diff options
Diffstat (limited to 'src/aof.c')
| -rw-r--r-- | src/aof.c | 694 |
1 files changed, 694 insertions, 0 deletions
diff --git a/src/aof.c b/src/aof.c new file mode 100644 index 000000000..51054b296 --- /dev/null +++ b/src/aof.c @@ -0,0 +1,694 @@ +#include "redis.h" + +#include <signal.h> +#include <fcntl.h> +#include <sys/stat.h> + +/* Called when the user switches from "appendonly yes" to "appendonly no" + * at runtime using the CONFIG command. */ +void stopAppendOnly(void) { + flushAppendOnlyFile(); + aof_fsync(server.appendfd); + close(server.appendfd); + + server.appendfd = -1; + server.appendseldb = -1; + server.appendonly = 0; + /* rewrite operation in progress? kill it, wait child exit */ + if (server.bgsavechildpid != -1) { + int statloc; + + if (kill(server.bgsavechildpid,SIGKILL) != -1) + wait3(&statloc,0,NULL); + /* reset the buffer accumulating changes while the child saves */ + sdsfree(server.bgrewritebuf); + server.bgrewritebuf = sdsempty(); + server.bgsavechildpid = -1; + } +} + +/* Called when the user switches from "appendonly no" to "appendonly yes" + * at runtime using the CONFIG command. */ +int startAppendOnly(void) { + server.appendonly = 1; + server.lastfsync = time(NULL); + server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644); + if (server.appendfd == -1) { + redisLog(REDIS_WARNING,"Used tried to switch on AOF via CONFIG, but I can't open the AOF file: %s",strerror(errno)); + return REDIS_ERR; + } + if (rewriteAppendOnlyFileBackground() == REDIS_ERR) { + server.appendonly = 0; + close(server.appendfd); + redisLog(REDIS_WARNING,"Used tried to switch on AOF via CONFIG, I can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.",strerror(errno)); + return REDIS_ERR; + } + return REDIS_OK; +} + +/* Write the append only file buffer on disk. + * + * Since we are required to write the AOF before replying to the client, + * and the only way the client socket can get a write is entering when the + * the event loop, we accumulate all the AOF writes in a memory + * buffer and write it on disk using this function just before entering + * the event loop again. */ +void flushAppendOnlyFile(void) { + time_t now; + ssize_t nwritten; + + if (sdslen(server.aofbuf) == 0) return; + + /* 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,server.aofbuf,sdslen(server.aofbuf)); + if (nwritten != (signed)sdslen(server.aofbuf)) { + /* Ooops, we are in troubles. The best thing to do for now is + * aborting instead of giving the illusion that everything is + * working as expected. */ + if (nwritten == -1) { + redisLog(REDIS_WARNING,"Exiting on error writing to the append-only file: %s",strerror(errno)); + } else { + redisLog(REDIS_WARNING,"Exiting on short write while writing to the append-only file: %s",strerror(errno)); + } + exit(1); + } + sdsfree(server.aofbuf); + server.aofbuf = sdsempty(); + + /* Don't Fsync if no-appendfsync-on-rewrite is set to yes and we have + * childs performing heavy I/O on disk. */ + if (server.no_appendfsync_on_rewrite && + (server.bgrewritechildpid != -1 || server.bgsavechildpid != -1)) + return; + /* Fsync if needed */ + now = time(NULL); + if (server.appendfsync == APPENDFSYNC_ALWAYS || + (server.appendfsync == APPENDFSYNC_EVERYSEC && + now-server.lastfsync > 1)) + { + /* aof_fsync is defined as fdatasync() for Linux in order to avoid + * flushing metadata. */ + aof_fsync(server.appendfd); /* Let's try to get this data on the disk */ + server.lastfsync = now; + } +} + +sds catAppendOnlyGenericCommand(sds buf, int argc, robj **argv) { + int j; + buf = sdscatprintf(buf,"*%d\r\n",argc); + for (j = 0; j < argc; j++) { + robj *o = getDecodedObject(argv[j]); + buf = sdscatprintf(buf,"$%lu\r\n",(unsigned