diff --git a/redis.c b/redis.c index 0040483a..19abda20 100644 --- a/redis.c +++ b/redis.c @@ -261,6 +261,9 @@ struct redisServer { int maxidletime; int dbnum; int daemonize; + int appendonly; + int appendfd; + int appendseldb; char *pidfile; int bgsaveinprogress; pid_t bgsavechildpid; @@ -269,6 +272,7 @@ struct redisServer { char *logfile; char *bindaddr; char *dbfilename; + char *appendfilename; char *requirepass; int shareobjects; /* Replication related */ @@ -364,6 +368,7 @@ static void incrRefCount(robj *o); static int rdbSaveBackground(char *filename); static robj *createStringObject(char *ptr, size_t len); static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc); +static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc); static int syncWithMaster(void); static robj *tryObjectSharing(robj *o); static int tryObjectEncoding(robj *o); @@ -1023,8 +1028,12 @@ static void initServerConfig() { server.bindaddr = NULL; server.glueoutputbuf = 1; server.daemonize = 0; + server.appendonly = 0; + server.appendfd = -1; + server.appendseldb = -1; /* Make sure the first time will not match */ server.pidfile = "/var/run/redis.pid"; server.dbfilename = "dump.rdb"; + server.appendfilename = "appendonly.log"; server.requirepass = NULL; server.shareobjects = 0; server.sharingpoolsize = 1024; @@ -1084,6 +1093,15 @@ static void initServer() { server.stat_numconnections = 0; server.stat_starttime = time(NULL); aeCreateTimeEvent(server.el, 1000, serverCron, NULL, NULL); + + if (server.appendonly) { + server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT); + if (server.appendfd == -1) { + redisLog(REDIS_WARNING, "Can't open the append-only file: %s", + strerror(errno)); + exit(1); + } + } } /* Empty the whole database */ @@ -1223,6 +1241,10 @@ static void loadServerConfig(char *filename) { if ((server.daemonize = yesnotoi(argv[1])) == -1) { err = "argument must be 'yes' or 'no'"; goto loaderr; } + } else if (!strcasecmp(argv[0],"appendonly") && argc == 2) { + if ((server.appendonly = yesnotoi(argv[1])) == -1) { + err = "argument must be 'yes' or 'no'"; goto loaderr; + } } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) { server.requirepass = zstrdup(argv[1]); } else if (!strcasecmp(argv[0],"pidfile") && argc == 2) { @@ -1538,6 +1560,8 @@ static int processCommand(redisClient *c) { /* Exec the command */ dirty = server.dirty; cmd->proc(c); + if (server.appendonly != 0) + feedAppendOnlyFile(cmd,c->db->id,c->argv,c->argc); if (server.dirty-dirty != 0 && listLength(server.slaves)) replicationFeedSlaves(server.slaves,cmd,c->db->id,c->argv,c->argc); if (listLength(server.monitors)) @@ -1622,6 +1646,54 @@ static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int di if (outv != static_outv) zfree(outv); } +/* TODO: translate EXPIREs into EXPIRETOs */ +static void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc) { + sds buf = sdsempty(); + int j; + ssize_t nwritten; + + /* The DB this command was targetting is not the same as the last command + * we appendend. To issue a SELECT command is needed. */ + if (dictid != server.appendseldb) { + char seldb[64]; + + snprintf(seldb,sizeof(seldb),"%d",dictid); + buf = sdscatprintf(buf,"*2\r\n$6\r\nSELECT\r\n$%d\r\n%s\r\n", + strlen(seldb),seldb); + } + /* Append the actual command */ + buf = sdscatprintf(buf,"*%d\r\n",argc); + for (j = 0; j < argc; j++) { + robj *o = argv[j]; + + if (o->encoding != REDIS_ENCODING_RAW) + o = getDecodedObject(o); + buf = sdscatprintf(buf,"$%d\r\n",sdslen(o->ptr)); + buf = sdscatlen(buf,o->ptr,sdslen(o->ptr)); + buf = sdscatlen(buf,"\r\n",2); + if (o != argv[j]) + decrRefCount(o); + } + /* We want to perform a single write. This should be guaranteed atomic + * at least if the filesystem we are writing is a real physical one. + * While this will save us against the server being killed I don't think + * there is much to do about the whole server stopping for power problems + * or alike */ + nwritten = write(server.appendfd,buf,sdslen(buf)); + if (nwritten != (unsigned)sdslen(buf)) { + /* Ooops, we are in troubles. The best thing to do for now is + * to simply exit instead to give the illusion that everything is + * working as expected. */ + if (nwritten == -1) { + redisLog(REDIS_WARNING,"Aborting on error writing to the append-only file: %s",strerror(errno)); + } else { + redisLog(REDIS_WARNING,"Aborting on short write while writing to the append-only file: %s",strerror(errno)); + } + abort(); + } + fsync(server.appendfd); /* Let's try to get this data on the disk */ +} + static void processInputBuffer(redisClient *c) { again: if (c->bulklen == -1) { diff --git a/redis.conf b/redis.conf index fc1e9dd9..fac5ba60 100644 --- a/redis.conf +++ b/redis.conf @@ -107,6 +107,23 @@ databases 16 # maxmemory +############################## APPEND ONLY MODE ############################### + +# By default Redis asynchronously dumps the dataset on disk. If you can live +# with the idea that the latest records will be lost if something like a crash +# happens this is the preferred way to run Redis. If instead you care a lot +# about your data and don't want to that a single record can get lost you should +# enable the append only mode: when this mode is enabled Redis will append +# every write operation received in the file appendonly.log. This file will +# be read on startup in order to rebuild the full dataset in memory. +# +# Note that you can have both the async dumps and the append only file if you +# like (you have to comment the "save" statements above to disable the dumps). +# Still if append only mode is enabled Redis will load the data from the +# log file at startup ignoring the dump.rdb file. + +# appendonly yes + ############################### ADVANCED CONFIG ############################### # Glue small output buffers together in order to send small replies in a