Clear the importing status from the slot if a CLUSTER SETSLOT command permanently...

[redis.git] / src / aof.c

diff --git a/src/aof.c b/src/aof.c
index 45dbc0db456dd81e6ee964f94559b04d12adb775..0dcf905eef99eb2c01cca60ae9b5fd8346163f61 100644 (file)
--- a/src/aof.c
+++ b/src/aof.c
@@ -1,4 +1,6 @@
 #include "redis.h"
 #include "redis.h"

+#include "bio.h"
+#include "rio.h"

 
 #include <signal.h>
 #include <fcntl.h>
 
 #include <signal.h>
 #include <fcntl.h>


@@ -10,10 +12,14 @@
 
 void aofUpdateCurrentSize(void);
 
 
 void aofUpdateCurrentSize(void);
 

+void aof_background_fsync(int fd) {
+    bioCreateBackgroundJob(REDIS_BIO_AOF_FSYNC,(void*)(long)fd,NULL,NULL);
+}
+

 /* Called when the user switches from "appendonly yes" to "appendonly no"
  * at runtime using the CONFIG command. */
 void stopAppendOnly(void) {
 /* Called when the user switches from "appendonly yes" to "appendonly no"
  * at runtime using the CONFIG command. */
 void stopAppendOnly(void) {

-    flushAppendOnlyFile();
+    flushAppendOnlyFile(1);

     aof_fsync(server.appendfd);
     close(server.appendfd);
 
     aof_fsync(server.appendfd);
     close(server.appendfd);
 


@@ -58,12 +64,51 @@ int startAppendOnly(void) {
  * 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
  * 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) {
+ * the event loop again.
+ *
+ * About the 'force' argument:
+ *
+ * When the fsync policy is set to 'everysec' we may delay the flush if there
+ * is still an fsync() going on in the background thread, since for instance
+ * on Linux write(2) will be blocked by the background fsync anyway.
+ * When this happens we remember that there is some aof buffer to be
+ * flushed ASAP, and will try to do that in the serverCron() function.
+ *
+ * However if force is set to 1 we'll write regardless of the background
+ * fsync. */
+void flushAppendOnlyFile(int force) {

     ssize_t nwritten;
     ssize_t nwritten;

+    int sync_in_progress = 0;

 
     if (sdslen(server.aofbuf) == 0) return;
 
 
     if (sdslen(server.aofbuf) == 0) return;
 

+    if (server.appendfsync == APPENDFSYNC_EVERYSEC)
+        sync_in_progress = bioPendingJobsOfType(REDIS_BIO_AOF_FSYNC) != 0;
+
+    if (server.appendfsync == APPENDFSYNC_EVERYSEC && !force) {
+        /* With this append fsync policy we do background fsyncing.
+         * If the fsync is still in progress we can try to delay
+         * the write for a couple of seconds. */
+        if (sync_in_progress) {
+            if (server.aof_flush_postponed_start == 0) {
+                /* No previous write postponinig, remember that we are
+                 * postponing the flush and return. */
+                server.aof_flush_postponed_start = server.unixtime;
+                return;
+            } else if (server.unixtime - server.aof_flush_postponed_start < 2) {
+                /* We were already waiting for fsync to finish, but for less
+                 * than two seconds this is still ok. Postpone again. */
+                return;
+            }
+            /* Otherwise fall trough, and go write since we can't wait
+             * over two seconds. */
+            redisLog(REDIS_NOTICE,"Asynchronous AOF fsync is taking too long (disk is busy?). Writing the AOF buffer without waiting for fsync to complete, this may slow down Redis.");
+        }
+    }
+    /* If you are following this code path, then we are going to write so
+     * set reset the postponed flush sentinel to zero. */
+    server.aof_flush_postponed_start = 0;
+

     /* 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
     /* 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


@@ -99,14 +144,15 @@ void flushAppendOnlyFile(void) {
             return;
 
     /* Perform the fsync if needed. */
             return;
 
