#include "redis.h"
+#include "bio.h"
+#include "rio.h"
#include <signal.h>
#include <fcntl.h>
#include <sys/resource.h>
#include <sys/wait.h>
+void aofUpdateCurrentSize(void);
+
+/* ----------------------------------------------------------------------------
+ * AOF rewrite buffer implementation.
+ *
+ * The following code implement a simple buffer used in order to accumulate
+ * changes while the background process is rewriting the AOF file.
+ *
+ * We only need to append, but can't just use realloc with a large block
+ * because 'huge' reallocs are not always handled as one could expect
+ * (via remapping of pages at OS level) but may involve copying data.
+ *
+ * For this reason we use a list of blocks, every block is
+ * AOF_RW_BUF_BLOCK_SIZE bytes.
+ * ------------------------------------------------------------------------- */
+
+#define AOF_RW_BUF_BLOCK_SIZE (1024*1024*10) /* 10 MB per block */
+
+typedef struct aofrwblock {
+ unsigned long used, free;
+ char buf[AOF_RW_BUF_BLOCK_SIZE];
+} aofrwblock;
+
+/* This function free the old AOF rewrite buffer if needed, and initialize
+ * a fresh new one. It tests for server.aof_rewrite_buf_blocks equal to NULL
+ * so can be used for the first initialization as well. */
+void aofRewriteBufferReset(void) {
+ if (server.aof_rewrite_buf_blocks)
+ listRelease(server.aof_rewrite_buf_blocks);
+
+ server.aof_rewrite_buf_blocks = listCreate();
+ listSetFreeMethod(server.aof_rewrite_buf_blocks,zfree);
+}
+
+/* Return the current size of the AOF rerwite buffer. */
+unsigned long aofRewriteBufferSize(void) {
+ listNode *ln = listLast(server.aof_rewrite_buf_blocks);
+ aofrwblock *block = ln ? ln->value : NULL;
+
+ if (block == NULL) return 0;
+ unsigned long size =
+ (listLength(server.aof_rewrite_buf_blocks)-1) * AOF_RW_BUF_BLOCK_SIZE;
+ size += block->used;
+ return size;
+}
+
+/* Append data to the AOF rewrite buffer, allocating new blocks if needed. */
+void aofRewriteBufferAppend(unsigned char *s, unsigned long len) {
+ listNode *ln = listLast(server.aof_rewrite_buf_blocks);
+ aofrwblock *block = ln ? ln->value : NULL;
+
+ while(len) {
+ /* If we already got at least an allocated block, try appending
+ * at least some piece into it. */
+ if (block) {
+ unsigned long thislen = (block->free < len) ? block->free : len;
+ if (thislen) { /* The current block is not already full. */
+ memcpy(block->buf+block->used, s, thislen);
+ block->used += thislen;
+ block->free -= thislen;
+ s += thislen;
+ len -= thislen;
+ }
+ }
+
+ if (len) { /* First block to allocate, or need another block. */
+ int numblocks;
+
+ block = zmalloc(sizeof(*block));
+ block->free = AOF_RW_BUF_BLOCK_SIZE;
+ block->used = 0;
+ listAddNodeTail(server.aof_rewrite_buf_blocks,block);
+
+ /* Log every time we cross more 10 or 100 blocks, respectively
+ * as a notice or warning. */
+ numblocks = listLength(server.aof_rewrite_buf_blocks);
+ if (((numblocks+1) % 10) == 0) {
+ int level = ((numblocks+1) % 100) == 0 ? REDIS_WARNING :
+ REDIS_NOTICE;
+ redisLog(level,"Background AOF buffer size: %lu MB",
+ aofRewriteBufferSize()/(1024*1024));
+ }
+ }
+ }
+}
+
+/* Write the buffer (possibly composed of multiple blocks) into the specified
+ * fd. If no short write or any other error happens -1 is returned,
