIterator(&icomp_, child_iters.data(), 2u);
 
-    db_iter_.reset(NewDBIterator(
+    options_.max_sequential_skip_in_iterations = 3;
+    db_iter_.reset(DBIter::NewIter(
         env_, ro_, ImmutableOptions(options_), MutableCFOptions(options_),
         BytewiseComparator(), merge_iter, nullptr /* version */,
-        8 /* read data earlier than seqId 8 */,
-        3 /* max iterators before reseek */, nullptr /* read_callback */));
+        8 /* read data earlier than seqId 8 */, nullptr /* read_callback */));
   }
 
   Env* env_;
@@ -3120,11 +3063,10 @@ TEST_F(DBIteratorTest, SeekPrefixTombstones) {
   internal_iter->Finish();
 
   ro.prefix_same_as_start = true;
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      10 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      10 /* sequence */, nullptr /* read_callback */));
 
   int skipped_keys = 0;
 
@@ -3157,11 +3099,10 @@ TEST_F(DBIteratorTest, SeekToFirstLowerBound) {
     Slice lower_bound(lower_bound_str);
     ro.iterate_lower_bound = &lower_bound;
     Options options;
-    std::unique_ptr<Iterator> db_iter(NewDBIterator(
+    std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
         env_, ro, ImmutableOptions(options), MutableCFOptions(options),
         BytewiseComparator(), internal_iter, nullptr /* version */,
-        10 /* sequence */, options.max_sequential_skip_in_iterations,
-        nullptr /* read_callback */));
+        10 /* sequence */, nullptr /* read_callback */));
 
     db_iter->SeekToFirst();
     if (i == kNumKeys + 1) {
@@ -3197,11 +3138,10 @@ TEST_F(DBIteratorTest, PrevLowerBound) {
   Slice lower_bound(lower_bound_str);
   ro.iterate_lower_bound = &lower_bound;
   Options options;
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      10 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      10 /* sequence */, nullptr /* read_callback */));
 
   db_iter->SeekToLast();
   for (int i = kNumKeys; i >= kLowerBound; --i) {
@@ -3226,11 +3166,10 @@ TEST_F(DBIteratorTest, SeekLessLowerBound) {
   Slice lower_bound(lower_bound_str);
   ro.iterate_lower_bound = &lower_bound;
   Options options;
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ro, ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      10 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      10 /* sequence */, nullptr /* read_callback */));
 
   auto before_lower_bound_str = std::to_string(kLowerBound - 1);
   Slice before_lower_bound(lower_bound_str);
@@ -3252,11 +3191,10 @@ TEST_F(DBIteratorTest, ReverseToForwardWithDisappearingKeys) {
   }
   internal_iter->Finish();
 
-  std::unique_ptr<Iterator> db_iter(NewDBIterator(
+  std::unique_ptr<Iterator> db_iter(DBIter::NewIter(
       env_, ReadOptions(), ImmutableOptions(options), MutableCFOptions(options),
       BytewiseComparator(), internal_iter, nullptr /* version */,
-      10 /* sequence */, options.max_sequential_skip_in_iterations,
-      nullptr /* read_callback */));
+      10 /* sequence */, nullptr /* read_callback */));
 
   db_iter->SeekForPrev("a");
   ASSERT_TRUE(db_iter->Valid());

db/db_iterator_test.cc

@@ -3824,6 +3824,166 @@ TEST_F(DBIteratorTest, IteratorsConsistentViewExplicitSnapshot) {
   }
 }
 
+TEST_P(DBIteratorTest, MemtableOpsScanFlushTriggerWithSeek) {
+  // Tests that option memtable_op_scan_flush_trigger works when the limit
+  // is reached during a Seek() operation.
+  const int kTrigger = 10;
+  Random* r = Random::GetTLSInstance();
+
+  for (int trigger : {kTrigger, kTrigger + 1}) {
+    for (bool delete_only : {false, true}) {
+      Options options;
+      options.create_if_missing = true;
+      options.memtable_op_scan_flush_trigger = trigger;
+      options.level_compaction_dynamic_level_bytes = true;
+      DestroyAndReopen(options);
+
+      // Base data that will be covered by a consecutive sequence of tombstones.
+      int kNumKeys = delete_only ? kTrigger : kTrigger / 2;
+      for (int i = 0; i < kNumKeys; ++i) {
+        ASSERT_OK(Put(Key(i), r->RandomString(100)));
+      }
+      ASSERT_OK(Flush());
+      ASSERT_OK(db_->CompactRange({}, nullptr, nullptr));
+      ASSERT_EQ(1, NumTableFilesAtLevel(6));
+
+      if (delete_only) {
+        for (int i = 0; i < kNumKeys; ++i) {
+          ASSERT_OK(SingleDelete(Key(i)));
+        }
+      } else {
+        for (int i = 0; i < kNumKeys; ++i) {
+          ASSERT_OK(Put(Key(i), r->RandomString(100)));
+        }
+        for (int i = 0; i < kNumKeys; ++i) {
+          ASSERT_OK(Delete(Key(i)));
+        }
+      }
+
+      SetPerfLevel(PerfLevel::kEnableCount);
+      get_perf_context()->Reset();
+      ReadOptions ro;
+      std::unique_ptr<Iterator> iter(db_->NewIterator(ro));
+
+      // Seek to the first key, this will scan through all the tombstones and
+      // hidden puts
+      iter->Seek(Key(0));
+      ASSERT_FALSE(
+          iter->Valid());  // All keys are deleted, so iterator is not valid
+      ASSERT_OK(iter->status());
+      ASSERT_EQ(get_perf_context()->next_on_memtable_count, kTrigger);
+
+      // Skipping kNumTrigger memtable entries in a single iterator operation
+      // should mark the memtable for flush.
+      //
+      // At the end of a write, we check and update memtable to request a flush
+      ASSERT_OK(Put(Key(11), "val"));
+      // Before a write, we schedule memtables for flush if requested.
+      ASSERT_OK(Put(Key(12), "val"));
+      ASSERT_OK(db_->WaitForCompact({}));
+
+      if (trigger <= kTrigger) {
+        // Check if memtable was flushed due to scan trigger
+        ASSERT_EQ(1, NumTableFilesAtLevel(0));
+        uint64_t val = 0;
+        ASSERT_TRUE(
+            db_->GetIntProperty("rocksdb.num-deletes-active-mem-table", &val));
+        ASSERT_EQ(0, val);
+      } else {
+        uint64_t val = 0;
+        ASSERT_TRUE(
+            db_->GetIntProperty("rocksdb.num-deletes-active-mem-table", &val));
+        ASSERT_EQ(kNumKeys, val);
+      }
+    }
+  }
+}
+
+TEST_P(DBIteratorTest, MemtableOpsScanFlushTriggerWithNext) {
+  // Tests that option memtable_op_scan_flush_trigger works when the limit
+  // is reached during a Next() operation, and not trigger a flush when
+  // the limit is reached across multiple Next() operations.
+  const int kTrigger = 10;
+  Random* r = Random::GetTLSInstance();
+
+  for (int trigger : {kTrigger, kTrigger + 1}) {
+    for (bool delete_only : {false, true}) {
+      Options options;
+      options.create_if_missing = true;
+      options.memtable_op_scan_flush_trigger = trigger;
+      options.level_compaction_dynamic_level_bytes = true;
+      DestroyAndReopen(options);
+
+      // Base data that will be covered by a consecutive sequence of tombstones.
+      int kNumKeys = delete_only ? kTrigger : kTrigger / 2;
+      for (int i = 0; i <= kNumKeys; ++i) {
+        ASSERT_OK(Put(Key(i), r->RandomString(100)));
+      }
+      ASSERT_OK(Flush());
+      ASSERT_OK(db_->CompactRange({}, nullptr, nullptr));
+      ASSERT_EQ(1, NumTableFilesAtLevel(6));
+
+      ASSERT_OK(Put(Key(0), "val"));
+      if (delete_only) {
+        for (int i = 1; i <= kNumKeys; ++i) {
+          ASSERT_OK(SingleDelete(Key(i)));
+        }
+      } else {
+        for (int i = 1; i <= kNumKeys; ++i) {
+          ASSERT_OK(Put(Key(i), r->RandomString(100)));
+        }
+        for (int i = 1; i <= kNumKeys; ++i) {
+          ASSERT_OK(Delete(Key(i)));
+        }
+      }
+
+      // Total number of tombstones and hidden puts scanned across multiple
+      // Next() operations below will be kTrigger, and it should not trigger a
+      // flush when the limit is kTrigger + 1.
+      ASSERT_OK(Put(Key(kNumKeys + 1), "v1"));
+      ASSERT_OK(Delete(Key(kNumKeys + 2)));
+      ASSERT_OK(Put(Key(kNumKeys + 3), "v3"));
+
+      SetPerfLevel(PerfLevel::kEnableCount);
+      get_perf_context()->Reset();
+      ReadOptions ro;
+      std::unique_ptr<Iterator> iter(db_->NewIterator(ro));
+      iter->Seek(Key(0));
+      ASSERT_TRUE(iter->Valid());
+      ASSERT_EQ(iter->value(), "val");
+      ASSERT_OK(iter->status());
+      ASSERT_EQ(get_perf_context()->next_on_memtable_count, 0);
+      iter->Next();
+      // kTrigger tombstones and invisible puts and 1 for the visible put
+      ASSERT_EQ(get_perf_context()->next_on_memtable_count, kTrigger + 1);
+      iter->Next();
+      ASSERT_EQ(get_perf_context()->next_on_memtable_count, kTrigger + 3);
+
+      // Skipping kNumTrigger memtable entries in a single iterator operation
+      // should mark the memtable for flush.
+      //
+      // At the end of a write, we check and update memtable to request a flush
+      ASSERT_OK(Put(Key(11), "val"));
+      // Before a write, we schedule memtables for flush if requested.
+      ASSERT_OK(Put(Key(12), "val"));
+      ASSERT_OK(db_->WaitForCompact({}));
+
+      if (trigger <= kTrigger) {
+        // Check if memtable was flushed due to scan trigger
+        ASSERT_EQ(1, NumTableFilesAtLevel(0));
+        uint64_t val = 0;
+        ASSERT_TRUE(
+            db_->GetIntProperty("rocksdb.num-deletes-active-mem-table", &val));
+        ASSERT_EQ(0, val);
+      } else {
+        uint64_t val = 0;
+        ASSERT_TRUE(
+            db_->GetIntProperty("rocksdb.num-deletes-active-mem-table", &val));
+        ASSERT_EQ(kNumKeys + 1, val);
+      }
+    }
+  }
+}
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {

db/db_kv_checksum_test.cc

@@ -312,12 +312,12 @@ TEST_P(DbKvChecksumTest, WriteToWALCorrupted) {
     // Corrupted write batch leads to read-only mode, so we have to
     // reopen for every attempt.
     Reopen(options);
-    auto log_size_pre_write = dbfull()->TEST_total_log_size();
+    auto log_size_pre_write = dbfull()->TEST_wals_total_size();
 
     SyncPoint::GetInstance()->EnableProcessing();
     ASSERT_TRUE(ExecuteWrite(nullptr /* cf_handle */).IsCorruption());
     // Confirm that nothing was written to WAL
-    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_total_log_size());
+    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_wals_total_size());
     ASSERT_TRUE(dbfull()->TEST_GetBGError().IsCorruption());
     SyncPoint::GetInstance()->DisableProcessing();
 
@@ -350,12 +350,12 @@ TEST_P(DbKvChecksumTest, WriteToWALWithColumnFamilyCorrupted) {
     // Corrupted write batch leads to read-only mode, so we have to
     // reopen for every attempt.
     ReopenWithColumnFamilies({kDefaultColumnFamilyName, "pikachu"}, options);
-    auto log_size_pre_write = dbfull()->TEST_total_log_size();
+    auto log_size_pre_write = dbfull()->TEST_wals_total_size();
 
     SyncPoint::GetInstance()->EnableProcessing();
     ASSERT_TRUE(ExecuteWrite(nullptr /* cf_handle */).IsCorruption());
     // Confirm that nothing was written to WAL
-    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_total_log_size());
+    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_wals_total_size());
     ASSERT_TRUE(dbfull()->TEST_GetBGError().IsCorruption());
     SyncPoint::GetInstance()->DisableProcessing();
 
@@ -487,7 +487,7 @@ TEST_P(DbKvChecksumTestMergedBatch, WriteToWALCorrupted) {
     // Reopen DB since it failed WAL write which lead to read-only mode
     Reopen(options);
     SyncPoint::GetInstance()->EnableProcessing();
-    auto log_size_pre_write = dbfull()->TEST_total_log_size();
+    auto log_size_pre_write = dbfull()->TEST_wals_total_size();
     leader_batch_and_status =
         GetWriteBatch(GetCFHandleToUse(nullptr, op_type1_),
                       8 /* protection_bytes_per_key */, op_type1_);
@@ -499,7 +499,7 @@ TEST_P(DbKvChecksumTestMergedBatch, WriteToWALCorrupted) {
     SyncPoint::GetInstance()->ClearCallBack("WriteThread::JoinBatchGroup:Wait");
     ASSERT_EQ(1, leader_count);
     // Nothing should have been written to WAL
-    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_total_log_size());
+    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_wals_total_size());
     ASSERT_TRUE(dbfull()->TEST_GetBGError().IsCorruption());
 
     corrupt_byte_offset++;
@@ -599,7 +599,7 @@ TEST_P(DbKvChecksumTestMergedBatch, WriteToWALWithColumnFamilyCorrupted) {
     // Reopen DB since it failed WAL write which lead to read-only mode
     ReopenWithColumnFamilies({kDefaultColumnFamilyName, "ramen"}, options);
     SyncPoint::GetInstance()->EnableProcessing();
-    auto log_size_pre_write = dbfull()->TEST_total_log_size();
+    auto log_size_pre_write = dbfull()->TEST_wals_total_size();
     leader_batch_and_status =
         GetWriteBatch(GetCFHandleToUse(handles_[1], op_type1_),
                       8 /* protection_bytes_per_key */, op_type1_);
@@ -612,7 +612,7 @@ TEST_P(DbKvChecksumTestMergedBatch, WriteToWALWithColumnFamilyCorrupted) {
 
     ASSERT_EQ(1, leader_count);
     // Nothing should have been written to WAL
-    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_total_log_size());
+    ASSERT_EQ(log_size_pre_write, dbfull()->TEST_wals_total_size());
     ASSERT_TRUE(dbfull()->TEST_GetBGError().IsCorruption());
 
     corrupt_byte_offset++;

db/db_options_test.cc

@@ -322,31 +322,26 @@ TEST_F(DBOptionsTest, SetWithCustomMemTableFactory) {
   }
   Options options;
   options.create_if_missing = true;
-  // Try with fail_if_options_file_error=false/true to update the options
-  for (bool on_error : {false, true}) {
-    options.fail_if_options_file_error = on_error;
-    options.env = env_;
-    options.disable_auto_compactions = false;
+  options.env = env_;
+  options.disable_auto_compactions = false;
 
-    options.memtable_factory.reset(new DummySkipListFactory());
-    Reopen(options);
+  options.memtable_factory.reset(new DummySkipListFactory());
+  Reopen(options);
 
-    ColumnFamilyHandle* cfh = dbfull()->DefaultColumnFamily();
-    ASSERT_OK(
-        dbfull()->SetOptions(cfh, {{"disable_auto_compactions", "true"}}));
-    ColumnFamilyDescriptor cfd;
-    ASSERT_OK(cfh->GetDescriptor(&cfd));
-    ASSERT_STREQ(cfd.options.memtable_factory->Name(),
-                 DummySkipListFactory::kClassName());
-    ColumnFamilyHandle* test = nullptr;
-    ASSERT_OK(dbfull()->CreateColumnFamily(options, "test", &test));
-    ASSERT_OK(test->GetDescriptor(&cfd));
-    ASSERT_STREQ(cfd.options.memtable_factory->Name(),
-                 DummySkipListFactory::kClassName());
+  ColumnFamilyHandle* cfh = dbfull()->DefaultColumnFamily();
+  ASSERT_OK(dbfull()->SetOptions(cfh, {{"disable_auto_compactions", "true"}}));
+  ColumnFamilyDescriptor cfd;
+  ASSERT_OK(cfh->GetDescriptor(&cfd));
+  ASSERT_STREQ(cfd.options.memtable_factory->Name(),
+               DummySkipListFactory::kClassName());
+  ColumnFamilyHandle* test = nullptr;
+  ASSERT_OK(dbfull()->CreateColumnFamily(options, "test", &test));
+  ASSERT_OK(test->GetDescriptor(&cfd));
+  ASSERT_STREQ(cfd.options.memtable_factory->Name(),
+               DummySkipListFactory::kClassName());
 
-    ASSERT_OK(dbfull()->DropColumnFamily(test));
-    delete test;
-  }
+  ASSERT_OK(dbfull()->DropColumnFamily(test));
+  delete test;
 }
 
 TEST_F(DBOptionsTest, SetBytesPerSync) {

db/db_secondary_test.cc

@@ -508,6 +508,81 @@ TEST_F(DBSecondaryTest, OpenAsSecondary) {
   verify_db_func("new_foo_value", "new_bar_value");
 }
 
+TEST_F(DBSecondaryTest, OptionsOverrideTest) {
+  Options options;
+  options.env = env_;
+  options.preserve_internal_time_seconds = 300;
+  options.compaction_readahead_size = 200;
+  options.blob_compaction_readahead_size = 100;
+  Reopen(options);
+
+  for (int i = 0; i < 3; ++i) {
+    ASSERT_OK(Put("foo", "foo_value" + std::to_string(i)));
+    ASSERT_OK(Put("bar", "bar_value" + std::to_string(i)));
+    ASSERT_OK(Flush());
+  }
+
+  CompactionServiceInput input;
+
+  ColumnFamilyMetaData meta;
+  db_->GetColumnFamilyMetaData(&meta);
+  for (auto& file : meta.levels[0].files) {
+    ASSERT_EQ(0, meta.levels[0].level);
+    input.input_files.push_back(file.name);
+  }
+  ASSERT_EQ(input.input_files.size(), 3);
+
+  input.output_level = 1;
+  input.options_file_number = dbfull()->GetVersionSet()->options_file_number();
+  input.cf_name = kDefaultColumnFamilyName;
+  ASSERT_OK(db_->GetDbIdentity(input.db_id));
+
+  ASSERT_EQ(db_->GetOptions().compaction_readahead_size, 200);
+  ASSERT_EQ(db_->GetOptions().blob_compaction_readahead_size, 100);
+
+  Close();
+
+  std::string compaction_input_binary;
+  ASSERT_OK(input.Write(&compaction_input_binary));
+  std::string compaction_result_binary;
+
+  CompactionServiceOptionsOverride override_options;
+  override_options.env = env_;
+  override_options.table_factory.reset(
+      NewBlockBasedTableFactory(BlockBasedTableOptions()));
+
+  ASSERT_OK(
+      StringToMap("compaction_readahead_size=8388608;"
+                  "blob_compaction_readahead_size=4194304;"
+                  "some_invalid_option=ignore_me;"
+                  "env=this_should_not_fail;"
+                  "max_open_files=100;",  // this should be always overriden as
+                                          // -1 in remote compaction
+                  &override_options.options_map));
+
+  bool verified = false;
+  ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(
+      "DBImplSecondary::OpenAndCompact::AfterOpenAsSecondary:0",
+      [&](void* arg) {
+        auto secondary_db = static_cast<DB*>(arg);
+        auto secondary_db_options = secondary_db->GetOptions();
+        // DBOption
+        ASSERT_EQ(secondary_db_options.compaction_readahead_size, 8388608);
+        ASSERT_EQ(secondary_db_options.max_open_files, -1);
+        // CFOption
+        ASSERT_EQ(secondary_db_options.blob_compaction_readahead_size, 4194304);
+        verified = true;
+      });
+  SyncPoint::GetInstance()->EnableProcessing();
+
+  ASSERT_OK(DB::OpenAndCompact(OpenAndCompactOptions(), dbname_,
+                               secondary_path_, compaction_input_binary,
+                               &compaction_result_binary, override_options));
+  SyncPoint::GetInstance()->DisableProcessing();
+  SyncPoint::GetInstance()->ClearAllCallBacks();
+  ASSERT_TRUE(verified);
+}
+
 namespace {
 class TraceFileEnv : public EnvWrapper {
  public:

db/db_test.cc

@@ -3351,11 +3351,6 @@ class ModelDB : public DB {
   using DB::NumberLevels;
   int NumberLevels(ColumnFamilyHandle* /*column_family*/) override { return 1; }
 
-  using DB::MaxMemCompactionLevel;
-  int MaxMemCompactionLevel(ColumnFamilyHandle* /*column_family*/) override {
-    return 1;
-  }
-
   using DB::Level0StopWriteTrigger;
   int Level0StopWriteTrigger(ColumnFamilyHandle* /*column_family*/) override {
     return -1;
@@ -3412,7 +3407,7 @@ class ModelDB : public DB {
   }
 
   Status GetCurrentWalFile(
-      std::unique_ptr<LogFile>* /*current_log_file*/) override {
+      std::unique_ptr<LogFile>* /*current_wal_file*/) override {
     return Status::OK();
   }
 
@@ -3451,6 +3446,11 @@ class ModelDB : public DB {
     return Status::OK();
   }
 
+  Status GetNewestUserDefinedTimestamp(
+      ColumnFamilyHandle* /*cf*/, std::string* /*newest_timestamp*/) override {
+    return Status::OK();
+  }
+
   ColumnFamilyHandle* DefaultColumnFamily() const override { return nullptr; }
 
  private:
@@ -6419,7 +6419,7 @@ TEST_F(DBTest, TestLogCleanup) {
 
   for (int i = 0; i < 100000; ++i) {
     ASSERT_OK(Put(Key(i), "val"));
-    // only 2 memtables will be alive, so logs_to_free needs to always be below
+    // only 2 memtables will be alive, so wals_to_free needs to always be below
     // 2
     ASSERT_LT(dbfull()->TEST_LogsToFreeSize(), static_cast<size_t>(3));
   }

db/db_test_util.cc

@@ -592,7 +592,6 @@ Options DBTestBase::GetOptions(
       options_override.level_compaction_dynamic_level_bytes;
   options.env = env_;
   options.create_if_missing = true;
-  options.fail_if_options_file_error = true;
   return options;
 }
 

db/db_wal_test.cc

@@ -3024,13 +3024,13 @@ TEST_F(DBWALTest, GetCompressedWalsAfterSync) {
   options.wal_compression = kZSTD;
   DestroyAndReopen(options);
 
