#include <fcntl.h>
#include <sys/stat.h>
+/* ---------------------------------- MASTER -------------------------------- */
+
void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
listNode *ln;
listIter li;
struct timeval tv;
gettimeofday(&tv,NULL);
- cmdrepr = sdscatprintf(cmdrepr,"%ld.%ld ",(long)tv.tv_sec,(long)tv.tv_usec);
+ cmdrepr = sdscatprintf(cmdrepr,"%ld.%06ld ",(long)tv.tv_sec,(long)tv.tv_usec);
if (dictid != 0) cmdrepr = sdscatprintf(cmdrepr,"(db %d) ", dictid);
for (j = 0; j < argc; j++) {
decrRefCount(cmdobj);
}
-int syncWrite(int fd, char *ptr, ssize_t size, int timeout) {
- ssize_t nwritten, ret = size;
- time_t start = time(NULL);
-
- timeout++;
- while(size) {
- if (aeWait(fd,AE_WRITABLE,1000) & AE_WRITABLE) {
- nwritten = write(fd,ptr,size);
- if (nwritten == -1) return -1;
- ptr += nwritten;
- size -= nwritten;
- }
- if ((time(NULL)-start) > timeout) {
- errno = ETIMEDOUT;
- return -1;
- }
- }
- return ret;
-}
-
-int syncRead(int fd, char *ptr, ssize_t size, int timeout) {
- ssize_t nread, totread = 0;
- time_t start = time(NULL);
-
- timeout++;
- while(size) {
- if (aeWait(fd,AE_READABLE,1000) & AE_READABLE) {
- nread = read(fd,ptr,size);
- if (nread == -1) return -1;
- ptr += nread;
- size -= nread;
- totread += nread;
- }
- if ((time(NULL)-start) > timeout) {
- errno = ETIMEDOUT;
- return -1;
- }
- }
- return totread;
-}
-
-int syncReadLine(int fd, char *ptr, ssize_t size, int timeout) {
- ssize_t nread = 0;
-
- size--;
- while(size) {
- char c;
-
- if (syncRead(fd,&c,1,timeout) == -1) return -1;
- if (c == '\n') {
- *ptr = '\0';
- if (nread && *(ptr-1) == '\r') *(ptr-1) = '\0';
- return nread;
- } else {
- *ptr++ = c;
- *ptr = '\0';
- nread++;
- }
- }
- return nread;
-}
-
void syncCommand(redisClient *c) {
/* ignore SYNC if aleady slave or in monitor mode */
if (c->flags & REDIS_SLAVE) return;
+ /* 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) {
+ addReplyError(c,"Can't SYNC while not connected with my master");
+ return;
+ }
+
/* SYNC can't be issued when the server has pending data to send to
* the client about already issued commands. We need a fresh reply
* buffer registering the differences between the BGSAVE and the current
* dataset, so that we can copy to other slaves if needed. */
if (listLength(c->reply) != 0) {
- addReplySds(c,sdsnew("-ERR SYNC is invalid with pending input\r\n"));
+ addReplyError(c,"SYNC is invalid with pending input");
return;
}
redisLog(REDIS_NOTICE,"Starting BGSAVE for SYNC");
if (rdbSaveBackground(server.dbfilename) != REDIS_OK) {
redisLog(REDIS_NOTICE,"Replication failed, can't BGSAVE");
- addReplySds(c,sdsnew("-ERR Unalbe to perform background save\r\n"));
+ addReplyError(c,"Unable to perform background save");
return;
}
c->replstate = REDIS_REPL_WAIT_BGSAVE_END;
}
}
+/* ----------------------------------- SLAVE -------------------------------- */
+
+/* Abort the async download of the bulk dataset while SYNC-ing with master */
+void replicationAbortSyncTransfer(void) {
+ redisAssert(server.replstate == 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;
+}
+
+/* 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");
+ }
+}
+
int syncWithMaster(void) {
char buf[1024], tmpfile[256], authcmd[1024];
- long dumpsize;
int fd = anetTcpConnect(NULL,server.masterhost,server.masterport);
int dfd, maxtries = 5;
strerror(errno));
return REDIS_ERR;
}
- /* Read the bulk write count */
- if (syncReadLine(fd,buf,1024,3600) == -1) {
- close(fd);
- redisLog(REDIS_WARNING,"I/O error reading bulk count from MASTER: %s",
- strerror(errno));
- return REDIS_ERR;
- }
- if (buf[0] != '$') {
- close(fd);
- redisLog(REDIS_WARNING,"Bad protocol from MASTER, the first byte is not '$', are you sure the host and port are right?");
- return REDIS_ERR;
- }
- dumpsize = strtol(buf+1,NULL,10);
- redisLog(REDIS_NOTICE,"Receiving %ld bytes data dump from MASTER",dumpsize);
- /* Read the bulk write data on a temp file */
+
+ /* Prepare a suitable temp file for bulk transfer */
while(maxtries--) {
snprintf(tmpfile,256,
"temp-%d.%ld.rdb",(int)time(NULL),(long int)getpid());
redisLog(REDIS_WARNING,"Opening the temp file needed for MASTER <-> SLAVE synchronization: %s",strerror(errno));
return REDIS_ERR;
}
- while(dumpsize) {
- int nread, nwritten;
- nread = read(fd,buf,(dumpsize < 1024)?dumpsize:1024);
- if (nread == -1) {
- redisLog(REDIS_WARNING,"I/O error trying to sync with MASTER: %s",
- strerror(errno));
- close(fd);
- close(dfd);
- return REDIS_ERR;
- }
- nwritten = write(dfd,buf,nread);
- if (nwritten == -1) {
- redisLog(REDIS_WARNING,"Write error writing to the DB dump file needed for MASTER <-> SLAVE synchrnonization: %s", strerror(errno));
- close(fd);
- close(dfd);
- return REDIS_ERR;
- }
- dumpsize -= nread;
- }
- close(dfd);
- if (rename(tmpfile,server.dbfilename) == -1) {
- redisLog(REDIS_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno));
- unlink(tmpfile);
+ /* Setup the non blocking download of the bulk file. */
+ if (aeCreateFileEvent(server.el, fd, AE_READABLE, readSyncBulkPayload, NULL)
+ == AE_ERR)
+ {
close(fd);
+ redisLog(REDIS_WARNING,"Can't create readable event for SYNC");
return REDIS_ERR;
}
- emptyDb();
- if (rdbLoad(server.dbfilename) != REDIS_OK) {
- redisLog(REDIS_WARNING,"Failed trying to load the MASTER synchronization DB from disk");
- close(fd);
- return REDIS_ERR;
- }
- server.master = createClient(fd);
- server.master->flags |= REDIS_MASTER;
- server.master->authenticated = 1;
- server.replstate = REDIS_REPL_CONNECTED;
+ server.replstate = REDIS_REPL_TRANSFER;
+ server.repl_transfer_left = -1;
+ server.repl_transfer_s = fd;
+ server.repl_transfer_fd = dfd;
+ server.repl_transfer_lastio = time(NULL);
+ server.repl_transfer_tmpfile = zstrdup(tmpfile);
return REDIS_OK;
}
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)");
}
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);
}
+
+/* --------------------------- REPLICATION CRON ---------------------------- */
+
+#define REDIS_REPL_TIMEOUT 60
+#define REDIS_REPL_PING_SLAVE_PERIOD 10
+
+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. */
+ if (write(slave->fd, "\n", 1) == -1) {
+ /* Don't worry, it's just a ping. */
+ }
+ }
+ }
+ }
+}
projects / redis.git / blobdiff