+ * otherwise the number of bytes written is returned. */
+ssize_t aofRewriteBufferWrite(int fd) {
+ listNode *ln;
+ listIter li;
+ ssize_t count = 0;
+
+ listRewind(server.aof_rewrite_buf_blocks,&li);
+ while((ln = listNext(&li))) {
+ aofrwblock *block = listNodeValue(ln);
+ ssize_t nwritten;
+
+ if (block->used) {
+ nwritten = write(fd,block->buf,block->used);
+ if (nwritten != block->used) {
+ if (nwritten == 0) errno = EIO;
+ return -1;
+ }
+ count += nwritten;
+ }
+ }
+ return count;
+}
+
+/* ----------------------------------------------------------------------------
+ * AOF file implementation
+ * ------------------------------------------------------------------------- */
+
+/* Starts a background task that performs fsync() against the specified
+ * file descriptor (the one of the AOF file) in another thread. */
+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) {
- flushAppendOnlyFile();
- aof_fsync(server.appendfd);
- close(server.appendfd);
-
- server.appendfd = -1;
- server.appendseldb = -1;
- server.appendonly = 0;
+ redisAssert(server.aof_state != REDIS_AOF_OFF);
+ flushAppendOnlyFile(1);
+ aof_fsync(server.aof_fd);
+ close(server.aof_fd);
+
+ server.aof_fd = -1;
+ server.aof_selected_db = -1;
+ server.aof_state = REDIS_AOF_OFF;
/* rewrite operation in progress? kill it, wait child exit */
- if (server.bgsavechildpid != -1) {
+ if (server.aof_child_pid != -1) {
int statloc;
- if (kill(server.bgsavechildpid,SIGKILL) != -1)
+ redisLog(REDIS_NOTICE,"Killing running AOF rewrite child: %ld",
+ (long) server.aof_child_pid);
+ if (kill(server.aof_child_pid,SIGKILL) != -1)
wait3(&statloc,0,NULL);
/* reset the buffer accumulating changes while the child saves */
- sdsfree(server.bgrewritebuf);
- server.bgrewritebuf = sdsempty();
- server.bgsavechildpid = -1;
+ aofRewriteBufferReset();
+ aofRemoveTempFile(server.aof_child_pid);
+ server.aof_child_pid = -1;
+ server.aof_rewrite_time_start = -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));
+ server.aof_last_fsync = server.unixtime;
+ server.aof_fd = open(server.aof_filename,O_WRONLY|O_APPEND|O_CREAT,0644);
+ redisAssert(server.aof_state == REDIS_AOF_OFF);
+ if (server.aof_fd == -1) {
+ redisLog(REDIS_WARNING,"Redis needs to enable the AOF but can't open the append only 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));
+ close(server.aof_fd);
+ redisLog(REDIS_WARNING,"Redis needs to enable the AOF but can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.");
return REDIS_ERR;
}
+ /* We correctly switched on AOF, now wait for the rerwite to be complete
+ * in order to append data on disk. */
+ server.aof_state = REDIS_AOF_WAIT_REWRITE;
return REDIS_OK;
}
* 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;
+ * 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;
-
- if (sdslen(server.aofbuf) == 0) return;
+ int sync_in_progress = 0;
+
+ if (sdslen(server.aof_buf) == 0) return;
+
+ if (server.aof_fsync == AOF_FSYNC_EVERYSEC)
+ sync_in_progress = bioPendingJobsOfType(REDIS_BIO_AOF_FSYNC) != 0;
+
+ if (server.aof_fsync == AOF_FSYNC_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. */
+ server.aof_delayed_fsync++;
+ 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
* 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)) {
