int appendfd;
int appendseldb;
char *pidfile;
- int bgsaveinprogress;
pid_t bgsavechildpid;
+ pid_t bgrewritechildpid;
+ sds bgrewritebuf; /* buffer taken by parent during oppend only rewrite */
struct saveparam *saveparams;
int saveparamslen;
char *logfile;
static int syncWithMaster(void);
static robj *tryObjectSharing(robj *o);
static int tryObjectEncoding(robj *o);
-static robj *getDecodedObject(const robj *o);
+static robj *getDecodedObject(robj *o);
static int removeExpire(redisDb *db, robj *key);
static int expireIfNeeded(redisDb *db, robj *key);
static int deleteIfVolatile(redisDb *db, robj *key);
static int processCommand(redisClient *c);
static void setupSigSegvAction(void);
static void rdbRemoveTempFile(pid_t childpid);
+static void aofRemoveTempFile(pid_t childpid);
static size_t stringObjectLen(robj *o);
static void processInputBuffer(redisClient *c);
static zskiplist *zslCreate(void);
static void lastsaveCommand(redisClient *c);
static void saveCommand(redisClient *c);
static void bgsaveCommand(redisClient *c);
+static void bgrewriteaofCommand(redisClient *c);
static void shutdownCommand(redisClient *c);
static void moveCommand(redisClient *c);
static void renameCommand(redisClient *c);
{"echo",echoCommand,2,REDIS_CMD_BULK},
{"save",saveCommand,1,REDIS_CMD_INLINE},
{"bgsave",bgsaveCommand,1,REDIS_CMD_INLINE},
+ {"bgrewriteaof",bgrewriteaofCommand,1,REDIS_CMD_INLINE},
{"shutdown",shutdownCommand,1,REDIS_CMD_INLINE},
{"lastsave",lastsaveCommand,1,REDIS_CMD_INLINE},
{"type",typeCommand,2,REDIS_CMD_INLINE},
static int dictEncObjKeyCompare(void *privdata, const void *key1,
const void *key2)
{
- const robj *o1 = key1, *o2 = key2;
-
- if (o1->encoding == REDIS_ENCODING_RAW &&
- o2->encoding == REDIS_ENCODING_RAW)
- return sdsDictKeyCompare(privdata,o1->ptr,o2->ptr);
- else {
- robj *dec1, *dec2;
- int cmp;
+ robj *o1 = (robj*) key1, *o2 = (robj*) key2;
+ int cmp;
- dec1 = o1->encoding != REDIS_ENCODING_RAW ?
- getDecodedObject(o1) : (robj*)o1;
- dec2 = o2->encoding != REDIS_ENCODING_RAW ?
- getDecodedObject(o2) : (robj*)o2;
- cmp = sdsDictKeyCompare(privdata,dec1->ptr,dec2->ptr);
- if (dec1 != o1) decrRefCount(dec1);
- if (dec2 != o2) decrRefCount(dec2);
- return cmp;
- }
+ o1 = getDecodedObject(o1);
+ o2 = getDecodedObject(o2);
+ cmp = sdsDictKeyCompare(privdata,o1->ptr,o2->ptr);
+ decrRefCount(o1);
+ decrRefCount(o2);
+ return cmp;
}
static unsigned int dictEncObjHash(const void *key) {
- const robj *o = key;
+ robj *o = (robj*) key;
- if (o->encoding == REDIS_ENCODING_RAW)
- return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
- else {
- robj *dec = getDecodedObject(o);
- unsigned int hash = dictGenHashFunction(dec->ptr, sdslen((sds)dec->ptr));
- decrRefCount(dec);
- return hash;
- }
+ o = getDecodedObject(o);
+ unsigned int hash = dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
+ decrRefCount(o);
+ return hash;
}
static dictType setDictType = {
}
}
+/* A background saving child (BGSAVE) terminated its work. Handle this. */
+void backgroundSaveDoneHandler(int statloc) {
+ int exitcode = WEXITSTATUS(statloc);
+ int bysignal = WIFSIGNALED(statloc);
+
+ if (!bysignal && exitcode == 0) {
+ redisLog(REDIS_NOTICE,
+ "Background saving terminated with success");
+ server.dirty = 0;
+ server.lastsave = time(NULL);
+ } else if (!bysignal && exitcode != 0) {
+ redisLog(REDIS_WARNING, "Background saving error");
+ } else {
+ redisLog(REDIS_WARNING,
+ "Background saving terminated by signal");
+ rdbRemoveTempFile(server.bgsavechildpid);
