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redis/src/aof.c
Yuan Wang 7f5f588232 AOF offset info (#13773) 
### Background 
AOF is often used as an effective data recovery method, but now if we
have two AOFs from different nodes, it is hard to learn which one has
latest data. Generally, we determine whose data is more up-to-date by
reading the latest modification time of the AOF file, but because of
replication delay, even if both master and replica write to the AOF at
the same time, the data in the master is more up-to-date (there are
commands that didn't arrive at the replica yet, or a large number of
commands have accumulated on replica side ), so we may make wrong
decision.

### Solution
The replication offset always increments when AOF is enabled even if
there is no replica, we think replication offset is better method to
determine which one has more up-to-date data, whoever has a larger
offset will have newer data, so we add the start replication offset info
for AOF, as bellow.
```
file appendonly.aof.2.base.rdb seq 2 type b
file appendonly.aof.2.incr.aof seq 2 type i startoffset 224
```
And if we close gracefully the AOF file, not a crash, such as
`shutdown`, `kill signal 15` or `config set appendonly no`, we will add
the end replication offset, as bellow.
```
file appendonly.aof.2.base.rdb seq 2 type b
file appendonly.aof.2.incr.aof seq 2 type i startoffset 224 endoffset 532
```

#### Things to pay attention to
- For BASE AOF, we do not add `startoffset` and `endoffset` info, since
we could not know the start replication replication of data, and it is
useless to help us to determine which one has more up-to-date data.
- For AOFs from old version, we also don't add `startoffset` and
`endoffset` info, since we also don't know start replication replication
of them. If we add the start offset from 0, we might make the judgment
even less accurate. For example, if the master has just rewritten the
AOF, its INCR AOF will inevitably be very small. However, if the replica
has not rewritten AOF for a long time, its INCR AOF might be much
larger. By applying the following method, we might make incorrect
decisions, so we still just check timestamp instead of adding offset
info
- If the last INCR AOF has `startoffset` or `endoffset`, we need to
restore `server.master_repl_offset` according to them to avoid the
rollback of the `startoffset` of next INCR AOF. If it has `endoffset`,
we just use this value as `server.master_repl_offset`, and a very
important thing is to remove this information from the manifest file to
avoid the next time we load the manifest file with wrong `endoffset`. If
it only has `startoffset`, we calculate `server.master_repl_offset` by
the `startoffset` plus the file size.

### How to determine which one has more up-to-date data
If AOF has a larger replication offset, it will have more up-to-date
data. The following is how to get AOF offset:

Read the AOF manifest file to obtain information about **the last INCR
AOF**
1. If the last INCR AOF has `endoffset` field, we can directly use the
`endoffset` to present the replication offset of AOF
2. If there is no `endoffset`(such as redis crashes abnormally), but
there is `startoffset` filed of the last INCR AOF, we can get the
replication offset of AOF by `startoffset` plus the file size
3. Finally, if the AOF doesn’t have both `startoffset` and `endoffset`,
maybe from old version, and new version redis has not rewritten AOF yet,
we still need to check the modification timestamp of the last INCR AOF

### TODO
Fix ping causing inconsistency between AOF size and replication
offset in the future PR. Because we increment the replication offset
when sending PING/REPLCONF to the replica but do not write data to the
AOF file, this might cause the starting offset of the AOF file plus its
size to be inconsistent with the actual replication offset.
2025-02-13 17:31:40 +08:00

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/*
* Copyright (c) 2009-Present, Redis Ltd.
* All rights reserved.
*
* Licensed under your choice of the Redis Source Available License 2.0
* (RSALv2) or the Server Side Public License v1 (SSPLv1).