-  // Write something to memtable and WAL so that log_empty_ will be false after
+  // Write something to memtable and WAL so that wal_empty_ will be false after
   // next DB::Open().
   ASSERT_OK(Put("a", "v"));
 
   Reopen(options);
 
-  // New WAL is created, thanks to !log_empty_.
+  // New WAL is created, thanks to !wal_empty_.
   ASSERT_OK(dbfull()->TEST_SwitchWAL());
 
   ASSERT_OK(Put("b", "v"));

db/db_with_timestamp_basic_test.cc

@@ -19,6 +19,13 @@
 #include "utilities/merge_operators/string_append/stringappend2.h"
 
 namespace ROCKSDB_NAMESPACE {
+namespace {
+std::string EncodeAsUint64(uint64_t v) {
+  std::string dst;
+  PutFixed64(&dst, v);
+  return dst;
+}
+}  // namespace
 class DBBasicTestWithTimestamp : public DBBasicTestWithTimestampBase {
  public:
   DBBasicTestWithTimestamp()
@@ -1480,13 +1487,24 @@ TEST_F(DBBasicTestWithTimestamp, ReseekToUserKeyBeforeSavedKey) {
   Close();
 }
 
-TEST_F(DBBasicTestWithTimestamp,
-       FIXME_ReverseIterationWithBlobAndUnpreparedValue) {
+class ReverseIterationWithUnpreparedBlobTest
+    : public DBBasicTestWithTimestampBase,
+      public testing::WithParamInterface<std::tuple<bool, uint64_t>> {
+ public:
+  ReverseIterationWithUnpreparedBlobTest()
+      : DBBasicTestWithTimestampBase(
+            "db_basic_test_with_timestamp_reverse_with_unprepare") {}
+};
+INSTANTIATE_TEST_CASE_P(ReverseIterationWithUnpreparedBlobTest,
+                        ReverseIterationWithUnpreparedBlobTest,
+                        ::testing::Combine(::testing::Values(true, false),
+                                           ::testing::Values(0, 2)));
+TEST_P(ReverseIterationWithUnpreparedBlobTest, Basic) {
   Options options = CurrentOptions();
   options.create_if_missing = true;
   options.env = env_;
   options.enable_blob_files = true;
-  options.max_sequential_skip_in_iterations = 0;
+  options.max_sequential_skip_in_iterations = std::get<1>(GetParam());
 
   const size_t kTimestampSize = Timestamp(0, 0).size();
   TestComparator test_cmp(kTimestampSize);
@@ -1501,7 +1519,7 @@ TEST_F(DBBasicTestWithTimestamp,
   for (uint64_t key = 0; key <= kMaxKey; ++key) {
     for (size_t i = 0; i < write_timestamps.size(); ++i) {
       ASSERT_OK(db_->Put(WriteOptions(), Key1(key), write_timestamps[i],
-                         "value" + std::to_string(i)));
+                         Key1(key) + "value" + std::to_string(i)));
     }
   }
 
@@ -1513,17 +1531,28 @@ TEST_F(DBBasicTestWithTimestamp,
 
     ReadOptions read_opts;
     read_opts.timestamp = &read_timestamp;
-    read_opts.allow_unprepared_value = true;
+    read_opts.allow_unprepared_value = std::get<0>(GetParam());
 
     std::unique_ptr<Iterator> it(db_->NewIterator(read_opts));
 
     it->SeekForPrev(Key1(kMaxKey));
-    ASSERT_TRUE(it->Valid());
-    ASSERT_OK(it->status());
+    uint64_t key = kMaxKey;
+    int count = 0;
+    while (it->Valid()) {
+      ASSERT_OK(it->status());
 
-    // FIXME: PrepareValue() should succeed and status() should remain OK
-    ASSERT_FALSE(it->PrepareValue());
-    ASSERT_TRUE(it->status().IsCorruption());
+      ASSERT_TRUE(it->PrepareValue());
+      ASSERT_TRUE(it->Valid());
+      ASSERT_OK(it->status());
+      ASSERT_EQ(it->key(), Key1(key));
+      ASSERT_EQ(it->timestamp(), Timestamp(3, 0));
+      ASSERT_EQ(it->value(), Key1(key) + "value" + std::to_string(1));
+      key--;
+      count++;
+      it->Prev();
+    }
+    ASSERT_OK(it->status());
+    ASSERT_EQ(kMaxKey + 1, count);
   }
 
   Close();
@@ -3746,17 +3775,42 @@ INSTANTIATE_TEST_CASE_P(
         test::UserDefinedTimestampTestMode::kStripUserDefinedTimestamp,
         test::UserDefinedTimestampTestMode::kNormal));
 
-TEST_F(DBBasicTestWithTimestamp, EnableDisableUDT) {
+// Test params:
+// 1) whether to flush before close
+class EnableDisableUDTTest : public DBBasicTestWithTimestampBase,
+                             public testing::WithParamInterface<bool> {
+ public:
+  EnableDisableUDTTest()
+      : DBBasicTestWithTimestampBase("/enable_disable_udt") {}
+};
+
+INSTANTIATE_TEST_CASE_P(EnableDisableUDTTest, EnableDisableUDTTest,
+                        ::testing::Values(true, false));
+
+TEST_P(EnableDisableUDTTest, Basic) {
   Options options = CurrentOptions();
+  // Un-flushed data before close will involve a WAL replay on DB reopen.
+  bool flush_before_close = GetParam();
   options.env = env_;
-  // Create a column family without user-defined timestamps.
   options.comparator = BytewiseComparator();
   options.persist_user_defined_timestamps = true;
   DestroyAndReopen(options);
 
+  ReadOptions ropts;
+  std::string read_ts;
+  std::string value;
+  std::string key_ts;
+
   // Create one SST file, its user keys have no user-defined timestamps.
-  ASSERT_OK(db_->Put(WriteOptions(), "foo", "val1"));
-  ASSERT_OK(Flush(0));
+  ASSERT_OK(db_->Put(WriteOptions(), "foo", "val0"));
+  ASSERT_OK(db_->Put(WriteOptions(), "bar", "val0"));
+  ASSERT_OK(db_->DeleteRange(WriteOptions(), "bar", "baz"));
+  ASSERT_OK(db_->Get(ReadOptions(), "foo", &value));
+  ASSERT_EQ("val0", value);
+  ASSERT_TRUE(db_->Get(ReadOptions(), "bar", &value).IsNotFound());
+  if (flush_before_close) {
+    ASSERT_OK(Flush(0));
+  }
   Close();
 
   // Reopen the existing column family and enable user-defined timestamps
@@ -3765,47 +3819,63 @@ TEST_F(DBBasicTestWithTimestamp, EnableDisableUDT) {
   options.persist_user_defined_timestamps = false;
   options.allow_concurrent_memtable_write = false;
   Reopen(options);
-
-  std::string value;
-  ASSERT_TRUE(db_->Get(ReadOptions(), "foo", &value).IsInvalidArgument());
-  std::string read_ts;
-  PutFixed64(&read_ts, 0);
-  ReadOptions ropts;
+  // Read data from previous session before and after compaction.
+  read_ts = EncodeAsUint64(1);
   Slice read_ts_slice = read_ts;
   ropts.timestamp = &read_ts_slice;
-  std::string key_ts;
-  // Entries in pre-existing SST files are treated as if they have minimum
-  // user-defined timestamps.
-  ASSERT_OK(db_->Get(ropts, "foo", &value, &key_ts));
-  ASSERT_EQ("val1", value);
-  ASSERT_EQ(read_ts, key_ts);
+  for (int i = 0; i < 2; i++) {
+    ASSERT_TRUE(db_->Get(ReadOptions(), "foo", &value).IsInvalidArgument());
+    // Entries in pre-existing SST files are treated as if they have minimum
+    // user-defined timestamps.
+    ASSERT_OK(db_->Get(ropts, "foo", &value, &key_ts));
+    ASSERT_EQ("val0", value);
+    ASSERT_EQ(EncodeAsUint64(0), key_ts);
+    ASSERT_TRUE(db_->Get(ropts, "bar", &value, &key_ts).IsNotFound());
+    ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+  }
 
   // Do timestamped read / write.
-  std::string write_ts;
-  PutFixed64(&write_ts, 1);
-  ASSERT_OK(db_->Put(WriteOptions(), "foo", write_ts, "val2"));
-  read_ts.clear();
-  PutFixed64(&read_ts, 1);
+  ASSERT_OK(db_->Put(WriteOptions(), "foo", EncodeAsUint64(1), "val1"));
+  ASSERT_OK(db_->Put(WriteOptions(), "bar", EncodeAsUint64(1), "val1"));
+  ASSERT_OK(db_->DeleteRange(WriteOptions(), "bar", "baz", EncodeAsUint64(2)));
   ASSERT_OK(db_->Get(ropts, "foo", &value, &key_ts));
-  ASSERT_EQ("val2", value);
-  ASSERT_EQ(write_ts, key_ts);
+  ASSERT_EQ("val1", value);
+  ASSERT_EQ(EncodeAsUint64(1), key_ts);
+  ASSERT_OK(db_->Get(ropts, "bar", &value, &key_ts));
+  ASSERT_EQ("val1", value);
+  ASSERT_EQ(EncodeAsUint64(1), key_ts);
+  read_ts = EncodeAsUint64(2);
+  ASSERT_TRUE(db_->Get(ropts, "bar", &value, &key_ts).IsNotFound());
   // The user keys in this SST file don't have user-defined timestamps either,
   // because `persist_user_defined_timestamps` flag is set to false.
-  ASSERT_OK(Flush(0));
+  if (flush_before_close) {
+    ASSERT_OK(Flush(0));
+  }
   Close();
 
   // Reopen the existing column family while disabling user-defined timestamps.
   options.comparator = BytewiseComparator();
   Reopen(options);
 
-  ASSERT_TRUE(db_->Get(ropts, "foo", &value).IsInvalidArgument());
-  ASSERT_OK(db_->Get(ReadOptions(), "foo", &value));
-  ASSERT_EQ("val2", value);
+  // Read data from previous session before and after compaction.
+  for (int i = 0; i < 2; i++) {
+    ASSERT_TRUE(db_->Get(ropts, "foo", &value).IsInvalidArgument());
+    ASSERT_OK(db_->Get(ReadOptions(), "foo", &value));
+    ASSERT_EQ("val1", value);
+    ASSERT_TRUE(db_->Get(ReadOptions(), "bar", &value).IsNotFound());
+    ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
+  }
 
   // Continue to write / read the column family without user-defined timestamps.
-  ASSERT_OK(db_->Put(WriteOptions(), "foo", "val3"));
+  ASSERT_OK(db_->Put(WriteOptions(), "foo", "val2"));
+  ASSERT_OK(db_->Put(WriteOptions(), "bar", "val2"));
+  ASSERT_OK(db_->DeleteRange(WriteOptions(), "bar", "baz"));
   ASSERT_OK(db_->Get(ReadOptions(), "foo", &value));
-  ASSERT_EQ("val3", value);
+  ASSERT_EQ("val2", value);
+  ASSERT_TRUE(db_->Get(ReadOptions(), "bar", &value).IsNotFound());
+  if (flush_before_close) {
+    ASSERT_OK(Flush(0));
+  }
   Close();
 }
 
@@ -4844,6 +4914,117 @@ TEST_F(DBBasicTestWithTimestamp, TimestampFilterTableReadOnGet) {
   Close();
 }
 
+class GetNewestUserDefinedTimestampTest : public DBBasicTestWithTimestampBase {
+ public:
+  explicit GetNewestUserDefinedTimestampTest()
+      : DBBasicTestWithTimestampBase("get_newest_udt_test") {}
+};
+
+TEST_F(GetNewestUserDefinedTimestampTest, Basic) {
+  std::string newest_timestamp;
+  // UDT disabled, get InvalidArgument.
+  ASSERT_TRUE(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp)
+                  .IsInvalidArgument());
+  Options options = CurrentOptions();
+  options.env = env_;
+  options.create_if_missing = true;
+  options.max_write_buffer_number = 5;
+  options.min_write_buffer_number_to_merge = 4;
+  options.comparator = test::BytewiseComparatorWithU64TsWrapper();
+
+  DestroyAndReopen(options);
+  // UDT persisted, get NotSupported.
+  ASSERT_TRUE(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp)
+                  .IsNotSupported());
+
+  options.persist_user_defined_timestamps = false;
+  options.allow_concurrent_memtable_write = false;
+
+  DestroyAndReopen(options);
+  ASSERT_TRUE(
+      db_->GetNewestUserDefinedTimestamp(nullptr, nullptr).IsInvalidArgument());
+
+  ColumnFamilyHandleImpl* cfh = static_cast_with_check<ColumnFamilyHandleImpl>(
+      db_->DefaultColumnFamily());
+  ColumnFamilyData* cfd = cfh->cfd();
+  // The column family hasn't seen any user defined timestamp
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_TRUE(newest_timestamp.empty());
+
+  ASSERT_OK(db_->Put(WriteOptions(), Key(1), EncodeAsUint64(1), "val1"));
+  // Testing get newest timestamp from mutable memtable.
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_EQ(EncodeAsUint64(1), newest_timestamp);
+
+  ASSERT_OK(db_->Put(WriteOptions(), Key(1), EncodeAsUint64(2), "val2"));
+  ASSERT_OK(dbfull()->TEST_SwitchMemtable(cfd));
+  // Testing get the newest timestamp from immutable memtable because the
+  // mutable one is empty.
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_EQ(EncodeAsUint64(2), newest_timestamp);
+
+  ASSERT_OK(db_->Put(WriteOptions(), Key(1), EncodeAsUint64(3), "val3"));
+  ASSERT_OK(db_->Put(WriteOptions(), Key(1), EncodeAsUint64(4), "val4"));
+  ASSERT_OK(dbfull()->TEST_SwitchMemtable(cfd));
+  // Testing get the newest timestamp from the more recent immutable memtable
+  // when there are multiple immutable memtables.
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_EQ(EncodeAsUint64(4), newest_timestamp);
+
+  ASSERT_OK(db_->Put(WriteOptions(), Key(1), EncodeAsUint64(5), "val5"));
+  // Testing get newest timestamp from mutable memtable when it has data, in the
+  // presence of immutable memtables.
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_EQ(EncodeAsUint64(5), newest_timestamp);
+
+  ASSERT_OK(Flush());
+  // After flushing and all the user defined timestamp are flushed. User defined
+  // timestamp info for SST files is available from MANIFEST.
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_EQ(EncodeAsUint64(5), newest_timestamp);
+
+  Reopen(options);
+  // Similar after flush, when there is no memtables, but some SST files,
+  // if MANIFEST records the upperbound of flushed timestamps because timestamps
+  // are not persisted in SST files, this info can be found.
+  ASSERT_OK(db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+  ASSERT_EQ(EncodeAsUint64(5), newest_timestamp);
+
+  Close();
+}
+
+TEST_F(GetNewestUserDefinedTimestampTest, ConcurrentWrites) {
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  options.comparator = test::BytewiseComparatorWithU64TsWrapper();
+  options.persist_user_defined_timestamps = false;
+  options.allow_concurrent_memtable_write = false;
+
+  DestroyAndReopen(options);
+
+  std::vector<std::thread> threads;
+  threads.reserve(10);
+  std::atomic<uint64_t> current_ts{0};
+  for (int i = 0; i < 10; i++) {
+    threads.emplace_back([this, i, &current_ts]() {
+      if (i % 2 == 0) {
+        std::string newest_timestamp;
+        ASSERT_OK(
+            db_->GetNewestUserDefinedTimestamp(nullptr, &newest_timestamp));
+      } else {
+        uint64_t write_ts = current_ts.fetch_add(1);
+        ASSERT_OK(db_->Put(WriteOptions(), Key(1), EncodeAsUint64(write_ts),
+                           "val" + std::to_string(i)));
+      }
+    });
+  }
+
+  for (auto& t : threads) {
+    t.join();
+  }
+  Close();
+}
+
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {

db/db_write_test.cc

@@ -987,7 +987,7 @@ TEST_P(DBWriteTest, RecycleLogToggleTest) {
 
   options.recycle_log_file_num = 1;
   Reopen(options);
-  // 1.log is added to alive_log_files_
+  // 1.log is added to alive_wal_files_
   ASSERT_OK(Put(Key(2), "val1"));
   ASSERT_OK(Flush());
   // 1.log should be deleted and not recycled, since it
@@ -1000,6 +1000,80 @@ TEST_P(DBWriteTest, RecycleLogToggleTest) {
   ASSERT_EQ(Get(Key(1)), "val2");
 }
 
+TEST_P(DBWriteTest, IngestWriteBatchWithIndex) {
+  if (GetParam() == kPipelinedWrite) {
+    return;
+  }
+
+  Options options = GetOptions();
+  options.disable_auto_compactions = true;
+  Reopen(options);
+  Options cf_options = GetOptions();
+  cf_options.merge_operator = MergeOperators::CreateStringAppendOperator();
+  CreateColumnFamilies({"cf1", "cf2"}, cf_options);
+  ReopenWithColumnFamilies({"default", "cf1", "cf2"},
+                           {options, cf_options, cf_options});
+
+  // default cf
+  auto wbwi1 = std::make_shared<WriteBatchWithIndex>(options.comparator, 0,
+                                                     /*overwrite_key=*/true);
+  ASSERT_OK(wbwi1->Put("key1", "value1"));
+  ASSERT_OK(wbwi1->Put("key2", "value2"));
+  if (GetParam() == kPipelinedWrite) {
+    ASSERT_TRUE(db_->IngestWriteBatchWithIndex({}, wbwi1).IsNotSupported());
+    return;
+  }
+  // Test disableWAL=false
+  ASSERT_TRUE(db_->IngestWriteBatchWithIndex({}, wbwi1).IsNotSupported());
+
+  WriteOptions wo;
+  wo.disableWAL = true;
+  ASSERT_OK(db_->IngestWriteBatchWithIndex(wo, wbwi1));
+  ASSERT_EQ("value1", Get("key1"));
+  ASSERT_EQ("value2", Get("key2"));
+
+  // Test with overwrites
+  auto wbwi = std::make_shared<WriteBatchWithIndex>(options.comparator, 0,
+                                                    /*overwrite_key=*/true);
+  ASSERT_OK(wbwi->Put("key2", "value3"));
+  ASSERT_OK(wbwi->Delete("key1"));  // Delete an existing key
+  ASSERT_OK(db_->IngestWriteBatchWithIndex(wo, wbwi));
+  ASSERT_EQ("NOT_FOUND", Get("key1"));
+  ASSERT_EQ("value3", Get("key2"));
+
+  auto wbwi2 = std::make_shared<WriteBatchWithIndex>(options.comparator, 0,
+                                                     /*overwrite_key=*/true);
+  ASSERT_OK(wbwi2->Put(handles_[1], "cf1_key1", "cf1_value1"));
+  ASSERT_OK(wbwi2->Delete(handles_[1], "cf1_key2"));
+  // Test ingestion with column family
+  ASSERT_OK(db_->IngestWriteBatchWithIndex(wo, wbwi2));
+  ASSERT_EQ("cf1_value1", Get(1, "cf1_key1"));
+  ASSERT_EQ("NOT_FOUND", Get(1, "cf1_key2"));
+
+  auto wbwi3 = std::make_shared<WriteBatchWithIndex>(options.comparator, 0,
+                                                     /*overwrite_key=*/true);
+  ASSERT_OK(wbwi3->Merge(handles_[2], "cf2_key1", "cf2_value1"));
+  ASSERT_OK(wbwi3->Merge(handles_[2], "cf2_key1", "cf2_value2"));
+  // Test ingestion with merge operations
+  ASSERT_OK(db_->IngestWriteBatchWithIndex(wo, wbwi3));
+  ASSERT_EQ("cf2_value1,cf2_value2", Get(2, "cf2_key1"));
+
+  // Test with overwrite_key = false
+  auto wbwi_no_overwrite = std::make_shared<WriteBatchWithIndex>(
+      options.comparator, 0, /*overwrite_key=*/false);
+  ASSERT_OK(wbwi_no_overwrite->Put("key1", "value1"));
+  Status s = db_->IngestWriteBatchWithIndex(wo, wbwi_no_overwrite);
+  ASSERT_TRUE(s.IsNotSupported());
+
+  auto empty_wbwi = std::make_shared<WriteBatchWithIndex>(
+      options.comparator, 0, /*overwrite_key=*/true);
+  ASSERT_OK(db_->IngestWriteBatchWithIndex(wo, empty_wbwi));
+
+  DestroyAndReopen(options);
+  // Should fail when trying to ingest to non-existent column family
+  ASSERT_NOK(db_->IngestWriteBatchWithIndex(wo, wbwi2));
+}
+
 INSTANTIATE_TEST_CASE_P(DBWriteTestInstance, DBWriteTest,
                         testing::Values(DBTestBase::kDefault,
                                         DBTestBase::kConcurrentWALWrites,

db/error_handler.cc

@@ -275,9 +275,6 @@ void ErrorHandler::HandleKnownErrors(const Status& bg_err,
     return;
   }
 