+ }
+ server.bgsavechildpid = -1;
+ /* Possibly there are slaves waiting for a BGSAVE in order to be served
+ * (the first stage of SYNC is a bulk transfer of dump.rdb) */
+ updateSlavesWaitingBgsave(exitcode == 0 ? REDIS_OK : REDIS_ERR);
+}
+
+/* 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_WARNING,"Parent diff flushed into the new append log file with success");
+ /* 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;
+ fsync(fd);
+ 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");
+ }
+cleanup:
+ sdsfree(server.bgrewritebuf);
+ server.bgrewritebuf = sdsempty();
+ aofRemoveTempFile(server.bgrewritechildpid);
+ server.bgrewritechildpid = -1;
+}
+
static int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
int j, loops = server.cronloops++;
REDIS_NOTUSED(eventLoop);
* if we resize the HT while there is the saving child at work actually
* a lot of memory movements in the parent will cause a lot of pages
* copied. */
- if (!server.bgsaveinprogress) tryResizeHashTables();
+ if (server.bgsavechildpid == -1) tryResizeHashTables();
/* Show information about connected clients */
if (!(loops % 5)) {
if (server.maxidletime && !(loops % 10))
closeTimedoutClients();
- /* Check if a background saving in progress terminated */
- if (server.bgsaveinprogress) {
+ /* Check if a background saving or AOF rewrite in progress terminated */
+ if (server.bgsavechildpid != -1 || server.bgrewritechildpid != -1) {
int statloc;
- if (wait3(&statloc,WNOHANG,NULL)) {
- int exitcode = WEXITSTATUS(statloc);
- int bysignal = WIFSIGNALED(statloc);
-
- if (!bysignal && exitcode == 0) {
- redisLog(REDIS_NOTICE,
- "Background saving terminated with success");
- server.dirty = 0;
- server.lastsave = time(NULL);
- } else if (!bysignal && exitcode != 0) {
- redisLog(REDIS_WARNING, "Background saving error");
+ pid_t pid;
+
+ if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
+ if (pid == server.bgsavechildpid) {
+ backgroundSaveDoneHandler(statloc);
} else {
- redisLog(REDIS_WARNING,
- "Background saving terminated by signal");
- rdbRemoveTempFile(server.bgsavechildpid);
+ backgroundRewriteDoneHandler(statloc);
}
- server.bgsaveinprogress = 0;
- server.bgsavechildpid = -1;
- updateSlavesWaitingBgsave(exitcode == 0 ? REDIS_OK : REDIS_ERR);
}
} else {
/* If there is not a background saving in progress check if
server.appendseldb = -1; /* Make sure the first time will not match */
server.pidfile = "/var/run/redis.pid";
server.dbfilename = "dump.rdb";
- server.appendfilename = "appendonly.log";
+ server.appendfilename = "appendonly.aof";
server.requirepass = NULL;
server.shareobjects = 0;
server.sharingpoolsize = 1024;
server.db[j].id = j;
}
server.cronloops = 0;
- server.bgsaveinprogress = 0;
server.bgsavechildpid = -1;
+ server.bgrewritechildpid = -1;
+ server.bgrewritebuf = sdsempty();
server.lastsave = time(NULL);
server.dirty = 0;
server.usedmemory = 0;
c->replstate == REDIS_REPL_ONLINE) &&
aeCreateFileEvent(server.el, c->fd, AE_WRITABLE,
sendReplyToClient, c) == AE_ERR) return;
- if (obj->encoding != REDIS_ENCODING_RAW) {
- obj = getDecodedObject(obj);
- } else {
- incrRefCount(obj);
- }
- listAddNodeTail(c->reply,obj);
+ listAddNodeTail(c->reply,getDecodedObject(obj));
}
static void addReplySds(redisClient *c, sds s) {
return REDIS_OK;
}
-/* Get a decoded version of an encoded object (returned as a new object) */
-static robj *getDecodedObject(const robj *o) {
+/* Get a decoded version of an encoded object (returned as a new object).