*/
#include "server.h"
#include "bio.h"
#include "rio.h"
#include "functions.h"
#include <signal.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <sys/param.h>
void freeClientArgv(client *c);
off_t getAppendOnlyFileSize(sds filename, int *status);
off_t getBaseAndIncrAppendOnlyFilesSize(aofManifest *am, int *status);
int getBaseAndIncrAppendOnlyFilesNum(aofManifest *am);
int aofFileExist(char *filename);
int rewriteAppendOnlyFile(char *filename);
aofManifest *aofLoadManifestFromFile(sds am_filepath);
void aofManifestFreeAndUpdate(aofManifest *am);
void aof_background_fsync_and_close(int fd);
/* When we call 'startAppendOnly', we will create a temp INCR AOF, and rename
* it to the real INCR AOF name when the AOFRW is done, so if want to know the
* accurate start offset of the INCR AOF, we need to record it when we create
* the temp INCR AOF. This variable is used to record the start offset, and
* set the start offset of the real INCR AOF when the AOFRW is done. */
static long long tempIncAofStartReplOffset = 0;
/* ----------------------------------------------------------------------------
* AOF Manifest file implementation.
*
* The following code implements the read/write logic of AOF manifest file, which
* is used to track and manage all AOF files.
*
* Append-only files consist of three types:
*
* BASE: Represents a Redis snapshot from the time of last AOF rewrite. The manifest
* file contains at most a single BASE file, which will always be the first file in the
* list.
*
* INCR: Represents all write commands executed by Redis following the last successful
* AOF rewrite. In some cases it is possible to have several ordered INCR files. For
* example:
* - During an on-going AOF rewrite
* - After an AOF rewrite was aborted/failed, and before the next one succeeded.
*
* HISTORY: After a successful rewrite, the previous BASE and INCR become HISTORY files.
* They will be automatically removed unless garbage collection is disabled.
*
* The following is a possible AOF manifest file content:
*
* file appendonly.aof.2.base.rdb seq 2 type b
* file appendonly.aof.1.incr.aof seq 1 type h
* file appendonly.aof.2.incr.aof seq 2 type h
* file appendonly.aof.3.incr.aof seq 3 type h
* file appendonly.aof.4.incr.aof seq 4 type i
* file appendonly.aof.5.incr.aof seq 5 type i
* ------------------------------------------------------------------------- */
/* Naming rules. */
#define BASE_FILE_SUFFIX ".base"
#define INCR_FILE_SUFFIX ".incr"
#define RDB_FORMAT_SUFFIX ".rdb"
#define AOF_FORMAT_SUFFIX ".aof"
#define MANIFEST_NAME_SUFFIX ".manifest"
#define TEMP_FILE_NAME_PREFIX "temp-"
/* AOF manifest key. */
#define AOF_MANIFEST_KEY_FILE_NAME "file"
#define AOF_MANIFEST_KEY_FILE_SEQ "seq"
#define AOF_MANIFEST_KEY_FILE_TYPE "type"
#define AOF_MANIFEST_KEY_FILE_STARTOFFSET "startoffset"
#define AOF_MANIFEST_KEY_FILE_ENDOFFSET "endoffset"
/* Create an empty aofInfo. */
aofInfo *aofInfoCreate(void) {
aofInfo *ai = zcalloc(sizeof(aofInfo));
ai->start_offset = -1;
ai->end_offset = -1;
return ai;
}
/* Free the aofInfo structure (pointed to by ai) and its embedded file_name. */
void aofInfoFree(aofInfo *ai) {
serverAssert(ai != NULL);
if (ai->file_name) sdsfree(ai->file_name);
zfree(ai);
}
/* Deep copy an aofInfo. */
aofInfo *aofInfoDup(aofInfo *orig) {
serverAssert(orig != NULL);
aofInfo *ai = aofInfoCreate();
ai->file_name = sdsdup(orig->file_name);
ai->file_seq = orig->file_seq;
ai->file_type = orig->file_type;
ai->start_offset = orig->start_offset;
ai->end_offset = orig->end_offset;
return ai;
}
/* Format aofInfo as a string and it will be a line in the manifest.