     /* Perform the fsync if needed. */

-    if (server.appendfsync == APPENDFSYNC_ALWAYS ||
-        (server.appendfsync == APPENDFSYNC_EVERYSEC &&
-         server.unixtime > server.lastfsync))
-    {
+    if (server.appendfsync == APPENDFSYNC_ALWAYS) {

         /* 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 = server.unixtime;
         /* 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 = server.unixtime;

+    } else if ((server.appendfsync == APPENDFSYNC_EVERYSEC &&
+                server.unixtime > server.lastfsync)) {
+        if (!sync_in_progress) aof_background_fsync(server.appendfd);
+        server.lastfsync = server.unixtime;

     }
 }
 
     }
 }
 


@@ -281,6 +327,8 @@ int loadAppendOnlyFile(char *filename) {
         }
         if (buf[0] != '*') goto fmterr;
         argc = atoi(buf+1);
         }
         if (buf[0] != '*') goto fmterr;
         argc = atoi(buf+1);

+        if (argc < 1) goto fmterr;
+

         argv = zmalloc(sizeof(robj*)*argc);
         for (j = 0; j < argc; j++) {
             if (fgets(buf,sizeof(buf),fp) == NULL) goto readerr;
         argv = zmalloc(sizeof(robj*)*argc);
         for (j = 0; j < argc; j++) {
             if (fgets(buf,sizeof(buf),fp) == NULL) goto readerr;


@@ -339,11 +387,26 @@ fmterr:
     exit(1);
 }
 
     exit(1);
 }
 

+/* Delegate writing an object to writing a bulk string or bulk long long.
+ * This is not placed in rio.c since that adds the redis.h dependency. */
+int rioWriteBulkObject(rio *r, 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 rioWriteBulkLongLong(r,(long)obj->ptr);
+    } else if (obj->encoding == REDIS_ENCODING_RAW) {
+        return rioWriteBulkString(r,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;
 /* 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;

+    rio aof;

     FILE *fp;
     char tmpfile[256];
     int j;
     FILE *fp;
     char tmpfile[256];
     int j;


@@ -357,6 +420,8 @@ int rewriteAppendOnlyFile(char *filename) {
         redisLog(REDIS_WARNING, "Failed rewriting the append only file: %s", strerror(errno));
         return REDIS_ERR;
     }
         redisLog(REDIS_WARNING, "Failed rewriting the append only file: %s", strerror(errno));
         return REDIS_ERR;
     }

+
+    rioInitWithFile(&aof,fp);

     for (j = 0; j < server.dbnum; j++) {
         char selectcmd[] = "*2\r\n$6\r\nSELECT\r\n";
         redisDb *db = server.db+j;
     for (j = 0; j < server.dbnum; j++) {
         char selectcmd[] = "*2\r\n$6\r\nSELECT\r\n";
         redisDb *db = server.db+j;


@@ -369,8 +434,8 @@ int rewriteAppendOnlyFile(char *filename) {
         }
 
         /* SELECT the new DB */
         }
 
         /* SELECT the new DB */

-        if (fwrite(selectcmd,sizeof(selectcmd)-1,1,fp) == 0) goto werr;
-        if (fwriteBulkLongLong(fp,j) == 0) goto werr;
+        if (rioWrite(&aof,selectcmd,sizeof(selectcmd)-1) == 0) goto werr;
+        if (rioWriteBulkLongLong(&aof,j) == 0) goto werr;

 
         /* Iterate this DB writing every entry */
         while((de = dictNext(di)) != NULL) {
 
         /* Iterate this DB writing every entry */
         while((de = dictNext(di)) != NULL) {


@@ -388,10 +453,10 @@ int rewriteAppendOnlyFile(char *filename) {
             if (o->type == REDIS_STRING) {
                 /* Emit a SET command */
                 char cmd[]="*3\r\n$3\r\nSET\r\n";
             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;
+                if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;

                 /* Key and value */
                 /* Key and value */

-                if (fwriteBulkObject(fp,&key) == 0) goto werr;
-                if (fwriteBulkObject(fp,o) == 0) goto werr;
+                if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                if (rioWriteBulkObject(&aof,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";
             } else if (o->type == REDIS_LIST) {
                 /* Emit the RPUSHes needed to rebuild the list */
                 char cmd[]="*3\r\n$5\r\nRPUSH\r\n";