+ * If the object is already raw-encoded just increment the ref count. */
+static robj *getDecodedObject(robj *o) {
robj *dec;
- assert(o->encoding != REDIS_ENCODING_RAW);
+ if (o->encoding == REDIS_ENCODING_RAW) {
+ incrRefCount(o);
+ return o;
+ }
if (o->type == REDIS_STRING && o->encoding == REDIS_ENCODING_INT) {
char buf[32];
/* Like rdbSaveStringObjectRaw() but handle encoded objects */
static int rdbSaveStringObject(FILE *fp, robj *obj) {
int retval;
- robj *dec;
- if (obj->encoding != REDIS_ENCODING_RAW) {
- dec = getDecodedObject(obj);
- retval = rdbSaveStringObjectRaw(fp,dec);
- decrRefCount(dec);
- return retval;
- } else {
- return rdbSaveStringObjectRaw(fp,obj);
- }
+ obj = getDecodedObject(obj);
+ retval = rdbSaveStringObjectRaw(fp,obj);
+ decrRefCount(obj);
+ return retval;
}
/* Save a double value. Doubles are saved as strings prefixed by an unsigned
static int rdbSaveBackground(char *filename) {
pid_t childpid;
- if (server.bgsaveinprogress) return REDIS_ERR;
+ if (server.bgsavechildpid != -1) return REDIS_ERR;
if ((childpid = fork()) == 0) {
/* Child */
close(server.fd);
return REDIS_ERR;
}
redisLog(REDIS_NOTICE,"Background saving started by pid %d",childpid);
- server.bgsaveinprogress = 1;
server.bgsavechildpid = childpid;
return REDIS_OK;
}
}
static void saveCommand(redisClient *c) {
- if (server.bgsaveinprogress) {
+ if (server.bgsavechildpid != -1) {
addReplySds(c,sdsnew("-ERR background save in progress\r\n"));
return;
}
}
static void bgsaveCommand(redisClient *c) {
- if (server.bgsaveinprogress) {
+ if (server.bgsavechildpid != -1) {
addReplySds(c,sdsnew("-ERR background save already in progress\r\n"));
return;
}
/* Kill the saving child if there is a background saving in progress.
We want to avoid race conditions, for instance our saving child may
overwrite the synchronous saving did by SHUTDOWN. */
- if (server.bgsaveinprogress) {
+ if (server.bgsavechildpid != -1) {
redisLog(REDIS_WARNING,"There is a live saving child. Killing it!");
kill(server.bgsavechildpid,SIGKILL);
rdbRemoveTempFile(server.bgsavechildpid);
}
/* The substitution object may be specially encoded. If so we create
- * a decoded object on the fly. */
- if (subst->encoding == REDIS_ENCODING_RAW)
- /* If we don't need to get a decoded object increment the refcount
- * so that the final decrRefCount() call will restore the original
- * count */
- incrRefCount(subst);
- else {
- subst = getDecodedObject(subst);
- }
+ * a decoded object on the fly. Otherwise getDecodedObject will just
+ * increment the ref count, that we'll decrement later. */
+ subst = getDecodedObject(subst);
ssub = subst->ptr;
if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
}
} else {
/* Compare elements directly */
- if (so1->obj->encoding == REDIS_ENCODING_RAW &&
- so2->obj->encoding == REDIS_ENCODING_RAW) {
- cmp = strcoll(so1->obj->ptr,so2->obj->ptr);
- } else {
- robj *dec1, *dec2;
-
- dec1 = so1->obj->encoding == REDIS_ENCODING_RAW ?
