add alpine ci run

* restore fork impl of save to slave sockets

* default to fork bgsave

.github/workflows/ci.yml

@@ -69,3 +69,14 @@ jobs:
           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 KEYDB_CFLAGS='-Werror' KEYDB_CXXFLAGS='-Werror' MALLOC=libc -j2
+
+  build-alpine:
+    runs-on: alpine-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: recursive
+    - name: make -j2
+      run: | 
+        apk add coreutils gcc linux-headers make musl-dev openssl-dev git util-linux-dev curl-dev g++ libunwind-dev bash perl git bzip2-dev zstd-dev lz4-dev snappy-dev
+        make -j2

src/IStorage.h

@@ -33,11 +33,10 @@ public:
     virtual bool enumerate(callback fn) const = 0;
     virtual size_t count() const = 0;
 
-    virtual void bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, char *rgfOverwrite, size_t celem) {
+    virtual void bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, size_t celem) {
         beginWriteBatch();
         for (size_t ielem = 0; ielem < celem; ++ielem) {
-            bool fOverwrite = (rgfOverwrite != nullptr) ? rgfOverwrite[ielem] : false;
-            insert(rgkeys[ielem], rgcbkeys[ielem], rgvals[ielem], rgcbvals[ielem], fOverwrite);
+            insert(rgkeys[ielem], rgcbkeys[ielem], rgvals[ielem], rgcbvals[ielem], false);
         }
         endWriteBatch();
     }

src/Makefile

@@ -349,7 +349,7 @@ endif
 # Alpine OS doesn't have support for the execinfo backtrace library we use for debug, so we provide an alternate implementation using libwunwind.
 OS := $(shell cat /etc/os-release | grep ID= | head -n 1 | cut -d'=' -f2)
 ifeq ($(OS),alpine)
-    FINAL_CXXFLAGS+=-DUNW_LOCAL_ONLY
+    FINAL_CXXFLAGS+=-DUNW_LOCAL_ONLY -DALPINE
     FINAL_LIBS += -lunwind
 endif
 

src/StorageCache.cpp

@@ -114,14 +114,13 @@ void StorageCache::insert(sds key, const void *data, size_t cbdata, bool fOverwr
 }
 
 long _dictKeyIndex(dict *d, const void *key, uint64_t hash, dictEntry **existing);
-void StorageCache::bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, char *rgfOverwrite, size_t celem)
+void StorageCache::bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, size_t celem)
 {
     std::vector<dictEntry*> vechashes;
     if (m_pdict != nullptr) {
         vechashes.reserve(celem);
 
         for (size_t ielem = 0; ielem < celem; ++ielem) {
-            if (rgfOverwrite != nullptr && rgfOverwrite[ielem]) continue;
             dictEntry *de = (dictEntry*)zmalloc(sizeof(dictEntry));
             de->key = (void*)dictGenHashFunction(rgkeys[ielem], (int)rgcbkeys[ielem]);
             de->v.u64 = 1;
@@ -153,7 +152,7 @@ void StorageCache::bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, si
     }
     ul.unlock();
 
-    m_spstorage->bulkInsert(rgkeys, rgcbkeys, rgvals, rgcbvals, rgfOverwrite, celem);
+    m_spstorage->bulkInsert(rgkeys, rgcbkeys, rgvals, rgcbvals, celem);
 
     bulkInsertsInProgress--;
 }

src/StorageCache.h

@@ -41,7 +41,7 @@ public:
     void clear(void(callback)(void*));
     void clearAsync();
     void insert(sds key, const void *data, size_t cbdata, bool fOverwrite);
-    void bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, char *rgfOverwrite, size_t celem);
+    void bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, size_t celem);
     void retrieve(sds key, IStorage::callbackSingle fn) const;
     bool erase(sds key);
     void emergencyFreeCache();

