X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/548efd91e5a33e1358213a902b8533d88f40f7cf..749817b7c3873f66c42e75a2bdc9b6a5aad5d67f:/src/redis.c diff --git a/src/redis.c b/src/redis.c index a76a5618..dacf4712 100644 --- a/src/redis.c +++ b/src/redis.c @@ -216,7 +216,7 @@ struct redisCommand redisCommandTable[] = { {"sync",syncCommand,1,"ars",0,NULL,0,0,0,0,0}, {"flushdb",flushdbCommand,1,"w",0,NULL,0,0,0,0,0}, {"flushall",flushallCommand,1,"w",0,NULL,0,0,0,0,0}, - {"sort",sortCommand,-2,"wm",0,NULL,1,1,1,0,0}, + {"sort",sortCommand,-2,"wmS",0,NULL,1,1,1,0,0}, {"info",infoCommand,-1,"r",0,NULL,0,0,0,0,0}, {"monitor",monitorCommand,1,"ars",0,NULL,0,0,0,0,0}, {"ttl",ttlCommand,2,"r",0,NULL,1,1,1,0,0}, @@ -232,17 +232,16 @@ struct redisCommand redisCommandTable[] = { {"publish",publishCommand,3,"rpf",0,NULL,0,0,0,0,0}, {"watch",watchCommand,-2,"rs",0,noPreloadGetKeys,1,-1,1,0,0}, {"unwatch",unwatchCommand,1,"rs",0,NULL,0,0,0,0,0}, - {"cluster",clusterCommand,-2,"ar",0,NULL,0,0,0,0,0}, {"restore",restoreCommand,4,"awm",0,NULL,1,1,1,0,0}, {"migrate",migrateCommand,6,"aw",0,NULL,0,0,0,0,0}, - {"asking",askingCommand,1,"r",0,NULL,0,0,0,0,0}, {"dump",dumpCommand,2,"ar",0,NULL,1,1,1,0,0}, {"object",objectCommand,-2,"r",0,NULL,2,2,2,0,0}, {"client",clientCommand,-2,"ar",0,NULL,0,0,0,0,0}, {"eval",evalCommand,-3,"wms",0,zunionInterGetKeys,0,0,0,0,0}, {"evalsha",evalShaCommand,-3,"wms",0,zunionInterGetKeys,0,0,0,0,0}, {"slowlog",slowlogCommand,-2,"r",0,NULL,0,0,0,0,0}, - {"script",scriptCommand,-2,"ras",0,NULL,0,0,0,0,0} + {"script",scriptCommand,-2,"ras",0,NULL,0,0,0,0,0}, + {"time",timeCommand,1,"rR",0,NULL,0,0,0,0,0} }; /*============================ Utility functions ============================ */ @@ -506,17 +505,6 @@ dictType keylistDictType = { dictListDestructor /* val destructor */ }; -/* Cluster nodes hash table, mapping nodes addresses 1.2.3.4:6379 to - * clusterNode structures. */ -dictType clusterNodesDictType = { - dictSdsHash, /* hash function */ - NULL, /* key dup */ - NULL, /* val dup */ - dictSdsKeyCompare, /* key compare */ - dictSdsDestructor, /* key destructor */ - NULL /* val destructor */ -}; - int htNeedsResize(dict *dict) { long long size, used; @@ -615,6 +603,101 @@ void updateLRUClock(void) { REDIS_LRU_CLOCK_MAX; } + +/* Add a sample to the operations per second array of samples. */ +void trackOperationsPerSecond(void) { + long long t = mstime() - server.ops_sec_last_sample_time; + long long ops = server.stat_numcommands - server.ops_sec_last_sample_ops; + long long ops_sec; + + ops_sec = t > 0 ? (ops*1000/t) : 0; + + server.ops_sec_samples[server.ops_sec_idx] = ops_sec; + server.ops_sec_idx = (server.ops_sec_idx+1) % REDIS_OPS_SEC_SAMPLES; + server.ops_sec_last_sample_time = mstime(); + server.ops_sec_last_sample_ops = server.stat_numcommands; +} + +/* Return the mean of all the samples. */ +long long getOperationsPerSecond(void) { + int j; + long long sum = 0; + + for (j = 0; j < REDIS_OPS_SEC_SAMPLES; j++) + sum += server.ops_sec_samples[j]; + return sum / REDIS_OPS_SEC_SAMPLES; +} + +void clientsCronHandleTimeout(redisClient *c) { + time_t now = server.unixtime; + + if (server.maxidletime && + !(c->flags & REDIS_SLAVE) && /* no timeout for slaves */ + !(c->flags & REDIS_MASTER) && /* no timeout for masters */ + !