-  ROCKS_LOG_INFO(db_options_.info_log,
-                 "ErrorHandler: Set regular background error\n");
-
   bool paranoid = db_options_.paranoid_checks;
   Status::Severity sev = Status::Severity::kFatalError;
   Status new_bg_err;
@@ -335,12 +332,21 @@ void ErrorHandler::HandleKnownErrors(const Status& bg_err,
     if (!s.ok() && (s.severity() > bg_error_.severity())) {
       bg_error_ = s;
     } else {
+      ROCKS_LOG_INFO(db_options_.info_log,
+                     "ErrorHandler: Hit less severe background error\n");
+
       // This error is less severe than previously encountered error. Don't
       // take any further action
       return;
     }
   }
 
+  bool stop = bg_error_.severity() >= Status::Severity::kHardError;
+  ROCKS_LOG_INFO(
+      db_options_.info_log,
+      "ErrorHandler: Set regular background error, auto_recovery=%d, stop=%d\n",
+      int{auto_recovery}, int{stop});
+
   recover_context_ = context;
   if (auto_recovery) {
     recovery_in_prog_ = true;
@@ -351,7 +357,7 @@ void ErrorHandler::HandleKnownErrors(const Status& bg_err,
       RecoverFromNoSpace();
     }
   }
-  if (bg_error_.severity() >= Status::Severity::kHardError) {
+  if (stop) {
     is_db_stopped_.store(true, std::memory_order_release);
   }
 }

db/external_sst_file_basic_test.cc

@@ -2693,6 +2693,81 @@ TEST_F(ExternalSSTFileBasicTest, IngestWithTemperature) {
   }
 }
 
+// This tests an internal user's exact usage and expectation of the
+// IngestExternalFiles APIs to bulk load and replace files.
+TEST_F(ExternalSSTFileBasicTest,
+       AtomicReplaceColumnFamilyWithIngestedVersionKey) {
+  Options options = GetDefaultOptions();
+  options.create_if_missing = true;
+  options.compaction_style = CompactionStyle::kCompactionStyleUniversal;
+  options.num_levels = 7;
+  options.disallow_memtable_writes = false;
+
+  DestroyAndReopen(options);
+  SstFileWriter sst_file_writer(EnvOptions(), options);
+  std::string data_file_original = sst_files_dir_ + "data_original";
+  ASSERT_OK(sst_file_writer.Open(data_file_original));
+  ASSERT_OK(sst_file_writer.Put("ukey1", "uval1_orig"));
+  ASSERT_OK(sst_file_writer.Put("ukey2", "uval2_orig"));
+  ASSERT_OK(sst_file_writer.Finish());
+  ASSERT_OK(db_->IngestExternalFile(db_->DefaultColumnFamily(),
+                                    {data_file_original},
+                                    IngestExternalFileOptions()));
+
+  ASSERT_OK(Put("data_version", "v_original"));
+  ASSERT_OK(Flush());
+  std::string value;
+  ASSERT_OK(db_->Get(ReadOptions(), "data_version", &value));
+  ASSERT_EQ(value, "v_original");
+  ASSERT_OK(db_->Get(ReadOptions(), "ukey1", &value));
+  ASSERT_EQ(value, "uval1_orig");
+  ASSERT_OK(db_->Get(ReadOptions(), "ukey2", &value));
+  ASSERT_EQ(value, "uval2_orig");
+  // Set up a 1) data version key file on L0, and 2) a user data file on L6
+  // to test the initial transitioning to use `atomic_replace_range`.
+  ASSERT_EQ("1,0,0,0,0,0,1", FilesPerLevel());
+
+  // Test multiple cycles of replacing by atomically ingest a data file and a
+  // version key file while replace the whole range in the column family.
+  for (int i = 0; i < 10; i++) {
+    std::string version_file_path =
+        sst_files_dir_ + "version" + std::to_string(i);
+    ASSERT_OK(sst_file_writer.Open(version_file_path));
+    ASSERT_OK(sst_file_writer.Put("data_version", "v" + std::to_string(i)));
+    ASSERT_OK(sst_file_writer.Finish());
+
+    std::string file_path = sst_files_dir_ + std::to_string(i);
+    ASSERT_OK(sst_file_writer.Open(file_path));
+    ASSERT_OK(sst_file_writer.Put("ukey1", "uval1" + std::to_string(i)));
+    ASSERT_OK(sst_file_writer.Put("ukey2", "uval2" + std::to_string(i)));
+    ASSERT_OK(sst_file_writer.Finish());
+
+    IngestExternalFileArg arg;
+    arg.column_family = db_->DefaultColumnFamily();
+    arg.external_files = {version_file_path, file_path};
+    arg.atomic_replace_range = {{nullptr, nullptr}};
+    // Test both fail_if_not_bottomost_level: true and false
+    arg.options.fail_if_not_bottommost_level = i % 2 == 0;
+    arg.options.snapshot_consistency = false;
+    // Ingest 1) a new data version file and 2) a new user data file while erase
+    // the whole column family
+    Status s = db_->IngestExternalFiles({arg});
+    ASSERT_OK(s);
+
+    // Check ingestion result and the expected LSM shape:
+    // Two files on L6, 1) a data version file 2) a user data file.
+    ASSERT_OK(db_->Get(ReadOptions(), "ukey1", &value));
+    ASSERT_EQ(value, "uval1" + std::to_string(i));
+    ASSERT_OK(db_->Get(ReadOptions(), "ukey2", &value));
+    ASSERT_EQ(value, "uval2" + std::to_string(i));
+    ASSERT_OK(db_->Get(ReadOptions(), "data_version", &value));
+    ASSERT_EQ(value, "v" + std::to_string(i));
+    ASSERT_EQ("0,0,0,0,0,0,2", FilesPerLevel());
+  }
+
+  Close();
+}
+
 TEST_F(ExternalSSTFileBasicTest, FailIfNotBottommostLevelAndDisallowMemtable) {
   for (bool disallow_memtable : {false, true}) {
     Options options = GetDefaultOptions();

db/external_sst_file_ingestion_job.cc

@@ -610,16 +610,8 @@ Status ExternalSstFileIngestionJob::AssignLevelsForOneBatch(
       current_time = oldest_ancester_time =
           static_cast<uint64_t>(temp_current_time);
     }
-    uint64_t tail_size = 0;
-    bool contain_no_data_blocks = file->table_properties.num_entries > 0 &&
-                                  (file->table_properties.num_entries ==
-                                   file->table_properties.num_range_deletions);
-    if (file->table_properties.tail_start_offset > 0 ||
-        contain_no_data_blocks) {
-      uint64_t file_size = file->fd.GetFileSize();
-      assert(file->table_properties.tail_start_offset <= file_size);
-      tail_size = file_size - file->table_properties.tail_start_offset;
-    }
+    uint64_t tail_size = FileMetaData::CalculateTailSize(
+        file->fd.GetFileSize(), file->table_properties);
 
     bool marked_for_compaction =
         file->table_properties.num_range_deletions == 1 &&

db/flush_job.cc

@@ -901,9 +901,9 @@ Status FlushJob::WriteLevel0Table() {
     for (ReadOnlyMemTable* m : mems_) {
       ROCKS_LOG_INFO(db_options_.info_log,
                      "[%s] [JOB %d] Flushing memtable id %" PRIu64
-                     " with next log file: %" PRIu64 "\n",
+                     " with next log file: %" PRIu64 ", marked_for_flush: %d\n",
                      cfd_->GetName().c_str(), job_context_->job_id, m->GetID(),
-                     m->GetNextLogNumber());
+                     m->GetNextLogNumber(), m->IsMarkedForFlush());
       if (logical_strip_timestamp) {
         memtables.push_back(m->NewTimestampStrippingIterator(
             ro, /*seqno_to_time_mapping=*/nullptr, &arena,

db/import_column_family_job.cc

@@ -201,15 +201,8 @@ Status ImportColumnFamilyJob::Run() {
       const auto& f = files_to_import_[i][j];
       const auto& file_metadata = *metadatas_[i][j];
 
-      uint64_t tail_size = 0;
-      bool contain_no_data_blocks = f.table_properties.num_entries > 0 &&
-                                    (f.table_properties.num_entries ==
-                                     f.table_properties.num_range_deletions);
-      if (f.table_properties.tail_start_offset > 0 || contain_no_data_blocks) {
-        uint64_t file_size = f.fd.GetFileSize();
-        assert(f.table_properties.tail_start_offset <= file_size);
-        tail_size = file_size - f.table_properties.tail_start_offset;
-      }
+      uint64_t tail_size = FileMetaData::CalculateTailSize(f.fd.GetFileSize(),
+                                                           f.table_properties);
 
       VersionEdit dummy_version_edit;
       dummy_version_edit.AddFile(

db/job_context.h

@@ -123,7 +123,7 @@ struct JobContext {
         break;
       }
     }
-    return memtables_to_free.size() > 0 || logs_to_free.size() > 0 ||
+    return memtables_to_free.size() > 0 || wals_to_free.size() > 0 ||
            job_snapshot != nullptr || sv_have_sth;
   }
 
@@ -193,7 +193,7 @@ struct JobContext {
   // contexts for installing superversions for multiple column families
   std::vector<SuperVersionContext> superversion_contexts;
 
-  autovector<log::Writer*> logs_to_free;
+  autovector<log::Writer*> wals_to_free;
 
   // the current manifest_file_number, log_number and prev_log_number
   // that corresponds to the set of files in 'live'.
@@ -207,8 +207,8 @@ struct JobContext {
   uint64_t prev_log_number;
 
   uint64_t min_pending_output = 0;
-  uint64_t prev_total_log_size = 0;
-  size_t num_alive_log_files = 0;
+  uint64_t prev_wals_total_size = 0;
+  size_t num_alive_wal_files = 0;
   uint64_t size_log_to_delete = 0;
 
   // Snapshot taken before flush/compaction job.
@@ -237,18 +237,18 @@ struct JobContext {
     for (auto m : memtables_to_free) {
       delete m;
     }
-    for (auto l : logs_to_free) {
+    for (auto l : wals_to_free) {
       delete l;
     }
 
     memtables_to_free.clear();
-    logs_to_free.clear();
+    wals_to_free.clear();
     job_snapshot.reset();
   }
 
   ~JobContext() {
     assert(memtables_to_free.size() == 0);
-    assert(logs_to_free.size() == 0);
+    assert(wals_to_free.size() == 0);
   }
 };
 

db/memtable.cc

@@ -147,7 +147,6 @@ MemTable::MemTable(const InternalKeyComparator& cmp,
   const Comparator* ucmp = cmp.user_comparator();
   assert(ucmp);
   ts_sz_ = ucmp->timestamp_size();
-  persist_user_defined_timestamps_ = ioptions.persist_user_defined_timestamps;
 }
 
 MemTable::~MemTable() {
@@ -175,6 +174,11 @@ size_t MemTable::ApproximateMemoryUsage() {
 }
 
 bool MemTable::ShouldFlushNow() {
+  if (IsMarkedForFlush()) {
+    // TODO: dedicated flush reason when marked for flush
+    return true;
+  }
+
   // This is set if memtable_max_range_deletions is > 0,
   // and that many range deletions are done
   if (memtable_max_range_deletions_ > 0 &&
@@ -1801,7 +1805,7 @@ uint64_t MemTable::GetMinLogContainingPrepSection() {
 }
 
 void MemTable::MaybeUpdateNewestUDT(const Slice& user_key) {
-  if (ts_sz_ == 0 || persist_user_defined_timestamps_) {
+  if (ts_sz_ == 0) {
     return;
   }
   const Comparator* ucmp = GetInternalKeyComparator().user_comparator();
@@ -1812,9 +1816,7 @@ void MemTable::MaybeUpdateNewestUDT(const Slice& user_key) {
 }
 
 const Slice& MemTable::GetNewestUDT() const {
-  // This path should not be invoked for MemTables that does not enable the UDT
-  // in Memtable only feature.
-  assert(ts_sz_ > 0 && !persist_user_defined_timestamps_);
+  assert(ts_sz_ > 0);
   return newest_udt_;
 }
 

db/memtable.h

@@ -30,6 +30,7 @@
 #include "rocksdb/db.h"
 #include "rocksdb/memtablerep.h"
 #include "table/multiget_context.h"
+#include "util/atomic.h"
 #include "util/cast_util.h"
 #include "util/dynamic_bloom.h"
 #include "util/hash.h"
@@ -354,13 +355,13 @@ class ReadOnlyMemTable {
   // be flushed to storage
   // REQUIRES: external synchronization to prevent simultaneous
   // operations on the same MemTable.
-  uint64_t GetNextLogNumber() const { return mem_next_logfile_number_; }
+  uint64_t GetNextLogNumber() const { return mem_next_walfile_number_; }
 
   // Sets the next active logfile number when this memtable is about to
   // be flushed to storage
   // REQUIRES: external synchronization to prevent simultaneous
   // operations on the same MemTable.
-  void SetNextLogNumber(uint64_t num) { mem_next_logfile_number_ = num; }
+  void SetNextLogNumber(uint64_t num) { mem_next_walfile_number_ = num; }
 
   // REQUIRES: db_mutex held.
   void SetID(uint64_t id) { id_ = id; }
@@ -496,6 +497,10 @@ class ReadOnlyMemTable {
     return false;
   }
 
+  void MarkForFlush() { marked_for_flush_.StoreRelaxed(true); }
+
+  bool IsMarkedForFlush() const { return marked_for_flush_.LoadRelaxed(); }
+
  protected:
   friend class MemTableList;
 
@@ -511,7 +516,7 @@ class ReadOnlyMemTable {
   VersionEdit edit_;
 
   // The log files earlier than this number can be deleted.
-  uint64_t mem_next_logfile_number_{0};
+  uint64_t mem_next_walfile_number_{0};
 
   // Memtable id to track flush.
   uint64_t id_ = 0;
@@ -524,6 +529,8 @@ class ReadOnlyMemTable {
 
   // Flush job info of the current memtable.
   std::unique_ptr<FlushJobInfo> flush_job_info_;
+
+  RelaxedAtomic<bool> marked_for_flush_{false};
 };
 
 class MemTable final : public ReadOnlyMemTable {
@@ -818,6 +825,8 @@ class MemTable final : public ReadOnlyMemTable {
            is_range_del_table_empty_;
   }
 
+  //  Gets the newest user defined timestamps in the memtable. This should only
+  //  be called when user defined timestamp is enabled.
   const Slice& GetNewestUDT() const override;
 
   // Returns Corruption status if verification fails.
@@ -893,14 +902,10 @@ class MemTable final : public ReadOnlyMemTable {
   // Size in bytes for the user-defined timestamps.
   size_t ts_sz_;
 
-  // Whether to persist user-defined timestamps
-  bool persist_user_defined_timestamps_;
-
   // Newest user-defined timestamp contained in this MemTable. For ts1, and ts2
   // if Comparator::CompareTimestamp(ts1, ts2) > 0, ts1 is considered newer than
   // ts2. We track this field for a MemTable if its column family has UDT
-  // feature enabled and the `persist_user_defined_timestamp` flag is false.
-  // Otherwise, this field just contains an empty Slice.
+  // feature enabled.
   Slice newest_udt_;
 
   // Updates flush_state_ using ShouldFlushNow()

db/memtable_list.cc

@@ -51,9 +51,7 @@ void MemTableListVersion::UnrefMemTable(
 
 MemTableListVersion::MemTableListVersion(
     size_t* parent_memtable_list_memory_usage, const MemTableListVersion& old)
-    : max_write_buffer_number_to_maintain_(
-          old.max_write_buffer_number_to_maintain_),
-      max_write_buffer_size_to_maintain_(
+    : max_write_buffer_size_to_maintain_(
           old.max_write_buffer_size_to_maintain_),
       parent_memtable_list_memory_usage_(parent_memtable_list_memory_usage) {
   memlist_ = old.memlist_;
@@ -69,10 +67,8 @@ MemTableListVersion::MemTableListVersion(
 
 MemTableListVersion::MemTableListVersion(
     size_t* parent_memtable_list_memory_usage,
-    int max_write_buffer_number_to_maintain,
     int64_t max_write_buffer_size_to_maintain)
-    : max_write_buffer_number_to_maintain_(max_write_buffer_number_to_maintain),
-      max_write_buffer_size_to_maintain_(max_write_buffer_size_to_maintain),
+    : max_write_buffer_size_to_maintain_(max_write_buffer_size_to_maintain),
       parent_memtable_list_memory_usage_(parent_memtable_list_memory_usage) {}
 
 void MemTableListVersion::Ref() { ++refs_; }
@@ -323,8 +319,7 @@ void MemTableListVersion::Remove(ReadOnlyMemTable* m,
   memlist_.remove(m);
 
   m->MarkFlushed();
-  if (max_write_buffer_size_to_maintain_ > 0 ||
-      max_write_buffer_number_to_maintain_ > 0) {
+  if (max_write_buffer_size_to_maintain_ > 0) {
     memlist_history_.push_front(m);
     // Unable to get size of mutable memtable at this point, pass 0 to
     // TrimHistory as a best effort.
@@ -356,9 +351,6 @@ bool MemTableListVersion::MemtableLimitExceeded(size_t usage) {
     // whether to trim history
     return MemoryAllocatedBytesExcludingLast() + usage >=
            static_cast<size_t>(max_write_buffer_size_to_maintain_);
-  } else if (max_write_buffer_number_to_maintain_ > 0) {
-    return memlist_.size() + memlist_history_.size() >
-           static_cast<size_t>(max_write_buffer_number_to_maintain_);
   } else {
     return false;
   }
@@ -382,6 +374,19 @@ bool MemTableListVersion::TrimHistory(autovector<ReadOnlyMemTable*>* to_delete,
   return ret;
 }
 
+const Slice& MemTableListVersion::GetNewestUDT() const {
+  static Slice kEmptySlice;
+  for (auto it = memlist_.begin(); it != memlist_.end(); ++it) {
+    ReadOnlyMemTable* m = *it;
+    Slice timestamp = m->GetNewestUDT();
+    assert(!timestamp.empty() || m->IsEmpty());
+    if (!timestamp.empty()) {
+      return m->GetNewestUDT();
+    }
+  }
+  return kEmptySlice;
+}
+
 // Returns true if there is at least one memtable on which flush has
 // not yet started.
 bool MemTableList::IsFlushPending() const {

db/memtable_list.h

@@ -45,7 +45,6 @@ class MemTableListVersion {
   explicit MemTableListVersion(size_t* parent_memtable_list_memory_usage,
                                const MemTableListVersion& old);
   explicit MemTableListVersion(size_t* parent_memtable_list_memory_usage,
-                               int max_write_buffer_number_to_maintain,
                                int64_t max_write_buffer_size_to_maintain);
 
   void Ref();
@@ -150,6 +149,12 @@ class MemTableListVersion {
 
   int NumFlushed() const { return static_cast<int>(memlist_history_.size()); }
 
+  // Gets the newest user defined timestamps from the immutable memtables.
+  // This returns the newest user defined timestamp found in the most recent
+  // immutable memtable. This should only be called when user defined timestamp
+  // is enabled.
+  const Slice& GetNewestUDT() const;
+
  private:
   friend class MemTableList;
 
@@ -209,8 +214,6 @@ class MemTableListVersion {
   // (used during Transaction validation)
   std::list<ReadOnlyMemTable*> memlist_history_;
 
-  // Maximum number of MemTables to keep in memory (including both flushed
-  const int max_write_buffer_number_to_maintain_;
   // Maximum size of MemTables to keep in memory (including both flushed
   // and not-yet-flushed tables).
   const int64_t max_write_buffer_size_to_maintain_;
@@ -238,13 +241,11 @@ class MemTableList {
  public:
   // A list of memtables.
   explicit MemTableList(int min_write_buffer_number_to_merge,
-                        int max_write_buffer_number_to_maintain,
                         int64_t max_write_buffer_size_to_maintain)
       : imm_flush_needed(false),
         imm_trim_needed(false),
         min_write_buffer_number_to_merge_(min_write_buffer_number_to_merge),
         current_(new MemTableListVersion(&current_memory_usage_,
-                                         max_write_buffer_number_to_maintain,
                                          max_write_buffer_size_to_maintain)),
         num_flush_not_started_(0),
         commit_in_progress_(false),

db/memtable_list_test.cc

@@ -220,7 +220,7 @@ class MemTableListTest : public testing::Test {
 
 TEST_F(MemTableListTest, Empty) {
   // Create an empty MemTableList and validate basic functions.
-  MemTableList list(1, 0, 0);
+  MemTableList list(1, 0);
 
   ASSERT_EQ(0, list.NumNotFlushed());
   ASSERT_FALSE(list.imm_flush_needed.load(std::memory_order_acquire));
@@ -239,10 +239,8 @@ TEST_F(MemTableListTest, Empty) {
 TEST_F(MemTableListTest, GetTest) {
   // Create MemTableList
   int min_write_buffer_number_to_merge = 2;
-  int max_write_buffer_number_to_maintain = 0;
   int64_t max_write_buffer_size_to_maintain = 0;
   MemTableList list(min_write_buffer_number_to_merge,
-                    max_write_buffer_number_to_maintain,
                     max_write_buffer_size_to_maintain);
 
   SequenceNumber seq = 1;
@@ -407,10 +405,8 @@ TEST_F(MemTableListTest, GetTest) {
 TEST_F(MemTableListTest, GetFromHistoryTest) {
   // Create MemTableList
   int min_write_buffer_number_to_merge = 2;
-  int max_write_buffer_number_to_maintain = 2;
   int64_t max_write_buffer_size_to_maintain = 2 * Arena::kInlineSize;
   MemTableList list(min_write_buffer_number_to_merge,
-                    max_write_buffer_number_to_maintain,
                     max_write_buffer_size_to_maintain);
 
   SequenceNumber seq = 1;
@@ -653,11 +649,9 @@ TEST_F(MemTableListTest, FlushPendingTest) {
 
   // Create MemTableList
   int min_write_buffer_number_to_merge = 3;
-  int max_write_buffer_number_to_maintain = 7;
   int64_t max_write_buffer_size_to_maintain =
       7 * static_cast<int>(options.write_buffer_size);
   MemTableList list(min_write_buffer_number_to_merge,
-                    max_write_buffer_number_to_maintain,
                     max_write_buffer_size_to_maintain);
 