src/config.cpp

@@ -2806,7 +2806,7 @@ standardConfig configs[] = {
     createBoolConfig("appendonly", NULL, MODIFIABLE_CONFIG, g_pserver->aof_enabled, 0, NULL, updateAppendonly),
     createBoolConfig("cluster-allow-reads-when-down", NULL, MODIFIABLE_CONFIG, g_pserver->cluster_allow_reads_when_down, 0, NULL, NULL),
     createBoolConfig("delete-on-evict", NULL, MODIFIABLE_CONFIG, cserver.delete_on_evict, 0, NULL, NULL),
-    createBoolConfig("use-fork", NULL, IMMUTABLE_CONFIG, cserver.fForkBgSave, 0, NULL, NULL),
+    createBoolConfig("use-fork", NULL, IMMUTABLE_CONFIG, cserver.fForkBgSave, 1, NULL, NULL),
     createBoolConfig("io-threads-do-reads", NULL, IMMUTABLE_CONFIG, fDummy, 0, NULL, NULL),
     createBoolConfig("time-thread-priority", NULL, IMMUTABLE_CONFIG, cserver.time_thread_priority, 0, NULL, NULL),
     createBoolConfig("prefetch-enabled", NULL, MODIFIABLE_CONFIG, g_pserver->prefetch_enabled, 1, NULL, NULL),

src/db.cpp

@@ -1737,6 +1737,9 @@ int dbSwapDatabases(int id1, int id2) {
         id2 < 0 || id2 >= cserver.dbnum) return C_ERR;
     if (id1 == id2) return C_OK;
     std::swap(g_pserver->db[id1], g_pserver->db[id2]);
+    
+    //swap db's id too, otherwise db does not match its id
+    std::swap(g_pserver->db[id1]->id, g_pserver->db[id2]->id);
 
     /* Note that we don't swap blocking_keys,
      * ready_keys and watched_keys, since we want clients to
@@ -1766,7 +1769,7 @@ int dbSwapDatabases(int id1, int id2) {
 
 /* SWAPDB db1 db2 */
 void swapdbCommand(client *c) {
-    int id1, id2;
+    int id1, id2, oriId;
 
     /* Not allowed in cluster mode: we have just DB 0 there. */
     if (g_pserver->cluster_enabled) {
@@ -1783,6 +1786,9 @@ void swapdbCommand(client *c) {
         "invalid second DB index") != C_OK)
         return;
 
+    //get client's original db's id
+    oriId=c->db->id;
+
     /* Swap... */
     if (dbSwapDatabases(id1,id2) == C_ERR) {
         addReplyError(c,"DB index is out of range");
@@ -1791,6 +1797,10 @@ void swapdbCommand(client *c) {
         RedisModuleSwapDbInfo si = {REDISMODULE_SWAPDBINFO_VERSION,(int32_t)id1,(int32_t)id2};
         moduleFireServerEvent(REDISMODULE_EVENT_SWAPDB,0,&si);
         g_pserver->dirty++;
+
+	//set client's db to original db
+        c->db=g_pserver->db[oriId];
+
         addReply(c,shared.ok);
     }
 }
@@ -1931,6 +1941,7 @@ void setExpire(client *c, redisDb *db, robj *key, expireEntry &&e)
  * is associated with this key (i.e. the key is non volatile) */
 expireEntry *redisDbPersistentDataSnapshot::getExpire(const char *key) {
     /* No expire? return ASAP */
+    std::unique_lock<fastlock> ul(g_expireLock);
     if (expireSize() == 0)
         return nullptr;
 