- so1->obj : getDecodedObject(so1->obj);
- dec2 = so2->obj->encoding == REDIS_ENCODING_RAW ?
- so2->obj : getDecodedObject(so2->obj);
- cmp = strcoll(dec1->ptr,dec2->ptr);
- if (dec1 != so1->obj) decrRefCount(dec1);
- if (dec2 != so2->obj) decrRefCount(dec2);
- }
+ robj *dec1, *dec2;
+
+ dec1 = getDecodedObject(so1->obj);
+ dec2 = getDecodedObject(so2->obj);
+ cmp = strcoll(dec1->ptr,dec2->ptr);
+ decrRefCount(dec1);
+ decrRefCount(dec2);
}
}
return server.sort_desc ? -cmp : cmp;
byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
if (!byval || byval->type != REDIS_STRING) continue;
if (alpha) {
- if (byval->encoding == REDIS_ENCODING_RAW) {
- vector[j].u.cmpobj = byval;
- incrRefCount(byval);
- } else {
- vector[j].u.cmpobj = getDecodedObject(byval);
- }
+ vector[j].u.cmpobj = getDecodedObject(byval);
} else {
if (byval->encoding == REDIS_ENCODING_RAW) {
vector[j].u.score = strtod(byval->ptr,NULL);
} else {
+ /* Don't need to decode the object if it's
+ * integer-encoded (the only encoding supported) so
+ * far. We can just cast it */
if (byval->encoding == REDIS_ENCODING_INT) {
vector[j].u.score = (long)byval->ptr;
} else
listLength(server.slaves),
server.usedmemory,
server.dirty,
- server.bgsaveinprogress,
+ server.bgsavechildpid != -1,
server.lastsave,
server.stat_numconnections,
server.stat_numcommands,
keys = dictSize(server.db[j].dict);
vkeys = dictSize(server.db[j].expires);
if (keys || vkeys) {
- info = sdscatprintf(info, "db%d: keys=%lld,expires=%lld\r\n",
+ info = sdscatprintf(info, "db%d:keys=%lld,expires=%lld\r\n",
j, keys, vkeys);
}
}
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.bgsaveinprogress) {
+ if (server.bgsavechildpid != -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 */
for (j = 0; j < argc; j++) {
robj *o = argv[j];
- if (o->encoding != REDIS_ENCODING_RAW)
- o = getDecodedObject(o);
+ o = getDecodedObject(o);
buf = sdscatprintf(buf,"$%d\r\n",sdslen(o->ptr));
buf = sdscatlen(buf,o->ptr,sdslen(o->ptr));
buf = sdscatlen(buf,"\r\n",2);
- if (o != argv[j])
- decrRefCount(o);
+ decrRefCount(o);
}
/* Free the objects from the modified argv for EXPIREAT */
exit(1);
}
+/* Write an object into a file in the bulk format $<count>\r\n<payload>\r\n */
+static int fwriteBulk(FILE *fp, robj *obj) {
+ char buf[128];
+ obj = getDecodedObject(obj);
+ snprintf(buf,sizeof(buf),"$%ld\r\n",(long)sdslen(obj->ptr));
+ if (fwrite(buf,strlen(buf),1,fp) == 0) goto err;
+ if (fwrite(obj->ptr,sdslen(obj->ptr),1,fp) == 0) goto err;
+ if (fwrite("\r\n",2,1,fp) == 0) goto err;
+ decrRefCount(obj);
+ return 1;
+err:
+ decrRefCount(obj);
+ return 0;
+}
+
+/* Write a double value in bulk format $<count>\r\n<payload>\r\n */
+static int fwriteBulkDouble(FILE *fp, double d) {
+ char buf[128], dbuf[128];
+
+ snprintf(dbuf,sizeof(dbuf),"%.17g\r\n",d);
+ snprintf(buf,sizeof(buf),"$%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 $<count>\r\n<payload>\r\n */
+static int fwriteBulkLong(FILE *fp, long l) {
+ char buf[128], lbuf[128];
+
+ snprintf(lbuf,sizeof(lbuf),"%ld\r\n",l);
