update deb pkg references and changelog

Replace mention of scratch-file-path with db-s3-object

.github/workflows/ci.yml

@@ -5,17 +5,14 @@ on: [push, pull_request]
 jobs:
 
   test-ubuntu-latest:
-    runs-on: self-hosted
+    runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
-      with:
-        submodules: true
+    - uses: actions/checkout@v2
     - name: make
       run: |
           sudo apt-get update
-          sudo apt-get -y remove libzstd || true
-          sudo apt-get -y install uuid-dev libcurl4-openssl-dev libbz2-dev zlib1g-dev libsnappy-dev liblz4-dev libzstd-dev libgflags-dev
-          make BUILD_TLS=yes -j2 KEYDB_CFLAGS='-Werror' KEYDB_CXXFLAGS='-Werror'
+          sudo apt-get -y install uuid-dev libcurl4-openssl-dev
+          make KEYDB_CFLAGS='-Werror' KEYDB_CXXFLAGS='-Werror' BUILD_TLS=yes -j2
     - name: gen-cert
       run: ./utils/gen-test-certs.sh
     - name: test-tls
@@ -31,9 +28,6 @@ jobs:
     - name: module tests
       run: |
           ./runtest-moduleapi
-    - name: rotation test
-      run: |
-          ./runtest-rotation
         
   build-ubuntu-old:
     runs-on: ubuntu-18.04
@@ -44,7 +38,6 @@ jobs:
         sudo apt-get update
         sudo apt-get -y install uuid-dev libcurl4-openssl-dev
         make -j2
-
   build-macos-latest:
     runs-on: macos-latest
     steps:
@@ -56,4 +49,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: make
+    - name: make
+      run: |
+          sudo apt-get update
+          sudo apt-get -y install uuid-dev libcurl4-openssl-dev
+          make KEYDB_CFLAGS='-Werror' KEYDB_CXXFLAGS='-Werror' MALLOC=libc -j2
+  build-ubuntu-32bit:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: make
+      run: |
+          sudo dpkg --add-architecture i386
+          sudo apt-get update
+          sudo apt-get -y install gcc-multilib g++-multilib libc6-dev-i386 lib32z1 uuid-dev:i386 libcurl4-openssl-dev:i386
+          make KEYDB_CFLAGS='-Werror' KEYDB_CXXFLAGS='-Werror' 32bit -j2

COPYING

@@ -1,12 +1,7 @@
-Code in this repository is non-free.  Portions of this code include or 
-are derivate works of code published under the BSD 3-clause license.  The
-license below applies ONLY TO THOSE PORTIONS.  Code authored by employees 
-or contractors of EQ Alpha Technology are not licensed for use without express
-written permission of EQ Alpha Technology.  All rights are reserved.
-
 Copyright (c) 2006-2020, Salvatore Sanfilippo
 Copyright (C) 2019-2021, John Sully
 Copyright (C) 2020-2021, EQ Alpha Technology Ltd.
+Copyright (C) 2022 Snap Inc.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

README.md

@@ -99,7 +99,7 @@ Avoid forwarding RREPLAY messages to other masters? WARNING: This setting is dan
 
 
 ```
-    scratch-file-path /path
+    db-s3-object /path/to/bucket
 ```
 If you would like KeyDB to dump and load directly to AWS S3 this option specifies the bucket.  Using this option with the traditional RDB options will result in KeyDB backing up twice to both locations.  If both are specified KeyDB will first attempt to load from the local dump file and if that fails load from S3.  This requires the AWS CLI tools to be installed and configured which are used under the hood to transfer the data.
 

pkg/deb/deb-buildsource.sh

@@ -23,8 +23,8 @@ pkg_name=keydb-$majorv:$version$distname
 
 # create build tree
 cd ../../../
-tar -czvf keydb_$version.orig.tar.gz --force-local keydb-internal
-cd keydb-internal/pkg/deb/
+tar -czvf keydb_$version.orig.tar.gz --force-local KeyDB
+cd KeyDB/pkg/deb/
 mkdir -p $pkg_name/tmp
 if [[ "$codename" == "xenial" ]] || [[ "$codename" == "stretch" ]]; then
 	cp -r debian_dh9 $pkg_name/tmp/debian

pkg/deb/debian/control

@@ -26,8 +26,8 @@ Build-Depends:
  libzstd-dev <!nocheck>
 Standards-Version: 4.2.1
 Homepage: https://docs.keydb.dev/
-Vcs-Git: https://github.com/EQ-Alpha/KeyDB.git
-Vcs-Browser: https://github.com/EQ-Alpha/KeyDB
+Vcs-Git: https://github.com/Snapchat/KeyDB.git
+Vcs-Browser: https://github.com/Snapchat/KeyDB
 