(c->flags & REDIS_BLOCKED) && /* no timeout for BLPOP */ + dictSize(c->pubsub_channels) == 0 && /* no timeout for pubsub */ + listLength(c->pubsub_patterns) == 0 && + (now - c->lastinteraction > server.maxidletime)) + { + redisLog(REDIS_VERBOSE,"Closing idle client"); + freeClient(c); + } else if (c->flags & REDIS_BLOCKED) { + if (c->bpop.timeout != 0 && c->bpop.timeout < now) { + addReply(c,shared.nullmultibulk); + unblockClientWaitingData(c); + } + } +} + +/* The client query buffer is an sds.c string that can end with a lot of + * free space not used, this function reclaims space if needed. */ +void clientsCronResizeQueryBuffer(redisClient *c) { + size_t querybuf_size = sdsAllocSize(c->querybuf); + time_t idletime = server.unixtime - c->lastinteraction; + + /* There are two conditions to resize the query buffer: + * 1) Query buffer is > BIG_ARG and too big for latest peak. + * 2) Client is inactive and the buffer is bigger than 1k. */ + if (((querybuf_size > REDIS_MBULK_BIG_ARG) && + (querybuf_size/(c->querybuf_peak+1)) > 2) || + (querybuf_size > 1024 && idletime > 2)) + { + /* Only resize the query buffer if it is actually wasting space. */ + if (sdsavail(c->querybuf) > 1024) { + c->querybuf = sdsRemoveFreeSpace(c->querybuf); + } + } + /* Reset the peak again to capture the peak memory usage in the next + * cycle. */ + c->querybuf_peak = 0; +} + +void clientsCron(void) { + /* Make sure to process at least 1/100 of clients per call. + * Since this function is called 10 times per second we are sure that + * in the worst case we process all the clients in 10 seconds. + * In normal conditions (a reasonable number of clients) we process + * all the clients in a shorter time. */ + int numclients = listLength(server.clients); + int iterations = numclients/100; + + if (iterations < 50) + iterations = (numclients < 50) ? numclients : 50; + while(listLength(server.clients) && iterations--) { + redisClient *c; + listNode *head; + + /* Rotate the list, take the current head, process. + * This way if the client must be removed from the list it's the + * first element and we don't incur into O(N) computation. */ + listRotate(server.clients); + head = listFirst(server.clients); + c = listNodeValue(head); + clientsCronHandleTimeout(c); + clientsCronResizeQueryBuffer(c); + } +} + int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) { int j, loops = server.cronloops; REDIS_NOTUSED(eventLoop); @@ -627,6 +710,8 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) { * To access a global var is faster than calling time(NULL) */ server.unixtime = time(NULL); + trackOperationsPerSecond(); + /* We have just 22 bits per object for LRU information. * So we use an (eventually wrapping) LRU clock with 10 seconds resolution. * 2^22 bits with 10 seconds resoluton is more or less 1.5 years. @@ -684,9 +769,8 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) { zmalloc_used_memory()); } - /* Close connections of timedout clients */ - if ((server.maxidletime && !(loops % 100)) || server.bpop_blocked_clients) - closeTimedoutClients(); + /* We need to do a few operations on clients asynchronously. */ + clientsCron(); /* Start a scheduled AOF rewrite if this was requested by the user while * a BGSAVE was in progress. */ @@ -764,9 +848,6 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) { * to detect transfer failures. */ if (!(loops % 10)) replicationCron(); - /* Run other sub-systems specific cron jobs */ - if (server.cluster_enabled && !(loops % 10)) clusterCron(); - server.cronloops++; return 100; } @@ -832,6 +913,8 @@ void createSharedObjects(void) { "-LOADING Redis is loading the dataset in memory\r\n")); shared.slowscripterr = createObject(REDIS_STRING,sdsnew( "-BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE.\r\n")); + shared.bgsaveerr = createObject(REDIS_STRING,sdsnew( + "-MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Write commands are disabled. Please check Redis logs for details about the error.\r\n")); shared.space = createObject(REDIS_STRING,sdsnew(" ")); shared.colon = createObject(REDIS_STRING,sdsnew(":")); shared.plus = createObject(REDIS_STRING,sdsnew("+")); @@ -851,15 +934,25 @@ void createSharedObjects(void) { shared.unsubscribebulk = createStringObject("$11\r\nunsubscribe\r\n",18); shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17); shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19); - shared.mbulk3 = createStringObject("*3\r\n",4); - shared.mbulk4 = createStringObject("*4\r\n",4); + shared.del = createStringObject("DEL",3); + shared.rpop = createStringObject("RPOP",4); + shared.lpop = createStringObject("LPOP",4); for (j = 0; j < REDIS_SHARED_INTEGERS; j++) { shared.integers[j] = createObject(REDIS_STRING,(void*)(long)j); shared.integers[j]->encoding = REDIS_ENCODING_INT; } + for (j = 0; j < REDIS_SHARED_BULKHDR_LEN; j++) { + shared.mbulkhdr[j] = createObject(REDIS_STRING, + sdscatprintf(sdsempty(),"*%d\r\n",j)); + shared.bulkhdr[j] = createObject(REDIS_STRING, + sdscatprintf(sdsempty(),"$%d\r\n",j)); + } } void initServerConfig() { + getRandomHexChars(server.runid,REDIS_RUN_ID_SIZE); + server.runid[REDIS_RUN_ID_SIZE] = '\0'; + server.arch_bits = (sizeof(long) == 8) ? 64 : 32; server.port = REDIS_SERVERPORT; server.bindaddr = NULL; server.unixsocket = NULL; @@ -899,8 +992,8 @@ void initServerConfig() { server.maxmemory = 0; server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU; server.maxmemory_samples = 3; - server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES; - server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE; + server.hash_max_ziplist_entries = REDIS_HASH_MAX_ZIPLIST_ENTRIES; + server.hash_max_ziplist_value = REDIS_HASH_MAX_ZIPLIST_VALUE; server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES; server.list_max_ziplist_value = REDIS_LIST_MAX_ZIPLIST_VALUE; server.set_max_intset_entries = REDIS_SET_MAX_INTSET_ENTRIES; @@ -909,8 +1002,6 @@ void initServerConfig() { server.shutdown_asap = 0; server.repl_ping_slave_period = REDIS_REPL_PING_SLAVE_PERIOD; server.repl_timeout = REDIS_REPL_TIMEOUT; - server.cluster_enabled = 0; - server.cluster.configfile = zstrdup("nodes.conf"); server.lua_caller = NULL; server.lua_time_limit = REDIS_LUA_TIME_LIMIT; server.lua_client = NULL; @@ -956,6 +1047,7 @@ void initServerConfig() { populateCommandTable(); server.delCommand = lookupCommandByCString("del"); server.multiCommand = lookupCommandByCString("multi"); + server.lpushCommand = lookupCommandByCString("lpush"); /* Slow log */ server.slowlog_log_slower_than = REDIS_SLOWLOG_LOG_SLOWER_THAN; @@ -1077,7 +1169,13 @@ void initServer() { server.stat_peak_memory = 0; server.stat_fork_time = 0; server.stat_rejected_conn = 0; + memset(server.ops_sec_samples,0,sizeof(server.ops_sec_samples)); + server.ops_sec_idx = 0; + server.ops_sec_last_sample_time = mstime(); + server.ops_sec_last_sample_ops = 0; server.unixtime = time(NULL); + server.lastbgsave_status = REDIS_OK; + server.stop_writes_on_bgsave_err = 1; aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL); if (server.ipfd > 0 && aeCreateFileEvent(server.el,server.ipfd,AE_READABLE, acceptTcpHandler,NULL) == AE_ERR) oom("creating file event"); @@ -1094,7 +1192,16 @@ void initServer() { } } - if (server.cluster_enabled) clusterInit(); + /* 32 bit instances are limited to 4GB of address space, so if there is + * no explicit limit in the user provided configuration we set a limit + * at 3.5GB using maxmemory with 'noeviction' policy'. This saves + * useless crashes of the Redis instance. */ + if (server.arch_bits == 32 && server.maxmemory == 0) { + redisLog(REDIS_WARNING,"Warning: 32 bit instance detected but no memory limit set. Setting 3.5 GB maxmemory limit with 'noeviction' policy now."); + server.maxmemory = 3584LL*(1024*1024); /* 3584 MB = 3.5 GB */ + server.maxmemory_policy = REDIS_MAXMEMORY_NO_EVICTION; + } + scriptingInit(); slowlogInit(); bioInit(); @@ -1144,6 +1251,43 @@ void resetCommandTableStats(void) { } } +/* ========================== Redis OP Array API ============================ */ + +void redisOpArrayInit(redisOpArray *oa) { + oa->ops = NULL; + oa->numops = 0; +} + +int redisOpArrayAppend(redisOpArray *oa, struct redisCommand *cmd, int dbid, + robj **argv, int argc, int target) +{ + redisOp *op; + + oa->ops = zrealloc(oa->ops,sizeof(redisOp)*(oa->numops+1)); + op = oa->ops+oa->numops; + op->cmd = cmd; + op->dbid = dbid; + op->argv = argv; + op->argc = argc; + op->target = target; + oa->numops++; + return oa->numops; +} + +void redisOpArrayFree(redisOpArray *oa) { + while(oa->numops) { + int j; + redisOp *op; + + oa->numops--; + op = oa->ops+oa->numops; + for (j = 0; j < op->argc; j++) + decrRefCount(op->argv[j]); + zfree(op->argv); + } + zfree(oa->ops); +} + /* ====================== Commands lookup and execution ===================== */ struct redisCommand *lookupCommand(sds name) { @@ -1159,25 +1303,84 @@ struct redisCommand *lookupCommandByCString(char *s) { return cmd; } +/* Propagate the specified command (in the context of the specified database id) + * to AOF, Slaves and Monitors. + * + * flags are an xor between: + * + REDIS_PROPAGATE_NONE (no propagation of command at all) + * + REDIS_PROPAGATE_AOF (propagate into the AOF file if is enabled) + * + REDIS_PROPAGATE_REPL (propagate into the replication link) + */ +void propagate(struct redisCommand *cmd, int dbid, robj **argv, int argc, + int flags) +{ + if (server.aof_state != REDIS_AOF_OFF && flags & REDIS_PROPAGATE_AOF) + feedAppendOnlyFile(cmd,dbid,argv,argc); + if (flags & REDIS_PROPAGATE_REPL && listLength(server.slaves)) + replicationFeedSlaves(server.slaves,dbid,argv,argc); +} + +/* Used inside commands to schedule the propagation of additional commands + * after the current command is propagated to AOF / Replication. */ +void alsoPropagate(struct redisCommand *cmd, int dbid, robj **argv, int argc, + int target) +{ + redisOpArrayAppend(&server.also_propagate,cmd,dbid,argv,argc,target); +} + /* Call() is the core of Redis execution of a command */ -void call(redisClient *c) { +void call(redisClient *c, int flags) { long long dirty, start = ustime(), duration; + /* Sent the command to clients in MONITOR mode, only if the commands are + * not geneated from reading an AOF. */ + if (listLength(server.monitors) && !server.loading) + replicationFeedMonitors(c,server.monitors,c->db->id,c->argv,c->argc); + + /* Call the command. */ + redisOpArrayInit(&server.also_propagate); dirty = server.dirty; c->cmd->proc(c); dirty = server.dirty-dirty; duration = ustime()-start; - c->cmd->microseconds += duration; - slowlogPushEntryIfNeeded(c->argv,c->argc,duration); - c->cmd->calls++; - - if (server.aof_state != REDIS_AOF_OFF && dirty > 