X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/2b2eca1f5643260ae7ca6bec70c263ff0db5a8e3..a1b1c1ea3adb864c8c2e3feb4eaed890a9b505cf:/src/replication.c diff --git a/src/replication.c b/src/replication.c index 9f8d9274..c1e46191 100644 --- a/src/replication.c +++ b/src/replication.c @@ -3,6 +3,7 @@ #include <sys/time.h> #include <unistd.h> #include <fcntl.h> +#include <sys/socket.h> #include <sys/stat.h> /* ---------------------------------- MASTER -------------------------------- */ @@ -10,38 +11,8 @@ void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) { listNode *ln; listIter li; - int outc = 0, j; - robj **outv; - /* We need 1+(ARGS*3) objects since commands are using the new protocol - * and we one 1 object for the first "*<count>\r\n" multibulk count, then - * for every additional object we have "$<count>\r\n" + object + "\r\n". */ - robj *static_outv[REDIS_STATIC_ARGS*3+1]; - robj *lenobj; - - if (argc <= REDIS_STATIC_ARGS) { - outv = static_outv; - } else { - outv = zmalloc(sizeof(robj*)*(argc*3+1)); - } + int j; - lenobj = createObject(REDIS_STRING, - sdscatprintf(sdsempty(), "*%d\r\n", argc)); - lenobj->refcount = 0; - outv[outc++] = lenobj; - for (j = 0; j < argc; j++) { - lenobj = createObject(REDIS_STRING, - sdscatprintf(sdsempty(),"$%lu\r\n", - (unsigned long) stringObjectLen(argv[j]))); - lenobj->refcount = 0; - outv[outc++] = lenobj; - outv[outc++] = argv[j]; - outv[outc++] = shared.crlf; - } - - /* Increment all the refcounts at start and decrement at end in order to - * be sure to free objects if there is no slave in a replication state - * able to be feed with commands */ - for (j = 0; j < outc; j++) incrRefCount(outv[j]); listRewind(slaves,&li); while((ln = listNext(&li))) { redisClient *slave = ln->value; @@ -49,47 +20,45 @@ void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) { /* Don't feed slaves that are still waiting for BGSAVE to start */ if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) continue; - /* Feed all the other slaves, MONITORs and so on */ + /* Feed slaves that are waiting for the initial SYNC (so these commands + * are queued in the output buffer until the intial SYNC completes), + * or are already in sync with the master. */ if (slave->slaveseldb != dictid) { robj *selectcmd; - switch(dictid) { - case 0: selectcmd = shared.select0; break; - case 1: selectcmd = shared.select1; break; - case 2: selectcmd = shared.select2; break; - case 3: selectcmd = shared.select3; break; - case 4: selectcmd = shared.select4; break; - case 5: selectcmd = shared.select5; break; - case 6: selectcmd = shared.select6; break; - case 7: selectcmd = shared.select7; break; - case 8: selectcmd = shared.select8; break; - case 9: selectcmd = shared.select9; break; - default: + if (dictid >= 0 && dictid < REDIS_SHARED_SELECT_CMDS) { + selectcmd = shared.select[dictid]; + incrRefCount(selectcmd); + } else { selectcmd = createObject(REDIS_STRING, sdscatprintf(sdsempty(),"select %d\r\n",dictid)); - selectcmd->refcount = 0; - break; } addReply(slave,selectcmd); + decrRefCount(selectcmd); slave->slaveseldb = dictid; } - for (j = 0; j < outc; j++) addReply(slave,outv[j]); + addReplyMultiBulkLen(slave,argc); + for (j = 0; j < argc; j++) addReplyBulk(slave,argv[j]); } - for (j = 0; j < outc; j++) decrRefCount(outv[j]); - if (outv != static_outv) zfree(outv); } -void replicationFeedMonitors(list *monitors, int dictid, robj **argv, int argc) { +void replicationFeedMonitors(redisClient *c, list *monitors, int dictid, robj **argv, int argc) { listNode *ln; listIter li; - int j; + int j, port; sds cmdrepr = sdsnew("+"); robj *cmdobj; + char ip[32]; struct timeval tv; gettimeofday(&tv,NULL); cmdrepr = sdscatprintf(cmdrepr,"%ld.