 Package: keydb
 Architecture: all

pkg/deb/debian_dh9/control

@@ -25,8 +25,8 @@ Build-Depends:
  libzstd-dev <!nocheck>
 Standards-Version: 4.2.1
 Homepage: https://docs.keydb.dev/
-Vcs-Git: https://github.com/EQ-Alpha/KeyDB.git
-Vcs-Browser: https://github.com/EQ-Alpha/KeyDB
+Vcs-Git: https://github.com/Snapchat/KeyDB.git
+Vcs-Browser: https://github.com/Snapchat/KeyDB
 
 Package: keydb
 Architecture: all

pkg/deb/master_changelog

@@ -1,3 +1,25 @@
+keydb (6:6.3.1-1distribution_placeholder) codename_placeholder; urgency=medium
+
+  * This point release contains fixes to bugs related to expires, active-rep, and rdb saving
+  * Issues fixed: #419, #422, #428
+  * PRs: #426, #429, #431, #433
+
+-- Ben Schermel <ben@eqalpha.com>  Mon, 23 May 2022 20:00:37 +0000
+
+keydb (6:6.3.0-1distribution_placeholder) codename_placeholder; urgency=medium
+
+  * This release open sources KeyDB Enterprise features into the open source project along with PSYNC for active replication
+  * Partial synchronization for active replication is introduced
+  * MVCC introduced into codebase from KeyDB Enterprise
+  * Async commands added: GET, MGET. These will see perf improvements
+  * KEYS and SCAN commands will no longer be blocking calls
+  * Async Rehash implemented for additional stability to perf
+  * IStorage interface added
+  * In-process background saving (forkless) to comply with maxmemory setting
+  * See v6.3.0 tagged release notes on github for a detailed explanation of these changes
+
+-- Ben Schermel <ben@eqalpha.com>  Wed, 11 May 2022 20:00:37 +0000
+
 keydb (6:6.2.2-1distribution_placeholder) codename_placeholder; urgency=medium
 
   * Acquire lock in module.cpp to fix module test break

pkg/docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM ubuntu:18.04
 SHELL ["/bin/bash","-c"]
 RUN groupadd -r keydb && useradd -r -g keydb keydb
 # use gosu for easy step-down from root: https://github.com/tianon/gosu/releases
@@ -77,7 +77,7 @@ RUN \
         mkdir /data && chown keydb:keydb /data; \
         mkdir /flash && chown keydb:keydb /flash; \
         mkdir -p /etc/keydb; \
-        cp /tmp/keydb-internal/keydb.conf /etc/keydb/; \
+        cp /tmp/KeyDB/keydb.conf /etc/keydb/; \
         sed -i 's/^\(daemonize .*\)$/# \1/' /etc/keydb/keydb.conf; \
         sed -i 's/^\(dir .*\)$/# \1\ndir \/data/' /etc/keydb/keydb.conf; \
         sed -i 's/^\(logfile .*\)$/# \1/' /etc/keydb/keydb.conf; \
@@ -110,8 +110,3 @@ ENV KEYDB_PRO_DIRECTORY=/usr/local/bin/
 ENTRYPOINT ["docker-entrypoint.sh"]
 EXPOSE 6379
 CMD ["keydb-server","/etc/keydb/keydb.conf"]
-
-
-
-
-