*
* When update this format, make sure to update redis-check-aof as well. */
sds aofInfoFormat(sds buf, aofInfo *ai) {
sds filename_repr = NULL;
if (sdsneedsrepr(ai->file_name))
filename_repr = sdscatrepr(sdsempty(), ai->file_name, sdslen(ai->file_name));
sds ret = sdscatprintf(buf, "%s %s %s %lld %s %c",
AOF_MANIFEST_KEY_FILE_NAME, filename_repr ? filename_repr : ai->file_name,
AOF_MANIFEST_KEY_FILE_SEQ, ai->file_seq,
AOF_MANIFEST_KEY_FILE_TYPE, ai->file_type);
if (ai->start_offset != -1) {
ret = sdscatprintf(ret, " %s %lld", AOF_MANIFEST_KEY_FILE_STARTOFFSET, ai->start_offset);
if (ai->end_offset != -1) {
ret = sdscatprintf(ret, " %s %lld", AOF_MANIFEST_KEY_FILE_ENDOFFSET, ai->end_offset);
}
}
ret = sdscatlen(ret, "\n", 1);
sdsfree(filename_repr);
return ret;
}
/* Method to free AOF list elements. */
void aofListFree(void *item) {
aofInfo *ai = (aofInfo *)item;
aofInfoFree(ai);
}
/* Method to duplicate AOF list elements. */
void *aofListDup(void *item) {
return aofInfoDup(item);
}
/* Create an empty aofManifest, which will be called in `aofLoadManifestFromDisk`. */
aofManifest *aofManifestCreate(void) {
aofManifest *am = zcalloc(sizeof(aofManifest));
am->incr_aof_list = listCreate();
am->history_aof_list = listCreate();
listSetFreeMethod(am->incr_aof_list, aofListFree);
listSetDupMethod(am->incr_aof_list, aofListDup);
listSetFreeMethod(am->history_aof_list, aofListFree);
listSetDupMethod(am->history_aof_list, aofListDup);
return am;
}
/* Free the aofManifest structure (pointed to by am) and its embedded members. */
void aofManifestFree(aofManifest *am) {
if (am->base_aof_info) aofInfoFree(am->base_aof_info);
if (am->incr_aof_list) listRelease(am->incr_aof_list);
if (am->history_aof_list) listRelease(am->history_aof_list);
zfree(am);
}
sds getAofManifestFileName(void) {
return sdscatprintf(sdsempty(), "%s%s", server.aof_filename,
MANIFEST_NAME_SUFFIX);
}
sds getTempAofManifestFileName(void) {
return sdscatprintf(sdsempty(), "%s%s%s", TEMP_FILE_NAME_PREFIX,
server.aof_filename, MANIFEST_NAME_SUFFIX);
}
/* Returns the string representation of aofManifest pointed to by am.
*
* The string is multiple lines separated by '\n', and each line represents
* an AOF file.
*
* Each line is space delimited and contains 6 fields, as follows:
* "file" [filename] "seq" [sequence] "type" [type]
*
* Where "file", "seq" and "type" are keywords that describe the next value,
* [filename] and [sequence] describe file name and order, and [type] is one
* of 'b' (base), 'h' (history) or 'i' (incr).
*
* The base file, if exists, will always be first, followed by history files,
* and incremental files.
*/
sds getAofManifestAsString(aofManifest *am) {
serverAssert(am != NULL);
sds buf = sdsempty();
listNode *ln;
listIter li;
/* 1. Add BASE File information, it is always at the beginning
* of the manifest file. */
if (am->base_aof_info) {
buf = aofInfoFormat(buf, am->base_aof_info);
}
/* 2. Add HISTORY type AOF information. */
listRewind(am->history_aof_list, &li);
while ((ln = listNext(&li)) != NULL) {
aofInfo *ai = (aofInfo*)ln->value;
buf = aofInfoFormat(buf, ai);
}
/* 3. Add INCR type AOF information. */
listRewind(am->incr_aof_list, &li);
while ((ln = listNext(&li)) != NULL) {
aofInfo *ai = (aofInfo*)ln->value;
buf = aofInfoFormat(buf, ai);
}
return buf;
}
/* Load the manifest information from the disk to `server.aof_manifest`
* when the Redis server start.
*
* During loading, this function does strict error checking and will abort
* the entire Redis server process on error (I/O error, invalid format, etc.)
*
* If the AOF directory or manifest file do not exist, this will be ignored
* in order to support seamless upgrades from previous versions which did not
* use them.