@@ -2727,8 +2738,11 @@ void redisDbPersistentData::clear(void(callback)(void*))
         m_cnewKeysPending = 0;
         m_fAllChanged++;
     }
+    {
+    std::unique_lock<fastlock> ul(g_expireLock);
     delete m_setexpire;
     m_setexpire = new (MALLOC_LOCAL) expireset();
+    }
     if (m_spstorage != nullptr)
         m_spstorage->clear(callback);
     dictEmpty(m_pdictTombstone,callback);
@@ -2861,7 +2875,8 @@ LNotFound:
             {
                 dictAdd(m_pdict, sdsNewKey, o);
                 o->SetFExpires(spexpire != nullptr);
-
+                
+                std::unique_lock<fastlock> ul(g_expireLock);
                 if (spexpire != nullptr)
                 {
                     auto itr = m_setexpire->find(sdsKey);
@@ -2884,6 +2899,7 @@ LNotFound:
     if (*pde != nullptr && dictGetVal(*pde) != nullptr)
     {
         robj *o = (robj*)dictGetVal(*pde);
+        std::unique_lock<fastlock> ul(g_expireLock);
         serverAssert(o->FExpires() == (m_setexpire->find(sdsKey) != m_setexpire->end()));
     }
 }
@@ -2908,13 +2924,15 @@ void redisDbPersistentData::storeDatabase()
     dictReleaseIterator(di);
 }
 
-/* static */ sds redisDbPersistentData::serializeChange(redisDbPersistentData *db, const char *key)
+/* static */ void redisDbPersistentData::serializeAndStoreChange(StorageCache *storage, redisDbPersistentData *db, const char *key, bool fUpdate)
 {
     auto itr = db->find_cached_threadsafe(key);
     if (itr == nullptr)
-        return nullptr;
+        return;
     robj *o = itr.val();
-    return serializeStoredObjectAndExpire(db, (const char*) itr.key(), o);
+    sds temp = serializeStoredObjectAndExpire(db, (const char*) itr.key(), o);
+    storage->insert((sds)key, temp, sdslen(temp), fUpdate);
+    sdsfree(temp);
 }
 
 bool redisDbPersistentData::processChanges(bool fSnapshot)
@@ -2957,30 +2975,10 @@ bool redisDbPersistentData::processChanges(bool fSnapshot)
             {
                 dictIterator *di = dictGetIterator(m_dictChanged);
                 dictEntry *de;
-                std::vector<char*> veckeys;
-                std::vector<size_t> veccbkeys;
-                std::vector<char*> vecvals;
-                std::vector<size_t> veccbvals;
-                std::vector<char> vecoverwrite;
-                veckeys.reserve(dictSize(m_dictChanged));
-                veccbkeys.reserve(dictSize(m_dictChanged));
-                vecvals.reserve(dictSize(m_dictChanged));
-                veccbvals.reserve(dictSize(m_dictChanged));
-                vecoverwrite.reserve(dictSize(m_dictChanged));
                 while ((de = dictNext(di)) != nullptr)
                 {
-                    sds val = serializeChange(this, (const char*)dictGetKey(de));
-                    if (val != nullptr) {
-                        veckeys.push_back((char*)dictGetKey(de));
-                        veccbkeys.push_back(sdslen((sds)dictGetKey(de)));
-                        vecvals.push_back(val);
-                        veccbvals.push_back(sdslen(val));
-                        vecoverwrite.push_back((bool)dictGetVal(de));
-                    }
+                    serializeAndStoreChange(m_spstorage.get(), this, (const char*)dictGetKey(de), (bool)dictGetVal(de));
                 }
-                m_spstorage->bulkInsert(veckeys.data(), veccbkeys.data(), vecvals.data(), veccbvals.data(), vecoverwrite.data(), veckeys.size());
-                for (auto val : vecvals)
-                    sdsfree(val);
                 dictReleaseIterator(di);
             }
         }
@@ -3014,7 +3012,7 @@ void redisDbPersistentData::processChangesAsync(std::atomic<int> &pendingJobs)
             vecvals.push_back(temp);
             veccbvals.push_back(sdslen(temp));
         }
-        m_spstorage->bulkInsert(veckeys.data(), veccbkeys.data(), vecvals.data(), veccbvals.data(), nullptr, veckeys.size());
+        m_spstorage->bulkInsert(veckeys.data(), veccbkeys.data(), vecvals.data(), veccbvals.data(), veckeys.size());
         for (auto val : vecvals)
             sdsfree(val);
         dictReleaseIterator(di);
@@ -3033,7 +3031,7 @@ void redisDbPersistentData::bulkDirectStorageInsert(char **rgKeys, size_t *rgcbK
         }
         aeReleaseLock();
     }
-    m_spstorage->bulkInsert(rgKeys, rgcbKeys, rgVals, rgcbVals, nullptr, celem);
+    m_spstorage->bulkInsert(rgKeys, rgcbKeys, rgVals, rgcbVals, celem);
 }
 