+ snprintf(buf,sizeof(buf),"$%lu\r\n",(unsigned long)strlen(lbuf)-2);
+ if (fwrite(buf,strlen(buf),1,fp) == 0) return 0;
+ if (fwrite(lbuf,strlen(lbuf),1,fp) == 0) return 0;
+ return 1;
+}
+
+/* Write a sequence of commands able to fully rebuild the dataset into
+ * "filename". Used both by REWRITEAOF and BGREWRITEAOF. */
+static 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 (fwriteBulkLong(fp,j+1) == 0) goto werr;
+
+ /* Iterate this DB writing every entry */
+ while((de = dictNext(di)) != NULL) {
+ robj *key = dictGetEntryKey(de);
+ robj *o = dictGetEntryVal(de);
+ time_t expiretime = getExpire(db,key);
+
+ /* Save the key and associated value */
+ if (rdbSaveStringObject(fp,key) == -1) goto werr;
+ 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 (fwriteBulk(fp,key) == 0) goto werr;
+ if (fwriteBulk(fp,o) == 0) goto werr;
+ } else if (o->type == REDIS_LIST) {
+ /* Emit the RPUSHes needed to rebuild the list */
+ list *list = o->ptr;
+ listNode *ln;
+
+ listRewind(list);
+ while((ln = listYield(list))) {
+ char cmd[]="*3\r\n$5\r\nRPUSH\r\n";
+ robj *eleobj = listNodeValue(ln);
+
+ if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr;
+ if (fwriteBulk(fp,key) == 0) goto werr;
+ if (fwriteBulk(fp,eleobj) == 0) goto werr;
+ }
+ } 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 (fwriteBulk(fp,key) == 0) goto werr;
+ if (fwriteBulk(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 (fwriteBulk(fp,key) == 0) goto werr;
+ if (fwriteBulkDouble(fp,*score) == 0) goto werr;
+ if (fwriteBulk(fp,eleobj) == 0) goto werr;
+ }
+ dictReleaseIterator(di);
+ } else {
+ assert(0 != 0);
+ }
+ /* Save the expire time */
+ if (expiretime != -1) {
+ char cmd[]="*3\r\n$6\r\nEXPIRE\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 (fwriteBulk(fp,key) == 0) goto werr;
+ if (fwriteBulkLong(fp,expiretime) == 0) goto werr;
+ }
+ }
+ dictReleaseIterator(di);
+ }
+
+ /* Make sure data will not remain on the OS's output buffers */
+ fflush(fp);
+ 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 fileon 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!
+ */
+static int rewriteAppendOnlyFileBackground(void) {
+ pid_t childpid;
+
+ if (server.bgrewritechildpid != -1) return REDIS_ERR;
+ if ((childpid = fork()) == 0) {
+ /* Child */
+ char tmpfile[256];
+ 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;
+ return REDIS_OK;
+ }
+ return REDIS_OK; /* unreached */
+}
+
+static 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) {
+ addReply(c,shared.ok);
+ } else {
+ addReply(c,shared.err);
+ }
+}
+
+static void aofRemoveTempFile(pid_t childpid) {
+ char tmpfile[256];
+
+ snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) childpid);
+ unlink(tmpfile);
+}
+
/* ================================= Debugging ============================== */
static void debugCommand(redisClient *c) {
listLength(server.slaves),
server.usedmemory,
server.dirty,
- server.bgsaveinprogress,
+ server.bgsavechildpid != -1,
server.lastsave,
server.stat_numconnections,
server.stat_numcommands,
projects / redis.git / commitdiff