+ nwritten = write(server.aof_fd,server.aof_buf,sdslen(server.aof_buf));
+ if (nwritten != (signed)sdslen(server.aof_buf)) {
/* 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) {
+ 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);
+ } else {
+ redisLog(REDIS_WARNING,"Exiting on short write while writing to "
+ "the append-only file: %s (nwritten=%ld, "
+ "expected=%ld)",
+ strerror(errno),
+ (long)nwritten,
+ (long)sdslen(server.aof_buf));
+
+ if (ftruncate(server.aof_fd, server.aof_current_size) == -1) {
+ redisLog(REDIS_WARNING, "Could not remove short write "
+ "from the append-only file. Redis may refuse "
+ "to load the AOF the next time it starts. "
+ "ftruncate: %s", strerror(errno));
+ }
+ }
+ exit(1);
}
- sdsfree(server.aofbuf);
- server.aofbuf = sdsempty();
+ server.aof_current_size += nwritten;
- /* 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))
+ /* Re-use AOF buffer when it is small enough. The maximum comes from the
+ * arena size of 4k minus some overhead (but is otherwise arbitrary). */
+ if ((sdslen(server.aof_buf)+sdsavail(server.aof_buf)) < 4000) {
+ sdsclear(server.aof_buf);
+ } else {
+ sdsfree(server.aof_buf);
+ server.aof_buf = sdsempty();
+ }
+
+ /* Don't fsync if no-appendfsync-on-rewrite is set to yes and there are
+ * children doing I/O in the background. */
+ if (server.aof_no_fsync_on_rewrite &&
+ (server.aof_child_pid != -1 || server.rdb_child_pid != -1))
return;
- /* Fsync if needed */
- now = time(NULL);
- if (server.appendfsync == APPENDFSYNC_ALWAYS ||
- (server.appendfsync == APPENDFSYNC_EVERYSEC &&
- now-server.lastfsync > 1))
- {
+
+ /* Perform the fsync if needed. */
+ if (server.aof_fsync == AOF_FSYNC_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 = now;
+ aof_fsync(server.aof_fd); /* Let's try to get this data on the disk */
+ server.aof_last_fsync = server.unixtime;
+ } else if ((server.aof_fsync == AOF_FSYNC_EVERYSEC &&
+ server.unixtime > server.aof_last_fsync)) {
+ if (!sync_in_progress) aof_background_fsync(server.aof_fd);
+ server.aof_last_fsync = server.unixtime;
}
}
-sds catAppendOnlyGenericCommand(sds buf, int argc, robj **argv) {
- int j;
- buf = sdscatprintf(buf,"*%d\r\n",argc);
+sds catAppendOnlyGenericCommand(sds dst, int argc, robj **argv) {
+ char buf[32];
+ int len, j;
+ robj *o;
+
+ buf[0] = '*';
+ len = 1+ll2string(buf+1,sizeof(buf)-1,argc);
+ buf[len++] = '\r';
+ buf[len++] = '\n';
+ dst = sdscatlen(dst,buf,len);
+
for (j = 0; j < argc; j++) {
- robj *o = getDecodedObject(argv[j]);
- buf = sdscatprintf(buf,"$%lu\r\n",(unsigned long)sdslen(o->ptr));
- buf = sdscatlen(buf,o->ptr,sdslen(o->ptr));
- buf = sdscatlen(buf,"\r\n",2);
+ o = getDecodedObject(argv[j]);
+ buf[0] = '$';
+ len = 1+ll2string(buf+1,sizeof(buf)-1,sdslen(o->ptr));
+ buf[len++] = '\r';
+ buf[len++] = '\n';
+ dst = sdscatlen(dst,buf,len);
+ dst = sdscatlen(dst,o->ptr,sdslen(o->ptr));
+ dst = sdscatlen(dst,"\r\n",2);
decrRefCount(o);
}
- return buf;
+ return dst;
}
-sds catAppendOnlyExpireAtCommand(sds buf, robj *key, robj *seconds) {
- int argc = 3;
- long when;
+/* Create the sds representation of an PEXPIREAT command, using
+ * 'seconds' as time to live and 'cmd' to understand what command
+ * we are translating into a PEXPIREAT.