*/
void aofLoadManifestFromDisk(void) {
server.aof_manifest = aofManifestCreate();
if (!dirExists(server.aof_dirname)) {
serverLog(LL_DEBUG, "The AOF directory %s doesn't exist", server.aof_dirname);
return;
}
sds am_name = getAofManifestFileName();
sds am_filepath = makePath(server.aof_dirname, am_name);
if (!fileExist(am_filepath)) {
serverLog(LL_DEBUG, "The AOF manifest file %s doesn't exist", am_name);
sdsfree(am_name);
sdsfree(am_filepath);
return;
}
aofManifest *am = aofLoadManifestFromFile(am_filepath);
if (am) aofManifestFreeAndUpdate(am);
sdsfree(am_name);
sdsfree(am_filepath);
}
/* Generic manifest loading function, used in `aofLoadManifestFromDisk` and redis-check-aof tool. */
#define MANIFEST_MAX_LINE 1024
aofManifest *aofLoadManifestFromFile(sds am_filepath) {
const char *err = NULL;
long long maxseq = 0;
aofManifest *am = aofManifestCreate();
FILE *fp = fopen(am_filepath, "r");
if (fp == NULL) {
serverLog(LL_WARNING, "Fatal error: can't open the AOF manifest "
"file %s for reading: %s", am_filepath, strerror(errno));
exit(1);
}
char buf[MANIFEST_MAX_LINE+1];
sds *argv = NULL;
int argc;
aofInfo *ai = NULL;
sds line = NULL;
int linenum = 0;
while (1) {
if (fgets(buf, MANIFEST_MAX_LINE+1, fp) == NULL) {
if (feof(fp)) {
if (linenum == 0) {
err = "Found an empty AOF manifest";
goto loaderr;
} else {
break;
}
} else {
err = "Read AOF manifest failed";
goto loaderr;
}
}
linenum++;
/* Skip comments lines */
if (buf[0] == '#') continue;
if (strchr(buf, '\n') == NULL) {
err = "The AOF manifest file contains too long line";
goto loaderr;
}
line = sdstrim(sdsnew(buf), " \t\r\n");
if (!sdslen(line)) {
err = "Invalid AOF manifest file format";
goto loaderr;
}
argv = sdssplitargs(line, &argc);
/* 'argc < 6' was done for forward compatibility. */
if (argv == NULL || argc < 6 || (argc % 2)) {
err = "Invalid AOF manifest file format";
goto loaderr;
}
ai = aofInfoCreate();
for (int i = 0; i < argc; i += 2) {
if (!strcasecmp(argv[i], AOF_MANIFEST_KEY_FILE_NAME)) {
ai->file_name = sdsnew(argv[i+1]);
if (!pathIsBaseName(ai->file_name)) {
err = "File can't be a path, just a filename";
goto loaderr;
}
} else if (!strcasecmp(argv[i], AOF_MANIFEST_KEY_FILE_SEQ)) {
ai->file_seq = atoll(argv[i+1]);
} else if (!strcasecmp(argv[i], AOF_MANIFEST_KEY_FILE_TYPE)) {
ai->file_type = (argv[i+1])[0];
} else if (!strcasecmp(argv[i], AOF_MANIFEST_KEY_FILE_STARTOFFSET)) {
ai->start_offset = atoll(argv[i+1]);
} else if (!strcasecmp(argv[i], AOF_MANIFEST_KEY_FILE_ENDOFFSET)) {
ai->end_offset = atoll(argv[i+1]);
}
/* else if (!strcasecmp(argv[i], AOF_MANIFEST_KEY_OTHER)) {} */
}
/* We have to make sure we load all the information. */
if (!ai->file_name || !ai->file_seq || !ai->file_type) {
err = "Invalid AOF manifest file format";
goto loaderr;
}
sdsfreesplitres(argv, argc);
argv = NULL;
if (ai->file_type == AOF_FILE_TYPE_BASE) {
if (am->base_aof_info) {
err = "Found duplicate base file information";
goto loaderr;
}
am->base_aof_info = ai;
am->curr_base_file_seq = ai->file_seq;
} else if (ai->file_type == AOF_FILE_TYPE_HIST) {
listAddNodeTail(am->history_aof_list, ai);
} else if (ai->file_type == AOF_FILE_TYPE_INCR) {
if (ai->file_seq <= maxseq) {
err = "Found a non-monotonic sequence number";
goto loaderr;
}
listAddNodeTail(am->incr_aof_list, ai);
am->curr_incr_file_seq = ai->file_seq;
maxseq = ai->file_seq;
} else {
err = "Unknown AOF file type";
goto loaderr;
}
sdsfree(line);
line = NULL;
ai = NULL;
}
fclose(fp);
return am;
loaderr:
/* Sanitizer suppression: may report a false positive if we goto loaderr
* and exit(1) without freeing these allocations. */
if (argv) sdsfreesplitres(argv, argc);
if (ai) aofInfoFree(ai);
serverLog(LL_WARNING, "\n*** FATAL AOF MANIFEST FILE ERROR ***\n");
if (line) {
serverLog(LL_WARNING, "Reading the manifest file, at line %d\n", linenum);
serverLog(LL_WARNING, ">>> '%s'\n", line);
}
serverLog(LL_WARNING, "%s\n", err);
exit(1);
}
/* Deep copy an aofManifest from orig.