 void redisDbPersistentData::commitChanges(const redisDbPersistentDataSnapshot **psnapshotFree)
@@ -3042,30 +3040,10 @@ void redisDbPersistentData::commitChanges(const redisDbPersistentDataSnapshot **
     {
         dictIterator *di = dictGetIterator(m_dictChangedStorageFlush);
         dictEntry *de;
-        std::vector<char*> veckeys;
-        std::vector<size_t> veccbkeys;
-        std::vector<char*> vecvals;
-        std::vector<size_t> veccbvals;
-        std::vector<char> vecoverwrite;
-        veckeys.reserve(dictSize(m_dictChanged));
-        veccbkeys.reserve(dictSize(m_dictChanged));
-        vecvals.reserve(dictSize(m_dictChanged));
-        veccbvals.reserve(dictSize(m_dictChanged));
-        vecoverwrite.resize(dictSize(m_dictChanged));
         while ((de = dictNext(di)) != nullptr)
         {
-            sds val = serializeChange((redisDbPersistentData*)m_pdbSnapshotStorageFlush, (const char*)dictGetKey(de));
-            if (val != nullptr) {
-                veckeys.push_back((char*)dictGetKey(de));
-                veccbkeys.push_back(sdslen((sds)dictGetKey(de)));
-                vecvals.push_back(val);
-                veccbvals.push_back(sdslen(val));
-                vecoverwrite.push_back((bool)dictGetVal(de));
-            }
+            serializeAndStoreChange(m_spstorage.get(), (redisDbPersistentData*)m_pdbSnapshotStorageFlush, (const char*)dictGetKey(de), (bool)dictGetVal(de));
         }
-        m_spstorage->bulkInsert(veckeys.data(), veccbkeys.data(), vecvals.data(), veccbvals.data(), vecoverwrite.data(), veckeys.size());
-        for (auto val : vecvals)
-            sdsfree(val);
         dictReleaseIterator(di);
         dictRelease(m_dictChangedStorageFlush);
         m_dictChangedStorageFlush = nullptr;
@@ -3294,6 +3272,7 @@ std::unique_ptr<expireEntry> deserializeExpire(sds key, const char *str, size_t
 
 sds serializeStoredObjectAndExpire(redisDbPersistentData *db, const char *key, robj_roptr o)
 {
+    std::unique_lock<fastlock> ul(g_expireLock);
     auto itrExpire = db->setexpire()->find(key);
     const expireEntry *pexpire = nullptr;
     if (itrExpire != db->setexpire()->end())
@@ -3418,6 +3397,7 @@ void redisDbPersistentData::prefetchKeysAsync(client *c, parsed_command &command
                     dictAdd(m_pdict, sharedKey, o);
                     o->SetFExpires(spexpire != nullptr);
 
+                    std::unique_lock<fastlock> ul(g_expireLock);
                     if (spexpire != nullptr)
                     {
                         auto itr = m_setexpire->find(sharedKey);

src/evict.cpp

@@ -380,7 +380,7 @@ size_t freeMemoryGetNotCountedMemory(void) {
 
     /* also don't count the replication backlog memory
      * that's where the replication clients get their memory from */
-    overhead += g_pserver->repl_backlog_size;
+    overhead += g_pserver->repl_backlog_size - g_pserver->repl_backlog_config_size;
 
     if (g_pserver->aof_state != AOF_OFF) {
         overhead += sdsalloc(g_pserver->aof_buf)+aofRewriteBufferSize();
@@ -771,6 +771,7 @@ int performEvictions(bool fPreSnapshot) {
                 if (db->removeCachedValue(bestkey, &deT)) {
                     mem_freed += splazy->addEntry(db->dictUnsafeKeyOnly(), deT);
                     ckeysFailed = 0;
+		    g_pserver->stat_evictedkeys++;
                 }
                 else {
                     delta = 0;

src/expire.cpp

@@ -481,6 +481,7 @@ void expireSlaveKeys(void) {
     if (slaveKeysWithExpire == NULL ||
         dictSize(slaveKeysWithExpire) == 0) return;
 