%06ld ",(long)tv.tv_sec,(long)tv.tv_usec); - if (dictid != 0) cmdrepr = sdscatprintf(cmdrepr,"(db %d) ", dictid); + if (c->flags & REDIS_LUA_CLIENT) { + cmdrepr = sdscatprintf(cmdrepr,"[%d lua] ", dictid); + } else { + anetPeerToString(c->fd,ip,&port); + cmdrepr = sdscatprintf(cmdrepr,"[%d %s:%d] ", dictid,ip,port); + } for (j = 0; j < argc; j++) { if (argv[j]->encoding == REDIS_ENCODING_INT) { @@ -118,7 +87,7 @@ void syncCommand(redisClient *c) { /* Refuse SYNC requests if we are a slave but the link with our master * is not ok... */ - if (server.masterhost && server.replstate != REDIS_REPL_CONNECTED) { + if (server.masterhost && server.repl_state != REDIS_REPL_CONNECTED) { addReplyError(c,"Can't SYNC while not connected with my master"); return; } @@ -135,7 +104,7 @@ void syncCommand(redisClient *c) { redisLog(REDIS_NOTICE,"Slave ask for synchronization"); /* Here we need to check if there is a background saving operation * in progress, or if it is required to start one */ - if (server.bgsavechildpid != -1) { + if (server.rdb_child_pid != -1) { /* Ok a background save is in progress. Let's check if it is a good * one for replication, i.e. if there is another slave that is * registering differences since the server forked to save */ @@ -151,8 +120,7 @@ void syncCommand(redisClient *c) { if (ln) { /* Perfect, the server is already registering differences for * another slave. Set the right state, and copy the buffer. */ - listRelease(c->reply); - c->reply = listDup(slave->reply); + copyClientOutputBuffer(c,slave); c->replstate = REDIS_REPL_WAIT_BGSAVE_END; redisLog(REDIS_NOTICE,"Waiting for end of BGSAVE for SYNC"); } else { @@ -164,7 +132,7 @@ void syncCommand(redisClient *c) { } else { /* Ok we don't have a BGSAVE in progress, let's start one */ redisLog(REDIS_NOTICE,"Starting BGSAVE for SYNC"); - if (rdbSaveBackground(server.dbfilename) != REDIS_OK) { + if (rdbSaveBackground(server.rdb_filename) != REDIS_OK) { redisLog(REDIS_NOTICE,"Replication failed, can't BGSAVE"); addReplyError(c,"Unable to perform background save"); return; @@ -178,6 +146,46 @@ void syncCommand(redisClient *c) { return; } +/* REPLCONF <option> <value> <option> <value> ... + * This command is used by a slave in order to configure the replication + * process before starting it with the SYNC command. + * + * Currently the only use of this command is to communicate to the master + * what is the listening port of the Slave redis instance, so that the + * master can accurately list slaves and their listening ports in + * the INFO output. + * + * In the future the same command can be used in order to configure + * the replication to initiate an incremental replication instead of a + * full resync. */ +void replconfCommand(redisClient *c) { + int j; + + if ((c->argc % 2) == 0) { + /* Number of arguments must be odd to make sure that every + * option has a corresponding value. */ + addReply(c,shared.syntaxerr); + return; + } + + /* Process every option-value pair. */ + for (j = 1; j < c->argc; j+=2) { + if (!strcasecmp(c->argv[j]->ptr,"listening-port")) { + long port; + + if ((getLongFromObjectOrReply(c,c->argv[j+1], + &port,NULL) != REDIS_OK)) + return; + c->slave_listening_port = port; + } else { + addReplyErrorFormat(c,"Unrecognized REPLCONF option: %s", + (char*)c->argv[j]->ptr); + return; + } + } + addReply(c,shared.ok); +} + void sendBulkToSlave(aeEventLoop *el, int fd, void *privdata, int mask) { redisClient *slave = privdata; REDIS_NOTUSED(el); @@ -227,7 +235,6 @@ void sendBulkToSlave(aeEventLoop *el, int fd, void *privdata, int mask) { freeClient(slave); return; } - addReplySds(slave,sdsempty()); redisLog(REDIS_NOTICE,"Synchronization with slave succeeded"); } } @@ -258,7 +265,7 @@ void updateSlavesWaitingBgsave(int bgsaveerr) { redisLog(REDIS_WARNING,"SYNC failed. BGSAVE child returned an error"); continue; } - if ((slave->repldbfd = open(server.dbfilename,O_RDONLY)) == -1 || + if ((slave->repldbfd = open(server.rdb_filename,O_RDONLY)) == -1 || redis_fstat(slave->repldbfd,&buf) == -1) { freeClient(slave); redisLog(REDIS_WARNING,"SYNC failed. Can't open/stat DB after BGSAVE: %s", strerror(errno)); @@ -275,7 +282,7 @@ void updateSlavesWaitingBgsave(int bgsaveerr) { } } if (startbgsave) { - if (rdbSaveBackground(server.dbfilename) != REDIS_OK) { + if (rdbSaveBackground(server.rdb_filename) != REDIS_OK) { listIter li; listRewind(server.slaves,&li); @@ -294,55 +301,61 @@ void updateSlavesWaitingBgsave(int bgsaveerr) { /* Abort the async download of the bulk dataset while SYNC-ing with master */ void replicationAbortSyncTransfer(void) { - redisAssert(server.replstate == REDIS_REPL_TRANSFER); + redisAssert(server.repl_state == REDIS_REPL_TRANSFER); aeDeleteFileEvent(server.el,server.repl_transfer_s,AE_READABLE); close(server.repl_transfer_s); close(server.repl_transfer_fd); unlink(server.repl_transfer_tmpfile); zfree(server.repl_transfer_tmpfile); - server.replstate = REDIS_REPL_CONNECT; + server.repl_state = REDIS_REPL_CONNECT; } /* Asynchronously read the SYNC payload we receive from a master */ +#define REPL_MAX_WRITTEN_BEFORE_FSYNC (1024*1024*8) /* 8 MB */ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) { char buf[4096]; ssize_t nread, readlen; + off_t left; REDIS_NOTUSED(el); REDIS_NOTUSED(privdata); REDIS_NOTUSED(mask); - /* If repl_transfer_left == -1 we still have to read the bulk length + /* If repl_transfer_size == -1 we still have to read the bulk length * from the master reply. */ - if (server.repl_transfer_left == -1) { - if (syncReadLine(fd,buf,1024,3600) == -1) { + if (server.repl_transfer_size == -1) { + if (syncReadLine(fd,buf,1024,server.repl_syncio_timeout*1000) == -1) { redisLog(REDIS_WARNING, "I/O error reading bulk count from MASTER: %s", strerror(errno)); - replicationAbortSyncTransfer(); - return; + goto error; } + if (buf[0] == '-') { redisLog(REDIS_WARNING, "MASTER aborted replication with an error: %s", buf+1); - replicationAbortSyncTransfer(); + goto error; + } else if (buf[0] == '\0') { + /* At this stage just a newline works as a PING in order to take + * the connection live. So we refresh our last interaction + * timestamp. */ + server.repl_transfer_lastio = server.unixtime; return; } else if (buf[0] != '$') { redisLog(REDIS_WARNING,"Bad protocol from MASTER, the first byte is not '$', are you sure the host and port are right?"); - replicationAbortSyncTransfer(); - return; + goto error; } - server.repl_transfer_left = strtol(buf+1,NULL,10); + server.repl_transfer_size = strtol(buf+1,NULL,10); redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: receiving %ld bytes from master", - server.repl_transfer_left); + server.repl_transfer_size); return; } /* Read bulk data */ - readlen = (server.repl_transfer_left < (signed)sizeof(buf)) ? - server.repl_transfer_left : (signed)sizeof(buf); + left = server.repl_transfer_size - server.repl_transfer_read; + readlen = (left < (signed)sizeof(buf)) ? left : (signed)sizeof(buf); nread = read(fd,buf,readlen); if (nread <= 0) { redisLog(REDIS_WARNING,"I/O error trying to sync with MASTER: %s", @@ -350,16 +363,29 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) { replicationAbortSyncTransfer(); return; } - server.repl_transfer_lastio = time(NULL); + server.repl_transfer_lastio = server.unixtime; if (write(server.repl_transfer_fd,buf,nread) != nread) { - redisLog(REDIS_WARNING,"Write error or short write writing to the DB dump file needed for MASTER <-> SLAVE synchrnonization: %s", strerror(errno)); - replicationAbortSyncTransfer(); - return; + redisLog(REDIS_WARNING,"Write error or short write writing to the DB dump file needed for MASTER <-> SLAVE synchronization: %s", strerror(errno)); + goto error; + } + server.repl_transfer_read += nread; + + /* Sync data on disk from time to time, otherwise at the end of the transfer + * we