pkg/docker/Dockerfile_Alpine

@@ -0,0 +1,77 @@
+FROM alpine:3.12
+# add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added
+RUN addgroup -S -g 1000 keydb && adduser -S -G keydb -u 999 keydb
+RUN mkdir -p /etc/keydb
+ARG BRANCH
+RUN set -eux; \
+        \
+        apk add --no-cache su-exec; \
+        apk add --no-cache --virtual .build-deps \
+                coreutils \
+                gcc \
+                linux-headers \
+                make \
+                musl-dev \
+                openssl-dev \
+                git \
+                util-linux-dev \
+                curl-dev \
+                g++ \
+                libunwind-dev \
+                bash \
+                perl \
+                git \
+        ; \
+        cd /tmp && git clone --branch $BRANCH https://github.com/Snapchat/KeyDB.git --recursive; \
+        cd /tmp/KeyDB; \
+        # disable protected mode as it relates to docker
+        grep -E '^ *createBoolConfig[(]"protected-mode",.*, *1 *,.*[)],$' ./src/config.cpp; \
+        sed -ri 's!^( *createBoolConfig[(]"protected-mode",.*, *)1( *,.*[)],)$!\10\2!' ./src/config.cpp; \
+        grep -E '^ *createBoolConfig[(]"protected-mode",.*, *0 *,.*[)],$' ./src/config.cpp; \
+        make -j$(nproc) BUILD_TLS=yes; \
+        cd src; \
+        strip keydb-cli keydb-benchmark keydb-check-rdb keydb-check-aof keydb-diagnostic-tool keydb-sentinel keydb-server; \
+        mv keydb-server keydb-cli keydb-benchmark keydb-check-rdb keydb-check-aof keydb-diagnostic-tool keydb-sentinel /usr/local/bin/; \
+        runDeps="$( \
+                scanelf --needed --nobanner --format '%n#p' --recursive /usr/local \
+                        | tr ',' '\n' \
+                        | sort -u \
+                        | awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
+        )"; \
+        apk add --no-network --virtual .keydb-rundeps $runDeps; \
+        apk del --no-network .build-deps; \
+        # create working directories and organize files
+        mkdir /data && chown keydb:keydb /data; \
+        mkdir /flash && chown keydb:keydb /flash; \
+        mkdir -p /etc/keydb; \
+        cp /tmp/KeyDB/keydb.conf /etc/keydb/; \
+        sed -i 's/^\(daemonize .*\)$/# \1/' /etc/keydb/keydb.conf; \
+        sed -i 's/^\(dir .*\)$/# \1\ndir \/data/' /etc/keydb/keydb.conf; \
+        sed -i 's/^\(logfile .*\)$/# \1/' /etc/keydb/keydb.conf; \
+        sed -i 's/protected-mode yes/protected-mode no/g' /etc/keydb/keydb.conf; \
+        sed -i 's/^\(bind .*\)$/# \1/' /etc/keydb/keydb.conf; \
+        ln -s keydb-cli redis-cli; \
+        cd /etc/keydb; \
+        ln -s keydb.conf redis.conf; \
+        rm -rf /tmp/*
+# generate entrypoint script
+RUN set -eux; \
+        echo '#!/bin/sh' > /usr/local/bin/docker-entrypoint.sh; \
+        echo 'set -e' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo "# first arg is '-f' or '--some-option'" >> /usr/local/bin/docker-entrypoint.sh; \
+        echo "# or first arg is `something.conf`" >> /usr/local/bin/docker-entrypoint.sh; \
+        echo 'if [ "${1#-}" != "$1" ] || [ "${1%.conf}" != "$1" ]; then' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo '        set -- keydb-server "$@"' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo 'fi' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo "# allow the container to be started with `--user`" >> /usr/local/bin/docker-entrypoint.sh; \
+        echo 'if [ "$1" = "keydb-server" -a "$(id -u)" = "0" ]; then' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo "        find . \! -user keydb -exec chown keydb '{}' +" >> /usr/local/bin/docker-entrypoint.sh; \
+        echo '        exec su-exec keydb "$0" "$@"' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo 'fi' >> /usr/local/bin/docker-entrypoint.sh; \
+        echo 'exec "$@"' >> /usr/local/bin/docker-entrypoint.sh; \
+        chmod +x /usr/local/bin/docker-entrypoint.sh
+VOLUME /data
+WORKDIR /data
+ENTRYPOINT ["docker-entrypoint.sh"]
+EXPOSE 6379
+CMD ["keydb-server", "/etc/keydb/keydb.conf"]

src/config.cpp

@@ -2782,7 +2782,7 @@ standardConfig configs[] = {
     createBoolConfig("disable-thp", NULL, MODIFIABLE_CONFIG, g_pserver->disable_thp, 1, NULL, NULL),
     createBoolConfig("cluster-allow-replica-migration", NULL, MODIFIABLE_CONFIG, g_pserver->cluster_allow_replica_migration, 1, NULL, NULL),
     createBoolConfig("replica-announced", NULL, MODIFIABLE_CONFIG, g_pserver->replica_announced, 1, NULL, NULL),
-    createBoolConfig("enable-async-commands", NULL, MODIFIABLE_CONFIG, g_pserver->enable_async_commands, 1, NULL, NULL),
+    createBoolConfig("enable-async-commands", NULL, MODIFIABLE_CONFIG, g_pserver->enable_async_commands, 0, NULL, NULL),
     createBoolConfig("multithread-load-enabled", NULL, MODIFIABLE_CONFIG, g_pserver->multithread_load_enabled, 0, NULL, NULL),
     createBoolConfig("active-client-balancing", NULL, MODIFIABLE_CONFIG, g_pserver->active_client_balancing, 1, NULL, NULL),
 