long)sdslen(o->ptr)); + buf = sdscatlen(buf,o->ptr,sdslen(o->ptr)); + buf = sdscatlen(buf,"\r\n",2); + decrRefCount(o); + } + return buf; +} + +sds catAppendOnlyExpireAtCommand(sds buf, robj *key, robj *seconds) { + int argc = 3; + long when; + robj *argv[3]; + + /* Make sure we can use strtol */ + seconds = getDecodedObject(seconds); + when = time(NULL)+strtol(seconds->ptr,NULL,10); + decrRefCount(seconds); + + argv[0] = createStringObject("EXPIREAT",8); + argv[1] = key; + argv[2] = createObject(REDIS_STRING, + sdscatprintf(sdsempty(),"%ld",when)); + buf = catAppendOnlyGenericCommand(buf, argc, argv); + decrRefCount(argv[0]); + decrRefCount(argv[2]); + return buf; +} + +void feedAppendOnlyFile(struct redisCommand *cmd, int dictid, robj **argv, int argc) { + sds buf = sdsempty(); + robj *tmpargv[3]; + + /* 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$6\r\nSELECT\r\n$%lu\r\n%s\r\n", + (unsigned long)strlen(seldb),seldb); + server.appendseldb = dictid; + } + + if (cmd->proc == expireCommand) { + /* Translate EXPIRE into EXPIREAT */ + buf = catAppendOnlyExpireAtCommand(buf,argv[1],argv[2]); + } else if (cmd->proc == setexCommand) { + /* Translate SETEX to SET and EXPIREAT */ + tmpargv[0] = createStringObject("SET",3); + tmpargv[1] = argv[1]; + tmpargv[2] = argv[3]; + buf = catAppendOnlyGenericCommand(buf,3,tmpargv); + decrRefCount(tmpargv[0]); + buf = catAppendOnlyExpireAtCommand(buf,argv[1],argv[2]); + } else { + buf = catAppendOnlyGenericCommand(buf,argc,argv); + } + + /* Append to the AOF buffer. This will be flushed on disk just before + * of re-entering the event loop, so before the client will get a + * positive reply about the operation performed. */ + server.aofbuf = sdscatlen(server.aofbuf,buf,sdslen(buf)); + + /* If a background append only file rewriting is in progress we want to + * accumulate the differences between the child DB and the current one + * in a buffer, so that when the child process will do its work we + * can append the differences to the new append only file. */ + if (server.bgrewritechildpid != -1) + server.bgrewritebuf = sdscatlen(server.bgrewritebuf,buf,sdslen(buf)); + + sdsfree(buf); +} + +/* In Redis commands are always executed in the context of a client, so in + * order to load the append only file we need to create a fake client. */ +struct redisClient *createFakeClient(void) { + struct redisClient *c = zmalloc(sizeof(*c)); + + selectDb(c,0); + c->fd = -1; + c->querybuf = sdsempty(); + c->argc = 0; + c->argv = NULL; + c->flags = 0; + /* We set the fake client as a slave waiting for the synchronization + * so that Redis will not try to send replies to this client. */ + c->replstate = REDIS_REPL_WAIT_BGSAVE_START; + c->reply = listCreate(); + listSetFreeMethod(c->reply,decrRefCount); + listSetDupMethod(c->reply,dupClientReplyValue); + initClientMultiState(c); + return c; +} + +void freeFakeClient(struct redisClient *c) { + sdsfree(c->querybuf); + listRelease(c->reply); + freeClientMultiState(c); + zfree(c); +} + +/* Replay the append log file. On error REDIS_OK is returned. On non fatal + * error (the append only file is zero-length) REDIS_ERR is returned. On + * fatal error an error message is logged and the program exists. */ +int loadAppendOnlyFile(char *filename) { + struct redisClient *fakeClient; + FILE *fp = fopen(filename,"r"); + struct redis_stat sb; + int appendonly = server.appendonly; + + if (redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) + return REDIS_ERR; + + if (fp == NULL) { + redisLog(REDIS_WARNING,"Fatal error: can't open the append log file for reading: %s",strerror(errno)); + exit(1); + } + + /* Temporarily disable AOF, to prevent EXEC from feeding a MULTI + * to the same file we're about to read. */ + server.appendonly = 0; + + fakeClient = createFakeClient(); + while(1) { + int argc, j; + unsigned long len; + robj **argv; + char buf[128]; + sds argsds; + struct redisCommand *cmd; + int force_swapout; + + if (fgets(buf,sizeof(buf),fp) == NULL) { + if (feof(fp)) + break; + else + goto readerr; + } + if (buf[0] != '*') goto fmterr; + argc = atoi(buf+1); + argv = zmalloc(sizeof(robj*)*argc); + for (j = 0; j < argc; j++) { + if (fgets(buf,sizeof(buf),fp) == NULL) goto readerr; + if (buf[0] != '$') goto fmterr; + len = strtol(buf+1,NULL,10); + argsds = sdsnewlen(NULL,len); + if (len && fread(argsds,len,1,fp) == 0) goto fmterr; + argv[j] = createObject(REDIS_STRING,argsds); + if (fread(buf,2,1,fp) == 0) goto fmterr; /* discard CRLF */ + } + + /* Command lookup */ + cmd = lookupCommand(argv[0]->ptr); + if (!cmd) { + redisLog(REDIS_WARNING,"Unknown command '%s' reading the append only file", argv[0]->ptr); + exit(1); + } + /* Try object encoding */ + if (cmd->flags & REDIS_CMD_BULK) + argv[argc-1] = tryObjectEncoding(argv[argc-1]); + /* Run the command in the context of a fake client */ + fakeClient->argc = argc; + fakeClient->argv = argv; + cmd->proc(fakeClient); + /* Discard the reply objects list from the fake client */ + while(listLength(fakeClient->reply)) + listDelNode(fakeClient->reply,listFirst(fakeClient->reply)); + /* Clean up, ready for the next command */ + for (j = 0; j < argc; j++) decrRefCount(argv[j]); + zfree(argv); + /* Handle swapping while loading big datasets when VM is on */ + force_swapout = 0; + if ((zmalloc_used_memory() - server.vm_max_memory) > 1024*1024*32) + force_swapout = 1; + + if (server.vm_enabled && force_swapout) { + while (zmalloc_used_memory() > server.vm_max_memory) { + if (vmSwapOneObjectBlocking() == REDIS_ERR) break; + } + } + } + + /* This point can only be reached when EOF is reached without errors. + * If the client is in the middle of a MULTI/EXEC, log error and quit. */ + if (fakeClient->flags & REDIS_MULTI) goto readerr; + + fclose(fp); + freeFakeClient(fakeClient); + server.appendonly = appendonly; + return REDIS_OK; + +readerr: + if (feof(fp)) { + redisLog(REDIS_WARNING,"Unexpected end of file reading the append only file"); + } else { + redisLog(REDIS_WARNING,"Unrecoverable error reading the append only file: %s", strerror(errno)); + } + exit(1); +fmterr: + redisLog(REDIS_WARNING,"Bad file format reading the append only file"); + exit(1); +} + +/* Write binary-safe string into a file in the bulkformat + * $<count>\r\n<payload>\r\n */ +int fwriteBulkString(FILE *fp, char *s, unsigned long len) { + char cbuf[128]; + int clen; + cbuf[0] = '$'; + clen = 1+ll2string(cbuf+1,sizeof(cbuf)-1,len); + cbuf[clen++] = '\r'; + cbuf[clen++] = '\n'; + if (fwrite(cbuf,clen,1,fp) == 0) return 0; + if (len > 0 && fwrite(s,len,1,fp) == 0) return 0; + if (fwrite("\r\n",2,1,fp) == 0) return 0; + return 1; +} + +/* Write a double value in bulk format $<count>\r\n<payload>\r\n */ +int fwriteBulkDouble(FILE *fp, double d) { + char buf[128], dbuf[128]; + + snprintf(dbuf,sizeof(dbuf),"%.17g\r\n",d); + snprintf(buf,sizeof(buf),"$%lu\r\n",(unsigned long)strlen(dbuf)-2); + if (fwrite(buf,strlen(buf),1,fp) == 0) return 0; + if (fwrite(dbuf,strlen(dbuf),1,fp) == 0) return 0; + return 1; +} + +/* Write a long value in bulk format $<count>\r\n<payload>\r\n */ +int fwriteBulkLongLong(FILE *fp, long long l) { + char bbuf[128], lbuf[128]; + unsigned int blen, llen; + llen = ll2string(lbuf,32,l); + blen = snprintf(bbuf,sizeof(bbuf),"$%u\r\n%s\r\n",llen,lbuf); + if (fwrite(bbuf,blen,1,fp) == 0) return 0; + return 1; +} + +/* Delegate writing an object to writing a bulk string or bulk long long. */ +int fwriteBulkObject(FILE *fp, robj *obj) { + /* Avoid