@@ -403,13 +468,13 @@ int rewriteAppendOnlyFile(char *filename) {
                     long long vlong;
 
                     while(ziplistGet(p,&vstr,&vlen,&vlong)) {
                     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 (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;

                         if (vstr) {
                         if (vstr) {

-                            if (fwriteBulkString(fp,(char*)vstr,vlen) == 0)
+                            if (rioWriteBulkString(&aof,(char*)vstr,vlen) == 0)

                                 goto werr;
                         } else {
                                 goto werr;
                         } else {

-                            if (fwriteBulkLongLong(fp,vlong) == 0)
+                            if (rioWriteBulkLongLong(&aof,vlong) == 0)

                                 goto werr;
                         }
                         p = ziplistNext(zl,p);
                                 goto werr;
                         }
                         p = ziplistNext(zl,p);


@@ -423,9 +488,9 @@ int rewriteAppendOnlyFile(char *filename) {
                     while((ln = listNext(&li))) {
                         robj *eleobj = listNodeValue(ln);
 
                     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;
+                        if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,eleobj) == 0) goto werr;

                     }
                 } else {
                     redisPanic("Unknown list encoding");
                     }
                 } else {
                     redisPanic("Unknown list encoding");


@@ -438,18 +503,18 @@ int rewriteAppendOnlyFile(char *filename) {
                     int ii = 0;
                     int64_t llval;
                     while(intsetGet(o->ptr,ii++,&llval)) {
                     int ii = 0;
                     int64_t llval;
                     while(intsetGet(o->ptr,ii++,&llval)) {

-                        if (fwrite(cmd,sizeof(cmd)-1,1,fp) == 0) goto werr;
-                        if (fwriteBulkObject(fp,&key) == 0) goto werr;
-                        if (fwriteBulkLongLong(fp,llval) == 0) goto werr;
+                        if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkLongLong(&aof,llval) == 0) goto werr;

                     }
                 } else if (o->encoding == REDIS_ENCODING_HT) {
                     dictIterator *di = dictGetIterator(o->ptr);
                     dictEntry *de;
                     while((de = dictNext(di)) != NULL) {
                         robj *eleobj = dictGetEntryKey(de);
                     }
                 } else if (o->encoding == REDIS_ENCODING_HT) {
                     dictIterator *di = dictGetIterator(o->ptr);
                     dictEntry *de;
                     while((de = dictNext(di)) != NULL) {
                         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;
+                        if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,eleobj) == 0) goto werr;

                     }
                     dictReleaseIterator(di);
                 } else {
                     }
                     dictReleaseIterator(di);
                 } else {


@@ -476,14 +541,14 @@ int rewriteAppendOnlyFile(char *filename) {
                         redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
                         score = zzlGetScore(sptr);
 
                         redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
                         score = zzlGetScore(sptr);
 

-                        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 (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkDouble(&aof,score) == 0) goto werr;

                         if (vstr != NULL) {
                         if (vstr != NULL) {

-                            if (fwriteBulkString(fp,(char*)vstr,vlen) == 0)
+                            if (rioWriteBulkString(&aof,(char*)vstr,vlen) == 0)

                                 goto werr;
                         } else {
                                 goto werr;
                         } else {

-                            if (fwriteBulkLongLong(fp,vll) == 0)
+                            if (rioWriteBulkLongLong(&aof,vll) == 0)

                                 goto werr;
                         }
                         zzlNext(zl,&eptr,&sptr);
                                 goto werr;
                         }
                         zzlNext(zl,&eptr,&sptr);


@@ -497,10 +562,10 @@ int rewriteAppendOnlyFile(char *filename) {
                         robj *eleobj = dictGetEntryKey(de);
                         double *score = dictGetEntryVal(de);
 
                         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;
+                        if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkDouble(&aof,*score) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,eleobj) == 0) goto werr;

