void slaveofCommand(redisClient *c) { if (!strcasecmp(c->argv[1]->ptr,"no") && !strcasecmp(c->argv[2]->ptr,"one")) { if (server.masterhost) { sdsfree(server.masterhost); server.masterhost = NULL; if (server.master) freeClient(server.master); if (server.replstate == REDIS_REPL_TRANSFER) replicationAbortSyncTransfer(); server.replstate = REDIS_REPL_NONE; redisLog(REDIS_NOTICE,"MASTER MODE enabled (user request)"); } } else { sdsfree(server.masterhost); server.masterhost = sdsdup(c->argv[1]->ptr); server.masterport = atoi(c->argv[2]->ptr); if (server.master) freeClient(server.master); if (server.replstate == REDIS_REPL_TRANSFER) replicationAbortSyncTransfer(); server.replstate = REDIS_REPL_CONNECT; redisLog(REDIS_NOTICE,"SLAVE OF %s:%d enabled (user request)", server.masterhost, server.masterport); } addReply(c,shared.ok); }
void slaveofCommand(redisClient *c) { if (!strcasecmp(c->argv[1]->ptr,"no") && !strcasecmp(c->argv[2]->ptr,"one")) { if (server.masterhost) { sdsfree(server.masterhost); server.masterhost = NULL; if (server.master) freeClient(server.master); if (server.repl_state == REDIS_REPL_TRANSFER) replicationAbortSyncTransfer(); 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 = port; if (server.master) freeClient(server.master); disconnectSlaves(); /* Force our slaves to resync with us as well. */ if (server.repl_state == REDIS_REPL_TRANSFER) replicationAbortSyncTransfer(); server.repl_state = REDIS_REPL_CONNECT; redisLog(REDIS_NOTICE,"SLAVE OF %s:%d enabled (user request)", server.masterhost, server.masterport); } addReply(c,shared.ok); }
void replicationCron(void) { /* Bulk transfer I/O timeout? */ if (server.masterhost && server.replstate == REDIS_REPL_TRANSFER && (time(NULL)-server.repl_transfer_lastio) > REDIS_REPL_TIMEOUT) { redisLog(REDIS_WARNING,"Timeout receiving bulk data from MASTER..."); replicationAbortSyncTransfer(); } /* Timed out master when we are an already connected slave? */ if (server.masterhost && server.replstate == REDIS_REPL_CONNECTED && (time(NULL)-server.master->lastinteraction) > REDIS_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) { redisLog(REDIS_NOTICE,"Connecting to MASTER..."); if (syncWithMaster() == REDIS_OK) { redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync started: SYNC sent"); if (server.appendonly) rewriteAppendOnlyFileBackground(); } } /* 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 % (REDIS_REPL_PING_SLAVE_PERIOD*10))) { 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("PING\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. */ write(slave->fd, "\n", 1); } } } }
/* This function aborts a non blocking replication attempt if there is one * in progress, by canceling the non-blocking connect attempt or * the initial bulk transfer. * * If there was a replication handshake in progress 1 is returned and * the replication state (server.repl_state) set to REDIS_REPL_CONNECT. * * Otherwise zero is returned and no operation is perforemd at all. */ int cancelReplicationHandshake(void) { if (server.repl_state == REDIS_REPL_TRANSFER) { replicationAbortSyncTransfer(); } else if (server.repl_state == REDIS_REPL_CONNECTING || server.repl_state == REDIS_REPL_RECEIVE_PONG) { undoConnectWithMaster(); } else { return 0; } return 1; }
/* Asynchronously read the SYNC payload we receive from a master */ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) { char buf[4096]; ssize_t nread, readlen; REDIS_NOTUSED(el); REDIS_NOTUSED(privdata); REDIS_NOTUSED(mask); /* If repl_transfer_left == -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) { redisLog(REDIS_WARNING, "I/O error reading bulk count from MASTER: %s", strerror(errno)); replicationAbortSyncTransfer(); return; } if (buf[0] == '-') { redisLog(REDIS_WARNING, "MASTER aborted replication with an error: %s", buf+1); replicationAbortSyncTransfer(); return; } 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 = time(NULL); 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; } server.repl_transfer_left = strtol(buf+1,NULL,10); redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: receiving %ld bytes from master", server.repl_transfer_left); return; } /* Read bulk data */ readlen = (server.repl_transfer_left < (signed)sizeof(buf)) ? server.repl_transfer_left : (signed)sizeof(buf); nread = read(fd,buf,readlen); if (nread <= 