*
* In `backgroundRewriteDoneHandler` and `openNewIncrAofForAppend`, we will
* first deep copy a temporary AOF manifest from the `server.aof_manifest` and
* try to modify it. Once everything is modified, we will atomically make the
* `server.aof_manifest` point to this temporary aof_manifest.
*/
aofManifest *aofManifestDup(aofManifest *orig) {
serverAssert(orig != NULL);
aofManifest *am = zcalloc(sizeof(aofManifest));
am->curr_base_file_seq = orig->curr_base_file_seq;
am->curr_incr_file_seq = orig->curr_incr_file_seq;
am->dirty = orig->dirty;
if (orig->base_aof_info) {
am->base_aof_info = aofInfoDup(orig->base_aof_info);
}
am->incr_aof_list = listDup(orig->incr_aof_list);
am->history_aof_list = listDup(orig->history_aof_list);
serverAssert(am->incr_aof_list != NULL);
serverAssert(am->history_aof_list != NULL);
return am;
}
/* Change the `server.aof_manifest` pointer to 'am' and free the previous
* one if we have. */
void aofManifestFreeAndUpdate(aofManifest *am) {
serverAssert(am != NULL);
if (server.aof_manifest) aofManifestFree(server.aof_manifest);
server.aof_manifest = am;
}
/* Called in `backgroundRewriteDoneHandler` to get a new BASE file
* name, and mark the previous (if we have) BASE file as HISTORY type.
*
* BASE file naming rules: `server.aof_filename`.seq.base.format
*
* for example:
* appendonly.aof.1.base.aof (server.aof_use_rdb_preamble is no)
* appendonly.aof.1.base.rdb (server.aof_use_rdb_preamble is yes)
*/
sds getNewBaseFileNameAndMarkPreAsHistory(aofManifest *am) {
serverAssert(am != NULL);
if (am->base_aof_info) {
serverAssert(am->base_aof_info->file_type == AOF_FILE_TYPE_BASE);
am->base_aof_info->file_type = AOF_FILE_TYPE_HIST;
listAddNodeHead(am->history_aof_list, am->base_aof_info);
}
char *format_suffix = server.aof_use_rdb_preamble ?
RDB_FORMAT_SUFFIX:AOF_FORMAT_SUFFIX;
aofInfo *ai = aofInfoCreate();
ai->file_name = sdscatprintf(sdsempty(), "%s.%lld%s%s", server.aof_filename,
++am->curr_base_file_seq, BASE_FILE_SUFFIX, format_suffix);
ai->file_seq = am->curr_base_file_seq;
ai->file_type = AOF_FILE_TYPE_BASE;
am->base_aof_info = ai;
am->dirty = 1;
return am->base_aof_info->file_name;
}
/* Get a new INCR type AOF name.