                     }
                     dictReleaseIterator(di);
                 } else {
                     }
                     dictReleaseIterator(di);
                 } else {


@@ -516,11 +581,11 @@ int rewriteAppendOnlyFile(char *filename) {
                     unsigned int flen, vlen;
 
                     while((p = zipmapNext(p,&field,&flen,&val,&vlen)) != NULL) {
                     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) == 0)
+                        if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkString(&aof,(char*)field,flen) == 0)

                             goto werr;
                             goto werr;

-                        if (fwriteBulkString(fp,(char*)val,vlen) == 0)
+                        if (rioWriteBulkString(&aof,(char*)val,vlen) == 0)

                             goto werr;
                     }
                 } else {
                             goto werr;
                     }
                 } else {


@@ -531,10 +596,10 @@ int rewriteAppendOnlyFile(char *filename) {
                         robj *field = dictGetEntryKey(de);
                         robj *val = dictGetEntryVal(de);
 
                         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) == 0) goto werr;
-                        if (fwriteBulkObject(fp,val) == 0) goto werr;
+                        if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,field) == 0) goto werr;
+                        if (rioWriteBulkObject(&aof,val) == 0) goto werr;

                     }
                     dictReleaseIterator(di);
                 }
                     }
                     dictReleaseIterator(di);
                 }


@@ -546,9 +611,9 @@ int rewriteAppendOnlyFile(char *filename) {
                 char cmd[]="*3\r\n$8\r\nEXPIREAT\r\n";
                 /* If this key is already expired skip it */
                 if (expiretime < now) continue;
                 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 (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
+                if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
+                if (rioWriteBulkLongLong(&aof,expiretime) == 0) goto werr;

             }
         }
         dictReleaseIterator(di);
             }
         }
         dictReleaseIterator(di);


@@ -669,56 +734,127 @@ void aofUpdateCurrentSize(void) {
  * Handle this. */
 void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
     if (!bysignal && exitcode == 0) {
  * Handle this. */
 void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
     if (!bysignal && exitcode == 0) {

-        int fd;
+        int newfd, oldfd;
+        int nwritten;

         char tmpfile[256];
         char tmpfile[256];

+        long long now = ustime();

 
         redisLog(REDIS_NOTICE,
 
         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));
+            "Background AOF rewrite terminated with success");
+
+        /* Flush the differences accumulated by the parent to the
+         * rewritten AOF. */
+        snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof",
+            (int)server.bgrewritechildpid);
+        newfd = open(tmpfile,O_WRONLY|O_APPEND);
+        if (newfd == -1) {
+            redisLog(REDIS_WARNING,
+                "Unable to open the temporary AOF produced by the child: %s", strerror(errno));

             goto cleanup;
         }
             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);
+
+        nwritten = write(newfd,server.bgrewritebuf,sdslen(server.bgrewritebuf));
+        if (nwritten != (signed)sdslen(server.bgrewritebuf)) {
+            if (nwritten == -1) {
+                redisLog(REDIS_WARNING,
+                    "Error trying to flush the parent diff to the rewritten AOF: %s", strerror(errno));
+            } else {
+                redisLog(REDIS_WARNING,
+                    "Short write trying to flush the parent diff to the rewritten AOF: %s", strerror(errno));
+            }
+            close(newfd);