may suffer a big delay as the memory buffers are copied into the + * actual disk. */ + if (server.repl_transfer_read >= + server.repl_transfer_last_fsync_off + REPL_MAX_WRITTEN_BEFORE_FSYNC) + { + off_t sync_size = server.repl_transfer_read - + server.repl_transfer_last_fsync_off; + rdb_fsync_range(server.repl_transfer_fd, + server.repl_transfer_last_fsync_off, sync_size); + server.repl_transfer_last_fsync_off += sync_size; } - server.repl_transfer_left -= nread; + /* Check if the transfer is now complete */ - if (server.repl_transfer_left == 0) { - if (rename(server.repl_transfer_tmpfile,server.dbfilename) == -1) { + if (server.repl_transfer_read == server.repl_transfer_size) { + if (rename(server.repl_transfer_tmpfile,server.rdb_filename) == -1) { redisLog(REDIS_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno)); replicationAbortSyncTransfer(); return; @@ -371,7 +397,7 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) { * rdbLoad() will call the event loop to process events from time to * time for non blocking loading. */ aeDeleteFileEvent(server.el,server.repl_transfer_s,AE_READABLE); - if (rdbLoad(server.dbfilename) != REDIS_OK) { + if (rdbLoad(server.rdb_filename) != REDIS_OK) { redisLog(REDIS_WARNING,"Failed trying to load the MASTER synchronization DB from disk"); replicationAbortSyncTransfer(); return; @@ -382,84 +408,258 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) { server.master = createClient(server.repl_transfer_s); server.master->flags |= REDIS_MASTER; server.master->authenticated = 1; - server.replstate = REDIS_REPL_CONNECTED; + server.repl_state = REDIS_REPL_CONNECTED; redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: Finished with success"); + /* Restart the AOF subsystem now that we finished the sync. This + * will trigger an AOF rewrite, and when done will start appending + * to the new file. */ + if (server.aof_state != REDIS_AOF_OFF) { + int retry = 10; + + stopAppendOnly(); + while (retry-- && startAppendOnly() == REDIS_ERR) { + redisLog(REDIS_WARNING,"Failed enabling the AOF after successful master synchrnization! Trying it again in one second."); + sleep(1); + } + if (!retry) { + redisLog(REDIS_WARNING,"FATAL: this slave instance finished the synchronization with its master, but the AOF can't be turned on. Exiting now."); + exit(1); + } + } } + + return; + +error: + replicationAbortSyncTransfer(); + return; } -int syncWithMaster(void) { - char buf[1024], tmpfile[256], authcmd[1024]; - int fd = anetTcpConnect(NULL,server.masterhost,server.masterport); +/* Send a synchronous command to the master. Used to send AUTH and + * REPLCONF commands before starting the replication with SYNC. + * + * On success NULL is returned. + * On error an sds string describing the error is returned. + */ +char *sendSynchronousCommand(int fd, ...) { + va_list ap; + sds cmd = sdsempty(); + char *arg, buf[256]; + + /* Create the command to send to the master, we use simple inline + * protocol for simplicity as currently we only send simple strings. */ + va_start(ap,fd); + while(1) { + arg = va_arg(ap, char*); + if (arg == NULL) break; + + if (sdslen(cmd) != 0) cmd = sdscatlen(cmd," ",1); + cmd = sdscat(cmd,arg); + } + cmd = sdscatlen(cmd,"\r\n",2); + + /* Transfer command to the server. */ + if (syncWrite(fd,cmd,sdslen(cmd),server.repl_syncio_timeout*1000) == -1) { + sdsfree(cmd); + return sdscatprintf(sdsempty(),"Writing to master: %s", + strerror(errno)); + } + sdsfree(cmd); + + /* Read the reply from the server. */ + if (syncReadLine(fd,buf,sizeof(buf),server.repl_syncio_timeout*1000) == -1) + { + return sdscatprintf(sdsempty(),"Reading from master: %s", + strerror(errno)); + } + + /* Check for errors from the server. */ + if (buf[0] != '+') { + return sdscatprintf(sdsempty(),"Error from master: %s", buf); + } + + return NULL; /* No errors. */ +} + +void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) { + char tmpfile[256], *err; int dfd, maxtries = 5; + int sockerr = 0; + socklen_t errlen = sizeof(sockerr); + REDIS_NOTUSED(el); + REDIS_NOTUSED(privdata); + REDIS_NOTUSED(mask); - if (fd == -1) { - redisLog(REDIS_WARNING,"Unable to connect to MASTER: %s", - strerror(errno)); - return REDIS_ERR; + /* If this event fired after the user turned the instance into a master + * with SLAVEOF NO ONE we must just return ASAP. */ + if (server.repl_state == REDIS_REPL_NONE) { + close(fd); + return; + } + + /* Check for errors in the socket. */ + if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &sockerr, &errlen) == -1) + sockerr = errno; + if (sockerr) { + aeDeleteFileEvent(server.el,fd,AE_READABLE|AE_WRITABLE); + redisLog(REDIS_WARNING,"Error condition on socket for SYNC: %s", + strerror(sockerr)); + goto error; + } + + /* If we were connecting, it's time to send a non blocking PING, we want to + * make sure the master is able to reply before going into the actual + * replication process where we have long timeouts in the order of + * seconds (in the meantime the slave would block). */ + if (server.repl_state == REDIS_REPL_CONNECTING) { + redisLog(REDIS_NOTICE,"Non blocking connect for SYNC fired the event."); + /* Delete the writable event so that the readable event remains + * registered and we can wait for the PONG reply. */ + aeDeleteFileEvent(server.el,fd,AE_WRITABLE); + server.repl_state = REDIS_REPL_RECEIVE_PONG; + /* Send the PING, don't check for errors at all, we have the timeout + * that will take care about this. */ + syncWrite(fd,"PING\r\n",6,100); + return; + } + + /* Receive the PONG command. */ + if (server.repl_state == REDIS_REPL_RECEIVE_PONG) { + char buf[1024]; + + /* Delete the readable event, we no longer need it now that there is + * the PING reply to read. */ + aeDeleteFileEvent(server.el,fd,AE_READABLE); + + /* Read the reply with explicit timeout. */ + buf[0] = '\0'; + if (syncReadLine(fd,buf,sizeof(buf), + server.repl_syncio_timeout*1000) == -1) + { + redisLog(REDIS_WARNING, + "I/O error reading PING reply from master: %s", + strerror(errno)); + goto error; + } + + /* We don't care about the reply, it can be +PONG or an error since + * the server requires AUTH. As long as it replies correctly, it's + * fine from our point of view. */ + if (buf[0] != '-' && buf[0] != '+') { + redisLog(REDIS_WARNING,"Unexpected reply to PING from master."); + goto error; + } else { + redisLog(REDIS_NOTICE, + "Master replied to PING, replication can continue..."); + } } /* AUTH with the master if required. */ if(server.masterauth) { - snprintf(authcmd, 1024, "AUTH %s\r\n", server.masterauth); - if (syncWrite(fd, authcmd, strlen(server.masterauth)+7, 5) == -1) { - close(fd); - redisLog(REDIS_WARNING,"Unable to AUTH to MASTER: %s", - strerror(errno)); - return REDIS_ERR; - } - /* Read the AUTH result. */ - if (syncReadLine(fd,buf,1024,3600) == -1) { - close(fd); - redisLog(REDIS_WARNING,"I/O error reading auth result from MASTER: %s", - strerror(errno)); - return REDIS_ERR; + err = sendSynchronousCommand(fd,"AUTH",server.masterauth,NULL); + if (err) { + redisLog(REDIS_WARNING,"Unable to AUTH to MASTER: %s",err); + sdsfree(err); + goto error; } - if (buf[0] != '+') { - close(fd); - redisLog(REDIS_WARNING,"Cannot AUTH to MASTER, is the masterauth password correct?"); - return REDIS_ERR; + } + + /* Set the slave port, so that Master's INFO command can list the + * slave listening port correctly. */ + { + sds port = sdsfromlonglong(server.port); + err = sendSynchronousCommand(fd,"REPLCONF","listening-port",port, + NULL); + sdsfree(port); + /* Ignore the error if any, not all the Redis versions support + * REPLCONF listening-port. */ + if (err) { + redisLog(REDIS_NOTICE,"(non critical): Master does not understand REPLCONF listening-port: %s", err); + sdsfree(err); } } /* Issue the SYNC command */ - if (syncWrite(fd,"SYNC \r\n",7,5) == -1) { - close(fd); + if (syncWrite(fd,"SYNC\r\n",6,server.repl_syncio_timeout*1000) == -1) { redisLog(REDIS_WARNING,"I/O error writing to MASTER: %s", strerror(errno)); - return REDIS_ERR; + goto error; } /* Prepare a suitable temp file for bulk transfer */ while(maxtries--) { snprintf(tmpfile,256, - "temp-%d.