+ *
+ * This command is used in order to translate EXPIRE and PEXPIRE commands
+ * into PEXPIREAT command so that we retain precision in the append only
+ * file, and the time is always absolute and not relative. */
+sds catAppendOnlyExpireAtCommand(sds buf, struct redisCommand *cmd, robj *key, robj *seconds) {
+ long long when;
robj *argv[3];
/* Make sure we can use strtol */
seconds = getDecodedObject(seconds);
- when = time(NULL)+strtol(seconds->ptr,NULL,10);
+ when = strtoll(seconds->ptr,NULL,10);
+ /* Convert argument into milliseconds for EXPIRE, SETEX, EXPIREAT */
+ if (cmd->proc == expireCommand || cmd->proc == setexCommand ||
+ cmd->proc == expireatCommand)
+ {
+ when *= 1000;
+ }
+ /* Convert into absolute time for EXPIRE, PEXPIRE, SETEX, PSETEX */
+ if (cmd->proc == expireCommand || cmd->proc == pexpireCommand ||
+ cmd->proc == setexCommand || cmd->proc == psetexCommand)
+ {
+ when += mstime();
+ }
decrRefCount(seconds);
- argv[0] = createStringObject("EXPIREAT",8);
+ argv[0] = createStringObject("PEXPIREAT",9);
argv[1] = key;
- argv[2] = createObject(REDIS_STRING,
- sdscatprintf(sdsempty(),"%ld",when));
- buf = catAppendOnlyGenericCommand(buf, argc, argv);
+ argv[2] = createStringObjectFromLongLong(when);
+ buf = catAppendOnlyGenericCommand(buf, 3, argv);
decrRefCount(argv[0]);
decrRefCount(argv[2]);
return buf;
/* 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) {
+ if (dictid != server.aof_selected_db) {
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;
+ server.aof_selected_db = 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 */
+ if (cmd->proc == expireCommand || cmd->proc == pexpireCommand ||
+ cmd->proc == expireatCommand) {
+ /* Translate EXPIRE/PEXPIRE/EXPIREAT into PEXPIREAT */
+ buf = catAppendOnlyExpireAtCommand(buf,cmd,argv[1],argv[2]);
+ } else if (cmd->proc == setexCommand || cmd->proc == psetexCommand) {
+ /* Translate SETEX/PSETEX to SET and PEXPIREAT */
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]);
+ buf = catAppendOnlyExpireAtCommand(buf,cmd,argv[1],argv[2]);
} else {
+ /* All the other commands don't need translation or need the
+ * same translation already operated in the command vector
+ * for the replication itself. */
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 (server.aof_state == REDIS_AOF_ON)
+ server.aof_buf = sdscatlen(server.aof_buf,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));
+ if (server.aof_child_pid != -1)
+ aofRewriteBufferAppend((unsigned char*)buf,sdslen(buf));
sdsfree(buf);
}
+/* ----------------------------------------------------------------------------
+ * AOF loading
+ * ------------------------------------------------------------------------- */
+
/* 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) {
selectDb(c,0);
c->fd = -1;
c->querybuf = sdsempty();
+ c->querybuf_peak = 0;
c->argc = 0;
c->argv = NULL;
c->bufpos = 0;
* so that Redis will not try to send replies to this client. */
c->replstate = REDIS_REPL_WAIT_BGSAVE_START;
c->reply = listCreate();
+ c->reply_bytes = 0;
+ c->obuf_soft_limit_reached_time = 0;
c->watched_keys = listCreate();
listSetFreeMethod(c->reply,decrRefCount);
listSetDupMethod(c->reply,dupClientReplyValue);
struct redisClient *fakeClient;
FILE *fp = fopen(filename,"r");
struct redis_stat sb;
- int appendonly = server.appendonly;
+ int old_aof_state = server.aof_state;
long loops = 0;
- if (redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0)
+ if (fp && redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) {
+ server.aof_current_size = 0;
+ fclose(fp);
return REDIS_ERR;
+ }
if (fp == NULL) {
redisLog(REDIS_WARNING,"Fatal error: can't open the append log file for reading: %s",strerror(errno));
/* Temporarily disable AOF, to prevent EXEC from feeding a MULTI
* to the same file we're about to read. */
- server.appendonly = 0;
+ server.aof_state = REDIS_AOF_OFF;
fakeClient = createFakeClient();
startLoading(fp);
}
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;
/* The fake client should not have a reply */
redisAssert(fakeClient->bufpos == 0 && listLength(fakeClient->reply) == 0);
-
- /* Clean up, ready for the next command */
- for (j = 0; j < argc; j++) decrRefCount(argv[j]);
- zfree(argv);
+ /* The fake client should never get blocked */
+ redisAssert((fakeClient->flags & REDIS_BLOCKED) == 0);
+
+ /* Clean up. Command code may have changed argv/argc so we use the
+ * argv/argc of the client instead of the local variables. */
+ for (j = 0; j < fakeClient->argc; j++)
+ decrRefCount(fakeClient->argv[j]);
+ zfree(fakeClient->argv);
}
/* This point can only be reached when EOF is reached without errors.
