+/* ----------------------------------- SLAVE -------------------------------- */
+
+/* Abort the async download of the bulk dataset while SYNC-ing with master */
+void replicationAbortSyncTransfer(void) {
+ 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.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_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;
+}
+
+/* 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;
projects / redis.git / blobdiff