+    std::unique_lock<fastlock> ul(g_expireLock);
     int cycles = 0, noexpire = 0;
     mstime_t start = mstime();
     while(1) {

src/object.cpp

@@ -1668,6 +1668,7 @@ robj *deserializeStoredObjectCore(const void *data, size_t cb)
 robj *deserializeStoredObject(const redisDbPersistentData *db, const char *key, const void *data, size_t cb)
 {
     robj *o = deserializeStoredObjectCore(data, cb);
+    std::unique_lock<fastlock> ul(g_expireLock);
     o->SetFExpires(db->setexpire()->exists(key));
     return o;
 }

src/rdb.cpp

@@ -1334,7 +1334,7 @@ int rdbSaveRio(rio *rdb, const redisDbPersistentDataSnapshot **rgpdb, int *error
     if (rdbSaveModulesAux(rdb, REDISMODULE_AUX_BEFORE_RDB) == -1) goto werr;
 
     for (j = 0; j < cserver.dbnum; j++) {
-        const redisDbPersistentDataSnapshot *db = rgpdb[j];
+        const redisDbPersistentDataSnapshot *db = rgpdb != nullptr ? rgpdb[j] : g_pserver->db[j];
         if (db->size() == 0) continue;
 
         /* Write the SELECT DB opcode */
@@ -1715,7 +1715,7 @@ void getTempFileName(char tmpfile[], int tmpfileNum) {
     char tmpfileNumString[214];
 
     /* Generate temp rdb file name using aync-signal safe functions. */
-    int pid_len = ll2string(pid, sizeof(pid), getpid());
+    int pid_len = ll2string(pid, sizeof(pid), g_pserver->in_fork_child ? getppid() : getpid());
     int tmpfileNum_len = ll2string(tmpfileNumString, sizeof(tmpfileNumString), tmpfileNum);
     strcpy(tmpfile, "temp-");
     strncpy(tmpfile+5, pid, pid_len);
@@ -3832,57 +3832,130 @@ int rdbSaveToSlavesSockets(rdbSaveInfo *rsi) {
     }
 
     /* Create the child process. */
-    openChildInfoPipe();
+    if (cserver.fForkBgSave) {
+        pid_t childpid;
+        if ((childpid = redisFork(CHILD_TYPE_RDB)) == 0) {
+            /* Child */
+            int retval, dummy;
+            rio rdb;
 
-    for (int idb = 0; idb < cserver.dbnum; ++idb)
-        args->rgpdb[idb] = g_pserver->db[idb]->createSnapshot(getMvccTstamp(), false /*fOptional*/);
+            rioInitWithFd(&rdb,args->rdb_pipe_write);
 
-    g_pserver->rdbThreadVars.tmpfileNum++;
-    g_pserver->rdbThreadVars.fRdbThreadCancel = false;
-    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));
+            redisSetProcTitle("keydb-rdb-to-slaves");
+            redisSetCpuAffinity(g_pserver->bgsave_cpulist);
 