0) { redisLog(REDIS_WARNING,"I/O error trying to sync with MASTER: %s", (nread == -1) ? strerror(errno) : "connection lost"); replicationAbortSyncTransfer(); return; } server.repl_transfer_lastio = time(NULL); 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; } 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) { redisLog(REDIS_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno)); replicationAbortSyncTransfer(); return; } redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: Loading DB in memory"); emptyDb(); /* Before loading the DB into memory we need to delete the readable * handler, otherwise it will get called recursively since * 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) { redisLog(REDIS_WARNING,"Failed trying to load the MASTER synchronization DB from disk"); replicationAbortSyncTransfer(); return; } /* Final setup of the connected slave <- master link */ zfree(server.repl_transfer_tmpfile); close(server.repl_transfer_fd); server.master = createClient(server.repl_transfer_s); server.master->flags |= REDIS_MASTER; server.master->authenticated = 1; server.replstate = REDIS_REPL_CONNECTED; redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: Finished with success"); } }
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.repl_state == REDIS_REPL_TRANSFER && (time(NULL)-server.repl_transfer_lastio) > server.repl_timeout) { 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.repl_state == REDIS_REPL_CONNECT) { redisLog(REDIS_NOTICE,"Connecting to MASTER..."); 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$4\r\nPING\r\n")); } else { /* Otherwise we are in the pre-synchronization stage. * Just a newline will do the work of refreshing the * connection last interaction time, and at the same time * we'll be sure that being a single char there are no * short-write problems. */ if (write(slave->fd, "\n", 1) == -1) { /* Don't worry, it's just a ping. */ } } } } }
/* Asynchronously read the SYNC payload we receive from a master */ #define REPL_MAX_WRITTEN_BEFORE_FSYNC (1024*1024*8) /* 8 MB */ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) { char buf[4096]; ssize_t nread, readlen; off_t left; REDIS_NOTUSED(el); REDIS_NOTUSED(privdata); REDIS_NOTUSED(mask); /* If repl_transfer_size == -1 we still have to read the bulk length * from the master reply. */ if (server.repl_transfer_size == -1) { if (syncReadLine(fd,buf,1024,server.repl_syncio_timeout*1000) == -1) { redisLog(REDIS_WARNING, "I/O error reading bulk count from MASTER: %s", strerror(errno)); goto error; } if (buf[0] == '-') { redisLog(REDIS_WARNING, "MASTER aborted replication with an error: %s", buf+1); goto error; } else if (buf[0] == '\0') { /* At this stage just a newline works as a PING in order to take * the connection live. So we refresh our last interaction * timestamp. */ server.repl_transfer_lastio = server.unixtime; return; } else if (buf[0] != '$') { redisLog(REDIS_WARNING,"Bad protocol from MASTER, the first byte is not '$', are you sure the host and port are right?"); goto error; } server.repl_transfer_size = strtol(buf+1,NULL,10); redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: receiving %ld bytes from master", server.repl_transfer_size); return; } /* Read bulk data */ 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", (nread == -1) ? strerror(errno) : "connection lost"); replicationAbortSyncTransfer(); return; } 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 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; } /* Check if the transfer is now complete */ 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; } redisLog(REDIS_NOTICE, "MASTER <-> SLAVE sync: Loading DB in memory"); emptyDb(); /* Before loading the DB into memory we need to delete the readable * handler, otherwise it will get called recursively since * 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.rdb_filename) != REDIS_OK) { redisLog(REDIS_WARNING,"Failed trying to load the MASTER synchronization DB from disk"); replicationAbortSyncTransfer(); return; } /* Final setup of the connected slave <- master link */ zfree(server.repl_transfer_tmpfile); close(server.repl_transfer_fd); server.master = createClient(server.repl_transfer_s); server.master->flags |= REDIS_MASTER; server.master->authenticated = 1; 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; }