src/db.cpp

@@ -2669,6 +2669,11 @@ void redisDbPersistentData::prepOverwriteForSnapshot(char *key)
         auto itr = m_pdbSnapshot->find_cached_threadsafe(key);
         if (itr.key() != nullptr)
         {
+            if (itr.val()->FExpires()) {
+                // Note: I'm sure we could handle this, but its too risky at the moment.
+                //  There are known bugs doing this with expires
+                return;
+            }
             sds keyNew = sdsdupshared(itr.key());
             if (dictAdd(m_pdictTombstone, keyNew, (void*)dictHashKey(m_pdict, key)) != DICT_OK)
                 sdsfree(keyNew);
@@ -3263,10 +3268,11 @@ bool redisDbPersistentData::prefetchKeysAsync(client *c, parsed_command &command
                     dictEntry **table;
                     __atomic_load(&c->db->m_pdict->ht[iht].table, &table, __ATOMIC_RELAXED);
                     if (table != nullptr) {
-                        dictEntry *de = table[hT];
+                        dictEntry *de;
+                        __atomic_load(&table[hT], &de, __ATOMIC_ACQUIRE);
                         while (de != nullptr) {
                             _mm_prefetch(dictGetKey(de), _MM_HINT_T2);
-                            de = de->next;
+                            __atomic_load(&de->next, &de, __ATOMIC_ACQUIRE);
                         }
                     }
                     if (!dictIsRehashing(c->db->m_pdict))

src/dict.cpp

@@ -128,6 +128,7 @@ int _dictInit(dict *d, dictType *type,
     d->pauserehash = 0;
     d->asyncdata = nullptr;
     d->refcount = 1;
+    d->noshrink = false;
     return DICT_OK;
 }
 
@@ -204,7 +205,7 @@ int dictMerge(dict *dst, dict *src)
     
     if (dictSize(dst) == 0)
     {
-        std::swap(*dst, *src);
+        dict::swap(*dst, *src);
         std::swap(dst->pauserehash, src->pauserehash);
         return DICT_OK;
     }
@@ -212,7 +213,7 @@ int dictMerge(dict *dst, dict *src)
     size_t expectedSize = dictSize(src) + dictSize(dst);
     if (dictSize(src) > dictSize(dst) && src->asyncdata == nullptr && dst->asyncdata == nullptr)
     {
-        std::swap(*dst, *src);
+        dict::swap(*dst, *src);
         std::swap(dst->pauserehash, src->pauserehash);
     }
 
@@ -402,7 +403,7 @@ int dictRehash(dict *d, int n) {
 
 dictAsyncRehashCtl::dictAsyncRehashCtl(struct dict *d, dictAsyncRehashCtl *next) : dict(d), next(next) {
     queue.reserve(c_targetQueueSize);
-    __atomic_fetch_add(&d->refcount, 1, __ATOMIC_RELEASE);
+    __atomic_fetch_add(&d->refcount, 1, __ATOMIC_ACQ_REL);
     this->rehashIdxBase = d->rehashidx;
 }
 
@@ -446,6 +447,9 @@ LDone:
 }
 
 void dictRehashAsync(dictAsyncRehashCtl *ctl) {
+    if (ctl->abondon.load(std::memory_order_acquire)) {
+        ctl->hashIdx = ctl->queue.size();
+    }
     for (size_t idx = ctl->hashIdx; idx < ctl->queue.size(); ++idx) {
         auto &wi = ctl->queue[idx];
         wi.hash = dictHashKey(ctl->dict, dictGetKey(wi.de));
@@ -455,6 +459,9 @@ void dictRehashAsync(dictAsyncRehashCtl *ctl) {
 }
 
 bool dictRehashSomeAsync(dictAsyncRehashCtl *ctl, size_t hashes) {
+    if (ctl->abondon.load(std::memory_order_acquire)) {
+        ctl->hashIdx = ctl->queue.size();
+    }
     size_t max = std::min(ctl->hashIdx + hashes, ctl->queue.size());
     for (; ctl->hashIdx < max; ++ctl->hashIdx) {
         auto &wi = ctl->queue[ctl->hashIdx];
@@ -465,6 +472,23 @@ bool dictRehashSomeAsync(dictAsyncRehashCtl *ctl, size_t hashes) {
     return ctl->hashIdx < ctl->queue.size();
 }
 