0) - feedAppendOnlyFile(c->cmd,c->db->id,c->argv,c->argc); - if ((dirty > 0 || c->cmd->flags & REDIS_CMD_FORCE_REPLICATION) && - listLength(server.slaves)) - replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc); - if (listLength(server.monitors)) - replicationFeedMonitors(server.monitors,c->db->id,c->argv,c->argc); + + /* When EVAL is called loading the AOF we don't want commands called + * from Lua to go into the slowlog or to populate statistics. */ + if (server.loading && c->flags & REDIS_LUA_CLIENT) + flags &= ~(REDIS_CALL_SLOWLOG | REDIS_CALL_STATS); + + /* Log the command into the Slow log if needed, and populate the + * per-command statistics that we show in INFO commandstats. */ + if (flags & REDIS_CALL_SLOWLOG) + slowlogPushEntryIfNeeded(c->argv,c->argc,duration); + if (flags & REDIS_CALL_STATS) { + c->cmd->microseconds += duration; + c->cmd->calls++; + } + + /* Propagate the command into the AOF and replication link */ + if (flags & REDIS_CALL_PROPAGATE) { + int flags = REDIS_PROPAGATE_NONE; + + if (c->cmd->flags & REDIS_CMD_FORCE_REPLICATION) + flags |= REDIS_PROPAGATE_REPL; + if (dirty) + flags |= (REDIS_PROPAGATE_REPL | REDIS_PROPAGATE_AOF); + if (flags != REDIS_PROPAGATE_NONE) + propagate(c->cmd,c->db->id,c->argv,c->argc,flags); + } + /* Commands such as LPUSH or BRPOPLPUSH may propagate an additional + * PUSH command. */ + if (server.also_propagate.numops) { + int j; + redisOp *rop; + + for (j = 0; j < server.also_propagate.numops; j++) { + rop = &server.also_propagate.ops[j]; + propagate(rop->cmd, rop->dbid, rop->argv, rop->argc, rop->target); + } + redisOpArrayFree(&server.also_propagate); + } server.stat_numcommands++; } @@ -1221,39 +1424,27 @@ int processCommand(redisClient *c) { return REDIS_OK; } - /* If cluster is enabled, redirect here */ - if (server.cluster_enabled && - !(c->cmd->getkeys_proc == NULL && c->cmd->firstkey == 0)) { - int hashslot; - - if (server.cluster.state != REDIS_CLUSTER_OK) { - addReplyError(c,"The cluster is down. Check with CLUSTER INFO for more information"); - return REDIS_OK; - } else { - int ask; - clusterNode *n = getNodeByQuery(c,c->cmd,c->argv,c->argc,&hashslot,&ask); - if (n == NULL) { - addReplyError(c,"Multi keys request invalid in cluster"); - return REDIS_OK; - } else if (n != server.cluster.myself) { - addReplySds(c,sdscatprintf(sdsempty(), - "-%s %d %s:%d\r\n", ask ? "ASK" : "MOVED", - hashslot,n->ip,n->port)); - return REDIS_OK; - } - } - } - /* Handle the maxmemory directive. * * First we try to free some memory if possible (if there are volatile * keys in the dataset). If there are not the only thing we can do * is returning an error. */ - if (server.maxmemory) freeMemoryIfNeeded(); - if (server.maxmemory && (c->cmd->flags & REDIS_CMD_DENYOOM) && - zmalloc_used_memory() > server.maxmemory) + if (server.maxmemory) { + int retval = freeMemoryIfNeeded(); + if ((c->cmd->flags & REDIS_CMD_DENYOOM) && retval == REDIS_ERR) { + addReplyError(c, + "command not allowed when used memory > 'maxmemory'"); + return REDIS_OK; + } + } + + /* Don't accept write commands if there are problems persisting on disk. */ + if (server.stop_writes_on_bgsave_err && + server.saveparamslen > 0 + && server.lastbgsave_status == REDIS_ERR && + c->cmd->flags & REDIS_CMD_WRITE) { - addReplyError(c,"command not allowed when used memory > 'maxmemory'"); + addReply(c, shared.bgsaveerr); return REDIS_OK; } @@ -1306,7 +1497,7 @@ int processCommand(redisClient *c) { queueMultiCommand(c); addReply(c,shared.queued); } else { - call(c); + call(c,REDIS_CALL_FULL); } return REDIS_OK; } @@ -1389,6 +1580,17 @@ void echoCommand(redisClient *c) { addReplyBulk(c,c->argv[1]); } +void timeCommand(redisClient *c) { + struct timeval tv; + + /* gettimeofday() can only fail if &tv is a bad addresss so we + * don't check for errors. */ + gettimeofday(&tv,NULL); + addReplyMultiBulkLen(c,2); + addReplyBulkLongLong(c,tv.tv_sec); + addReplyBulkLongLong(c,tv.tv_usec); +} + /* Convert an amount of bytes into a human readable string in the form * of 100B, 2G, 100M, 4K, and so forth. */ void bytesToHuman(char *s, unsigned long long n) { @@ -1439,10 +1641,11 @@ sds genRedisInfoString(char *section) { "redis_version:%s\r\n" "redis_git_sha1:%s\r\n" "redis_git_dirty:%d\r\n" - "arch_bits:%s\r\n" + "arch_bits:%d\r\n" "multiplexing_api:%s\r\n" "gcc_version:%d.%d.%d\r\n" "process_id:%ld\r\n" + "run_id:%s\r\n" "tcp_port:%d\r\n" "uptime_in_seconds:%ld\r\n" "uptime_in_days:%ld\r\n" @@ -1450,7 +1653,7 @@ sds genRedisInfoString(char *section) { REDIS_VERSION, redisGitSHA1(), strtol(redisGitDirty(),NULL,10) > 0, - (sizeof(long) == 8) ? "64" : "32", + server.arch_bits, aeGetApiName(), #ifdef __GNUC__ __GNUC__,__GNUC_MINOR__,__GNUC_PATCHLEVEL__, @@ -1458,6 +1661,7 @@ sds genRedisInfoString(char *section) { 0,0,0, #endif (long) getpid(), + server.runid, server.port, uptime, uptime/(3600*24), @@ -1517,12 +1721,14 @@ sds genRedisInfoString(char *section) { "changes_since_last_save:%lld\r\n" "bgsave_in_progress:%d\r\n" "last_save_time:%ld\r\n" + "last_bgsave_status:%s\r\n" "bgrewriteaof_in_progress:%d\r\n", server.loading, server.aof_state != REDIS_AOF_OFF, server.dirty, server.rdb_child_pid != -1, server.lastsave, + server.lastbgsave_status == REDIS_OK ? "ok" : "err", server.aof_child_pid != -1); if (server.aof_state != REDIS_AOF_OFF) { @@ -1578,6 +1784,7 @@ sds genRedisInfoString(char *section) { "# Stats\r\n" "total_connections_received:%lld\r\n" "total_commands_processed:%lld\r\n" + "instantaneous_ops_per_sec:%lld\r\n" "rejected_connections:%lld\r\n" "expired_keys:%lld\r\n" "evicted_keys:%lld\r\n" @@ -1588,6 +1795,7 @@ sds genRedisInfoString(char *section) { "latest_fork_usec:%lld\r\n", server.stat_numconnections, server.stat_numcommands, + getOperationsPerSecond(), server.stat_rejected_conn, server.stat_expiredkeys, server.stat_evictedkeys, @@ -1703,15 +1911,6 @@ sds genRedisInfoString(char *section) { } } - /* Clusetr */ - if (allsections || defsections || !strcasecmp(section,"cluster")) { - if (sections++) info = sdscat(info,"\r\n"); - info = sdscatprintf(info, - "# Cluster\r\n" - "cluster_enabled:%d\r\n", - server.cluster_enabled); - } - /* Key space */ if (allsections || defsections || !strcasecmp(section,"keyspace")) { if (sections++) info = sdscat(info,"\r\n"); @@ -1757,23 +1956,57 @@ void monitorCommand(redisClient *c) { /* ============================ Maxmemory directive ======================== */ /* This function gets called when 'maxmemory' is set on the config file to limit - * the max memory used by the server, and we are out of memory. - * This function will try to, in order: + * the max memory used by the server, before processing a command. + * + * The goal of the function is to free enough memory to keep Redis under the + * configured memory limit. * - * - Free objects from the free list - * - Try to remove keys with an EXPIRE set + * The function starts calculating how many bytes should be freed to keep + * Redis under the limit, and enters a loop selecting the best keys to + * evict accordingly to the