-        /* Undo the state change. The caller will perform cleanup on
-            * all the slaves in BGSAVE_START state, but an early call to
-            * replicationSetupSlaveForFullResync() turned it into BGSAVE_END */
-        listRewind(g_pserver->slaves,&li);
-        while((ln = listNext(&li))) {
-            client *replica = (client*)ln->value;
-            if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_END) {
-                replica->replstate = SLAVE_STATE_WAIT_BGSAVE_START;
+            retval = rdbSaveRioWithEOFMark(&rdb,nullptr,nullptr,rsi);
+            if (retval == C_OK && rioFlush(&rdb) == 0)
+                retval = C_ERR;
+
+            if (retval == C_OK) {
+                sendChildCowInfo(CHILD_INFO_TYPE_RDB_COW_SIZE, "RDB");
             }
-        }
-        close(args->rdb_pipe_write);
-        close(g_pserver->rdb_pipe_read);
-        zfree(g_pserver->rdb_pipe_conns);
-        close(args->safe_to_exit_pipe);
-        g_pserver->rdb_pipe_conns = NULL;
-        g_pserver->rdb_pipe_numconns = 0;
-        g_pserver->rdb_pipe_numconns_writing = 0;
-        args->rsi.~rdbSaveInfo();
-        zfree(args);
-        closeChildInfoPipe();
-        return C_ERR;
-    }
-    pthread_attr_destroy(&tattr);
-    g_pserver->child_type = CHILD_TYPE_RDB;
 
-    serverLog(LL_NOTICE,"Background RDB transfer started");
-    g_pserver->rdb_save_time_start = time(NULL);
-    serverAssert(!g_pserver->rdbThreadVars.fRdbThreadActive);
-    g_pserver->rdbThreadVars.rdb_child_thread = child;
-    g_pserver->rdbThreadVars.fRdbThreadActive = true;
-    g_pserver->rdb_child_type = RDB_CHILD_TYPE_SOCKET;
-    aePostFunction(g_pserver->rgthreadvar[IDX_EVENT_LOOP_MAIN].el, []{
-        if (aeCreateFileEvent(serverTL->el, g_pserver->rdb_pipe_read, AE_READABLE, rdbPipeReadHandler,NULL) == AE_ERR) {
-            serverPanic("Unrecoverable error creating server.rdb_pipe_read file event.");
+            rioFreeFd(&rdb);
+            /* wake up the reader, tell it we're done. */
+            close(args->rdb_pipe_write);
+            close(g_pserver->rdb_child_exit_pipe); /* close write end so that we can detect the close on the parent. */
+            /* hold exit until the parent tells us it's safe. we're not expecting
+            * to read anything, just get the error when the pipe is closed. */
+            dummy = read(args->safe_to_exit_pipe, pipefds, 1);
+            UNUSED(dummy);
+            exitFromChild((retval == C_OK) ? 0 : 1);
+        } else {
+            /* Parent */
+            close(args->safe_to_exit_pipe);
+            if (childpid == -1) {
+                serverLog(LL_WARNING,"Can't save in background: fork: %s",
+                    strerror(errno));
+
+                /* Undo the state change. The caller will perform cleanup on
+                * all the slaves in BGSAVE_START state, but an early call to
+                * replicationSetupSlaveForFullResync() turned it into BGSAVE_END */
+                listRewind(g_pserver->slaves,&li);
+                while((ln = listNext(&li))) {
+                    client *replica = (client*)ln->value;
+                    if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_END) {
+                        replica->replstate = SLAVE_STATE_WAIT_BGSAVE_START;
+                    }
+                }
+                close(args->rdb_pipe_write);
+                close(g_pserver->rdb_pipe_read);