+
+void discontinueAsyncRehash(dict *d) {
+    // We inform our async rehashers and the completion function the results are to be
+    //  abandoned.  We keep the asyncdata linked in so that dictEntry's are still added
+    //  to the GC list.  This is because we can't gurantee when the other threads will
+    //  stop looking at them.
+    if (d->asyncdata != nullptr) {
+        auto adata = d->asyncdata;
+        while (adata != nullptr && !adata->abondon.load(std::memory_order_relaxed)) {
+            adata->abondon = true;
+            adata = adata->next;
+        }
+        if (dictIsRehashing(d))
+            d->rehashidx = 0;
+    }
+}
+
 void dictCompleteRehashAsync(dictAsyncRehashCtl *ctl, bool fFree) {
     dict *d = ctl->dict;
     assert(ctl->done);
@@ -786,6 +810,8 @@ int _dictClear(dict *d, dictht *ht, void(callback)(void *)) {
         if (callback && (i & 65535) == 0) callback(d->privdata);
 
         if ((he = ht->table[i]) == NULL) continue;
+        dictEntry *deNull = nullptr;
+        __atomic_store(&ht->table[i], &deNull, __ATOMIC_RELEASE);
         while(he) {
             nextHe = he->next;
             if (d->asyncdata && (ssize_t)i < d->rehashidx) {

src/dict.h

@@ -110,12 +110,16 @@ struct dictAsyncRehashCtl {
     std::atomic<bool> abondon { false };
 
     dictAsyncRehashCtl(struct dict *d, dictAsyncRehashCtl *next);
+    dictAsyncRehashCtl(const dictAsyncRehashCtl&) = delete;
+    dictAsyncRehashCtl(dictAsyncRehashCtl&&) = delete;
     ~dictAsyncRehashCtl();
 };
 #else
 struct  dictAsyncRehashCtl;
 #endif
 
+void discontinueAsyncRehash(dict *d);
+
 typedef struct dict {
     dictType *type;
     void *privdata;
@@ -125,6 +129,24 @@ typedef struct dict {
     dictAsyncRehashCtl *asyncdata;
     int16_t pauserehash; /* If >0 rehashing is paused (<0 indicates coding error) */
     uint8_t noshrink = false;
+
+#ifdef __cplusplus
+    dict() = default;
+    dict(dict &) = delete;  // No Copy Ctor
+
+    static void swap(dict& a, dict& b) {
+        discontinueAsyncRehash(&a);
+        discontinueAsyncRehash(&b);
+        std::swap(a.type, b.type);
+        std::swap(a.privdata, b.privdata);
+        std::swap(a.ht[0], b.ht[0]);
+        std::swap(a.ht[1], b.ht[1]);
+        std::swap(a.rehashidx, b.rehashidx);
+        // Never swap refcount - they are attached to the specific dict obj
+        std::swap(a.pauserehash, b.pauserehash);
+        std::swap(a.noshrink, b.noshrink);
+    }
+#endif
 } dict;
 
 /* If safe is set to 1 this is a safe iterator, that means, you can call

src/gc.h

@@ -2,6 +2,7 @@
 #include <vector>
 #include <assert.h>
 #include <unordered_set>
+#include <list>
 
 struct ICollectable
 {
@@ -45,14 +46,14 @@ public:
     void shutdown()
     {
         std::unique_lock<fastlock> lock(m_lock);
-        m_vecepochs.clear();
+        m_listepochs.clear();
         m_setepochOutstanding.clear();
     }
 
     bool empty() const
     {
         std::unique_lock<fastlock> lock(m_lock);
-        return m_vecepochs.empty();
+        return m_listepochs.empty();
     }
 
     void endEpoch(uint64_t epoch, bool fNoFree = false)
@@ -63,12 +64,12 @@ public:
         m_setepochOutstanding.erase(epoch);
         if (fNoFree)
             return;
-        std::vector<EpochHolder> vecclean;
+        std::list<EpochHolder> listclean;
         