using getDecodedObject to help copy-on-write (we are often + * in a child process when this function is called). */ + if (obj->encoding == REDIS_ENCODING_INT) { + return fwriteBulkLongLong(fp,(long)obj->ptr); + } else if (obj->encoding == REDIS_ENCODING_RAW) { + return fwriteBulkString(fp,obj->ptr,sdslen(obj->ptr)); + } else { + redisPanic("Unknown string encoding"); + } +} + +/* Write a sequence of commands able to fully rebuild the dataset into + * "filename". Used both by REWRITEAOF and BGREWRITEAOF. */ +int rewriteAppendOnlyFile(char *filename) { + dictIterator *di = NULL; + dictEntry *de; + FILE *fp; + char tmpfile[256]; + int j; + time_t now = time(NULL); + + /* Note that we have to use a different temp name here compared to the + * one used by rewriteAppendOnlyFileBackground() function. */ + snprintf(tmpfile,256,"temp-rewriteaof-%d.aof", (int) getpid()); + fp = fopen(tmpfile,"w"); + if (!fp) { + redisLog(REDIS_WARNING, "Failed rewriting the append only file: %s", strerror(errno)); + return REDIS_ERR; + } + for (j = 0; j < server.dbnum; j++) { + char selectcmd[] = "*2\r\n$6\r\nSELECT\r\n"; + redisDb *db = server.db+j; + dict *d = db->dict; + if (dictSize(d) == 0) continue; + di = dictGetIterator(d); + if (!di) { + fclose(fp); + return REDIS_ERR; + } + + /* SELECT the new DB */ + if (fwrite(selectcmd,sizeof(selectcmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkLongLong(fp,j) == 0) goto werr; + + /* Iterate this DB writing every entry */ + while((de = dictNext(di)) != NULL) { + sds keystr = dictGetEntryKey(de); + robj key, *o; + time_t expiretime; + int swapped; + + keystr = dictGetEntryKey(de); + o = dictGetEntryVal(de); + initStaticStringObject(key,keystr); + /* If the value for this key is swapped, load a preview in memory. + * We use a "swapped" flag to remember if we need to free the + * value object instead to just increment the ref count anyway + * in order to avoid copy-on-write of pages if we are forked() */ + if (!server.vm_enabled || o->storage == REDIS_VM_MEMORY || + o->storage == REDIS_VM_SWAPPING) { + swapped = 0; + } else { + o = vmPreviewObject(o); + swapped = 1; + } + expiretime = getExpire(db,&key); + + /* Save the key and associated value */ + if (o->type == REDIS_STRING) { + /* Emit a SET command */ + char cmd[]="*3\r\n$3\r\nSET\r\n"; + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + /* Key and value */ + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkObject(fp,o) == 0) goto werr; + } else if (o->type == REDIS_LIST) { + /* Emit the RPUSHes needed to rebuild the list */ + char cmd[]="*3\r\n$5\r\nRPUSH\r\n"; + if (o->encoding == REDIS_ENCODING_ZIPLIST) { + unsigned char *zl = o->ptr; + unsigned char *p = ziplistIndex(zl,0); + unsigned char *vstr; + unsigned int vlen; + long long vlong; + + while(ziplistGet(p,&vstr,&vlen,&vlong)) { + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (vstr) { + if (fwriteBulkString(fp,(char*)vstr,vlen) == 0) + goto werr; + } else { + if (fwriteBulkLongLong(fp,vlong) == 0) + goto werr; + } + p = ziplistNext(zl,p); + } + } else if (o->encoding == REDIS_ENCODING_LINKEDLIST) { + list *list = o->ptr; + listNode *ln; + listIter li; + + listRewind(list,&li); + while((ln = listNext(&li))) { + robj *eleobj = listNodeValue(ln); + + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkObject(fp,eleobj) == 0) goto werr; + } + } else { + redisPanic("Unknown list encoding"); + } + } else if (o->type == REDIS_SET) { + /* Emit the SADDs needed to rebuild the set */ + dict *set = o->ptr; + dictIterator *di = dictGetIterator(set); + dictEntry *de; + + while((de = dictNext(di)) != NULL) { + char cmd[]="*3\r\n$4\r\nSADD\r\n"; + robj *eleobj = dictGetEntryKey(de); + + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkObject(fp,eleobj) == 