   // Create some MemTables
@@ -949,13 +943,11 @@ TEST_F(MemTableListTest, AtomicFlushTest) {
 
   // Create MemTableLists
   int min_write_buffer_number_to_merge = 3;
-  int max_write_buffer_number_to_maintain = 7;
   int64_t max_write_buffer_size_to_maintain =
       7 * static_cast<int64_t>(options.write_buffer_size);
   autovector<MemTableList*> lists;
   for (int i = 0; i != num_cfs; ++i) {
     lists.emplace_back(new MemTableList(min_write_buffer_number_to_merge,
-                                        max_write_buffer_number_to_maintain,
                                         max_write_buffer_size_to_maintain));
   }
 
@@ -1104,11 +1096,9 @@ TEST_F(MemTableListWithTimestampTest, GetTableNewestUDT) {
 
   // Create MemTableList
   int min_write_buffer_number_to_merge = 1;
-  int max_write_buffer_number_to_maintain = 4;
   int64_t max_write_buffer_size_to_maintain =
       4 * static_cast<int>(options.write_buffer_size);
   MemTableList list(min_write_buffer_number_to_merge,
-                    max_write_buffer_number_to_maintain,
                     max_write_buffer_size_to_maintain);
 
   // Create some MemTables

db/plain_table_db_test.cc

@@ -1339,11 +1339,7 @@ TEST_P(PlainTableDBTest, AdaptiveTable) {
 INSTANTIATE_TEST_CASE_P(PlainTableDBTest, PlainTableDBTest, ::testing::Bool());
 
 TEST_P(PlainTableDBTest, DeleteRangeNotSupported) {
-  // XXX: After attempting DeleteRange with PlainTable, Writes will permanently
-  // fail. Even if re-opening the DB, if WAL is used, the WAL is not recoverable
-  // (without manual intervention). Furthermore, a partial write batch can
-  // be exposed to readers, breaking WriteBatch atomicity.
-  for (bool use_write_batch : {/*false, */ true}) {
+  for (bool use_write_batch : {false, true}) {
     DestroyAndReopen();
 
     ASSERT_OK(Put("a0001111", "1"));
@@ -1362,12 +1358,7 @@ TEST_P(PlainTableDBTest, DeleteRangeNotSupported) {
     ASSERT_EQ(Get("a0001111"), "1");
     ASSERT_EQ(Get("b0001111"), "2");
     ASSERT_EQ(Get("c0001111"), "3");
-    if (use_write_batch) {
-      // XXX: broken WriteBatch atomicity
-      ASSERT_EQ(Get("d0001111"), "4");
-    } else {
-      ASSERT_EQ(Get("d0001111"), "NOT_FOUND");
-    }
+    ASSERT_EQ(Get("d0001111"), "NOT_FOUND");  // expect WriteBatch atomicity
     ASSERT_EQ(Get("e0001111"), "NOT_FOUND");
 
     ASSERT_EQ(Put("e0001111", "5").code(), Status::Code::kNotSupported);
@@ -1377,8 +1368,14 @@ TEST_P(PlainTableDBTest, DeleteRangeNotSupported) {
     ASSERT_EQ(dbfull()->TEST_FlushMemTable().code(),
               Status::Code::kNotSupported);
 
-    // XXX: WAL is not recoverable
-    ASSERT_EQ(TryReopen().code(), Status::Code::kNotSupported);
+    // WAL is recoverable (at least in standard configurations)
+    ASSERT_OK(TryReopen());
+
+    ASSERT_EQ(Get("a0001111"), "1");
+    ASSERT_EQ(Get("b0001111"), "2");
+    ASSERT_EQ(Get("c0001111"), "3");
+    ASSERT_EQ(Get("d0001111"), "NOT_FOUND");
+    ASSERT_EQ(Get("e0001111"), "NOT_FOUND");
   }
 }
 

db/repair.cc

@@ -578,14 +578,7 @@ class Repairer {
           static_cast<bool>(props->user_defined_timestamps_persisted);
     }
     if (status.ok()) {
-      uint64_t tail_size = 0;
-      bool contain_no_data_blocks =
-          props->num_entries > 0 &&
-          (props->num_entries == props->num_range_deletions);
-      if (props->tail_start_offset > 0 || contain_no_data_blocks) {
-        assert(props->tail_start_offset <= file_size);
-        tail_size = file_size - props->tail_start_offset;
-      }
+      uint64_t tail_size = FileMetaData::CalculateTailSize(file_size, *props);
       t->meta.tail_size = tail_size;
     }
     ColumnFamilyData* cfd = nullptr;

db/version_edit.h

@@ -380,6 +380,33 @@ struct FileMetaData {
     assert(!res || fd.smallest_seqno == fd.largest_seqno);
     return res;
   }
+
+  static uint64_t CalculateTailSize(uint64_t file_size,
+                                    const TableProperties& props) {
+#ifndef NDEBUG
+    bool skip = false;
+    TEST_SYNC_POINT_CALLBACK("FileMetaData::CalculateTailSize", &skip);
+    if (skip) {
+      return 0;
+    }
+#endif  // NDEBUG
+    uint64_t tail_size = 0;
+
+    // Differentiate between a file with no data blocks (tail_start_offset = 0)
+    // and a file with unknown tail_start_offset (also set to 0 due to
+    // non-negative integer storage limitation)
+    bool contain_no_data_blocks =
+        props.num_entries == 0 ||
+        (props.num_entries > 0 &&
+         (props.num_entries == props.num_range_deletions));
+
+    if (props.tail_start_offset > 0 || contain_no_data_blocks) {
+      assert(props.tail_start_offset <= file_size);
+      tail_size = file_size - props.tail_start_offset;
+    }
+
+    return tail_size;
+  }
 };
 
 // A compressed copy of file meta data that just contain minimum data needed

db/version_set.cc

@@ -1002,7 +1002,8 @@ class LevelIterator final : public InternalIterator {
         skip_filters_(skip_filters),
         allow_unprepared_value_(allow_unprepared_value),
         is_next_read_sequential_(false),
-        to_return_sentinel_(false) {
+        to_return_sentinel_(false),
+        scan_opts_(nullptr) {
     // Empty level is not supported.
     assert(flevel_ != nullptr && flevel_->num_files > 0);
     if (range_tombstone_iter_ptr_) {
@@ -1098,6 +1099,13 @@ class LevelIterator final : public InternalIterator {
     read_seq_ = read_seq;
   }
 
+  void Prepare(const std::vector<ScanOptions>* scan_opts) override {
+    scan_opts_ = scan_opts;
+    if (file_iter_.iter()) {
+      file_iter_.Prepare(scan_opts_);
+    }
+  }
+
  private:
   // Return true if at least one invalid file is seen and skipped.
   bool SkipEmptyFileForward();
@@ -1223,6 +1231,7 @@ class LevelIterator final : public InternalIterator {
   bool prefix_exhausted_ = false;
   // Whether next/prev key is a sentinel key.
   bool to_return_sentinel_ = false;
+  const std::vector<ScanOptions>* scan_opts_;
 
   // Sets flags for if we should return the sentinel key next.
   // The condition for returning sentinel is reaching the end of current
@@ -1533,6 +1542,11 @@ void LevelIterator::SetFileIterator(InternalIterator* iter) {
   }
 
   InternalIterator* old_iter = file_iter_.Set(iter);
+  // Since this is a new table iterator, no need to call Prepare() if
+  // scan_opts_ is null
+  if (iter && scan_opts_) {
+    file_iter_.Prepare(scan_opts_);
+  }
 
   // Update the read pattern for PrefetchBuffer.
   if (is_next_read_sequential_) {

db/write_thread.h

@@ -132,7 +132,7 @@ class WriteThread {
     size_t protection_bytes_per_key;
     PreReleaseCallback* pre_release_callback;
     PostMemTableCallback* post_memtable_callback;
-    uint64_t log_used;  // log number that this batch was inserted into
+    uint64_t wal_used;  // log number that this batch was inserted into
     uint64_t log_ref;   // log number that memtable insert should reference
     WriteCallback* callback;
     UserWriteCallback* user_write_cb;
@@ -161,7 +161,7 @@ class WriteThread {
           protection_bytes_per_key(0),
           pre_release_callback(nullptr),
           post_memtable_callback(nullptr),
-          log_used(0),
+          wal_used(0),
           log_ref(0),
           callback(nullptr),
           user_write_cb(nullptr),
@@ -190,7 +190,7 @@ class WriteThread {
           protection_bytes_per_key(_batch->GetProtectionBytesPerKey()),
           pre_release_callback(_pre_release_callback),
           post_memtable_callback(_post_memtable_callback),
-          log_used(0),
+          wal_used(0),
           log_ref(_log_ref),
           callback(_callback),
           user_write_cb(_user_write_cb),

db_stress_tool/db_stress_common.h

@@ -106,7 +106,6 @@ DECLARE_uint64(db_write_buffer_size);
 DECLARE_int32(write_buffer_size);
 DECLARE_int32(max_write_buffer_number);
 DECLARE_int32(min_write_buffer_number_to_merge);
-DECLARE_int32(max_write_buffer_number_to_maintain);
 DECLARE_int64(max_write_buffer_size_to_maintain);
 DECLARE_bool(use_write_buffer_manager);
 DECLARE_double(memtable_prefix_bloom_size_ratio);
@@ -321,7 +320,6 @@ DECLARE_int32(approximate_size_one_in);
 DECLARE_bool(best_efforts_recovery);
 DECLARE_bool(skip_verifydb);
 DECLARE_bool(paranoid_file_checks);
-DECLARE_bool(fail_if_options_file_error);
 DECLARE_uint64(batch_protection_bytes_per_key);
 DECLARE_uint32(memtable_protection_bytes_per_key);
 DECLARE_uint32(block_protection_bytes_per_key);
@@ -424,6 +422,8 @@ DECLARE_uint32(commit_bypass_memtable_one_in);
 DECLARE_bool(track_and_verify_wals);
 DECLARE_bool(enable_remote_compaction);
 DECLARE_bool(auto_refresh_iterator_with_snapshot);
+DECLARE_uint32(memtable_op_scan_flush_trigger);
+DECLARE_uint32(ingest_wbwi_one_in);
 
 constexpr long KB = 1024;
 constexpr int kRandomValueMaxFactor = 3;

db_stress_tool/db_stress_gflags.cc

@@ -168,20 +168,6 @@ DEFINE_int32(min_write_buffer_number_to_merge,
              "writing less data to storage if there are duplicate records in"
              " each of these individual write buffers.");
 
-DEFINE_int32(max_write_buffer_number_to_maintain,
-             ROCKSDB_NAMESPACE::Options().max_write_buffer_number_to_maintain,
-             "The total maximum number of write buffers to maintain in memory "
-             "including copies of buffers that have already been flushed. "
-             "Unlike max_write_buffer_number, this parameter does not affect "
-             "flushing. This controls the minimum amount of write history "
-             "that will be available in memory for conflict checking when "
-             "Transactions are used. If this value is too low, some "
-             "transactions may fail at commit time due to not being able to "
-             "determine whether there were any write conflicts. Setting this "
-             "value to 0 will cause write buffers to be freed immediately "
-             "after they are flushed.  If this value is set to -1, "
-             "'max_write_buffer_number' will be used.");
-
 DEFINE_int64(max_write_buffer_size_to_maintain,
              ROCKSDB_NAMESPACE::Options().max_write_buffer_size_to_maintain,
              "The total maximum size of write buffers to maintain in memory "
@@ -856,6 +842,11 @@ DEFINE_bool(track_and_verify_wals,
 DEFINE_bool(enable_remote_compaction, false,
             "Enable (simulated) Remote Compaction");
 
+DEFINE_uint32(ingest_wbwi_one_in, 0,
+              "If set, will call"
+              "IngestWriteBatchWithIndex() instead of regular write operations "
+              "once every N writes.");
+
 static bool ValidateInt32Percent(const char* flagname, int32_t value) {
   if (value < 0 || value > 100) {
     fprintf(stderr, "Invalid value for --%s: %d, 0<= pct <=100 \n", flagname,
@@ -1098,10 +1089,6 @@ DEFINE_bool(paranoid_file_checks, true,
             "After writing every SST file, reopen it and read all the keys "
             "and validate checksums");
 
-DEFINE_bool(fail_if_options_file_error, false,
-            "Fail operations that fail to detect or properly persist options "
-            "file.");
-
 DEFINE_uint64(batch_protection_bytes_per_key, 0,
               "If nonzero, enables integrity protection in `WriteBatch` at the "
               "specified number of bytes per key. Currently the only supported "
@@ -1487,4 +1474,9 @@ DEFINE_bool(
     ROCKSDB_NAMESPACE::ReadOptions().auto_refresh_iterator_with_snapshot,
     "ReadOptions.auto_refresh_iterator_with_snapshot");
 
+DEFINE_uint32(
+    memtable_op_scan_flush_trigger,
+    ROCKSDB_NAMESPACE::ColumnFamilyOptions().memtable_op_scan_flush_trigger,
+    "Sets CF option memtable_op_scan_flush_trigger.");
+
 #endif  // GFLAGS

db_stress_tool/db_stress_listener.h

@@ -265,7 +265,7 @@ class DbStressListener : public EventListener {
       fault_fs_guard->DisableAllThreadLocalErrorInjection();
       // TODO(hx235): only exempt the flush thread during error recovery instead
       // of all the flush threads from error injection
-      fault_fs_guard->SetIOActivtiesExcludedFromFaultInjection(
+      fault_fs_guard->SetIOActivitiesExcludedFromFaultInjection(
           {Env::IOActivity::kFlush});
     }
   }
@@ -275,7 +275,7 @@ class DbStressListener : public EventListener {
     RandomSleep();
     if (FLAGS_error_recovery_with_no_fault_injection && fault_fs_guard) {
       fault_fs_guard->EnableAllThreadLocalErrorInjection();
-      fault_fs_guard->SetIOActivtiesExcludedFromFaultInjection({});
+      fault_fs_guard->SetIOActivitiesExcludedFromFaultInjection({});
     }
   }
 

db_stress_tool/db_stress_test_base.cc

@@ -3376,8 +3376,6 @@ void StressTest::PrintEnv() const {
           FLAGS_sync_fault_injection);
   fprintf(stdout, "Best efforts recovery     : %d\n",
           static_cast<int>(FLAGS_best_efforts_recovery));
-  fprintf(stdout, "Fail if OPTIONS file error: %d\n",
-          static_cast<int>(FLAGS_fail_if_options_file_error));
   fprintf(stdout, "User timestamp size bytes : %d\n",
           static_cast<int>(FLAGS_user_timestamp_size));
   fprintf(stdout, "Persist user defined timestamps : %d\n",
@@ -4047,8 +4045,6 @@ void InitializeOptionsFromFlags(
   options.max_write_buffer_number = FLAGS_max_write_buffer_number;
   options.min_write_buffer_number_to_merge =
       FLAGS_min_write_buffer_number_to_merge;
-  options.max_write_buffer_number_to_maintain =
-      FLAGS_max_write_buffer_number_to_maintain;
   options.max_write_buffer_size_to_maintain =
       FLAGS_max_write_buffer_size_to_maintain;
   options.memtable_prefix_bloom_size_ratio =
@@ -4257,7 +4253,6 @@ void InitializeOptionsFromFlags(
 
   options.best_efforts_recovery = FLAGS_best_efforts_recovery;
   options.paranoid_file_checks = FLAGS_paranoid_file_checks;
-  options.fail_if_options_file_error = FLAGS_fail_if_options_file_error;
 
   if (FLAGS_user_timestamp_size > 0) {
     CheckAndSetOptionsForUserTimestamp(options);
@@ -4321,6 +4316,8 @@ void InitializeOptionsFromFlags(
   if (FLAGS_enable_remote_compaction) {
     options.compaction_service = std::make_shared<DbStressCompactionService>();
   }
+
+  options.memtable_op_scan_flush_trigger = FLAGS_memtable_op_scan_flush_trigger;
 }
 
 void InitializeOptionsGeneral(

db_stress_tool/no_batched_ops_stress.cc

@@ -1845,7 +1845,17 @@ class NonBatchedOpsStressTest : public StressTest {
       } else if (FLAGS_use_merge) {
         if (!FLAGS_use_txn) {
           if (FLAGS_user_timestamp_size == 0) {
-            s = db_->Merge(write_opts, cfh, k, v);
+            if (FLAGS_ingest_wbwi_one_in &&
+                thread->rand.OneIn(FLAGS_ingest_wbwi_one_in)) {
+              auto wbwi = std::make_shared<WriteBatchWithIndex>(
+                  options_.comparator, 0, /*overwrite_key=*/true);
+              s = wbwi->Merge(cfh, k, v);
+              if (s.ok()) {
+                s = db_->IngestWriteBatchWithIndex(write_opts, wbwi);
+              }
+            } else {
+              s = db_->Merge(write_opts, cfh, k, v);
+            }
           } else {
             s = db_->Merge(write_opts, cfh, k, write_ts, v);
           }
@@ -1857,7 +1867,17 @@ class NonBatchedOpsStressTest : public StressTest {
       } else {
         if (!FLAGS_use_txn) {
           if (FLAGS_user_timestamp_size == 0) {
-            s = db_->Put(write_opts, cfh, k, v);
+            if (FLAGS_ingest_wbwi_one_in &&
+                thread->rand.OneIn(FLAGS_ingest_wbwi_one_in)) {
+              auto wbwi = std::make_shared<WriteBatchWithIndex>(
+                  options_.comparator, 0, /*overwrite_key=*/true);
+              s = wbwi->Put(cfh, k, v);
+              if (s.ok()) {
+                s = db_->IngestWriteBatchWithIndex(write_opts, wbwi);
+              }
+            } else {
+              s = db_->Put(write_opts, cfh, k, v);
+            }
           } else {
             s = db_->Put(write_opts, cfh, k, write_ts, v);
           }
@@ -1949,7 +1969,17 @@ class NonBatchedOpsStressTest : public StressTest {
         }
         if (!FLAGS_use_txn) {
           if (FLAGS_user_timestamp_size == 0) {
-            s = db_->Delete(write_opts, cfh, key);
+            if (FLAGS_ingest_wbwi_one_in &&
+                thread->rand.OneIn(FLAGS_ingest_wbwi_one_in)) {
+              auto wbwi = std::make_shared<WriteBatchWithIndex>(
+                  options_.comparator, 0, /*overwrite_key=*/true);
+              s = wbwi->Delete(cfh, key);
+              if (s.ok()) {
+                s = db_->IngestWriteBatchWithIndex(write_opts, wbwi);
+              }
+            } else {
+              s = db_->Delete(write_opts, cfh, key);
+            }
           } else {
             s = db_->Delete(write_opts, cfh, key, write_ts);
           }
@@ -2006,7 +2036,17 @@ class NonBatchedOpsStressTest : public StressTest {
         }
         if (!FLAGS_use_txn) {
           if (FLAGS_user_timestamp_size == 0) {
-            s = db_->SingleDelete(write_opts, cfh, key);
+            if (FLAGS_ingest_wbwi_one_in &&
+                thread->rand.OneIn(FLAGS_ingest_wbwi_one_in)) {
+              auto wbwi = std::make_shared<WriteBatchWithIndex>(
+                  options_.comparator, 0, /*overwrite_key=*/true);
+              s = wbwi->SingleDelete(cfh, key);
+              if (s.ok()) {
+                s = db_->IngestWriteBatchWithIndex(write_opts, wbwi);
+              }
+            } else {
+              s = db_->SingleDelete(write_opts, cfh, key);
+            }
           } else {
             s = db_->SingleDelete(write_opts, cfh, key, write_ts);
           }

env/fs_posix.cc

@@ -322,8 +322,17 @@ class PosixFileSystem : public FileSystem {
     if (options.use_mmap_writes) {
       MaybeForceDisableMmap(fd);
     }
+    uint64_t initial_file_size = 0;
+    if (reopen) {
+      s = GetFileSize(fname, IOOptions(), &initial_file_size, nullptr);
+      if (!s.ok()) {
+        close(fd);
+        return s;
+      }
+    }
     if (options.use_mmap_writes && !forceMmapOff_) {
-      result->reset(new PosixMmapFile(fname, fd, page_size_, options));
+      result->reset(
+          new PosixMmapFile(fname, fd, page_size_, options, initial_file_size));
     } else if (options.use_direct_writes && !options.use_mmap_writes) {
 #ifdef OS_MACOSX
       if (fcntl(fd, F_NOCACHE, 1) == -1) {
@@ -343,7 +352,7 @@ class PosixFileSystem : public FileSystem {
 #endif
       result->reset(new PosixWritableFile(
           fname, fd, GetLogicalBlockSizeForWriteIfNeeded(options, fname, fd),
-          options));
+          options, initial_file_size));
     } else {
       // disable mmap writes
       EnvOptions no_mmap_writes_options = options;
@@ -352,7 +361,7 @@ class PosixFileSystem : public FileSystem {
           new PosixWritableFile(fname, fd,
                                 GetLogicalBlockSizeForWriteIfNeeded(
                                     no_mmap_writes_options, fname, fd),
-                                no_mmap_writes_options));
+                                no_mmap_writes_options, initial_file_size));
     }
     return s;
   }
@@ -418,7 +427,8 @@ class PosixFileSystem : public FileSystem {
       MaybeForceDisableMmap(fd);
     }
     if (options.use_mmap_writes && !forceMmapOff_) {
-      result->reset(new PosixMmapFile(fname, fd, page_size_, options));
+      result->reset(new PosixMmapFile(fname, fd, page_size_, options,
+                                      /*initial_file_size=*/0));
     } else if (options.use_direct_writes && !options.use_mmap_writes) {
 #ifdef OS_MACOSX
       if (fcntl(fd, F_NOCACHE, 1) == -1) {
@@ -438,16 +448,16 @@ class PosixFileSystem : public FileSystem {
 #endif
       result->reset(new PosixWritableFile(
           fname, fd, GetLogicalBlockSizeForWriteIfNeeded(options, fname, fd),
-          options));
+          options, /*initial_file_size=*/0));
     } else {
       // disable mmap writes
       FileOptions no_mmap_writes_options = options;
       no_mmap_writes_options.use_mmap_writes = false;
-      result->reset(
-          new PosixWritableFile(fname, fd,
-                                GetLogicalBlockSizeForWriteIfNeeded(
-                                    no_mmap_writes_options, fname, fd),
-                                no_mmap_writes_options));
+      result->reset(new PosixWritableFile(
+          fname, fd,
+          GetLogicalBlockSizeForWriteIfNeeded(no_mmap_writes_options, fname,
+                                              fd),
+          no_mmap_writes_options, /*initial_file_size=*/0));
     }
     return s;
   }

env/io_posix.cc

@@ -1138,7 +1138,8 @@ IOStatus PosixMmapFile::Msync() {
 }
 
 PosixMmapFile::PosixMmapFile(const std::string& fname, int fd, size_t page_size,
-                             const EnvOptions& options)
+                             const EnvOptions& options,
+                             uint64_t initial_file_size)
     : filename_(fname),
       fd_(fd),
       page_size_(page_size),
@@ -1147,7 +1148,7 @@ PosixMmapFile::PosixMmapFile(const std::string& fname, int fd, size_t page_size,
       limit_(nullptr),
       dst_(nullptr),
       last_sync_(nullptr),
-      file_offset_(0) {
+      file_offset_(initial_file_size) {
 #ifdef ROCKSDB_FALLOCATE_PRESENT
   allow_fallocate_ = options.allow_fallocate;
   fallocate_with_keep_size_ = options.fallocate_with_keep_size;
@@ -1317,12 +1318,13 @@ IOStatus PosixMmapFile::Allocate(uint64_t offset, uint64_t len,
  */
 PosixWritableFile::PosixWritableFile(const std::string& fname, int fd,
                                      size_t logical_block_size,
-                                     const EnvOptions& options)
+                                     const EnvOptions& options,
+                                     uint64_t initial_file_size)
     : FSWritableFile(options),
       filename_(fname),
       use_direct_io_(options.use_direct_writes),
       fd_(fd),
-      filesize_(0),
+      filesize_(initial_file_size),
       logical_sector_size_(logical_block_size) {
 #ifdef ROCKSDB_FALLOCATE_PRESENT
   allow_fallocate_ = options.allow_fallocate;

env/io_posix.h

@@ -374,7 +374,8 @@ class PosixWritableFile : public FSWritableFile {
  public:
   explicit PosixWritableFile(const std::string& fname, int fd,
                              size_t logical_block_size,
-                             const EnvOptions& options);
+                             const EnvOptions& options,
+                             uint64_t initial_file_size);
   virtual ~PosixWritableFile();
 