+                zfree(g_pserver->rdb_pipe_conns);
+                g_pserver->rdb_pipe_conns = NULL;
+                g_pserver->rdb_pipe_numconns = 0;
+                g_pserver->rdb_pipe_numconns_writing = 0;
+                args->rsi.~rdbSaveInfo();
+                zfree(args);
+            } else {
+                serverLog(LL_NOTICE,"Background RDB transfer started by pid %ld",
+                    (long)childpid);
+                g_pserver->rdb_save_time_start = time(NULL);
+                g_pserver->rdb_child_type = RDB_CHILD_TYPE_SOCKET;
+                g_pserver->rdbThreadVars.fRdbThreadActive = true;
+                updateDictResizePolicy();
+                close(args->rdb_pipe_write); /* close write in parent so that it can detect the close on the child. */
+                aePostFunction(g_pserver->rgthreadvar[IDX_EVENT_LOOP_MAIN].el, []{
+                    if (aeCreateFileEvent(serverTL->el, g_pserver->rdb_pipe_read, AE_READABLE, rdbPipeReadHandler, nullptr) == AE_ERR) {
+                        serverPanic("Unrecoverable error creating g_pserver->rdb_pipe_read file event.");
+                    }
+                });
+            }
+            return (childpid == -1) ? C_ERR : C_OK;
         }
-    });
+    }
+    else {
+        openChildInfoPipe();
+
+        for (int idb = 0; idb < cserver.dbnum; ++idb)
+            args->rgpdb[idb] = g_pserver->db[idb]->createSnapshot(getMvccTstamp(), false /*fOptional*/);
+
+        g_pserver->rdbThreadVars.tmpfileNum++;
+        g_pserver->rdbThreadVars.fRdbThreadCancel = false;
+        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));
+
+            /* Undo the state change. The caller will perform cleanup on
+                * all the slaves in BGSAVE_START state, but an early call to
+                * replicationSetupSlaveForFullResync() turned it into BGSAVE_END */
+            listRewind(g_pserver->slaves,&li);
+            while((ln = listNext(&li))) {
+                client *replica = (client*)ln->value;
+                if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_END) {
+                    replica->replstate = SLAVE_STATE_WAIT_BGSAVE_START;
+                }
+            }
+            close(args->rdb_pipe_write);
+            close(g_pserver->rdb_pipe_read);
+            zfree(g_pserver->rdb_pipe_conns);
+            close(args->safe_to_exit_pipe);
+            g_pserver->rdb_pipe_conns = NULL;
+            g_pserver->rdb_pipe_numconns = 0;
+            g_pserver->rdb_pipe_numconns_writing = 0;
+            args->rsi.~rdbSaveInfo();
+            zfree(args);
+            closeChildInfoPipe();
+            return C_ERR;
+        }
+        pthread_attr_destroy(&tattr);
+        g_pserver->child_type = CHILD_TYPE_RDB;
+
+        serverLog(LL_NOTICE,"Background RDB transfer started");
+        g_pserver->rdb_save_time_start = time(NULL);
+        serverAssert(!g_pserver->rdbThreadVars.fRdbThreadActive);
+        g_pserver->rdbThreadVars.rdb_child_thread = child;
+        g_pserver->rdbThreadVars.fRdbThreadActive = true;
+        g_pserver->rdb_child_type = RDB_CHILD_TYPE_SOCKET;
+        aePostFunction(g_pserver->rgthreadvar[IDX_EVENT_LOOP_MAIN].el, []{
+            if (aeCreateFileEvent(serverTL->el, g_pserver->rdb_pipe_read, AE_READABLE, rdbPipeReadHandler, nullptr) == AE_ERR) {
+                serverPanic("Unrecoverable error creating server.rdb_pipe_read file event.");
+            }
+        });
+    }
 