             goto cleanup;
         }
             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. */
+
+        redisLog(REDIS_NOTICE,
+            "Parent diff successfully flushed to the rewritten AOF (%lu bytes)", nwritten);
+
+        /* The only remaining thing to do is to rename the temporary file to
+         * the configured file and switch the file descriptor used to do AOF
+         * writes. We don't want close(2) or rename(2) calls to block the
+         * server on old file deletion.
+         *
+         * There are two possible scenarios:
+         *
+         * 1) AOF is DISABLED and this was a one time rewrite. The temporary
+         * file will be renamed to the configured file. When this file already
+         * exists, it will be unlinked, which may block the server.
+         *
+         * 2) AOF is ENABLED and the rewritten AOF will immediately start
+         * receiving writes. After the temporary file is renamed to the
+         * configured file, the original AOF file descriptor will be closed.
+         * Since this will be the last reference to that file, closing it
+         * causes the underlying file to be unlinked, which may block the
+         * server.
+         *
+         * To mitigate the blocking effect of the unlink operation (either
+         * caused by rename(2) in scenario 1, or by close(2) in scenario 2), we
+         * use a background thread to take care of this. First, we
+         * make scenario 1 identical to scenario 2 by opening the target file
+         * when it exists. The unlink operation after the rename(2) will then
+         * be executed upon calling close(2) for its descriptor. Everything to
+         * guarantee atomicity for this switch has already happened by then, so
+         * we don't care what the outcome or duration of that close operation
+         * is, as long as the file descriptor is released again. */
+        if (server.appendfd == -1) {
+            /* AOF disabled */
+
+             /* Don't care if this fails: oldfd will be -1 and we handle that.
+              * One notable case of -1 return is if the old file does
+              * not exist. */
+             oldfd = open(server.appendfilename,O_RDONLY|O_NONBLOCK);
+        } else {
+            /* AOF enabled */
+            oldfd = -1; /* We'll set this to the current AOF filedes later. */
+        }
+
+        /* Rename the temporary file. This will not unlink the target file if
+         * it exists, because we reference it with "oldfd". */

         if (rename(tmpfile,server.appendfilename) == -1) {
         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);
+            redisLog(REDIS_WARNING,
+                "Error trying to rename the temporary AOF: %s", strerror(errno));
+            close(newfd);
+            if (oldfd != -1) close(oldfd);

             goto cleanup;
         }
             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.");
+
+        if (server.appendfd == -1) {
+            /* AOF disabled, we don't need to set the AOF file descriptor
+             * to this new file, so we can close it. */
+            close(newfd);
+        } else {
+            /* AOF enabled, replace the old fd with the new one. */
+            oldfd = server.appendfd;
+            server.appendfd = newfd;
+            if (server.appendfsync == APPENDFSYNC_ALWAYS)
+                aof_fsync(newfd);
+            else if (server.appendfsync == APPENDFSYNC_EVERYSEC)
+                aof_background_fsync(newfd);
+            server.appendseldb = -1; /* Make sure SELECT is re-issued */

             aofUpdateCurrentSize();
             server.auto_aofrewrite_base_size = server.appendonly_current_size;
             aofUpdateCurrentSize();
             server.auto_aofrewrite_base_size = server.appendonly_current_size;

-        } else {
-            /* If append only is disabled we just generate a dump in this
-             * format. Why not? */
-            close(fd);
+
+            /* Clear regular AOF buffer since its contents was just written to
+             * the new AOF from the background rewrite buffer. */
+            sdsfree(server.aofbuf);
+            server.aofbuf = sdsempty();

         }
         }

+
+        redisLog(REDIS_NOTICE, "Background AOF rewrite successful");
+
+        /* Asynchronously close the overwritten AOF. */
+        if (oldfd != -1) bioCreateBackgroundJob(REDIS_BIO_CLOSE_FILE,(void*)(long)oldfd,NULL,NULL);
+
+        redisLog(REDIS_VERBOSE,
+            "Background AOF rewrite signal handler took %lldus", ustime()-now);

     } else if (!bysignal && exitcode != 0) {
     } else if (!bysignal && exitcode != 0) {

-        redisLog(REDIS_WARNING, "Background append only file rewriting error");
+        redisLog(REDIS_WARNING,
+            "Background AOF rewrite terminated with error");

     } else {
         redisLog(REDIS_WARNING,
     } else {
         redisLog(REDIS_WARNING,

-            "Background append only file rewriting terminated by signal %d",
-            bysignal);
+            "Background AOF rewrite terminated by signal %d", bysignal);

     }
     }

+

 cleanup:
     sdsfree(server.bgrewritebuf);
     server.bgrewritebuf = sdsempty();
 cleanup:
     sdsfree(server.bgrewritebuf);
     server.bgrewritebuf = sdsempty();