0) goto werr; + } + dictReleaseIterator(di); + } else if (o->type == REDIS_ZSET) { + /* Emit the ZADDs needed to rebuild the sorted set */ + zset *zs = o->ptr; + dictIterator *di = dictGetIterator(zs->dict); + dictEntry *de; + + while((de = dictNext(di)) != NULL) { + char cmd[]="*4\r\n$4\r\nZADD\r\n"; + robj *eleobj = dictGetEntryKey(de); + double *score = dictGetEntryVal(de); + + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkDouble(fp,*score) == 0) goto werr; + if (fwriteBulkObject(fp,eleobj) == 0) goto werr; + } + dictReleaseIterator(di); + } else if (o->type == REDIS_HASH) { + char cmd[]="*4\r\n$4\r\nHSET\r\n"; + + /* Emit the HSETs needed to rebuild the hash */ + if (o->encoding == REDIS_ENCODING_ZIPMAP) { + unsigned char *p = zipmapRewind(o->ptr); + unsigned char *field, *val; + unsigned int flen, vlen; + + while((p = zipmapNext(p,&field,&flen,&val,&vlen)) != NULL) { + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkString(fp,(char*)field,flen) == -1) + return -1; + if (fwriteBulkString(fp,(char*)val,vlen) == -1) + return -1; + } + } else { + dictIterator *di = dictGetIterator(o->ptr); + dictEntry *de; + + while((de = dictNext(di)) != NULL) { + robj *field = dictGetEntryKey(de); + robj *val = dictGetEntryVal(de); + + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkObject(fp,field) == -1) return -1; + if (fwriteBulkObject(fp,val) == -1) return -1; + } + dictReleaseIterator(di); + } + } else { + redisPanic("Unknown object type"); + } + /* Save the expire time */ + if (expiretime != -1) { + char cmd[]="*3\r\n$8\r\nEXPIREAT\r\n"; + /* If this key is already expired skip it */ + if (expiretime < now) continue; + if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr; + if (fwriteBulkObject(fp,&key) == 0) goto werr; + if (fwriteBulkLongLong(fp,expiretime) == 0) goto werr; + } + if (swapped) decrRefCount(o); + } + dictReleaseIterator(di); + } + + /* Make sure data will not remain on the OS's output buffers */ + fflush(fp); + aof_fsync(fileno(fp)); + fclose(fp); + + /* Use RENAME to make sure the DB file is changed atomically only + * if the generate DB file is ok. */ + if (rename(tmpfile,filename) == -1) { + redisLog(REDIS_WARNING,"Error moving temp append only file on the final destination: %s", strerror(errno)); + unlink(tmpfile); + return REDIS_ERR; + } + redisLog(REDIS_NOTICE,"SYNC append only file rewrite performed"); + return REDIS_OK; + +werr: + fclose(fp); + unlink(tmpfile); + redisLog(REDIS_WARNING,"Write error writing append only file on disk: %s", strerror(errno)); + if (di) dictReleaseIterator(di); + return REDIS_ERR; +} + +/* This is how rewriting of the append only file in background works: + * + * 1) The user calls BGREWRITEAOF + * 2) Redis calls this function, that forks(): + * 2a) the child rewrite the append only file in a temp file. + * 2b) the parent accumulates differences in server.bgrewritebuf. + * 3) When the child finished '2a' exists. + * 4) The parent will trap the exit code, if it's OK, will append the + * data accumulated into server.bgrewritebuf into the temp file, and + * finally will rename(2) the temp file in the actual file name. + * The the new file is reopened as the new append only file. Profit! + */ +int rewriteAppendOnlyFileBackground(void) { + pid_t childpid; + + if (server.bgrewritechildpid != -1) return REDIS_ERR; + if (server.vm_enabled) waitEmptyIOJobsQueue(); + if ((childpid = fork()) == 0) { + /* Child */ + char tmpfile[256]; + + if (server.vm_enabled) vmReopenSwapFile(); + close(server.fd); + snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid()); + if (rewriteAppendOnlyFile(tmpfile) == REDIS_OK) { + _exit(0); + } else { + _exit(1); + } + } else { + /* Parent */ + if (childpid == -1) { + redisLog(REDIS_WARNING, + "Can't rewrite append only file in background: fork: %s", + strerror(errno)); + return REDIS_ERR; + } + redisLog(REDIS_NOTICE, + "Background append only file rewriting started by pid %d",childpid); + server.bgrewritechildpid = childpid; + updateDictResizePolicy(); + /* We set appendseldb to -1 in order to force the next call to the + * feedAppendOnlyFile() to issue a SELECT command, so the differences + * accumulated by the parent into server.bgrewritebuf will start + * with a SELECT statement and it will be safe to merge. */ + server.appendseldb = -1; + return REDIS_OK; + } + return REDIS_OK; /* unreached */ +} + +void bgrewriteaofCommand(redisClient *c) { + if (server.bgrewritechildpid != -1) { + addReplySds(c,sdsnew("-ERR background append only file rewriting already in progress\r\n")); + return; + } + if (rewriteAppendOnlyFileBackground() == REDIS_OK) { + char *status = "+Background append only file rewriting started\r\n"; + addReplySds(c,sdsnew(status)); + } else { + addReply(c,shared.err); + } +} + +void aofRemoveTempFile(pid_t childpid) { + char tmpfile[256]; + + snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) childpid); + unlink(tmpfile); +} + +/* A background append only file rewriting (BGREWRITEAOF) terminated its work. + * Handle this. */ +void backgroundRewriteDoneHandler(int statloc) { + int exitcode = WEXITSTATUS(statloc); + int bysignal = WIFSIGNALED(statloc); + + if (!bysignal && exitcode == 0) { + int fd; + char tmpfile[256]; + + redisLog(REDIS_NOTICE, + "Background append only file rewriting terminated with success"); + /* Now it's time to flush the differences accumulated by the parent */ + snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) server.bgrewritechildpid); + fd = open(tmpfile,O_WRONLY|O_APPEND); + if (fd == -1) { + redisLog(REDIS_WARNING, "Not able to open the temp append only file produced by the child: %s", strerror(errno)); + goto cleanup; + } + /* Flush our data... */ + if (write(fd,server.bgrewritebuf,sdslen(server.bgrewritebuf)) != + (signed) sdslen(server.bgrewritebuf)) { + redisLog(REDIS_WARNING, "Error or short write trying to flush the parent diff of the append log file in the child temp file: %s", strerror(errno)); + close(fd); + goto cleanup; + } + redisLog(REDIS_NOTICE,"Parent diff flushed into the new append log file with success (%lu bytes)",sdslen(server.bgrewritebuf)); + /* Now our work is to rename the temp file into the stable file. And + * switch the file descriptor used by the server for append only. */ + if (rename(tmpfile,server.appendfilename) == -1) { + redisLog(REDIS_WARNING,"Can't rename the temp append only file into the stable one: %s", strerror(errno)); + close(fd); + goto cleanup; + } + /* Mission completed... almost */ + redisLog(REDIS_NOTICE,"Append only file successfully rewritten."); + if (server.appendfd != -1) { + /* If append only is actually enabled... */ + close(server.appendfd); + server.appendfd = fd; + if (server.appendfsync != APPENDFSYNC_NO) aof_fsync(fd); + server.appendseldb = -1; /* Make sure it will issue SELECT */ + redisLog(REDIS_NOTICE,"The new append only file was selected for future appends."); + } else { + /* If append only is disabled we just generate a dump in this + * format. Why not? */ + close(fd); + } + } else if (!bysignal && exitcode != 0) { + redisLog(REDIS_WARNING, "Background append only file rewriting error"); + } else { + redisLog(REDIS_WARNING, + "Background append only file rewriting terminated by signal %d", + WTERMSIG(statloc)); + } +cleanup: + sdsfree(server.bgrewritebuf); + server.bgrewritebuf = sdsempty(); + aofRemoveTempFile(server.bgrewritechildpid); + server.bgrewritechildpid = -1; +} |