     return C_OK; /* Unreached. */
 }

src/server.cpp

@@ -5172,7 +5172,7 @@ int prepareForShutdown(int flags) {
          * to unlink file actully) in background thread.
          * The temp rdb file fd may won't be closed when redis exits quickly,
          * but OS will close this fd when process exits. */
-        rdbRemoveTempFile(g_pserver->child_pid, 0);
+        rdbRemoveTempFile(g_pserver->rdbThreadVars.tmpfileNum, 0);
     }
 
     /* Kill module child if there is one. */

src/server.h

@@ -1217,7 +1217,7 @@ protected:
     uint64_t m_mvccCheckpoint = 0;
 
 private:
-    static sds serializeChange(redisDbPersistentData *db, const char *key);
+    static void serializeAndStoreChange(StorageCache *storage, redisDbPersistentData *db, const char *key, bool fUpdate);
 
     void ensure(const char *key);
     void ensure(const char *key, dictEntry **de);
@@ -3894,14 +3894,30 @@ void incrementMvccTstamp();
 
 #if __GNUC__ >= 7 && !defined(NO_DEPRECATE_FREE)
  [[deprecated]]
+#ifdef ALPINE
+void *calloc(size_t count, size_t size);
+#else
 void *calloc(size_t count, size_t size) noexcept;
+#endif
  [[deprecated]]
+#ifdef ALPINE
+void free(void *ptr);
+#else
 void free(void *ptr) noexcept;
+#endif
  [[deprecated]]
+#ifdef ALPINE
+void *malloc(size_t size);
+#else
 void *malloc(size_t size) noexcept;
+#endif
  [[deprecated]]
+#ifdef ALPINE
+void *realloc(void *ptr, size_t size);
+#else
 void *realloc(void *ptr, size_t size) noexcept;
 #endif
+#endif
 
 /* Debugging stuff */
 void bugReportStart(void);

src/storage/rocksdb.cpp

@@ -43,9 +43,8 @@ void RocksDBStorageProvider::insert(const char *key, size_t cchKey, void *data,
         ++m_count;
 }
 
-void RocksDBStorageProvider::bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, char *rgfOverwrite, size_t celem)
+void RocksDBStorageProvider::bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, size_t celem)
 {
-    size_t coverwrites = 0;
     if (celem >= 16384) {
         rocksdb::Options options = DefaultRocksDBOptions();
         rocksdb::SstFileWriter sst_file_writer(rocksdb::EnvOptions(), options, options.comparator);
@@ -93,15 +92,8 @@ void RocksDBStorageProvider::bulkInsert(char **rgkeys, size_t *rgcbkeys, char **
         m_spdb->Write(WriteOptions(), spbatch.get());
     }
 
-    if (rgfOverwrite != nullptr) {
-        for (size_t ielem = 0; ielem < celem; ++ielem) {
-            if (rgfOverwrite[ielem])
-                ++coverwrites;
-        }
-    }
-
     std::unique_lock<fastlock> l(m_lock);
-    m_count += celem - coverwrites;
+    m_count += celem;
 }
 
 bool RocksDBStorageProvider::erase(const char *key, size_t cchKey)

src/storage/rocksdb.h

@@ -38,7 +38,7 @@ public:
     virtual void beginWriteBatch() override;
     virtual void endWriteBatch() override;
 
-    virtual void bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, char *rgfOverwrite, size_t celem) override;
+    virtual void bulkInsert(char **rgkeys, size_t *rgcbkeys, char **rgvals, size_t *rgcbvals, size_t celem) override;
 
     virtual void batch_lock() override;
     virtual void batch_unlock() override;

utils/create-cluster/create-cluster

@@ -26,7 +26,11 @@ then
     while [ $((PORT < ENDPORT)) != "0" ]; do
         PORT=$((PORT+1))
         echo "Starting $PORT"
-        $BIN_PATH/keydb-server --port $PORT  --protected-mode $PROTECTED_MODE --cluster-enabled yes --cluster-config-file nodes-${PORT}.conf --cluster-node-timeout $TIMEOUT --appendonly yes --appendfilename appendonly-${PORT}.aof --dbfilename dump-${PORT}.rdb --logfile ${PORT}.log --daemonize yes ${ADDITIONAL_OPTIONS}
+        if [ "$2" == "flash" ]
+        then
+            ADDITIONAL_OPTIONS="--save \"\" \"\" \"\" --semi-ordered-set-bucket-size 8 --client-output-buffer-limit replica 1 1 0 --maxmemory 100000000 --storage-provider flash ./$PORT.flash"
+        fi
+        $BIN_PATH/keydb-server --server-threads 4 --port $PORT  --protected-mode $PROTECTED_MODE --cluster-enabled yes --cluster-config-file nodes-${PORT}.conf --cluster-node-timeout $TIMEOUT --dbfilename dump-${PORT}.rdb --logfile ${PORT}.log --daemonize yes ${ADDITIONAL_OPTIONS}
     done
     exit 0
 fi
@@ -97,6 +101,8 @@ then
     rm -rf appendonly*.aof
     rm -rf dump*.rdb
     rm -rf nodes*.conf
+    rm -rf *.flash
+    rm -rf temp*.rdb
     exit 0
 fi