%ld.rdb",(int)time(NULL),(long int)getpid()); + "temp-%d.%ld.rdb",(int)server.unixtime,(long int)getpid()); dfd = open(tmpfile,O_CREAT|O_WRONLY|O_EXCL,0644); if (dfd != -1) break; sleep(1); } if (dfd == -1) { - close(fd); redisLog(REDIS_WARNING,"Opening the temp file needed for MASTER <-> SLAVE synchronization: %s",strerror(errno)); - return REDIS_ERR; + goto error; } /* Setup the non blocking download of the bulk file. */ - if (aeCreateFileEvent(server.el, fd, AE_READABLE, readSyncBulkPayload, NULL) + if (aeCreateFileEvent(server.el,fd, AE_READABLE,readSyncBulkPayload,NULL) == AE_ERR) + { + redisLog(REDIS_WARNING,"Can't create readable event for SYNC"); + goto error; + } + + server.repl_state = REDIS_REPL_TRANSFER; + server.repl_transfer_size = -1; + server.repl_transfer_read = 0; + server.repl_transfer_last_fsync_off = 0; + server.repl_transfer_fd = dfd; + server.repl_transfer_lastio = server.unixtime; + server.repl_transfer_tmpfile = zstrdup(tmpfile); + return; + +error: + close(fd); + server.repl_transfer_s = -1; + server.repl_state = REDIS_REPL_CONNECT; + return; +} + +int connectWithMaster(void) { + int fd; + + fd = anetTcpNonBlockConnect(NULL,server.masterhost,server.masterport); + if (fd == -1) { + redisLog(REDIS_WARNING,"Unable to connect to MASTER: %s", + strerror(errno)); + return REDIS_ERR; + } + + if (aeCreateFileEvent(server.el,fd,AE_READABLE|AE_WRITABLE,syncWithMaster,NULL) == + AE_ERR) { close(fd); redisLog(REDIS_WARNING,"Can't create readable event for SYNC"); return REDIS_ERR; } - server.replstate = REDIS_REPL_TRANSFER; - server.repl_transfer_left = -1; + + server.repl_transfer_lastio = server.unixtime; server.repl_transfer_s = fd; - server.repl_transfer_fd = dfd; - server.repl_transfer_lastio = time(NULL); - server.repl_transfer_tmpfile = zstrdup(tmpfile); + server.repl_state = REDIS_REPL_CONNECTING; return REDIS_OK; } +/* This function can be called when a non blocking connection is currently + * in progress to undo it. */ +void undoConnectWithMaster(void) { + int fd = server.repl_transfer_s; + + redisAssert(server.repl_state == REDIS_REPL_CONNECTING || + server.repl_state == REDIS_REPL_RECEIVE_PONG); + aeDeleteFileEvent(server.el,fd,AE_READABLE|AE_WRITABLE); + close(fd); + server.repl_transfer_s = -1; + server.repl_state = REDIS_REPL_CONNECT; +} + void slaveofCommand(redisClient *c) { if (!strcasecmp(c->argv[1]->ptr,"no") && !strcasecmp(c->argv[2]->ptr,"one")) { @@ -467,19 +667,37 @@ void slaveofCommand(redisClient *c) { sdsfree(server.masterhost); server.masterhost = NULL; if (server.master) freeClient(server.master); - if (server.replstate == REDIS_REPL_TRANSFER) + if (server.repl_state == REDIS_REPL_TRANSFER) replicationAbortSyncTransfer(); - server.replstate = REDIS_REPL_NONE; + else if (server.repl_state == REDIS_REPL_CONNECTING || + server.repl_state == REDIS_REPL_RECEIVE_PONG) + undoConnectWithMaster(); + server.repl_state = REDIS_REPL_NONE; redisLog(REDIS_NOTICE,"MASTER MODE enabled (user request)"); } } else { + long port; + + if ((getLongFromObjectOrReply(c, c->argv[2], &port, NULL) != REDIS_OK)) + return; + + /* Check if we are already attached to the specified slave */ + if (server.masterhost && !strcasecmp(server.masterhost,c->argv[1]->ptr) + && server.masterport == port) { + redisLog(REDIS_NOTICE,"SLAVE OF would result into synchronization with the master we are already connected with. No operation