fclose(fp);
freeFakeClient(fakeClient);
- server.appendonly = appendonly;
+ server.aof_state = old_aof_state;
stopLoading();
+ aofUpdateCurrentSize();
+ server.aof_rewrite_base_size = server.aof_current_size;
return REDIS_OK;
readerr:
exit(1);
}
+/* ----------------------------------------------------------------------------
+ * AOF rewrite
+ * ------------------------------------------------------------------------- */
+
+/* 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");
+ }
+}
+
+/* Emit the commands needed to rebuild a list object.
+ * The function returns 0 on error, 1 on success. */
+int rewriteListObject(rio *r, robj *key, robj *o) {
+ long long count = 0, items = listTypeLength(o);
+
+ 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 (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items) == 0) return 0;
+ if (rioWriteBulkString(r,"RPUSH",5) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+ if (vstr) {
+ if (rioWriteBulkString(r,(char*)vstr,vlen) == 0) return 0;
+ } else {
+ if (rioWriteBulkLongLong(r,vlong) == 0) return 0;
+ }
+ p = ziplistNext(zl,p);
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+ } 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 (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items) == 0) return 0;
+ if (rioWriteBulkString(r,"RPUSH",5) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+ if (rioWriteBulkObject(r,eleobj) == 0) return 0;
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+ } else {
+ redisPanic("Unknown list encoding");
+ }
+ return 1;
+}
+
+/* Emit the commands needed to rebuild a set object.
+ * The function returns 0 on error, 1 on success. */
+int rewriteSetObject(rio *r, robj *key, robj *o) {
+ long long count = 0, items = setTypeSize(o);
+
+ if (o->encoding == REDIS_ENCODING_INTSET) {
+ int ii = 0;
+ int64_t llval;
+
+ while(intsetGet(o->ptr,ii++,&llval)) {
+ if (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items) == 0) return 0;
+ if (rioWriteBulkString(r,"SADD",4) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+ if (rioWriteBulkLongLong(r,llval) == 0) return 0;
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+ } else if (o->encoding == REDIS_ENCODING_HT) {
+ dictIterator *di = dictGetIterator(o->ptr);
+ dictEntry *de;
+
+ while((de = dictNext(di)) != NULL) {
+ robj *eleobj = dictGetKey(de);
+ if (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items) == 0) return 0;
+ if (rioWriteBulkString(r,"SADD",4) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+ if (rioWriteBulkObject(r,eleobj) == 0) return 0;
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+ dictReleaseIterator(di);
+ } else {
+ redisPanic("Unknown set encoding");
+ }
+ return 1;
+}
+
+/* Emit the commands needed to rebuild a sorted set object.
+ * The function returns 0 on error, 1 on success. */
+int rewriteSortedSetObject(rio *r, robj *key, robj *o) {
+ long long count = 0, items = zsetLength(o);
+
+ if (o->encoding == REDIS_ENCODING_ZIPLIST) {
+ unsigned char *zl = o->ptr;
+ unsigned char *eptr, *sptr;
+ unsigned char *vstr;
+ unsigned int vlen;
+ long long vll;
+ double score;
+
+ eptr = ziplistIndex(zl,0);
+ redisAssert(eptr != NULL);
+ sptr = ziplistNext(zl,eptr);
+ redisAssert(sptr != NULL);
+
+ while (eptr != NULL) {
+ redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
+ score = zzlGetScore(sptr);
+
+ if (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items*2) == 0) return 0;
+ if (rioWriteBulkString(r,"ZADD",4) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+ if (rioWriteBulkDouble(r,score) == 0) return 0;
+ if (vstr != NULL) {
+ if (rioWriteBulkString(r,(char*)vstr,vlen) == 0) return 0;
+ } else {
+ if (rioWriteBulkLongLong(r,vll) == 0) return 0;
+ }
+ zzlNext(zl,&eptr,&sptr);
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+ } else if (o->encoding == REDIS_ENCODING_SKIPLIST) {
+ zset *zs = o->ptr;
+ dictIterator *di = dictGetIterator(zs->dict);
+ dictEntry *de;
+
+ while((de = dictNext(di)) != NULL) {
+ robj *eleobj = dictGetKey(de);
+ double *score = dictGetVal(de);
+
+ if (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items*2) == 0) return 0;
+ if (rioWriteBulkString(r,"ZADD",4) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+ if (rioWriteBulkDouble(r,*score) == 0) return 0;
+ if (rioWriteBulkObject(r,eleobj) == 0) return 0;
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+ dictReleaseIterator(di);
+ } else {
+ redisPanic("Unknown sorted zset encoding");
+ }
+ return 1;
+}
+
+/* Write either the key or the value of the currently selected item of an hash.