*
* INCR AOF naming rules: `server.aof_filename`.seq.incr.aof
*
* for example:
* appendonly.aof.1.incr.aof
*/
sds getNewIncrAofName(aofManifest *am, long long start_reploff) {
aofInfo *ai = aofInfoCreate();
ai->file_type = AOF_FILE_TYPE_INCR;
ai->file_name = sdscatprintf(sdsempty(), "%s.%lld%s%s", server.aof_filename,
++am->curr_incr_file_seq, INCR_FILE_SUFFIX, AOF_FORMAT_SUFFIX);
ai->file_seq = am->curr_incr_file_seq;
ai->start_offset = start_reploff;
listAddNodeTail(am->incr_aof_list, ai);
am->dirty = 1;
return ai->file_name;
}
/* Get temp INCR type AOF name. */
sds getTempIncrAofName(void) {
return sdscatprintf(sdsempty(), "%s%s%s", TEMP_FILE_NAME_PREFIX, server.aof_filename,
INCR_FILE_SUFFIX);
}
/* Get the last INCR AOF name or create a new one. */
sds getLastIncrAofName(aofManifest *am) {
serverAssert(am != NULL);
/* If 'incr_aof_list' is empty, just create a new one. */
if (!listLength(am->incr_aof_list)) {
return getNewIncrAofName(am, server.master_repl_offset);
}
/* Or return the last one. */
listNode *lastnode = listIndex(am->incr_aof_list, -1);
aofInfo *ai = listNodeValue(lastnode);
return ai->file_name;
}
/* Called in `backgroundRewriteDoneHandler`. when AOFRW success, This
* function will change the AOF file type in 'incr_aof_list' from
* AOF_FILE_TYPE_INCR to AOF_FILE_TYPE_HIST, and move them to the
* 'history_aof_list'.
*/
void markRewrittenIncrAofAsHistory(aofManifest *am) {
serverAssert(am != NULL);
if (!listLength(am->incr_aof_list)) {
return;
}
listNode *ln;
listIter li;
listRewindTail(am->incr_aof_list, &li);
/* "server.aof_fd != -1" means AOF enabled, then we must skip the
* last AOF, because this file is our currently writing. */
if (server.aof_fd != -1) {
ln = listNext(&li);
serverAssert(ln != NULL);
}
/* Move aofInfo from 'incr_aof_list' to 'history_aof_list'. */
while ((ln = listNext(&li)) != NULL) {
aofInfo *ai = (aofInfo*)ln->value;
serverAssert(ai->file_type == AOF_FILE_TYPE_INCR);
aofInfo *hai = aofInfoDup(ai);
hai->file_type = AOF_FILE_TYPE_HIST;
listAddNodeHead(am->history_aof_list, hai);
listDelNode(am->incr_aof_list, ln);
}
am->dirty = 1;
}
/* Write the formatted manifest string to disk. */
int writeAofManifestFile(sds buf) {
int ret = C_OK;
ssize_t nwritten;
int len;
sds am_name = getAofManifestFileName();
sds am_filepath = makePath(server.aof_dirname, am_name);
sds tmp_am_name = getTempAofManifestFileName();
sds tmp_am_filepath = makePath(server.aof_dirname, tmp_am_name);
int fd = open(tmp_am_filepath, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd == -1) {
serverLog(LL_WARNING, "Can't open the AOF manifest file %s: %s",
tmp_am_name, strerror(errno));
ret = C_ERR;
goto cleanup;
}
len = sdslen(buf);
while(len) {
nwritten = write(fd, buf, len);
if (nwritten < 0) {
if (errno == EINTR) continue;
serverLog(LL_WARNING, "Error trying to write the temporary AOF manifest file %s: %s",
tmp_am_name, strerror(errno));
ret = C_ERR;
goto cleanup;
}
len -= nwritten;
buf += nwritten;
}
if (redis_fsync(fd) == -1) {
serverLog(LL_WARNING, "Fail to fsync the temp AOF file %s: %s.",
tmp_am_name, strerror(errno));
ret = C_ERR;
goto cleanup;
}
if (rename(tmp_am_filepath, am_filepath) != 0) {
serverLog(LL_WARNING,
"Error trying to rename the temporary AOF manifest file %s into %s: %s",
tmp_am_name, am_name, strerror(errno));
ret = C_ERR;
goto cleanup;
}
/* Also sync the AOF directory as new AOF files may be added in the directory */
if (fsyncFileDir(am_filepath) == -1) {
serverLog(LL_WARNING, "Fail to fsync AOF directory %s: %s.",
am_filepath, strerror(errno));
ret = C_ERR;
goto cleanup;
}
cleanup:
if (fd != -1) close(fd);
sdsfree(am_name);
sdsfree(am_filepath);
sdsfree(tmp_am_name);
sdsfree(tmp_am_filepath);
return ret;
}
/* Persist the aofManifest information pointed to by am to disk. */
int persistAofManifest(aofManifest *am) {
if (am->dirty == 0) {
return C_OK;
}
sds amstr = getAofManifestAsString(am);
int ret = writeAofManifestFile(amstr);
sdsfree(amstr);
if (ret == C_OK) am->dirty = 0;
return ret;
}
/* Called in `loadAppendOnlyFiles` when we upgrade from a old version redis.