         // No outstanding epochs?
         if (m_setepochOutstanding.empty())
         {
-            vecclean = std::move(m_vecepochs);  // Everything goes!
+            listclean = std::move(m_listepochs);  // Everything goes!
         }
         else
         {
@@ -77,18 +78,20 @@ public:
                 return; // No available epochs to free
 
             // Clean any epochs available (after the lock)
-            for (size_t iepoch = 0; iepoch < m_vecepochs.size(); ++iepoch)
+            for (auto itr = m_listepochs.begin(); itr != m_listepochs.end(); /* itr incremented in loop*/)
             {
-                auto &e = m_vecepochs[iepoch];
+                auto &e = *itr;
+                auto itrNext = itr;
+                ++itrNext;
                 if (e < minepoch)
                 {
-                    vecclean.emplace_back(std::move(e));
-                    m_vecepochs.erase(m_vecepochs.begin() + iepoch);
-                    --iepoch;
+                    listclean.emplace_back(std::move(e));
+                    m_listepochs.erase(itr);
                 }
+                itr = itrNext;
             }
 
-            assert(vecclean.empty() || fMinElement);
+            assert(listclean.empty() || fMinElement);
         }
 
         lock.unlock();  // don't hold it for the potentially long delete of vecclean
@@ -100,13 +103,13 @@ public:
         serverAssert(m_setepochOutstanding.find(epoch) != m_setepochOutstanding.end());
         serverAssert(sp->FWillFreeChildDebug() == false);
 
-        auto itr = std::find(m_vecepochs.begin(), m_vecepochs.end(), m_epochNext+1);
-        if (itr == m_vecepochs.end())
+        auto itr = std::find(m_listepochs.begin(), m_listepochs.end(), m_epochNext+1);
+        if (itr == m_listepochs.end())
         {
             EpochHolder e;
             e.tstamp = m_epochNext+1;
             e.m_vecObjs.push_back(std::move(sp));
-            m_vecepochs.emplace_back(std::move(e));
+            m_listepochs.emplace_back(std::move(e));
         }
         else
         {
@@ -117,7 +120,7 @@ public:
 private:
     mutable fastlock m_lock { "Garbage Collector"};
 
-    std::vector<EpochHolder> m_vecepochs;
+    std::list<EpochHolder> m_listepochs;
     std::unordered_set<uint64_t> m_setepochOutstanding;
     uint64_t m_epochNext = 0;
 };

src/networking.cpp

@@ -1810,6 +1810,8 @@ int writeToClient(client *c, int handler_installed) {
        is a replica, so only attempt to do so if that's the case. */
     if (c->flags & CLIENT_SLAVE && !(c->flags & CLIENT_MONITOR) && c->replstate == SLAVE_STATE_ONLINE) {
         std::unique_lock<fastlock> repl_backlog_lock (g_pserver->repl_backlog_lock);
+        // Ensure all writes to the repl backlog are visible
+        std::atomic_thread_fence(std::memory_order_acquire);
 
         while (clientHasPendingReplies(c)) {
             long long repl_end_idx = getReplIndexFromOffset(c->repl_end_off);
@@ -2077,8 +2079,6 @@ int handleClientsWithPendingWrites(int iel, int aof_state) {
         * that may trigger write error or recreate handler. */
         if ((flags & CLIENT_PROTECTED) && !(flags & CLIENT_SLAVE)) continue;
 
-        //std::unique_lock<decltype(c->lock)> lock(c->lock);
-
         /* Don't write to clients that are going to be closed anyway. */
         if (c->flags & CLIENT_CLOSE_ASAP) continue;
 
@@ -2096,6 +2096,7 @@ int handleClientsWithPendingWrites(int iel, int aof_state) {
 
         /* If after the synchronous writes above we still have data to
         * output to the client, we need to install the writable handler. */
+        std::unique_lock<decltype(c->lock)> lock(c->lock);
         if (clientHasPendingReplies(c)) {
             if (connSetWriteHandlerWithBarrier(c->conn, sendReplyToClient, ae_flags, true) == C_ERR) {
                 freeClientAsync(c);
@@ -2742,9 +2743,10 @@ void readQueryFromClient(connection *conn) {
         parseClientCommandBuffer(c);
         if (g_pserver->enable_async_commands && !serverTL->disable_async_commands && listLength(g_pserver->monitors) == 0 && (aeLockContention() || serverTL->rgdbSnapshot[c->db->id] || g_fTestMode)) {
             // Frequent writers aren't good candidates for this optimization, they cause us to renew the snapshot too often
-            //  so we exclude them unless the snapshot we need already exists
+            //  so we exclude them unless the snapshot we need already exists.
+            // Note: In test mode we want to create snapshots as often as possibl to excercise them - we don't care about perf
             bool fSnapshotExists = c->db->mvccLastSnapshot >= c->mvccCheckpoint;
-            bool fWriteTooRecent = (((getMvccTstamp() - c->mvccCheckpoint) >> MVCC_MS_SHIFT) < static_cast<uint64_t>(g_pserver->snapshot_slip)/2);
+            bool fWriteTooRecent = !g_fTestMode && (((getMvccTstamp() - c->mvccCheckpoint) >> MVCC_MS_SHIFT) < static_cast<uint64_t>(g_pserver->snapshot_slip)/2);
 