+ * The 'hi' argument passes a valid Redis hash iterator.
+ * The 'what' filed specifies if to write a key or a value and can be
+ * either REDIS_HASH_KEY or REDIS_HASH_VALUE.
+ *
+ * The function returns 0 on error, non-zero on success. */
+static int rioWriteHashIteratorCursor(rio *r, hashTypeIterator *hi, int what) {
+ if (hi->encoding == REDIS_ENCODING_ZIPLIST) {
+ unsigned char *vstr = NULL;
+ unsigned int vlen = UINT_MAX;
+ long long vll = LLONG_MAX;
+
+ hashTypeCurrentFromZiplist(hi, what, &vstr, &vlen, &vll);
+ if (vstr) {
+ return rioWriteBulkString(r, (char*)vstr, vlen);
+ } else {
+ return rioWriteBulkLongLong(r, vll);
+ }
+
+ } else if (hi->encoding == REDIS_ENCODING_HT) {
+ robj *value;
+
+ hashTypeCurrentFromHashTable(hi, what, &value);
+ return rioWriteBulkObject(r, value);
+ }
+
+ redisPanic("Unknown hash encoding");
+ return 0;
+}
+
+/* Emit the commands needed to rebuild a hash object.
+ * The function returns 0 on error, 1 on success. */
+int rewriteHashObject(rio *r, robj *key, robj *o) {
+ hashTypeIterator *hi;
+ long long count = 0, items = hashTypeLength(o);
+
+ hi = hashTypeInitIterator(o);
+ while (hashTypeNext(hi) != REDIS_ERR) {
+ if (count == 0) {
+ int cmd_items = (items > REDIS_AOF_REWRITE_ITEMS_PER_CMD) ?
+ REDIS_AOF_REWRITE_ITEMS_PER_CMD : items;
+
+ if (rioWriteBulkCount(r,'*',2+cmd_items*2) == 0) return 0;
+ if (rioWriteBulkString(r,"HMSET",5) == 0) return 0;
+ if (rioWriteBulkObject(r,key) == 0) return 0;
+ }
+
+ if (rioWriteHashIteratorCursor(r, hi, REDIS_HASH_KEY) == 0) return 0;
+ if (rioWriteHashIteratorCursor(r, hi, REDIS_HASH_VALUE) == 0) return 0;
+ if (++count == REDIS_AOF_REWRITE_ITEMS_PER_CMD) count = 0;
+ items--;
+ }
+
+ hashTypeReleaseIterator(hi);
+
+ return 1;
+}
+
/* Write a sequence of commands able to fully rebuild the dataset into
- * "filename". Used both by REWRITEAOF and BGREWRITEAOF. */
+ * "filename". Used both by REWRITEAOF and BGREWRITEAOF.