   // Need to implement this so the file is truncated correctly
@@ -469,7 +470,7 @@ class PosixMmapFile : public FSWritableFile {
 
  public:
   PosixMmapFile(const std::string& fname, int fd, size_t page_size,
-                const EnvOptions& options);
+                const EnvOptions& options, uint64_t initial_file_size);
   ~PosixMmapFile();
 
   // Means Close() will properly take care of truncate

file/file_prefetch_buffer.cc

@@ -126,6 +126,8 @@ Status FilePrefetchBuffer::Read(BufferInfo* buf, const IOOptions& opts,
 
   if (usage_ == FilePrefetchBufferUsage::kUserScanPrefetch) {
     RecordTick(stats_, PREFETCH_BYTES, read_len);
+  } else if (usage_ == FilePrefetchBufferUsage::kCompactionPrefetch) {
+    RecordInHistogram(stats_, COMPACTION_PREFETCH_BYTES, read_len);
   }
   if (!use_fs_buffer) {
     // Update the buffer size.
@@ -154,7 +156,9 @@ Status FilePrefetchBuffer::ReadAsync(BufferInfo* buf, const IOOptions& opts,
                                &(buf->del_fn_), /*aligned_buf =*/nullptr);
   req.status.PermitUncheckedError();
   if (s.ok()) {
-    RecordTick(stats_, PREFETCH_BYTES, read_len);
+    if (usage_ == FilePrefetchBufferUsage::kUserScanPrefetch) {
+      RecordTick(stats_, PREFETCH_BYTES, read_len);
+    }
     buf->async_read_in_progress_ = true;
   }
   return s;

file/file_prefetch_buffer.h

@@ -134,6 +134,7 @@ struct BufferInfo {
 enum class FilePrefetchBufferUsage {
   kTableOpenPrefetchTail,
   kUserScanPrefetch,
+  kCompactionPrefetch,
   kUnknown,
 };
 
@@ -574,6 +575,9 @@ class FilePrefetchBuffer {
                            size_t& read_len, uint64_t& aligned_useful_len);
 
   void UpdateStats(bool found_in_buffer, size_t length_found) {
+    if (usage_ != FilePrefetchBufferUsage::kUserScanPrefetch) {
+      return;
+    }
     if (found_in_buffer) {
       RecordTick(stats_, PREFETCH_HITS);
     }

file/prefetch_test.cc

@@ -299,9 +299,18 @@ TEST_P(PrefetchTest, Basic) {
   const uint64_t prev_table_open_prefetch_tail_hit =
       options.statistics->getTickerCount(TABLE_OPEN_PREFETCH_TAIL_HIT);
 
+  HistogramData pre_compaction_prefetch_bytes;
+  options.statistics->histogramData(COMPACTION_PREFETCH_BYTES,
+                                    &pre_compaction_prefetch_bytes);
+  ASSERT_EQ(pre_compaction_prefetch_bytes.count, 0);
+
   // commenting out the line below causes the example to work correctly
   ASSERT_OK(db_->CompactRange(CompactRangeOptions(), &least, &greatest));
 
+  HistogramData post_compaction_prefetch_bytes;
+  options.statistics->histogramData(COMPACTION_PREFETCH_BYTES,
+                                    &post_compaction_prefetch_bytes);
+
   HistogramData cur_table_open_prefetch_tail_read;
   options.statistics->histogramData(TABLE_OPEN_PREFETCH_TAIL_READ_BYTES,
                                     &cur_table_open_prefetch_tail_read);
@@ -318,6 +327,7 @@ TEST_P(PrefetchTest, Basic) {
     ASSERT_GT(fs->GetPrefetchCount(), 1);
     ASSERT_EQ(0, buff_prefetch_count);
     fs->ClearPrefetchCount();
+    ASSERT_EQ(post_compaction_prefetch_bytes.count, 0);
   } else {
     ASSERT_FALSE(fs->IsPrefetchCalled());
     // To rule out false positive by the SST file tail prefetch during
@@ -331,6 +341,20 @@ TEST_P(PrefetchTest, Basic) {
               prev_table_open_prefetch_tail_hit);
     ASSERT_GE(cur_table_open_prefetch_tail_miss,
               prev_table_open_prefetch_tail_miss);
+
+    ASSERT_GT(post_compaction_prefetch_bytes.count, 0);
+
+    // Not an exact match due to potential roundup/down for alignment
+    auto expected_compaction_readahead_size =
+        Options().compaction_readahead_size;
+    ASSERT_LE(post_compaction_prefetch_bytes.max,
+              expected_compaction_readahead_size * 1.1);
+    ASSERT_GE(post_compaction_prefetch_bytes.max,
+              expected_compaction_readahead_size * 0.9);
+    ASSERT_LE(post_compaction_prefetch_bytes.average,
+              expected_compaction_readahead_size * 1.1);
+    ASSERT_GE(post_compaction_prefetch_bytes.average,
+              expected_compaction_readahead_size * 0.9);
   }
 
   for (bool disable_io : {false, true}) {
@@ -3251,8 +3275,9 @@ TEST_F(FilePrefetchBufferTest, SyncReadaheadStats) {
   ReadaheadParams readahead_params;
   readahead_params.initial_readahead_size = 8192;
   readahead_params.max_readahead_size = 8192;
-  FilePrefetchBuffer fpb(readahead_params, true, false, fs(), nullptr,
-                         stats.get());
+  FilePrefetchBuffer fpb(
+      readahead_params, true, false, fs(), nullptr, stats.get(),
+      nullptr /* cb */, FilePrefetchBufferUsage::kUserScanPrefetch /* usage */);
   Slice result;
   // Simulate a seek of 4096 bytes at offset 0. Due to the readahead settings,
   // it will do a read of offset 0 and length - (4096 + 8192) 12288.
@@ -3497,9 +3522,10 @@ TEST_P(FSBufferPrefetchTest, FSBufferPrefetchStatsInternals) {
   size_t num_buffers = use_async_prefetch ? 2 : 1;
   readahead_params.num_buffers = num_buffers;
 
-  FilePrefetchBuffer fpb(readahead_params, true /* enable */,
-                         false /* track_min_offset */, fs(), clock(),
-                         stats.get());
+  FilePrefetchBuffer fpb(
+      readahead_params, true /* enable */, false /* track_min_offset */, fs(),
+      clock(), stats.get(), nullptr /* cb */,
+      FilePrefetchBufferUsage::kUserScanPrefetch /* usage */);
 
   int overlap_buffer_write_ct = 0;
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->SetCallBack(

include/rocksdb/advanced_iterator.h

@@ -0,0 +1,36 @@
+//  Copyright (c) Meta Platforms, Inc. and affiliates.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include "rocksdb/slice.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+enum class IterBoundCheck : char {
+  kUnknown = 0,
+  kOutOfBound,
+  kInbound,
+};
+
+// This structure encapsulates the result of NextAndGetResult()
+struct IterateResult {
+  // The lifetime of key is guaranteed until Next()/NextAndGetResult() is
+  // called.
+  Slice key;
+  // If the iterator becomes invalid after a NextAndGetResult(), the table
+  // iterator should set this to indicate whether it became invalid due
+  // to the next key being out of bound (kOutOfBound) or it reached end
+  // of file (kUnknown). If the iiterator is still valid, this should
+  // be set to kInbound.
+  IterBoundCheck bound_check_result = IterBoundCheck::kUnknown;
+  // If false, PrepareValue() needs to be called before value()
+  // This is useful if the table reader wants to materialize the value in a
+  // lazy manner. In that case, it can set this to false and RocksDB
+  // guarantees that it'll call PrepareValue() before calling value().
+  bool value_prepared = true;
+};
+
+}  // namespace ROCKSDB_NAMESPACE

include/rocksdb/advanced_options.h

@@ -171,15 +171,6 @@ struct AdvancedColumnFamilyOptions {
   // Default: 1
   int min_write_buffer_number_to_merge = 1;
 
-  // DEPRECATED
-  // The total maximum number of write buffers to maintain in memory including
-  // copies of buffers that have already been flushed.  Unlike
-  // max_write_buffer_number, this parameter does not affect flushing.
-  // This parameter is being replaced by max_write_buffer_size_to_maintain.
-  // If both parameters are set to non-zero values, this parameter will be
-  // ignored.
-  int max_write_buffer_number_to_maintain = 0;
-
   // The target number of write history bytes to hold in memory. Write history
   // comprises the latest write buffers (memtables). To reach the target, write
   // buffers that were most recently flushed to SST files may be retained in
@@ -1105,6 +1096,20 @@ struct AdvancedColumnFamilyOptions {
   // additional key comparison during memtable lookup.
   bool paranoid_memory_checks = false;
 
+  // When an iterator scans this number of invisible entries (tombstones or
+  // hidden puts) from the active memtable during a single iterator operation,
+  // we will attempt to flush the memtable. Currently only forward scans are
+  // supported (SeekToFirst(), Seek() and Next()).
+  // This option helps to reduce the overhead of scanning through a
+  // large number of entries in memtable.
+  // Users should consider enable deletion-triggered-compaction (see
+  // CompactOnDeletionCollectorFactory) together with this option to compact
+  // away tombstones after the memtable is flushed.
+  //
+  // Default: 0 (disabled)
+  // Dynamically changeable through the SetOptions() API.
+  uint32_t memtable_op_scan_flush_trigger = 0;
+
   // Create ColumnFamilyOptions with default values for all fields
   AdvancedColumnFamilyOptions();
   // Create ColumnFamilyOptions from Options

include/rocksdb/c.h

@@ -1341,6 +1341,11 @@ extern ROCKSDB_LIBRARY_API void rocksdb_options_set_periodic_compaction_seconds(
     rocksdb_options_t*, uint64_t);
 extern ROCKSDB_LIBRARY_API uint64_t
 rocksdb_options_get_periodic_compaction_seconds(rocksdb_options_t*);
+extern ROCKSDB_LIBRARY_API void
+rocksdb_options_set_memtable_op_scan_flush_trigger(rocksdb_options_t*,
+                                                   uint32_t);
+extern ROCKSDB_LIBRARY_API uint32_t
+rocksdb_options_get_memtable_op_scan_flush_trigger(rocksdb_options_t*);
 
 enum {
   rocksdb_statistics_level_disable_all = 0,
@@ -1448,11 +1453,6 @@ rocksdb_options_set_min_write_buffer_number_to_merge(rocksdb_options_t*, int);
 extern ROCKSDB_LIBRARY_API int
 rocksdb_options_get_min_write_buffer_number_to_merge(rocksdb_options_t*);
 extern ROCKSDB_LIBRARY_API void
-rocksdb_options_set_max_write_buffer_number_to_maintain(rocksdb_options_t*,
-                                                        int);
-extern ROCKSDB_LIBRARY_API int
-rocksdb_options_get_max_write_buffer_number_to_maintain(rocksdb_options_t*);
-extern ROCKSDB_LIBRARY_API void
 rocksdb_options_set_max_write_buffer_size_to_maintain(rocksdb_options_t*,
                                                       int64_t);
 extern ROCKSDB_LIBRARY_API int64_t

include/rocksdb/db.h

@@ -22,6 +22,7 @@
 #include "rocksdb/iterator.h"
 #include "rocksdb/listener.h"
 #include "rocksdb/metadata.h"
+#include "rocksdb/multi_scan.h"
 #include "rocksdb/options.h"
 #include "rocksdb/snapshot.h"
 #include "rocksdb/sst_file_writer.h"
@@ -30,6 +31,7 @@
 #include "rocksdb/types.h"
 #include "rocksdb/user_write_callback.h"
 #include "rocksdb/utilities/table_properties_collectors.h"
+#include "rocksdb/utilities/write_batch_with_index.h"
 #include "rocksdb/version.h"
 #include "rocksdb/wide_columns.h"
 
@@ -616,7 +618,7 @@ class DB {
                        const Slice& /*key*/, const Slice& /*ts*/,
                        const Slice& /*value*/);
 
-  // Apply the specified updates to the database.
+  // Apply the specified updates atomically to the database.
   // If `updates` contains no update, WAL will still be synced if
   // options.sync=true.
   // Returns OK on success, non-OK on failure.
@@ -632,6 +634,21 @@ class DB {
         "WriteWithCallback not implemented for this interface.");
   }
 
+  // EXPERIMENTAL, subject to change
+  // Ingest a WriteBatchWithIndex into DB, bypassing memtable writes for better
+  // write performance. Useful when there is a large number of updates
+  // in the write batch.
+  // The WriteBatchWithIndex must be created with overwrite_key=true.
+  // Currently this requires WriteOptions::disableWAL=true.
+  // The following options are currently not supported:
+  // - unordered_write
+  // - enable_pipelined_write
+  virtual Status IngestWriteBatchWithIndex(
+      const WriteOptions& /*options*/,
+      std::shared_ptr<WriteBatchWithIndex> /*wbwi*/) {
+    return Status::NotSupported("IngestWriteBatchWithIndex not implemented.");
+  }
+
   // If the column family specified by "column_family" contains an entry for
   // "key", return the corresponding value in "*value". If the entry is a plain
   // key-value, return the value as-is; if it is a wide-column entity, return
@@ -1073,6 +1090,18 @@ class DB {
       const ReadOptions& options,
       const std::vector<ColumnFamilyHandle*>& column_families) = 0;
 
+  // Get an iterator that scans multiple key ranges. The scan ranges should
+  // be in increasing order of start key. See multi_scan_iterator.h for more
+  // details.
+  virtual std::unique_ptr<MultiScan> NewMultiScan(
+      const ReadOptions& /*options*/, ColumnFamilyHandle* /*column_family*/,
+      const std::vector<ScanOptions>& /*scan_opts*/) {
+    std::unique_ptr<Iterator> iter(NewErrorIterator(Status::NotSupported()));
+    std::unique_ptr<MultiScan> ms_iter =
+        std::make_unique<MultiScan>(std::move(iter));
+    return ms_iter;
+  }
+
   // Return a handle to the current DB state.  Iterators created with
   // this handle will all observe a stable snapshot of the current DB
   // state.  The caller must call ReleaseSnapshot(result) when the
@@ -1658,9 +1687,12 @@ class DB {
   virtual int NumberLevels(ColumnFamilyHandle* column_family) = 0;
   virtual int NumberLevels() { return NumberLevels(DefaultColumnFamily()); }
 
+  // DEPRECATED:
   // Maximum level to which a new compacted memtable is pushed if it
   // does not create overlap.
-  virtual int MaxMemCompactionLevel(ColumnFamilyHandle* column_family) = 0;
+  virtual int MaxMemCompactionLevel(ColumnFamilyHandle* /*column_family*/) {
+    return 0;
+  }
   virtual int MaxMemCompactionLevel() {
     return MaxMemCompactionLevel(DefaultColumnFamily());
   }
@@ -1766,6 +1798,25 @@ class DB {
   virtual Status GetFullHistoryTsLow(ColumnFamilyHandle* column_family,
                                      std::string* ts_low) = 0;
 
+  // EXPERIMENTAL
+  // Get the newest timestamp of the column family. This is only for when the
+  // column family enables user defined timestamp and when timestamps are not
+  // persisted in SST files, a.k.a `persist_user_defined_timestamps=false`.
+  // This checks the mutable memtable, the immutable memtable and the SST files,
+  // and returns the first newest user defined timestamp found.
+  // When user defined timestamp is not persisted in SST files, metadata in
+  // MANIFEST tracks the most recently seen timestamp for SST files, so the
+  // newest timestamp in SST files can be found.
+  // OK status is returned if finding the newest timestamp succeeds, if
+  // `newest_timestamp` is empty, it means the column family hasn't seen any
+  // timestamp. The returned timestamp is encoded, util method `DecodeU64Ts` can
+  // be used to decode it into uint64_t.
+  // User-defined timestamp is required to be increasing per key, the return
+  // value of this API would be most useful if the user-defined timestamp is
+  // monotonically increasing across keys.
+  virtual Status GetNewestUserDefinedTimestamp(
+      ColumnFamilyHandle* column_family, std::string* newest_timestamp) = 0;
+
   // Suspend deleting obsolete files. Compactions will continue to occur,
   // but no obsolete files will be deleted. To resume file deletions, each
   // call to DisableFileDeletions() must be matched by a subsequent call to
@@ -1877,12 +1928,12 @@ class DB {
   // Retrieve information about the current wal file
   //
   // Note that the log might have rolled after this call in which case
-  // the current_log_file would not point to the current log file.
+  // the current_wal_file would not point to the current log file.
   //
-  // Additionally, for the sake of optimization current_log_file->StartSequence
+  // Additionally, for the sake of optimization current_wal_file->StartSequence
   // would always be set to 0
   virtual Status GetCurrentWalFile(
-      std::unique_ptr<WalFile>* current_log_file) = 0;
+      std::unique_ptr<WalFile>* current_wal_file) = 0;
 
   // IngestExternalFile() will load a list of external SST files (1) into the DB
   // Two primary modes are supported:

include/rocksdb/experimental.h

@@ -21,6 +21,11 @@ Status SuggestCompactRange(DB* db, ColumnFamilyHandle* column_family,
                            const Slice* begin, const Slice* end);
 Status SuggestCompactRange(DB* db, const Slice* begin, const Slice* end);
 
+// DEPRECATED: this API may be removed in a future release.
+// This operation can be done through CompactRange() by setting
+// CompactRangeOptions::bottommost_level_compaction set to
+// BottommostLevelCompaction::kSkip and setting target level.
+//
 // Move all L0 files to target_level skipping compaction.
 // This operation succeeds only if the files in L0 have disjoint ranges; this
 // is guaranteed to happen, for instance, if keys are inserted in sorted

include/rocksdb/external_table.h

@@ -5,9 +5,11 @@
 
 #pragma once
 
+#include "rocksdb/advanced_iterator.h"
 #include "rocksdb/customizable.h"
 #include "rocksdb/file_checksum.h"
-#include "rocksdb/iterator.h"
+#include "rocksdb/file_system.h"
+#include "rocksdb/iterator_base.h"
 #include "rocksdb/options.h"
 #include "rocksdb/status.h"
 
@@ -58,6 +60,47 @@ class ExternalTableFactory;
 // the external table implementation.
 // TODO: Specify which options are relevant
 