             // The check below avoids running async commands if this is a frequent writer unless a snapshot is already there to service it
             if (!fWriteTooRecent || fSnapshotExists) {

src/rdb.cpp

@@ -1657,13 +1657,18 @@ int launchRdbSaveThread(pthread_t &child, rdbSaveInfo *rsi)
 
         g_pserver->rdbThreadVars.tmpfileNum++;
         g_pserver->rdbThreadVars.fRdbThreadCancel = false;
-        if (pthread_create(&child, NULL, rdbSaveThread, args)) {
+        pthread_attr_t tattr;
+        pthread_attr_init(&tattr);
+        pthread_attr_setstacksize(&tattr, 1 << 23); // 8 MB
+        if (pthread_create(&child, &tattr, rdbSaveThread, args)) {
+            pthread_attr_destroy(&tattr);
             for (int idb = 0; idb < cserver.dbnum; ++idb)
                 g_pserver->db[idb]->endSnapshot(args->rgpdb[idb]);
             args->~rdbSaveThreadArgs();
             zfree(args);
             return C_ERR;
         }
+        pthread_attr_destroy(&tattr);
         g_pserver->child_type = CHILD_TYPE_RDB;
     }
     return C_OK;
@@ -3049,7 +3054,9 @@ void rdbLoadProgressCallback(rio *r, const void *buf, size_t len) {
         (r->keys_since_last_callback >= g_pserver->loading_process_events_interval_keys)))
     {
         rdbAsyncWorkThread *pwthread = reinterpret_cast<rdbAsyncWorkThread*>(r->chksum_arg);
-        bool fUpdateReplication = (g_pserver->mstime - r->last_update) > 1000;
+        mstime_t mstime;
+        __atomic_load(&g_pserver->mstime, &mstime, __ATOMIC_RELAXED);
+        bool fUpdateReplication = (mstime - r->last_update) > 1000;
 
         if (fUpdateReplication) {
             listIter li;
@@ -3832,7 +3839,11 @@ int rdbSaveToSlavesSockets(rdbSaveInfo *rsi) {
 
     g_pserver->rdbThreadVars.tmpfileNum++;
     g_pserver->rdbThreadVars.fRdbThreadCancel = false;
-    if (pthread_create(&child, nullptr, rdbSaveToSlavesSocketsThread, args)) {
+    pthread_attr_t tattr;
+    pthread_attr_init(&tattr);
+    pthread_attr_setstacksize(&tattr, 1 << 23); // 8 MB
+    if (pthread_create(&child, &tattr, rdbSaveToSlavesSocketsThread, args)) {
+        pthread_attr_destroy(&tattr);
         serverLog(LL_WARNING,"Can't save in background: fork: %s",
             strerror(errno));
 
@@ -3858,6 +3869,7 @@ int rdbSaveToSlavesSockets(rdbSaveInfo *rsi) {
         closeChildInfoPipe();
         return C_ERR;
     }
+    pthread_attr_destroy(&tattr);
     g_pserver->child_type = CHILD_TYPE_RDB;
 
     serverLog(LL_NOTICE,"Background RDB transfer started");

src/replication.cpp

@@ -264,9 +264,8 @@ void resizeReplicationBacklog(long long newsize) {
         newsize = CONFIG_REPL_BACKLOG_MIN_SIZE;
     if (g_pserver->repl_backlog_size == newsize) return;
 