performed."); + addReplySds(c,sdsnew("+OK Already connected to specified master\r\n")); + return; + } + /* There was no previous master or the user specified a different one, + * we can continue. */ sdsfree(server.masterhost); server.masterhost = sdsdup(c->argv[1]->ptr); - server.masterport = atoi(c->argv[2]->ptr); + server.masterport = port; if (server.master) freeClient(server.master); - if (server.replstate == REDIS_REPL_TRANSFER) + disconnectSlaves(); /* Force our slaves to resync with us as well. */ + if (server.repl_state == REDIS_REPL_TRANSFER) replicationAbortSyncTransfer(); - server.replstate = REDIS_REPL_CONNECT; + server.repl_state = REDIS_REPL_CONNECT; redisLog(REDIS_NOTICE,"SLAVE OF %s:%d enabled (user request)", server.masterhost, server.masterport); } @@ -488,23 +706,69 @@ void slaveofCommand(redisClient *c) { /* --------------------------- REPLICATION CRON ---------------------------- */ -#define REDIS_REPL_TRANSFER_TIMEOUT 60 - void replicationCron(void) { + /* Non blocking connection timeout? */ + if (server.masterhost && + (server.repl_state == REDIS_REPL_CONNECTING || + server.repl_state == REDIS_REPL_RECEIVE_PONG) && + (time(NULL)-server.repl_transfer_lastio) > server.repl_timeout) + { + redisLog(REDIS_WARNING,"Timeout connecting to the MASTER..."); + undoConnectWithMaster(); + } + /* Bulk transfer I/O timeout? */ - if (server.masterhost && server.replstate == REDIS_REPL_TRANSFER && - (time(NULL)-server.repl_transfer_lastio) > REDIS_REPL_TRANSFER_TIMEOUT) + if (server.masterhost && server.repl_state == REDIS_REPL_TRANSFER && + (time(NULL)-server.repl_transfer_lastio) > server.repl_timeout) { - redisLog(REDIS_WARNING,"Timeout receiving bulk data from MASTER..."); + redisLog(REDIS_WARNING,"Timeout receiving bulk data from MASTER... If the problem persists try to set the 'repl-timeout' parameter in redis.conf to a larger value."); replicationAbortSyncTransfer(); } + /* Timed out master when we are an already connected slave? */ + if (server.masterhost && server.repl_state == REDIS_REPL_CONNECTED && + (time(NULL)-server.master->lastinteraction) > server.repl_timeout) + { + redisLog(REDIS_WARNING,"MASTER time out: no data nor PING received..."); + freeClient(server.master); + } + /* Check if we should connect to a MASTER */ - if (server.replstate == REDIS_REPL_CONNECT) { + if (server.repl_state == REDIS_REPL_CONNECT) { redisLog(REDIS_NOTICE,"Connecting to MASTER..."); - if (syncWithMaster() == REDIS_OK) { - redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync started: SYNC sent"); - if (server.appendonly) rewriteAppendOnlyFileBackground(); + if (connectWithMaster() == REDIS_OK) { + redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync started"); + } + } + + /* If we have attached slaves, PING them from time to time. + * So slaves can implement an explicit timeout to masters, and will + * be able to detect a link disconnection even if the TCP connection + * will not actually go down. */ + if (!(server.cronloops % (server.repl_ping_slave_period * REDIS_HZ))) { + listIter li; + listNode *ln; + + listRewind(server.slaves,&li); + while((ln = listNext(&li))) { + redisClient *slave = ln->value; + + /* Don't ping slaves that are in the middle of a bulk transfer + * with the master for first synchronization. */ + if (slave->replstate == REDIS_REPL_SEND_BULK) continue; + if (slave->replstate == REDIS_REPL_ONLINE) { + /* If the slave is online send a normal ping */ + addReplySds(slave,sdsnew("*1\r\n$4\r\nPING\r\n")); + } else { + /* Otherwise we are in the pre-synchronization stage. + * Just a newline will do the work of refreshing the + * connection last interaction time, and at the same time + * we'll be sure that being a single char there are no + * short-write problems. */ + if (write(slave->fd, "\n", 1) == -1) { + /* Don't worry, it's just a ping. */ + } + } } } }