+class ExternalTableIterator : public IteratorBase {
+ public:
+  virtual ~ExternalTableIterator() {}
+
+  // This can optionally be called to prepare the iterator for a series
+  // of scans. The scan_opts parameter specifies the order of scans to
+  // follow, as well as the limits for those scans. After calling this,
+  // the caller will Seek() the iterator to successive start keys in scan_opts.
+  //
+  // If Prepare() is called again with a different scan_opts pointer, it
+  // means the iterator will be reused for a new multi scan. If scan_opts
+  // is null, then the previous Prepare() can be discarded.
+  //
+  // The caller guarantees the lifetime of scan_opts until its either cleared
+  // or replaced by another Prepare().
+  // TODO: Update the contract to trim the scan_opts range to only include
+  // scans that potentially intersect the file key range.
+  //
+  // If the sequence of Seeks is interrupted by seeking to some other target
+  // key, then the iterator is free to discard anything done during Prepare.
+  virtual void Prepare(const ScanOptions scan_opts[], size_t num_opts) = 0;
+
+  // Similar to Next(), except it also fills the result and returns whether
+  // the iterator is on a valid key or not
+  virtual bool NextAndGetResult(IterateResult* result) = 0;
+
+  // Prepares the value if its lazily materialized. The implementation can
+  // request that this be called by setting value_prepared to false in
+  // IterateResult. Next() should always implicitly materialize the
+  // value.
+  bool PrepareValue() override = 0;
+
+  // Return the current key's value
+  virtual Slice value() const = 0;
+
+  // Return the current position bounds check result - kInbound if the
+  // position is a valid key, kOutOfBound if the key is out of bound (i.e
+  // scan has terminated), or kUnknown if end of file.
+  virtual IterBoundCheck UpperBoundCheckResult() = 0;
+};
+
 class ExternalTableReader {
  public:
   virtual ~ExternalTableReader() {}
@@ -65,8 +108,9 @@ class ExternalTableReader {
   // Return an Iterator that can be used to scan the table file.
   // The read_options can optionally contain the upper bound
   // key (exclusive) of the scan in iterate_upper_bound.
-  virtual Iterator* NewIterator(const ReadOptions& read_options,
-                                const SliceTransform* prefix_extractor) = 0;
+  virtual ExternalTableIterator* NewIterator(
+      const ReadOptions& read_options,
+      const SliceTransform* prefix_extractor) = 0;
 
   // Point lookup the given key and return its value
   virtual Status Get(const ReadOptions& read_options, const Slice& key,
@@ -153,11 +197,17 @@ class ExternalTableBuilder {
 struct ExternalTableOptions {
   const std::shared_ptr<const SliceTransform>& prefix_extractor;
   const Comparator* comparator;
+  const std::shared_ptr<FileSystem>& fs;
+  const FileOptions& file_options;
 
   ExternalTableOptions(
       const std::shared_ptr<const SliceTransform>& _prefix_extractor,
-      const Comparator* _comparator)
-      : prefix_extractor(_prefix_extractor), comparator(_comparator) {}
+      const Comparator* _comparator, const std::shared_ptr<FileSystem>& _fs,
+      const FileOptions& _file_options)
+      : prefix_extractor(_prefix_extractor),
+        comparator(_comparator),
+        fs(_fs),
+        file_options(_file_options) {}
 };
 
 struct ExternalTableBuilderOptions {
@@ -194,9 +244,11 @@ class ExternalTableFactory : public Customizable {
       const ExternalTableOptions& table_options,
       std::unique_ptr<ExternalTableReader>* table_reader) const = 0;
 
+  // The table builder should use the file pointer to append to the file.
+  // Do not sync or close the file after finishing. RocksDB will do that.
   virtual ExternalTableBuilder* NewTableBuilder(
       const ExternalTableBuilderOptions& builder_options,
-      const std::string& file_path) const = 0;
+      const std::string& file_path, FSWritableFile* file) const = 0;
 };
 
 // Allocate a TableFactory that wraps around an ExternalTableFactory. Use this

include/rocksdb/iterator.h

@@ -21,6 +21,7 @@
 #include <string>
 
 #include "rocksdb/iterator_base.h"
+#include "rocksdb/options.h"
 #include "rocksdb/wide_columns.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -93,6 +94,18 @@ class Iterator : public IteratorBase {
     assert(false);
     return Slice();
   }
+
+  // RocksDB Internal - DO NOT USE
+  // Prepare the iterator to scan the ranges specified in scan_opts. The
+  // upper bound and other table specific limits may be specified. This will
+  // typically be followed by Seeks to the start keys in the order they're
+  // specified in scan_opts. If the user does a Seek to some other target key,
+  // the iterator should disregard the scan_opts from that point onwards and
+  // behave like a normal iterator. Its the user's responsibility to again
+  // call Prepare().
+  // If Prepare() is called, it overrides the iterate_upper_bound in
+  // ReadOptions
+  virtual void Prepare(const std::vector<ScanOptions>& /*scan_opts*/) {}
 };
 
 // Return an empty iterator (yields nothing).

include/rocksdb/multi_scan.h

@@ -0,0 +1,237 @@
+//  Copyright (c) Meta Platforms, Inc. and affiliates.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include "rocksdb/iterator.h"
+#include "rocksdb/options.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// EXPERIMENTAL
+//
+// An iterator that returns results from multiple scan ranges. The ranges are
+// expected to be in increasing sorted order.
+// The results are returned in nested container objects that can be iterated
+// using an std::input_iterator.
+//
+// MultiScan
+//     |
+//     ---
+//       |
+//  MultiScanIterator  <-- std::input_iterator (returns a Scan object for each
+//         |                                    scan range)
+//         ---
+//           |
+//          Scan
+//            |
+//            ---
+//              |
+//          ScanIterator <-- std::input_iterator (returns the KVs of a single
+//                                                scan range)
+//
+// The application on top of RocksDB
+// would use this as follows -
+//
+//  std::vector<ScanOptions> scans{{.start = Slice("bar")},
+//                              {.start = Slice("foo")}};
+//  std::unique_ptr<MultiScan> iter.reset(
+//                                      db->NewMultiScan());
+//  try {
+//    for (auto scan : *iter) {
+//      for (auto it : scan) {
+//        // Do something with key - it.first
+//        // Do something with value - it.second
+//      }
+//    }
+//  } catch (MultiScanException& ex) {
+//    // Check ex.status()
+//  } catch (std::logic_error& ex) {
+//    // Check ex.what()
+//  }
+
+class MultiScanException : public std::runtime_error {
+ public:
+  explicit MultiScanException(Status& s)
+      : std::runtime_error(s.ToString()), s_(s) {}
+
+  Status& status() { return s_; }
+
+ private:
+  Status s_;
+};
+
+// A container object encapsulating a single scan range. It supports an
+// std::input_iterator for a single pass iteration of the KVs in the range.
+// A Status exception is thrown if there is an error in scanning the range.
+class Scan {
+ public:
+  class ScanIterator;
+
+  explicit Scan(Iterator* db_iter) : db_iter_(db_iter) {}
+
+  ScanIterator begin() { return ScanIterator(db_iter_); }
+
+  std::nullptr_t end() { return nullptr; }
+
+  class ScanIterator {
+   public:
+    using self_type = ScanIterator;
+    using value_type = std::pair<Slice, Slice>;
+    using reference = std::pair<Slice, Slice>&;
+    using pointer = std::pair<Slice, Slice>*;
+    using difference_type = int;
+    using iterator_category = std::input_iterator_tag;
+
+    explicit ScanIterator(Iterator* db_iter) : db_iter_(db_iter) {
+      valid_ = db_iter_->Valid();
+      if (valid_) {
+        result_ = value_type(db_iter_->key(), db_iter_->value());
+      }
+    }
+
+    ScanIterator() : db_iter_(nullptr), valid_(false) {}
+
+    ~ScanIterator() { assert(status_.ok()); }
+
+    ScanIterator& operator++() {
+      if (!valid_) {
+        throw std::logic_error("Trying to advance invalid iterator");
+      } else {
+        db_iter_->Next();
+        status_ = db_iter_->status();
+        if (!status_.ok()) {
+          throw MultiScanException(status_);
+        } else {
+          valid_ = db_iter_->Valid();
+          if (valid_) {
+            result_ = value_type(db_iter_->key(), db_iter_->value());
+          }
+        }
+      }
+      return *this;
+    }
+
+    bool operator==(std::nullptr_t /*other*/) const { return !valid_; }
+
+    bool operator!=(std::nullptr_t /*other*/) const { return valid_; }
+
+    reference operator*() {
+      if (!valid_) {
+        throw std::logic_error("Trying to deref invalid iterator");
+      }
+      return result_;
+    }
+    reference operator->() {
+      if (!valid_) {
+        throw std::logic_error("Trying to deref invalid iterator");
+      }
+      return result_;
+    }
+
+   private:
+    Iterator* db_iter_;
+    bool valid_;
+    Status status_;
+    value_type result_;
+  };
+
+ private:
+  Iterator* db_iter_;
+};
+
+// A container object encapsulating the scan ranges for a multi scan.
+// It supports an std::input_iterator for a single pass iteration of the
+// ScanOptions in scan_opts, which can be dereferenced to get the container
+// (Scan) for a single range.
+// A Status exception is thrown if there is an error.
+class MultiScan {
+ public:
+  MultiScan(const std::vector<ScanOptions>& scan_opts,
+            std::unique_ptr<Iterator>&& db_iter)
+      : scan_opts_(scan_opts), db_iter_(std::move(db_iter)) {}
+
+  explicit MultiScan(std::unique_ptr<Iterator>&& db_iter)
+      : db_iter_(std::move(db_iter)) {}
+
+  class MultiScanIterator {
+   public:
+    MultiScanIterator(const MultiScanIterator&) = delete;
+    MultiScanIterator operator=(MultiScanIterator&) = delete;
+
+    using self_type = MultiScanIterator;
+    using value_type = Scan;
+    using reference = Scan&;
+    using pointer = Scan*;
+    using difference_type = int;
+    using iterator_category = std::input_iterator_tag;
+
+    MultiScanIterator(const std::vector<ScanOptions>& scan_opts,
+                      Iterator* db_iter)
+        : scan_opts_(scan_opts), idx_(0), db_iter_(db_iter), scan_(db_iter_) {
+      if (scan_opts_.empty()) {
+        throw std::logic_error("Zero scans in multi-scan");
+      }
+      db_iter_->Seek(*scan_opts_[idx_].range.start);
+      status_ = db_iter_->status();
+      if (!status_.ok()) {
+        throw MultiScanException(status_);
+      }
+    }
+
+    explicit MultiScanIterator(const std::vector<ScanOptions>& scan_opts)
+        : scan_opts_(scan_opts),
+          idx_(scan_opts_.size()),
+          db_iter_(nullptr),
+          scan_(nullptr) {}
+
+    ~MultiScanIterator() { assert(status_.ok()); }
+
+    MultiScanIterator& operator++() {
+      if (idx_ >= scan_opts_.size()) {
+        throw std::logic_error("Index out of range");
+      }
+      idx_++;
+      if (idx_ < scan_opts_.size()) {
+        db_iter_->Seek(*scan_opts_[idx_].range.start);
+        status_ = db_iter_->status();
+        if (!status_.ok()) {
+          throw MultiScanException(status_);
+        }
+      }
+      return *this;
+    }
+
+    bool operator==(std::nullptr_t /*other*/) const {
+      return idx_ >= scan_opts_.size();
+    }
+
+    bool operator!=(std::nullptr_t /*other*/) const {
+      return idx_ < scan_opts_.size();
+    }
+
+    reference operator*() { return scan_; }
+    reference operator->() { return scan_; }
+
+   private:
+    const std::vector<ScanOptions>& scan_opts_;
+    size_t idx_;
+    Iterator* db_iter_;
+    Status status_;
+    Scan scan_;
+  };
+
+  MultiScanIterator begin() {
+    return MultiScanIterator(scan_opts_, db_iter_.get());
+  }
+
+  std::nullptr_t end() { return nullptr; }
+
+ private:
+  const std::vector<ScanOptions> scan_opts_;
+  std::unique_ptr<Iterator> db_iter_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE

include/rocksdb/options.h

@@ -477,12 +477,19 @@ struct CompactionServiceJobInfo {
   bool is_manual_compaction;
   bool bottommost_level;
 
+  // the smallest input level of the compaction.
+  // (same as Compaction::start_level and CompactionJobInfo::base_input_level)
+  int base_input_level;
+  // the output level of the compaction.
+  int output_level;
+
   CompactionServiceJobInfo(std::string db_name_, std::string db_id_,
                            std::string db_session_id_, uint64_t job_id_,
                            Env::Priority priority_,
                            CompactionReason compaction_reason_,
                            bool is_full_compaction_, bool is_manual_compaction_,
-                           bool bottommost_level_)
+                           bool bottommost_level_, int base_input_level_,
+                           int output_level_)
       : db_name(std::move(db_name_)),
         db_id(std::move(db_id_)),
         db_session_id(std::move(db_session_id_)),
@@ -491,7 +498,9 @@ struct CompactionServiceJobInfo {
         compaction_reason(compaction_reason_),
         is_full_compaction(is_full_compaction_),
         is_manual_compaction(is_manual_compaction_),
-        bottommost_level(bottommost_level_) {}
+        bottommost_level(bottommost_level_),
+        base_input_level(base_input_level_),
+        output_level(output_level_) {}
 };
 
 struct CompactionServiceScheduleResponse {
@@ -815,6 +824,7 @@ struct DBOptions {
   // If it is non empty, the log files will be in the specified dir,
   // and the db data dir's absolute path will be used as the log file
   // name's prefix.
+  // NOTE: not for WALs
   std::string db_log_dir = "";
 
   // This specifies the absolute dir path for write-ahead logs (WAL).
@@ -895,21 +905,24 @@ struct DBOptions {
   // be created.
   // If max_log_file_size == 0, all logs will be written to one
   // log file.
+  // NOTE: not for WALs
   size_t max_log_file_size = 0;
 
   // Time for the info log file to roll (in seconds).
   // If specified with non-zero value, log file will be rolled
   // if it has been active longer than `log_file_time_to_roll`.
   // Default: 0 (disabled)
+  // NOTE: not for WALs
   size_t log_file_time_to_roll = 0;
 
   // Maximal info log files to be kept.
   // Default: 1000
+  // NOTE: not for WALs
   size_t keep_log_file_num = 1000;
 
-  // Recycle log files.
-  // If non-zero, we will reuse previously written log files for new
-  // logs, overwriting the old data.  The value indicates how many
+  // Recycle WAL files.
+  // If non-zero, we will reuse previously written WAL files for new
+  // WALs, overwriting the old data.  The value indicates how many
   // such files we will keep around at any point in time for later
   // use.  This is more efficient because the blocks are already
   // allocated and fdatasync does not need to update the inode after
@@ -1297,14 +1310,6 @@ struct DBOptions {
   // currently.
   WalFilter* wal_filter = nullptr;
 
-  // DEPRECATED: This option might be removed in a future release.
-  //
-  // If true, then DB::Open, CreateColumnFamily, DropColumnFamily, and
-  // SetOptions will fail if options file is not properly persisted.
-  //
-  // DEFAULT: true
-  bool fail_if_options_file_error = true;
-
   // If true, then print malloc stats together with rocksdb.stats
   // when printing to LOG.
   // DEFAULT: false
@@ -1423,9 +1428,10 @@ struct DBOptions {
   // prefix_same_as_start=true can take advantage of prefix seek optimizations.
   bool prefix_seek_opt_in_only = false;
 
-  // The number of bytes to prefetch when reading the log. This is mostly useful
-  // for reading a remotely located log, as it can save the number of
-  // round-trips. If 0, then the prefetching is disabled.
+  // The number of bytes to prefetch when reading the DB manifest and WAL files
+  // during DB::Open (and variants). This is mostly useful for reading a
+  // remotely located log, as it can save the number of round-trips. If 0, then
+  // the prefetching is disabled.
   //
   // Default: 0
   size_t log_readahead_size = 0;
@@ -1703,6 +1709,50 @@ enum ReadTier {
   kMemtableTier = 0x3     // data in memtable. used for memtable-only iterators.
 };
 
+// A range of keys. In case of user_defined timestamp, if enabled, `start` and
+// `limit` should point to key without timestamp part.
+struct Range {
+  Slice start;
+  Slice limit;
+
+  Range() {}
+  Range(const Slice& s, const Slice& l) : start(s), limit(l) {}
+};
+
+// A key range with optional endpoints. In case of user_defined timestamp, if
+// enabled, `start` and `limit` should point to key without timestamp part.
+struct RangeOpt {
+  // When start.has_value() == false, refers to starting before every key
+  OptSlice start;
+  // When limit.has_value() == false, refers to ending after every key
+  OptSlice limit;
+
+  RangeOpt() {}
+  RangeOpt(const OptSlice& s, const OptSlice& l) : start(s), limit(l) {}
+};
+
+// EXPERIMENTAL
+//
+// Options for a RocksDB scan request. Only forward scans for now.
+// We may add other options such as prefix scan in the future.
+struct ScanOptions {
+  // The scan range. Mandatory for start to be set, limit is optional
+  RangeOpt range;
+
+  // A map of name,value pairs that can be passed by the user to an
+  // external table reader. This is completely opaque to RocksDB and is
+  // ignored by the natively supported table readers like block based and plain
+  // table. This is only useful for Iterator.
+  std::optional<std::unordered_map<std::string, std::string>> property_bag;
+
+  // An unbounded scan with a start key
+  explicit ScanOptions(const Slice& _start) : range(_start, OptSlice()) {}
+
+  // A bounded scan with a start key and upper bound
+  ScanOptions(const Slice& _start, const Slice& _upper_bound)
+      : range(_start, _upper_bound) {}
+};
+
 // Options that control read operations
 struct ReadOptions {
   // *** BEGIN options relevant to point lookups as well as scans ***
@@ -1784,6 +1834,10 @@ struct ReadOptions {
   // block cache.
   bool fill_cache = true;
 
+  // DEPRECATED: This option might be removed in a future release.
+  // There should be no noticeable performance difference whether this option
+  // is turned on or off when a DB does not use DeleteRange().
+  //
   // If true, range tombstones handling will be skipped in key lookup paths.
   // For DB instances that don't use DeleteRange() calls, this setting can
   // be used to optimize the read performance.
@@ -1996,22 +2050,6 @@ struct ReadOptions {
   // EXPERIMENTAL
   Env::IOActivity io_activity = Env::IOActivity::kUnknown;
 
-  // EXPERIMENTAL
-  // An optional weight of values to be returned by a scan. Once the
-  // weight is reached or exceeded the scan is terminated (i.e Next()
-  // invalidates the iterator). In the case of a DB with one of the built-in
-  // table formats, such as BlockBasedTable, the weight is simply the number
-  // of key-value pairs. In the case of an ExternalTableReader, the weight is
-  // passed through to the table reader and the interpretation is upto the
-  // reader implementation.
-  uint64_t weight = 0;
-
-  // A map of name,value pairs that can be passed by the user to an
-  // external table reader. This is completely opaque to RocksDB and is
-  // ignored by the natively supported table readers like block based and plain
-  // table. This is only useful for Iterator.
-  std::optional<std::unordered_map<std::string, std::string>> property_bag;
-
   // *** END options for RocksDB internal use only ***
 
   ReadOptions() {}
@@ -2245,29 +2283,6 @@ struct CompactRangeOptions {
   double blob_garbage_collection_age_cutoff = -1;
 };
 
-// A range of keys. In case of user_defined timestamp, if enabled, `start` and
-// `limit` should point to key without timestamp part.
-struct Range {
-  Slice start;
-  Slice limit;
-
-  Range() {}
-  Range(const Slice& s, const Slice& l) : start(s), limit(l) {}
-};
-
-// A key range with optional endpoints. In case of user_defined timestamp, if
-// enabled, `start` and `limit` should point to key without timestamp part.
-struct RangeOpt {
-  // When start.has_value() == false, refers to starting before every key
-  OptSlice start;
-  // When limit.has_value() == false, refers to ending after every key
-  OptSlice limit;
-
-  RangeOpt() {}
-  RangeOpt(const OptSlice& s, const OptSlice& l) : start(s), limit(l) {}
-  // RangeOpt(const Slice& s, const Slice& l) : start(s), limit(l) {}
-};
-
 // IngestExternalFileOptions is used by IngestExternalFile()
 struct IngestExternalFileOptions {
   // Can be set to true to move the files instead of copying them.
@@ -2500,10 +2515,16 @@ struct CompactionServiceOptionsOverride {
   // to set it here.
   std::shared_ptr<Statistics> statistics = nullptr;
 
+  // Info Log. If not overriden, default one will be used.
+  std::shared_ptr<Logger> info_log = nullptr;
+
   // Only compaction generated SST files use this user defined table properties
   // collector.
   std::vector<std::shared_ptr<TablePropertiesCollectorFactory>>
       table_properties_collector_factories;
+
+  // All other options to override. Unknown options will be ignored.
+  std::unordered_map<std::string, std::string> options_map;
 };
 
 struct OpenAndCompactOptions {

include/rocksdb/statistics.h

@@ -520,10 +520,11 @@ enum Tickers : uint32_t {
   // Number of bytes prefetched during user initiated scan
   PREFETCH_BYTES,
 
-  // Number of prefetched bytes that were actually useful
+  // Number of prefetched bytes that were actually useful during user initiated
+  // scan
   PREFETCH_BYTES_USEFUL,
 
-  // Number of FS reads avoided due to scan prefetching
+  // Number of FS reads avoided due to prefetching during user initiated scan
   PREFETCH_HITS,
 
   // Footer corruption detected when opening an SST file for reading
@@ -657,13 +658,17 @@ enum Histograms : uint32_t {
   ASYNC_READ_BYTES,
   POLL_WAIT_MICROS,
 
+  // Number of bytes for RocksDB's prefetching (as opposed to file
+  // system's prefetch) on SST file during compaction read
+  COMPACTION_PREFETCH_BYTES,
+
   // Number of prefetched bytes discarded by RocksDB.
   PREFETCHED_BYTES_DISCARDED,
 
   // Wait time for aborting async read in FilePrefetchBuffer destructor
   ASYNC_PREFETCH_ABORT_MICROS,
 
-  // Number of bytes read for RocksDB's prefetching contents (as opposed to file
+  // Number of bytes for RocksDB's prefetching contents (as opposed to file
   // system's prefetch) from the end of SST table during block based table open
   TABLE_OPEN_PREFETCH_TAIL_READ_BYTES,
 

include/rocksdb/utilities/stackable_db.h

@@ -289,6 +289,13 @@ class StackableDB : public DB {
     return db_->NewAttributeGroupIterator(options, column_families);
   }
 
+  using DB::NewMultiScan;
+  std::unique_ptr<MultiScan> NewMultiScan(
+      const ReadOptions& opts, ColumnFamilyHandle* column_family,
+      const std::vector<ScanOptions>& scan_opts) override {
+    return db_->NewMultiScan(opts, column_family, scan_opts);
+  }
+
   const Snapshot* GetSnapshot() override { return db_->GetSnapshot(); }
 
   void ReleaseSnapshot(const Snapshot* snapshot) override {
@@ -505,13 +512,18 @@ class StackableDB : public DB {
     return db_->GetFullHistoryTsLow(column_family, ts_low);
   }
 