-    std::unique_lock<fastlock> repl_backlog_lock (g_pserver->repl_backlog_lock);
-
     if (g_pserver->repl_backlog != NULL) {
+        std::unique_lock<fastlock> repl_backlog_lock(g_pserver->repl_backlog_lock);
         /* What we actually do is to flush the old buffer and realloc a new
          * empty one. It will refill with new data incrementally.
          * The reason is that copying a few gigabytes adds latency and even
@@ -357,7 +356,7 @@ void freeReplicationBacklog(void) {
 void feedReplicationBacklog(const void *ptr, size_t len) {
     serverAssert(GlobalLocksAcquired());
     const unsigned char *p = (const unsigned char*)ptr;
-
+    std::unique_lock<fastlock> repl_backlog_lock(g_pserver->repl_backlog_lock, std::defer_lock);
 
     if (g_pserver->repl_batch_idxStart >= 0) {
         /* We are lower bounded by the lowest replica offset, or the batch offset start if not applicable */
@@ -417,6 +416,8 @@ void feedReplicationBacklog(const void *ptr, size_t len) {
                 // We need to update a few variables or later asserts will notice we dropped data
                 g_pserver->repl_batch_offStart = g_pserver->master_repl_offset + len;
                 g_pserver->repl_lowest_off = -1;
+                if (!repl_backlog_lock.owns_lock())
+                    repl_backlog_lock.lock();   // we need to acquire the lock if we'll be overwriting data that writeToClient may be reading
             }
         }
     }
@@ -5599,6 +5600,9 @@ void flushReplBacklogToClients()
         serverAssert(g_pserver->master_repl_offset - g_pserver->repl_batch_offStart <= g_pserver->repl_backlog_size);
         serverAssert(g_pserver->repl_batch_idxStart != g_pserver->repl_backlog_idx);
 
+        // Repl backlog writes must become visible to all threads at this point
+        std::atomic_thread_fence(std::memory_order_release);
+
         listIter li;
         listNode *ln;
         listRewind(g_pserver->slaves, &li);

src/server.cpp

@@ -2109,8 +2109,10 @@ void databasesCron(bool fMainThread) {
                         aeAcquireLock();
                     }
 
-                    dictCompleteRehashAsync(serverTL->rehashCtl, true /*fFree*/);
-                    serverTL->rehashCtl = nullptr;
+                    if (serverTL->rehashCtl->done.load(std::memory_order_relaxed)) {
+                        dictCompleteRehashAsync(serverTL->rehashCtl, true /*fFree*/);
+                        serverTL->rehashCtl = nullptr;
+                    }
                 }
 
                 serverAssert(serverTL->rehashCtl == nullptr);
@@ -5532,6 +5534,8 @@ sds genRedisInfoString(const char *section) {
         }
 
         unsigned int lruclock = g_pserver->lruclock.load();
+        ustime_t ustime;
+        __atomic_load(&g_pserver->ustime, &ustime, __ATOMIC_RELAXED);
         info = sdscatfmt(info,
             "# Server\r\n"
             "redis_version:%s\r\n"
@@ -5574,7 +5578,7 @@ sds genRedisInfoString(const char *section) {
             supervised,
             g_pserver->runid,
             g_pserver->port ? g_pserver->port : g_pserver->tls_port,
-            (int64_t)g_pserver->ustime,
+            (int64_t)ustime,
             (int64_t)uptime,
             (int64_t)(uptime/(3600*24)),
             g_pserver->hz.load(),
@@ -7604,7 +7608,7 @@ int main(int argc, char **argv) {
         try {
             loadDataFromDisk();
         } catch (ShutdownException) {
-            exit(EXIT_SUCCESS);
+            _Exit(EXIT_SUCCESS);
         }
 
         if (g_pserver->cluster_enabled) {
@@ -7721,7 +7725,9 @@ int main(int argc, char **argv) {
     g_pserver->garbageCollector.shutdown();
     delete g_pserver->m_pstorageFactory;
 
-    return 0;
+    // Don't return because we don't want to run any global dtors
+    _Exit(EXIT_SUCCESS);
+    return 0;   // Ensure we're well formed even though this won't get hit
 }
 
 /* The End */

src/snapshot.cpp

@@ -26,17 +26,6 @@ public:
     std::vector<dictEntry*> vecde;
 };
 
-void discontinueAsyncRehash(dict *d) {
-    if (d->asyncdata != nullptr) {
-        auto adata = d->asyncdata;
-        while (adata != nullptr) {
-            adata->abondon = true;
-            adata = adata->next;
-        }
-        d->rehashidx = 0;
-    }
-}
-
 const redisDbPersistentDataSnapshot *redisDbPersistentData::createSnapshot(uint64_t mvccCheckpoint, bool fOptional)
 {
     serverAssert(GlobalLocksAcquired());