configured policy. * - * It is not possible to free enough memory to reach used-memory < maxmemory - * the server will start refusing commands that will enlarge even more the - * memory usage. + * If all the bytes needed to return back under the limit were freed the + * function returns REDIS_OK, otherwise REDIS_ERR is returned, and the caller + * should block the execution of commands that will result in more memory + * used by the server. */ -void freeMemoryIfNeeded(void) { - /* Remove keys accordingly to the active policy as long as we are - * over the memory limit. */ - if (server.maxmemory_policy == REDIS_MAXMEMORY_NO_EVICTION) return; +int freeMemoryIfNeeded(void) { + size_t mem_used, mem_tofree, mem_freed; + int slaves = listLength(server.slaves); + + /* Remove the size of slaves output buffers and AOF buffer from the + * count of used memory. */ + mem_used = zmalloc_used_memory(); + if (slaves) { + listIter li; + listNode *ln; + + listRewind(server.slaves,&li); + while((ln = listNext(&li))) { + redisClient *slave = listNodeValue(ln); + unsigned long obuf_bytes = getClientOutputBufferMemoryUsage(slave); + if (obuf_bytes > mem_used) + mem_used = 0; + else + mem_used -= obuf_bytes; + } + } + if (server.aof_state != REDIS_AOF_OFF) { + mem_used -= sdslen(server.aof_buf); + mem_used -= sdslen(server.aof_rewrite_buf); + } - while (server.maxmemory && zmalloc_used_memory() > server.maxmemory) { - int j, k, freed = 0; + /* Check if we are over the memory limit. */ + if (mem_used <= server.maxmemory) return REDIS_OK; + + if (server.maxmemory_policy == REDIS_MAXMEMORY_NO_EVICTION) + return REDIS_ERR; /* We need to free memory, but policy forbids. */ + + /* Compute how much memory we need to free. */ + mem_tofree = mem_used - server.maxmemory; + mem_freed = 0; + while (mem_freed < mem_tofree) { + int j, k, keys_freed = 0; for (j = 0; j < server.dbnum; j++) { long bestval = 0; /* just to prevent warning */ @@ -1846,16 +2079,36 @@ void freeMemoryIfNeeded(void) { /* Finally remove the selected key. */ if (bestkey) { + long long delta; + robj *keyobj = createStringObject(bestkey,sdslen(bestkey)); propagateExpire(db,keyobj); + /* We compute the amount of memory freed by dbDelete() alone. + * It is possible that actually the memory needed to propagate + * the DEL in AOF and replication link is greater than the one + * we are freeing removing the key, but we can't account for + * that otherwise we would never exit the loop. + * + * AOF and Output buffer memory will be freed eventually so + * we only care about memory used by the key space. */ + delta = (long long) zmalloc_used_memory(); dbDelete(db,keyobj); + delta -= (long long) zmalloc_used_memory(); + mem_freed += delta; server.stat_evictedkeys++; decrRefCount(keyobj); - freed++; + keys_freed++; + + /* When the memory to free starts to be big enough, we may + * start spending so much time here that is impossible to + * deliver data to the slaves fast enough, so we force the + * transmission here inside the loop. */ + if (slaves) flushSlavesOutputBuffers(); } } - if (!freed) return; /* nothing to free... */ + if (!keys_freed) return REDIS_ERR; /* nothing to free... */ } + return REDIS_OK; } /* =================================== Main! ================================ */ @@ -1937,7 +2190,7 @@ void redisAsciiArt(void) { redisGitSHA1(), strtol(redisGitDirty(),NULL,10) > 0, (sizeof(long) == 8) ? "64" : "32", - server.cluster_enabled ? "cluster" : "stand alone", + "stand alone", server.port, (long) getpid() );