+  Status GetNewestUserDefinedTimestamp(ColumnFamilyHandle* column_family,
+                                       std::string* newest_timestamp) override {
+    return db_->GetNewestUserDefinedTimestamp(column_family, newest_timestamp);
+  }
+
   Status GetSortedWalFiles(VectorWalPtr& files) override {
     return db_->GetSortedWalFiles(files);
   }
 
   Status GetCurrentWalFile(
-      std::unique_ptr<WalFile>* current_log_file) override {
-    return db_->GetCurrentWalFile(current_log_file);
+      std::unique_ptr<WalFile>* current_wal_file) override {
+    return db_->GetCurrentWalFile(current_wal_file);
   }
 
   Status GetCreationTimeOfOldestFile(uint64_t* creation_time) override {

include/rocksdb/utilities/transaction_db.h

@@ -24,9 +24,16 @@ class SecondaryIndex;
 class TransactionDBMutexFactory;
 
 enum TxnDBWritePolicy {
-  WRITE_COMMITTED = 0,  // write only the committed data
-  WRITE_PREPARED,       // write data after the prepare phase of 2pc
-  WRITE_UNPREPARED      // write data before the prepare phase of 2pc
+  // Write data at transaction commit time
+  WRITE_COMMITTED = 0,
+
+  // EXPERIMENTAL: The remaining write policies are not as mature, well
+  // validated, nor as compatible with other features as WRITE_COMMITTED.
+
+  // Write data after the prepare phase of 2pc
+  WRITE_PREPARED,
+  // Write data before the prepare phase of 2pc
+  WRITE_UNPREPARED
 };
 
 constexpr uint32_t kInitialMaxDeadlocks = 5;
@@ -361,6 +368,8 @@ struct TransactionOptions {
   // Only supports write-committed policy. If set to true, the transaction will
   // skip memtable write and ingest into the DB directly during Commit(). This
   // makes Commit() much faster for transactions with many operations.
+  // Transaction neeeds to call Prepare() before Commit() for this option to
+  // take effect.
   // Transactions with Merge() or PutEntity() is not supported yet.
   //
   // Note that the transaction will be ingested as an immutable memtable for

include/rocksdb/utilities/write_batch_with_index.h

@@ -90,6 +90,8 @@ class WBWIIterator {
   // Returns n where the current entry is the n-th update to the current key.
   // The update count starts from 1.
   // Only valid if WBWI is created with overwrite_key = true.
+  // With overwrite_key=false, update count for each entry is not maintained,
+  // see UpdateExistingEntryWithCfId().
   virtual uint32_t GetUpdateCount() const { return 0; }
 };
 
@@ -374,9 +376,6 @@ class WriteBatchWithIndex : public WriteBatchBase {
     uint32_t entry_count = 0;
     uint32_t overwritten_sd_count = 0;
   };
-  // Will track CF ID, per CF entry count and overwritten sd count.
-  // Should be enabled when WBWI is empty for correct tracking.
-  void SetTrackPerCFStat(bool track);
   const std::unordered_map<uint32_t, CFStat>& GetCFStats() const;
 
   bool GetOverwriteKey() const;

include/rocksdb/version.h

@@ -13,7 +13,7 @@
 // minor or major version number planned for release.
 #define ROCKSDB_MAJOR 10
 #define ROCKSDB_MINOR 2
-#define ROCKSDB_PATCH 0
+#define ROCKSDB_PATCH 1
 
 // Do not use these. We made the mistake of declaring macros starting with
 // double underscore. Now we have to live with our choice. We'll deprecate these

java/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.4)
+cmake_minimum_required(VERSION 3.11)
 
 set(JAVA_JUNIT_VERSION "4.13.1")
 set(JAVA_HAMCR_VERSION "2.2")

java/rocksjni/options.cc

@@ -2055,29 +2055,6 @@ void Java_org_rocksdb_Options_setWalFilter(JNIEnv*, jclass, jlong jhandle,
   opt->wal_filter = wal_filter;
 }
 
-/*
- * Class:     org_rocksdb_Options
- * Method:    setFailIfOptionsFileError
- * Signature: (JZ)V
- */
-void Java_org_rocksdb_Options_setFailIfOptionsFileError(
-    JNIEnv*, jclass, jlong jhandle, jboolean jfail_if_options_file_error) {
-  auto* opt = reinterpret_cast<ROCKSDB_NAMESPACE::Options*>(jhandle);
-  opt->fail_if_options_file_error =
-      static_cast<bool>(jfail_if_options_file_error);
-}
-
-/*
- * Class:     org_rocksdb_Options
- * Method:    failIfOptionsFileError
- * Signature: (J)Z
- */
-jboolean Java_org_rocksdb_Options_failIfOptionsFileError(JNIEnv*, jclass,
-                                                         jlong jhandle) {
-  auto* opt = reinterpret_cast<ROCKSDB_NAMESPACE::Options*>(jhandle);
-  return static_cast<jboolean>(opt->fail_if_options_file_error);
-}
-
 /*
  * Class:     org_rocksdb_Options
  * Method:    setDumpMallocStats
@@ -2456,28 +2433,6 @@ void Java_org_rocksdb_Options_setMinWriteBufferNumberToMerge(
       ->min_write_buffer_number_to_merge =
       static_cast<int>(jmin_write_buffer_number_to_merge);
 }
-/*
- * Class:     org_rocksdb_Options
- * Method:    maxWriteBufferNumberToMaintain
- * Signature: (J)I
- */
-jint Java_org_rocksdb_Options_maxWriteBufferNumberToMaintain(JNIEnv*, jclass,
-                                                             jlong jhandle) {
-  return reinterpret_cast<ROCKSDB_NAMESPACE::Options*>(jhandle)
-      ->max_write_buffer_number_to_maintain;
-}
-
-/*
- * Class:     org_rocksdb_Options
- * Method:    setMaxWriteBufferNumberToMaintain
- * Signature: (JI)V
- */
-void Java_org_rocksdb_Options_setMaxWriteBufferNumberToMaintain(
-    JNIEnv*, jclass, jlong jhandle, jint jmax_write_buffer_number_to_maintain) {
-  reinterpret_cast<ROCKSDB_NAMESPACE::Options*>(jhandle)
-      ->max_write_buffer_number_to_maintain =
-      static_cast<int>(jmax_write_buffer_number_to_maintain);
-}
 
 /*
  * Class:     org_rocksdb_Options
@@ -4496,29 +4451,6 @@ void Java_org_rocksdb_ColumnFamilyOptions_setMinWriteBufferNumberToMerge(
       static_cast<int>(jmin_write_buffer_number_to_merge);
 }
 
-/*
- * Class:     org_rocksdb_ColumnFamilyOptions
- * Method:    maxWriteBufferNumberToMaintain
- * Signature: (J)I
- */
-jint Java_org_rocksdb_ColumnFamilyOptions_maxWriteBufferNumberToMaintain(
-    JNIEnv*, jclass, jlong jhandle) {
-  return reinterpret_cast<ROCKSDB_NAMESPACE::ColumnFamilyOptions*>(jhandle)
-      ->max_write_buffer_number_to_maintain;
-}
-
-/*
- * Class:     org_rocksdb_ColumnFamilyOptions
- * Method:    setMaxWriteBufferNumberToMaintain
- * Signature: (JI)V
- */
-void Java_org_rocksdb_ColumnFamilyOptions_setMaxWriteBufferNumberToMaintain(
-    JNIEnv*, jclass, jlong jhandle, jint jmax_write_buffer_number_to_maintain) {
-  reinterpret_cast<ROCKSDB_NAMESPACE::ColumnFamilyOptions*>(jhandle)
-      ->max_write_buffer_number_to_maintain =
-      static_cast<int>(jmax_write_buffer_number_to_maintain);
-}
-
 /*
  * Class:     org_rocksdb_ColumnFamilyOptions
  * Method:    setCompressionType
@@ -7524,29 +7456,6 @@ void Java_org_rocksdb_DBOptions_setWalFilter(JNIEnv*, jclass, jlong jhandle,
   opt->wal_filter = wal_filter;
 }
 
-/*
- * Class:     org_rocksdb_DBOptions
- * Method:    setFailIfOptionsFileError
- * Signature: (JZ)V
- */
-void Java_org_rocksdb_DBOptions_setFailIfOptionsFileError(
-    JNIEnv*, jclass, jlong jhandle, jboolean jfail_if_options_file_error) {
-  auto* opt = reinterpret_cast<ROCKSDB_NAMESPACE::DBOptions*>(jhandle);
-  opt->fail_if_options_file_error =
-      static_cast<bool>(jfail_if_options_file_error);
-}
-
-/*
- * Class:     org_rocksdb_DBOptions
- * Method:    failIfOptionsFileError
- * Signature: (J)Z
- */
-jboolean Java_org_rocksdb_DBOptions_failIfOptionsFileError(JNIEnv*, jclass,
-                                                           jlong jhandle) {
-  auto* opt = reinterpret_cast<ROCKSDB_NAMESPACE::DBOptions*>(jhandle);
-  return static_cast<jboolean>(opt->fail_if_options_file_error);
-}
-
 /*
  * Class:     org_rocksdb_DBOptions
  * Method:    setDumpMallocStats

java/rocksjni/portal.h

@@ -5889,8 +5889,11 @@ class HistogramTypeJni {
         return 0x3C;
       case ROCKSDB_NAMESPACE::Histograms::TABLE_OPEN_PREFETCH_TAIL_READ_BYTES:
         return 0x3D;
+      case ROCKSDB_NAMESPACE::Histograms::COMPACTION_PREFETCH_BYTES:
+        return 0x3F;
       case ROCKSDB_NAMESPACE::Histograms::HISTOGRAM_ENUM_MAX:
-        // 0x3D for backwards compatibility on current minor version.
+        // 0x3E is reserved for backwards compatibility on current minor
+        // version.
         return 0x3E;
       default:
         // undefined/default
@@ -6033,8 +6036,11 @@ class HistogramTypeJni {
       case 0x3D:
         return ROCKSDB_NAMESPACE::Histograms::
             TABLE_OPEN_PREFETCH_TAIL_READ_BYTES;
+      case 0x3F:
+        return ROCKSDB_NAMESPACE::Histograms::COMPACTION_PREFETCH_BYTES;
       case 0x3E:
-        // 0x1F for backwards compatibility on current minor version.
+        // 0x3E is reserved for backwards compatibility on current minor
+        // version.
         return ROCKSDB_NAMESPACE::Histograms::HISTOGRAM_ENUM_MAX;
 
       default:

java/src/main/java/org/rocksdb/AdvancedColumnFamilyOptionsInterface.java

@@ -44,53 +44,6 @@ public interface AdvancedColumnFamilyOptionsInterface<
    */
   int minWriteBufferNumberToMerge();
 
-  /**
-   * The total maximum number of write buffers to maintain in memory including
-   * copies of buffers that have already been flushed.  Unlike
-   * {@link AdvancedMutableColumnFamilyOptionsInterface#maxWriteBufferNumber()},
-   * this parameter does not affect flushing.
-   * This controls the minimum amount of write history that will be available
-   * in memory for conflict checking when Transactions are used.
-   * <p>
-   * When using an OptimisticTransactionDB:
-   * If this value is too low, some transactions may fail at commit time due
-   * to not being able to determine whether there were any write conflicts.
-   * <p>
-   * When using a TransactionDB:
-   * If Transaction::SetSnapshot is used, TransactionDB will read either
-   * in-memory write buffers or SST files to do write-conflict checking.
-   * Increasing this value can reduce the number of reads to SST files
-   * done for conflict detection.
-   * <p>
-   * Setting this value to 0 will cause write buffers to be freed immediately
-   * after they are flushed.
-   * If this value is set to -1,
-   * {@link AdvancedMutableColumnFamilyOptionsInterface#maxWriteBufferNumber()}
-   * will be used.
-   * <p>
-   * Default:
-   * If using a TransactionDB/OptimisticTransactionDB, the default value will
-   * be set to the value of
-   * {@link AdvancedMutableColumnFamilyOptionsInterface#maxWriteBufferNumber()}
-   * if it is not explicitly set by the user. Otherwise, the default is 0.
-   *
-   * @param maxWriteBufferNumberToMaintain The maximum number of write
-   *     buffers to maintain
-   *
-   * @return the reference to the current options.
-   */
-  T setMaxWriteBufferNumberToMaintain(
-      int maxWriteBufferNumberToMaintain);
-
-  /**
-   * The total maximum number of write buffers to maintain in memory including
-   * copies of buffers that have already been flushed.
-   *
-   * @return maxWriteBufferNumberToMaintain The maximum number of write buffers
-   *     to maintain
-   */
-  int maxWriteBufferNumberToMaintain();
-
   /**
    * Allows thread-safe inplace updates.
    * If inplace_callback function is not set,

java/src/main/java/org/rocksdb/ColumnFamilyOptions.java

@@ -835,19 +835,6 @@ public class ColumnFamilyOptions
     return paranoidFileChecks(nativeHandle_);
   }
 
-  @Override
-  public ColumnFamilyOptions setMaxWriteBufferNumberToMaintain(
-      final int maxWriteBufferNumberToMaintain) {
-    setMaxWriteBufferNumberToMaintain(
-        nativeHandle_, maxWriteBufferNumberToMaintain);
-    return this;
-  }
-
-  @Override
-  public int maxWriteBufferNumberToMaintain() {
-    return maxWriteBufferNumberToMaintain(nativeHandle_);
-  }
-
   @Override
   public ColumnFamilyOptions setCompactionPriority(
       final CompactionPriority compactionPriority) {
@@ -1467,9 +1454,6 @@ public class ColumnFamilyOptions
   private static native int[] maxBytesForLevelMultiplierAdditional(long handle);
   private static native void setParanoidFileChecks(long handle, boolean paranoidFileChecks);
   private static native boolean paranoidFileChecks(long handle);
-  private static native void setMaxWriteBufferNumberToMaintain(
-      final long handle, final int maxWriteBufferNumberToMaintain);
-  private static native int maxWriteBufferNumberToMaintain(final long handle);
   private static native void setCompactionPriority(
       final long handle, final byte compactionPriority);
   private static native byte compactionPriority(final long handle);

java/src/main/java/org/rocksdb/HistogramType.java

@@ -210,7 +210,9 @@ public enum HistogramType {
    */
   TABLE_OPEN_PREFETCH_TAIL_READ_BYTES((byte) 0x3D),
 
-  // 0x3E for backwards compatibility on current minor version.
+  COMPACTION_PREFETCH_BYTES((byte) 0x3F),
+
+  // 0x3E is reserved for backwards compatibility on current minor version.
   HISTOGRAM_ENUM_MAX((byte) 0x3E);
 
   private final byte value;

java/src/main/java/org/rocksdb/Options.java

@@ -1762,19 +1762,6 @@ public class Options extends RocksObject
     return paranoidFileChecks(nativeHandle_);
   }
 
-  @Override
-  public Options setMaxWriteBufferNumberToMaintain(
-      final int maxWriteBufferNumberToMaintain) {
-    setMaxWriteBufferNumberToMaintain(
-        nativeHandle_, maxWriteBufferNumberToMaintain);
-    return this;
-  }
-
-  @Override
-  public int maxWriteBufferNumberToMaintain() {
-    return maxWriteBufferNumberToMaintain(nativeHandle_);
-  }
-
   @Override
   public Options setCompactionPriority(
       final CompactionPriority compactionPriority) {
@@ -2443,9 +2430,6 @@ public class Options extends RocksObject
   private static native int[] maxBytesForLevelMultiplierAdditional(long handle);
   private static native void setParanoidFileChecks(long handle, boolean paranoidFileChecks);
   private static native boolean paranoidFileChecks(long handle);
-  private static native void setMaxWriteBufferNumberToMaintain(
-      final long handle, final int maxWriteBufferNumberToMaintain);
-  private static native int maxWriteBufferNumberToMaintain(final long handle);
   private static native void setCompactionPriority(
       final long handle, final byte compactionPriority);
   private static native byte compactionPriority(final long handle);

java/src/main/java/org/rocksdb/ReadOptions.java

@@ -398,7 +398,10 @@ public class ReadOptions extends RocksObject {
    * Default: false
    *
    * @return true if keys deleted using the DeleteRange() API will be visible
+   *
+   * @deprecated This option may be remove in a future release.
    */
+  @Deprecated
   public boolean ignoreRangeDeletions() {
     assert(isOwningHandle());
     return ignoreRangeDeletions(nativeHandle_);
@@ -414,7 +417,10 @@ public class ReadOptions extends RocksObject {
    * @param ignoreRangeDeletions true if keys deleted using the DeleteRange()
    *     API should be visible
    * @return the reference to the current ReadOptions.
+   *
+   * @deprecated This option may be remove in a future release.
    */
+  @Deprecated
   public ReadOptions setIgnoreRangeDeletions(final boolean ignoreRangeDeletions) {
     assert(isOwningHandle());
     setIgnoreRangeDeletions(nativeHandle_, ignoreRangeDeletions);

java/src/main/java/org/rocksdb/RocksDB.java

@@ -4126,6 +4126,7 @@ public class RocksDB extends RocksObject {
    *
    * @return the maximum level
    */
+  @Deprecated
   public int maxMemCompactionLevel() {
     return maxMemCompactionLevel(null);
   }
@@ -4633,10 +4634,13 @@ public class RocksDB extends RocksObject {
    * @param targetLevel the target level for L0
    *
    * @throws RocksDBException if an error occurs whilst promoting L0
+   *
+   * @deprecated this API may be removed in a future release.
    */
+  @Deprecated
   public void promoteL0(
-      /* @Nullable */final ColumnFamilyHandle columnFamilyHandle,
-      final int targetLevel) throws RocksDBException {
+      /* @Nullable */ final ColumnFamilyHandle columnFamilyHandle, final int targetLevel)
+      throws RocksDBException {
     promoteL0(nativeHandle_,
         columnFamilyHandle == null ? 0 : columnFamilyHandle.nativeHandle_,
         targetLevel);
@@ -4648,9 +4652,11 @@ public class RocksDB extends RocksObject {
    * @param targetLevel the target level for L0
    *
    * @throws RocksDBException if an error occurs whilst promoting L0
+   *
+   * @deprecated this API may be removed in a future release.
    */
-  public void promoteL0(final int targetLevel)
-      throws RocksDBException {
+  @Deprecated
+  public void promoteL0(final int targetLevel) throws RocksDBException {
     promoteL0(null, targetLevel);
   }
 

java/src/main/java/org/rocksdb/Transaction.java

@@ -203,7 +203,7 @@ public class Transaction extends RocksObject {
    * Status::Busy() may be returned if the transaction could not guarantee
    * that there are no write conflicts. Status::TryAgain() may be returned
    * if the memtable history size is not large enough
-   *  (See max_write_buffer_number_to_maintain).
+   *  (See max_write_buffer_size_to_maintain).
    * <p>
    * If this transaction was created by a {@link TransactionDB},
    * Status::Expired() may be returned if this transaction has lived for
@@ -689,8 +689,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -770,8 +769,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -821,8 +819,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -880,8 +877,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -933,8 +929,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -988,8 +983,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -1050,8 +1044,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -1106,8 +1099,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *     {@link Status.Code#MergeInProgress} if merge operations cannot be
    *     resolved.
    *
@@ -1393,8 +1385,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *
    * @param columnFamilyHandle The column family to put the key/value into
    * @param key the specified key to be inserted.
@@ -1430,8 +1421,7 @@ public class Transaction extends RocksObject {
    *     {@link Status.Code#Busy} if there is a write conflict,
    *     {@link Status.Code#TimedOut} if a lock could not be acquired,
    *     {@link Status.Code#TryAgain} if the memtable history size is not large
-   *         enough. See
-   *         {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *         enough.
    *
    * @param columnFamilyHandle The column family to put the key/value into
    * @param key the specified key to be inserted.
@@ -1460,8 +1450,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param key the specified key to be inserted.
    * @param value the value associated with the specified key.
@@ -1536,8 +1525,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param key the specified key to be inserted.
    * @param value the value associated with the specified key.
@@ -1575,8 +1563,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to put the key/value into
    * @param key the specified key to be inserted.
@@ -1645,8 +1632,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to merge the key/value into
    * @param key the specified key to be merged.
@@ -1683,8 +1669,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to merge the key/value into
    * @param key the specified key to be merged.
@@ -1713,8 +1698,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param key the specified key to be merged.
    * @param value the value associated with the specified key.
@@ -1741,8 +1725,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param key the specified key to be merged.
    * @param value the value associated with the specified key.
@@ -1778,8 +1761,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle in which to apply the merge
    * @param key the specified key to be merged.
@@ -1821,8 +1803,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle in which to apply the merge
    * @param key the specified key to be merged.
@@ -1849,8 +1830,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to delete the key/value from
    * @param key the specified key to be deleted.
@@ -1885,8 +1865,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to delete the key/value from
    * @param key the specified key to be deleted.
@@ -1914,8 +1893,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param key the specified key to be deleted.
    *
@@ -2001,8 +1979,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to delete the key/value from
    * @param key the specified key to be deleted.
@@ -2038,8 +2015,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param columnFamilyHandle The column family to delete the key/value from
    * @param key the specified key to be deleted.
@@ -2068,8 +2044,7 @@ public class Transaction extends RocksObject {
    *    {@link Status.Code#Busy} if there is a write conflict,
    *    {@link Status.Code#TimedOut} if a lock could not be acquired,
    *    {@link Status.Code#TryAgain} if the memtable history size is not large
-   *       enough. See
-   *       {@link ColumnFamilyOptions#maxWriteBufferNumberToMaintain()}
+   *       enough.
    *
    * @param key the specified key to be deleted.
    *