+ *
+ * In order to minimize the number of commands needed in the rewritten
+ * log Redis uses variadic commands when possible, such as RPUSH, SADD
+ * and ZADD. However at max REDIS_AOF_REWRITE_ITEMS_PER_CMD items per time
+ * are inserted using a single command. */
int rewriteAppendOnlyFile(char *filename) {
dictIterator *di = NULL;
dictEntry *de;
+ rio aof;
FILE *fp;
char tmpfile[256];
int j;
- time_t now = time(NULL);
+ long long now = mstime();
/* 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));
+ redisLog(REDIS_WARNING, "Opening the temp file for AOF rewrite in rewriteAppendOnlyFile(): %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;
dict *d = db->dict;
if (dictSize(d) == 0) continue;
- di = dictGetIterator(d);
+ di = dictGetSafeIterator(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;
+ 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) {
- sds keystr = dictGetEntryKey(de);
+ sds keystr;
robj key, *o;
- time_t expiretime;
+ long long expiretime;
- keystr = dictGetEntryKey(de);
- o = dictGetEntryVal(de);
+ keystr = dictGetKey(de);
+ o = dictGetVal(de);
initStaticStringObject(key,keystr);
expiretime = getExpire(db,&key);
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 */
- 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";
- 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");
- }
+ if (rewriteListObject(&aof,&key,o) == 0) goto werr;
} else if (o->type == REDIS_SET) {
- char cmd[]="*3\r\n$4\r\nSADD\r\n";
-
- /* Emit the SADDs needed to rebuild the set */
- if (o->encoding == REDIS_ENCODING_INTSET) {
- 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;
- }
- } 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;
- }
- dictReleaseIterator(di);
- } else {
- redisPanic("Unknown set encoding");
- }
+ if (rewriteSetObject(&aof,&key,o) == 0) goto werr;
} 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);
+ if (rewriteSortedSetObject(&aof,&key,o) == 0) goto werr;
} 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) == 0)
- goto werr;
- if (fwriteBulkString(fp,(char*)val,vlen) == 0)
- goto werr;
- }
- } 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) == 0) goto werr;
- if (fwriteBulkObject(fp,val) == 0) goto werr;
- }
- dictReleaseIterator(di);
- }
+ if (rewriteHashObject(&aof,&key,o) == 0) goto werr;
} else {
redisPanic("Unknown object type");
}
/* Save the expire time */
if (expiretime != -1) {
- char cmd[]="*3\r\n$8\r\nEXPIREAT\r\n";
+ char cmd[]="*3\r\n$9\r\nPEXPIREAT\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);
* 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.
+ * 2b) the parent accumulates differences in server.aof_rewrite_buf.
* 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
+ * data accumulated into server.aof_rewrite_buf 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;
+ long long start;
- if (server.bgrewritechildpid != -1) return REDIS_ERR;
- if (server.ds_enabled != 0) {
- redisLog(REDIS_WARNING,"BGREWRITEAOF called with diskstore enabled: AOF is not supported when diskstore is enabled. Operation not performed.");
- return REDIS_ERR;
- }
+ if (server.aof_child_pid != -1) return REDIS_ERR;
+ start = ustime();
if ((childpid = fork()) == 0) {
- /* Child */
char tmpfile[256];
+ /* Child */
if (server.ipfd > 0) close(server.ipfd);
if (server.sofd > 0) close(server.sofd);
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
if (rewriteAppendOnlyFile(tmpfile) == REDIS_OK) {
- _exit(0);
+ exitFromChild(0);
} else {
- _exit(1);
+ exitFromChild(1);
}
} else {
/* Parent */
+ server.stat_fork_time = ustime()-start;
if (childpid == -1) {
redisLog(REDIS_WARNING,
"Can't rewrite append only file in background: fork: %s",
}
redisLog(REDIS_NOTICE,
"Background append only file rewriting started by pid %d",childpid);
- server.bgrewritechildpid = childpid;
+ server.aof_rewrite_scheduled = 0;
+ server.aof_rewrite_time_start = time(NULL);
+ server.aof_child_pid = 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
+ * accumulated by the parent into server.aof_rewrite_buf will start
* with a SELECT statement and it will be safe to merge. */
- server.appendseldb = -1;
+ server.aof_selected_db = -1;
return REDIS_OK;
}
return REDIS_OK; /* unreached */
}
void bgrewriteaofCommand(redisClient *c) {
- if (server.bgrewritechildpid != -1) {
+ if (server.aof_child_pid != -1) {
addReplyError(c,"Background append only file rewriting already in progress");
- return;
- }
- if (rewriteAppendOnlyFileBackground() == REDIS_OK) {
+ } else if (server.rdb_child_pid != -1) {
+ server.aof_rewrite_scheduled = 1;
+ addReplyStatus(c,"Background append only file rewriting scheduled");
+ } else if (rewriteAppendOnlyFileBackground() == REDIS_OK) {
addReplyStatus(c,"Background append only file rewriting started");
} else {
addReply(c,shared.err);
unlink(tmpfile);
}
+/* Update the server.aof_current_size filed explicitly using stat(2)
+ * to check the size of the file. This is useful after a rewrite or after
+ * a restart, normally the size is updated just adding the write length
+ * to the current length, that is much faster. */
+void aofUpdateCurrentSize(void) {
+ struct redis_stat sb;
+
+ if (redis_fstat(server.aof_fd,&sb) == -1) {
+ redisLog(REDIS_WARNING,"Unable to obtain the AOF file length. stat: %s",
+ strerror(errno));
+ } else {
+ server.aof_current_size = sb.st_size;
+ }
+}
+
/* A background append only file rewriting (BGREWRITEAOF) terminated its work.