java/src/test/java/org/rocksdb/ColumnFamilyOptionsTest.java

@@ -561,19 +561,6 @@ public class ColumnFamilyOptionsTest {
     }
   }
 
-  @Test
-  public void maxWriteBufferNumberToMaintain() {
-    try (final ColumnFamilyOptions opt = new ColumnFamilyOptions()) {
-      int intValue = rand.nextInt();
-      // Size has to be positive
-      intValue = (intValue < 0) ? -intValue : intValue;
-      intValue = (intValue == 0) ? intValue + 1 : intValue;
-      opt.setMaxWriteBufferNumberToMaintain(intValue);
-      assertThat(opt.maxWriteBufferNumberToMaintain()).
-          isEqualTo(intValue);
-    }
-  }
-
   @Test
   public void compactionPriorities() {
     try (final ColumnFamilyOptions opt = new ColumnFamilyOptions()) {

java/src/test/java/org/rocksdb/DBOptionsTest.java

@@ -656,15 +656,6 @@ public class DBOptionsTest {
     }
   }
 
-  @Test
-  public void failIfOptionsFileError() {
-    try (final DBOptions opt = new DBOptions()) {
-      final boolean boolValue = rand.nextBoolean();
-      opt.setFailIfOptionsFileError(boolValue);
-      assertThat(opt.failIfOptionsFileError()).isEqualTo(boolValue);
-    }
-  }
-
   @Test
   public void dumpMallocStats() {
     try (final DBOptions opt = new DBOptions()) {

java/src/test/java/org/rocksdb/MutableColumnFamilyOptionsTest.java

@@ -96,30 +96,54 @@ public class MutableColumnFamilyOptionsTest {
   public void mutableColumnFamilyOptions_parse_getOptions_output() {
     final String optionsString =
         "bottommost_compression=kDisableCompressionOption;  sample_for_compression=0;  "
-        + "blob_garbage_collection_age_cutoff=0.250000;  blob_garbage_collection_force_threshold=0.800000;"
-        + "arena_block_size=1048576;  enable_blob_garbage_collection=false;  level0_stop_writes_trigger=36;  min_blob_size=65536;"
-        + "blob_compaction_readahead_size=262144;  blob_file_starting_level=5;  prepopulate_blob_cache=kDisable;"
-        + "compaction_options_universal={allow_trivial_move=false;stop_style=kCompactionStopStyleTotalSize;min_merge_width=2;"
-        + "compression_size_percent=-1;max_size_amplification_percent=200;max_merge_width=4294967295;size_ratio=1;};  "
-        + "target_file_size_base=67108864;  max_bytes_for_level_base=268435456;  memtable_whole_key_filtering=false;  "
-        + "soft_pending_compaction_bytes_limit=68719476736;  blob_compression_type=kNoCompression;  max_write_buffer_number=2;  "
-        + "ttl=2592000;  compaction_options_fifo={allow_compaction=false;age_for_warm=0;max_table_files_size=1073741824;};  "
-        + "check_flush_compaction_key_order=true;  max_successive_merges=0;  inplace_update_num_locks=10000;  "
-        + "bottommost_compression_opts={enabled=false;parallel_threads=1;zstd_max_train_bytes=0;max_dict_bytes=0;"
+        + "blob_garbage_collection_age_cutoff=0.250000;  "
+        + "blob_garbage_collection_force_threshold=0.800000;"
+        + "arena_block_size=1048576;  enable_blob_garbage_collection=false;  "
+        + "level0_stop_writes_trigger=36;  min_blob_size=65536;"
+        + "blob_compaction_readahead_size=262144;  blob_file_starting_level=5;  "
+        + "prepopulate_blob_cache=kDisable;"
+        + "compaction_options_universal={allow_trivial_move=false;stop_style="
+        + "kCompactionStopStyleTotalSize;min_merge_width=2;"
+        + "compression_size_percent=-1;max_size_amplification_percent=200;max_merge_width="
+        + "4294967295;size_ratio=1;};  "
+        + "target_file_size_base=67108864;  max_bytes_for_level_base=268435456;  "
+        + "memtable_whole_key_filtering=false;  "
+        + "soft_pending_compaction_bytes_limit=68719476736;  blob_compression_type=kNoCompression; "
+        + " max_write_buffer_number=2;  "
+        + "ttl=2592000;  "
+        + "compaction_options_fifo={allow_compaction=false;age_for_warm=0;max_table_files_size="
+        + "1073741824;};  "
+        + "check_flush_compaction_key_order=true;  max_successive_merges=0;  "
+        + "inplace_update_num_locks=10000;  "
+        + "bottommost_compression_opts={enabled=false;parallel_threads=1;zstd_max_train_bytes=0;"
+        + "max_dict_bytes=0;"
         + "strategy=0;max_dict_buffer_bytes=0;level=32767;window_bits=-14;};  "
-        + "target_file_size_multiplier=1;  max_bytes_for_level_multiplier_additional=5:{7}:{9}:{11}:{13}:{15}:{17};  "
-        + "enable_blob_files=true;  level0_slowdown_writes_trigger=20;  compression=kLZ4HCCompression;  level0_file_num_compaction_trigger=4;  "
-        + "blob_file_size=268435456;  prefix_extractor=nullptr;  max_bytes_for_level_multiplier=10.000000;  write_buffer_size=67108864;  "
-        + "disable_auto_compactions=false;  max_compaction_bytes=1677721600;  memtable_huge_page_size=0;  "
-        + "compression_opts={enabled=false;parallel_threads=1;zstd_max_train_bytes=0;max_dict_bytes=0;strategy=0;max_dict_buffer_bytes=0;"
+        + "target_file_size_multiplier=1;  "
+        + "max_bytes_for_level_multiplier_additional=5:{7}:{9}:{11}:{13}:{15}:{17};  "
+        + "enable_blob_files=true;  level0_slowdown_writes_trigger=20;  "
+        + "compression=kLZ4HCCompression;  level0_file_num_compaction_trigger=4;  "
+        + "blob_file_size=268435456;  prefix_extractor=nullptr;  "
+        + "max_bytes_for_level_multiplier=10.000000;  write_buffer_size=67108864;  "
+        + "disable_auto_compactions=false;  max_compaction_bytes=1677721600;  "
+        + "memtable_huge_page_size=0;  "
+        + "compression_opts={enabled=false;parallel_threads=1;zstd_max_train_bytes=0;max_dict_"
+        + "bytes=0;strategy=0;max_dict_buffer_bytes=0;"
         + "level=32767;window_bits=-14;};  "
-        + "hard_pending_compaction_bytes_limit=274877906944;  periodic_compaction_seconds=0;  paranoid_file_checks=true;  "
-        + "memtable_prefix_bloom_size_ratio=7.500000;  max_sequential_skip_in_iterations=8;  report_bg_io_stats=true;  "
-        + "compaction_pri=kMinOverlappingRatio;  compaction_style=kCompactionStyleLevel;  memtable_factory=SkipListFactory;  "
-        + "comparator=leveldb.BytewiseComparator;  bloom_locality=0;  compaction_filter_factory=nullptr;  "
-        + "min_write_buffer_number_to_merge=1;  max_write_buffer_number_to_maintain=0;  compaction_filter=nullptr;  merge_operator=nullptr;  "
-        + "num_levels=7;  optimize_filters_for_hits=false;  force_consistency_checks=true;  table_factory=BlockBasedTable;  "
-        + "max_write_buffer_size_to_maintain=0;  memtable_insert_with_hint_prefix_extractor=nullptr;  level_compaction_dynamic_level_bytes=false;  "
+        + "hard_pending_compaction_bytes_limit=274877906944;  periodic_compaction_seconds=0;  "
+        + "paranoid_file_checks=true;  "
+        + "memtable_prefix_bloom_size_ratio=7.500000;  max_sequential_skip_in_iterations=8;  "
+        + "report_bg_io_stats=true;  "
+        + "compaction_pri=kMinOverlappingRatio;  compaction_style=kCompactionStyleLevel;  "
+        + "memtable_factory=SkipListFactory;  "
+        + "comparator=leveldb.BytewiseComparator;  bloom_locality=0;  "
+        + "compaction_filter_factory=nullptr;  "
+        + "min_write_buffer_number_to_merge=1;  compaction_filter=nullptr;  "
+        + "merge_operator=nullptr;  "
+        + "num_levels=7;  optimize_filters_for_hits=false;  force_consistency_checks=true;  "
+        + "table_factory=BlockBasedTable;  "
+        + "max_write_buffer_size_to_maintain=0;  "
+        + "memtable_insert_with_hint_prefix_extractor=nullptr;  "
+        + "level_compaction_dynamic_level_bytes=false;  "
         + "inplace_update_support=false;  experimental_mempurge_threshold=0.003";
 
     final MutableColumnFamilyOptions.MutableColumnFamilyOptionsBuilder cf =

java/src/test/java/org/rocksdb/OptionsTest.java

@@ -902,15 +902,6 @@ public class OptionsTest {
     }
   }
 
-  @Test
-  public void failIfOptionsFileError() {
-    try (final Options opt = new Options()) {
-      final boolean boolValue = rand.nextBoolean();
-      opt.setFailIfOptionsFileError(boolValue);
-      assertThat(opt.failIfOptionsFileError()).isEqualTo(boolValue);
-    }
-  }
-
   @Test
   public void dumpMallocStats() {
     try (final Options opt = new Options()) {
@@ -1201,19 +1192,6 @@ public class OptionsTest {
     }
   }
 
-  @Test
-  public void maxWriteBufferNumberToMaintain() {
-    try (final Options options = new Options()) {
-      int intValue = rand.nextInt();
-      // Size has to be positive
-      intValue = (intValue < 0) ? -intValue : intValue;
-      intValue = (intValue == 0) ? intValue + 1 : intValue;
-      options.setMaxWriteBufferNumberToMaintain(intValue);
-      assertThat(options.maxWriteBufferNumberToMaintain()).
-          isEqualTo(intValue);
-    }
-  }
-
   @Test
   public void compactionPriorities() {
     try (final Options options = new Options()) {

java/src/test/java/org/rocksdb/RocksDBTest.java

@@ -1563,16 +1563,6 @@ public class RocksDBTest {
     }
   }
 
-  @Test
-  public void maxMemCompactionLevel() throws RocksDBException {
-    try (final Options options = new Options().setCreateIfMissing(true)) {
-      final String dbPath = dbFolder.getRoot().getAbsolutePath();
-      try (final RocksDB db = RocksDB.open(options, dbPath)) {
-        assertThat(db.maxMemCompactionLevel()).isEqualTo(0);
-      }
-    }
-  }
-
   @Test
   public void level0StopWriteTrigger() throws RocksDBException {
     try (final Options options = new Options().setCreateIfMissing(true)) {

memtable/wbwi_memtable.h

@@ -235,7 +235,7 @@ class WBWIMemTable final : public ReadOnlyMemTable {
   uint64_t num_entries_;
   // WBWI can contains updates to multiple CFs. `cf_id_` determines which CF
   // this memtable is for.
-  uint32_t cf_id_;
+  const uint32_t cf_id_;
 };
 
 class WBWIMemTableIterator final : public InternalIterator {

monitoring/statistics.cc

@@ -336,6 +336,7 @@ const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
      "rocksdb.error.handler.autoresume.retry.count"},
     {ASYNC_READ_BYTES, "rocksdb.async.read.bytes"},
     {POLL_WAIT_MICROS, "rocksdb.poll.wait.micros"},
+    {COMPACTION_PREFETCH_BYTES, "rocksdb.compaction.prefetch.bytes"},
     {PREFETCHED_BYTES_DISCARDED, "rocksdb.prefetched.bytes.discarded"},
     {ASYNC_PREFETCH_ABORT_MICROS, "rocksdb.async.prefetch.abort.micros"},
     {TABLE_OPEN_PREFETCH_TAIL_READ_BYTES,

monitoring/stats_history_test.cc

@@ -616,7 +616,7 @@ TEST_F(StatsHistoryTest, ForceManualFlushStatsCF) {
   // LogNumbers: default: 16, stats: 10, pikachu: 5
   // Since in recovery process, cfd_stats column is created after WAL is
   // created, synced and MANIFEST is persisted, its log number which depends on
-  // logfile_number_ will be different. Since "pikachu" is never flushed, thus
+  // cur_wal_number_ will be different. Since "pikachu" is never flushed, thus
   // its log_number should be the smallest of the three.
   ASSERT_OK(Flush());
   ASSERT_LT(cfd_test->GetLogNumber(), cfd_stats->GetLogNumber());

options/cf_options.cc

@@ -694,7 +694,10 @@ static std::unordered_map<std::string, OptionTypeInfo>
          {offsetof(struct MutableCFOptions, memtable_max_range_deletions),
           OptionType::kUInt32T, OptionVerificationType::kNormal,
           OptionTypeFlags::kMutable}},
-
+        {"memtable_op_scan_flush_trigger",
+         {offsetof(struct MutableCFOptions, memtable_op_scan_flush_trigger),
+          OptionType::kUInt32T, OptionVerificationType::kNormal,
+          OptionTypeFlags::kMutable}},
 };
 
 static std::unordered_map<std::string, OptionTypeInfo>
@@ -749,9 +752,7 @@ static std::unordered_map<std::string, OptionTypeInfo>
          {0, OptionType::kInt, OptionVerificationType::kDeprecated,
           OptionTypeFlags::kNone}},
         {"max_write_buffer_number_to_maintain",
-         {offsetof(struct ImmutableCFOptions,
-                   max_write_buffer_number_to_maintain),
-          OptionType::kInt, OptionVerificationType::kNormal,
+         {0, OptionType::kInt, OptionVerificationType::kDeprecated,
           OptionTypeFlags::kNone, nullptr}},
         {"max_write_buffer_size_to_maintain",
          {offsetof(struct ImmutableCFOptions,
@@ -987,8 +988,6 @@ ImmutableCFOptions::ImmutableCFOptions(const ColumnFamilyOptions& cf_options)
       compaction_filter_factory(cf_options.compaction_filter_factory),
       min_write_buffer_number_to_merge(
           cf_options.min_write_buffer_number_to_merge),
-      max_write_buffer_number_to_maintain(
-          cf_options.max_write_buffer_number_to_maintain),
       max_write_buffer_size_to_maintain(
           cf_options.max_write_buffer_size_to_maintain),
       inplace_update_support(cf_options.inplace_update_support),
@@ -1180,6 +1179,8 @@ void MutableCFOptions::Dump(Logger* log) const {
                  bottommost_file_compaction_delay);
   ROCKS_LOG_INFO(log, "                   uncache_aggressiveness: %" PRIu32,
                  uncache_aggressiveness);
+  ROCKS_LOG_INFO(log, "             memtable_op_scan_flush_trigger: %" PRIu32,
+                 memtable_op_scan_flush_trigger);
 
   // Universal Compaction Options
   ROCKS_LOG_INFO(log, "compaction_options_universal.size_ratio : %d",

options/cf_options.h

@@ -40,8 +40,6 @@ struct ImmutableCFOptions {
 
   int min_write_buffer_number_to_merge;
 
-  int max_write_buffer_number_to_maintain;
-
   int64_t max_write_buffer_size_to_maintain;
 
   bool inplace_update_support;
@@ -175,7 +173,8 @@ struct MutableCFOptions {
         memtable_max_range_deletions(options.memtable_max_range_deletions),
         bottommost_file_compaction_delay(
             options.bottommost_file_compaction_delay),
-        uncache_aggressiveness(options.uncache_aggressiveness) {
+        uncache_aggressiveness(options.uncache_aggressiveness),
+        memtable_op_scan_flush_trigger(options.memtable_op_scan_flush_trigger) {
     RefreshDerivedOptions(options.num_levels, options.compaction_style);
   }
 
@@ -230,7 +229,8 @@ struct MutableCFOptions {
         sample_for_compression(0),
         memtable_max_range_deletions(0),
         bottommost_file_compaction_delay(0),
-        uncache_aggressiveness(0) {}
+        uncache_aggressiveness(0),
+        memtable_op_scan_flush_trigger(0) {}
 
   explicit MutableCFOptions(const Options& options);
 
@@ -338,6 +338,7 @@ struct MutableCFOptions {
   uint32_t memtable_max_range_deletions;
   uint32_t bottommost_file_compaction_delay;
   uint32_t uncache_aggressiveness;
+  uint32_t memtable_op_scan_flush_trigger;
 
   // Derived options
   // Per-level target file size.

options/db_options.cc

@@ -319,8 +319,7 @@ static std::unordered_map<std::string, OptionTypeInfo>
           OptionType::kBoolean, OptionVerificationType::kNormal,
           OptionTypeFlags::kNone}},
         {"fail_if_options_file_error",
-         {offsetof(struct ImmutableDBOptions, fail_if_options_file_error),
-          OptionType::kBoolean, OptionVerificationType::kNormal,
+         {0, OptionType::kBoolean, OptionVerificationType::kDeprecated,
           OptionTypeFlags::kNone}},
         {"enable_pipelined_write",
          {offsetof(struct ImmutableDBOptions, enable_pipelined_write),
@@ -772,7 +771,6 @@ ImmutableDBOptions::ImmutableDBOptions(const DBOptions& options)
       allow_2pc(options.allow_2pc),
       row_cache(options.row_cache),
       wal_filter(options.wal_filter),
-      fail_if_options_file_error(options.fail_if_options_file_error),
       dump_malloc_stats(options.dump_malloc_stats),
       avoid_flush_during_recovery(options.avoid_flush_during_recovery),
       allow_ingest_behind(options.allow_ingest_behind),

options/db_options.h

@@ -77,7 +77,6 @@ struct ImmutableDBOptions {
   bool allow_2pc;
   std::shared_ptr<Cache> row_cache;
   WalFilter* wal_filter;
-  bool fail_if_options_file_error;
   bool dump_malloc_stats;
   bool avoid_flush_during_recovery;
   bool allow_ingest_behind;

options/options.cc

@@ -43,8 +43,6 @@ AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions(const Options& options)
     : max_write_buffer_number(options.max_write_buffer_number),
       min_write_buffer_number_to_merge(
           options.min_write_buffer_number_to_merge),
-      max_write_buffer_number_to_maintain(
-          options.max_write_buffer_number_to_maintain),
       max_write_buffer_size_to_maintain(
           options.max_write_buffer_size_to_maintain),
       inplace_update_support(options.inplace_update_support),
@@ -113,7 +111,8 @@ AdvancedColumnFamilyOptions::AdvancedColumnFamilyOptions(const Options& options)
       blob_file_starting_level(options.blob_file_starting_level),
       blob_cache(options.blob_cache),
       prepopulate_blob_cache(options.prepopulate_blob_cache),
-      persist_user_defined_timestamps(options.persist_user_defined_timestamps) {
+      persist_user_defined_timestamps(options.persist_user_defined_timestamps),
+      memtable_op_scan_flush_trigger(options.memtable_op_scan_flush_trigger) {
   assert(memtable_factory.get() != nullptr);
   if (max_bytes_for_level_multiplier_additional.size() <
       static_cast<unsigned int>(num_levels)) {
@@ -192,8 +191,6 @@ void ColumnFamilyOptions::Dump(Logger* log) const {
   ROCKS_LOG_HEADER(log, "            Options.num_levels: %d", num_levels);
   ROCKS_LOG_HEADER(log, "       Options.min_write_buffer_number_to_merge: %d",
                    min_write_buffer_number_to_merge);
-  ROCKS_LOG_HEADER(log, "    Options.max_write_buffer_number_to_maintain: %d",
-                   max_write_buffer_number_to_maintain);
   ROCKS_LOG_HEADER(log,
                    "    Options.max_write_buffer_size_to_maintain: %" PRIu64,
                    max_write_buffer_size_to_maintain);
@@ -287,6 +284,9 @@ void ColumnFamilyOptions::Dump(Logger* log) const {
   ROCKS_LOG_HEADER(log,
                    "      Options.max_sequential_skip_in_iterations: %" PRIu64,
                    max_sequential_skip_in_iterations);
+  ROCKS_LOG_HEADER(
+      log, "           Options.memtable_op_scan_flush_trigger: %" PRIu32,
+      memtable_op_scan_flush_trigger);
   ROCKS_LOG_HEADER(log,
                    "                   Options.max_compaction_bytes: %" PRIu64,
                    max_compaction_bytes);

options/options_helper.cc

@@ -153,8 +153,6 @@ void BuildDBOptions(const ImmutableDBOptions& immutable_db_options,
   options.allow_2pc = immutable_db_options.allow_2pc;
   options.row_cache = immutable_db_options.row_cache;
   options.wal_filter = immutable_db_options.wal_filter;
-  options.fail_if_options_file_error =
-      immutable_db_options.fail_if_options_file_error;
   options.dump_malloc_stats = immutable_db_options.dump_malloc_stats;
   options.avoid_flush_during_recovery =
       immutable_db_options.avoid_flush_during_recovery;
@@ -301,6 +299,8 @@ void UpdateColumnFamilyOptions(const MutableCFOptions& moptions,
   cf_opts->default_write_temperature = moptions.default_write_temperature;
   cf_opts->memtable_max_range_deletions = moptions.memtable_max_range_deletions;
   cf_opts->uncache_aggressiveness = moptions.uncache_aggressiveness;
+  cf_opts->memtable_op_scan_flush_trigger =
+      moptions.memtable_op_scan_flush_trigger;
 }
 
 void UpdateColumnFamilyOptions(const ImmutableCFOptions& ioptions,
@@ -313,8 +313,6 @@ void UpdateColumnFamilyOptions(const ImmutableCFOptions& ioptions,
   cf_opts->compaction_filter_factory = ioptions.compaction_filter_factory;
   cf_opts->min_write_buffer_number_to_merge =
       ioptions.min_write_buffer_number_to_merge;
-  cf_opts->max_write_buffer_number_to_maintain =
-      ioptions.max_write_buffer_number_to_maintain;
   cf_opts->max_write_buffer_size_to_maintain =
       ioptions.max_write_buffer_size_to_maintain;
   cf_opts->inplace_update_support = ioptions.inplace_update_support;