* Handle this. */
void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
if (!bysignal && exitcode == 0) {
- int fd;
+ int newfd, oldfd;
char tmpfile[256];
+ long long now = ustime();
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.aof_child_pid);
+ 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;
}
- /* 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);
+
+ if (aofRewriteBufferWrite(newfd) == -1) {
+ redisLog(REDIS_WARNING,
+ "Error trying to flush the parent diff to the rewritten AOF: %s", strerror(errno));
+ close(newfd);
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);
+
+ redisLog(REDIS_NOTICE,
+ "Parent diff successfully flushed to the rewritten AOF (%lu bytes)", aofRewriteBufferSize());
+
+ /* 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.aof_fd == -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.aof_filename,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.aof_filename) == -1) {
+ redisLog(REDIS_WARNING,
+ "Error trying to rename the temporary AOF file: %s", strerror(errno));
+ close(newfd);
+ if (oldfd != -1) close(oldfd);
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.aof_fd == -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 {
- /* If append only is disabled we just generate a dump in this
- * format. Why not? */
- close(fd);
+ /* AOF enabled, replace the old fd with the new one. */
+ oldfd = server.aof_fd;
+ server.aof_fd = newfd;
+ if (server.aof_fsync == AOF_FSYNC_ALWAYS)
+ aof_fsync(newfd);
+ else if (server.aof_fsync == AOF_FSYNC_EVERYSEC)
+ aof_background_fsync(newfd);
+ server.aof_selected_db = -1; /* Make sure SELECT is re-issued */
+ aofUpdateCurrentSize();
+ server.aof_rewrite_base_size = server.aof_current_size;
+
+ /* Clear regular AOF buffer since its contents was just written to
+ * the new AOF from the background rewrite buffer. */
+ sdsfree(server.aof_buf);
+ server.aof_buf = sdsempty();
}
+
+ server.aof_lastbgrewrite_status = REDIS_OK;
+
+ redisLog(REDIS_NOTICE, "Background AOF rewrite finished successfully");
+ /* Change state from WAIT_REWRITE to ON if needed */
+ if (server.aof_state == REDIS_AOF_WAIT_REWRITE)
+ server.aof_state = REDIS_AOF_ON;
+
+ /* 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) {
- redisLog(REDIS_WARNING, "Background append only file rewriting error");
+ server.aof_lastbgrewrite_status = REDIS_ERR;
+
+ redisLog(REDIS_WARNING,
+ "Background AOF rewrite terminated with error");
} else {
+ server.aof_lastbgrewrite_status = REDIS_ERR;
+
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();
- aofRemoveTempFile(server.bgrewritechildpid);
- server.bgrewritechildpid = -1;
+ aofRewriteBufferReset();
+ aofRemoveTempFile(server.aof_child_pid);
+ server.aof_child_pid = -1;
+ server.aof_rewrite_time_last = time(NULL)-server.aof_rewrite_time_start;
+ server.aof_rewrite_time_start = -1;
+ /* Schedule a new rewrite if we are waiting for it to switch the AOF ON. */
+ if (server.aof_state == REDIS_AOF_WAIT_REWRITE)
+ server.aof_rewrite_scheduled = 1;
}
projects / redis.git / blobdiff