*
* 1) Create AOF directory use 'server.aof_dirname' as the name.
* 2) Use 'server.aof_filename' to construct a BASE type aofInfo and add it to
* aofManifest, then persist the manifest file to AOF directory.
* 3) Move the old AOF file (server.aof_filename) to AOF directory.
*
* If any of the above steps fails or crash occurs, this will not cause any
* problems, and redis will retry the upgrade process when it restarts.
*/
void aofUpgradePrepare(aofManifest *am) {
serverAssert(!aofFileExist(server.aof_filename));
/* Create AOF directory use 'server.aof_dirname' as the name. */
if (dirCreateIfMissing(server.aof_dirname) == -1) {
serverLog(LL_WARNING, "Can't open or create append-only dir %s: %s",
server.aof_dirname, strerror(errno));
exit(1);
}
/* Manually construct a BASE type aofInfo and add it to aofManifest. */
if (am->base_aof_info) aofInfoFree(am->base_aof_info);
aofInfo *ai = aofInfoCreate();
ai->file_name = sdsnew(server.aof_filename);
ai->file_seq = 1;
ai->file_type = AOF_FILE_TYPE_BASE;
am->base_aof_info = ai;
am->curr_base_file_seq = 1;
am->dirty = 1;
/* Persist the manifest file to AOF directory. */
if (persistAofManifest(am) != C_OK) {
exit(1);
}
/* Move the old AOF file to AOF directory. */
sds aof_filepath = makePath(server.aof_dirname, server.aof_filename);
if (rename(server.aof_filename, aof_filepath) == -1) {
serverLog(LL_WARNING,
"Error trying to move the old AOF file %s into dir %s: %s",
server.aof_filename,
server.aof_dirname,
strerror(errno));
sdsfree(aof_filepath);
exit(1);
}
sdsfree(aof_filepath);
serverLog(LL_NOTICE, "Successfully migrated an old-style AOF file (%s) into the AOF directory (%s).",
server.aof_filename, server.aof_dirname);
}
/* When AOFRW success, the previous BASE and INCR AOFs will
* become HISTORY type and be moved into 'history_aof_list'.
*
* The function will traverse the 'history_aof_list' and submit
* the delete task to the bio thread.
*/
int aofDelHistoryFiles(void) {
if (server.aof_manifest == NULL ||
server.aof_disable_auto_gc == 1 ||
!listLength(server.aof_manifest->history_aof_list))
{
return C_OK;
}
listNode *ln;
listIter li;
listRewind(server.aof_manifest->history_aof_list, &li);
while ((ln = listNext(&li)) != NULL) {
aofInfo *ai = (aofInfo*)ln->value;
serverAssert(ai->file_type == AOF_FILE_TYPE_HIST);
serverLog(LL_NOTICE, "Removing the history file %s in the background", ai->file_name);
sds aof_filepath = makePath(server.aof_dirname, ai->file_name);
bg_unlink(aof_filepath);
sdsfree(aof_filepath);
listDelNode(server.aof_manifest->history_aof_list, ln);
}
server.aof_manifest->dirty = 1;
return persistAofManifest(server.aof_manifest);
}
/* Used to clean up temp INCR AOF when AOFRW fails. */
void aofDelTempIncrAofFile(void) {
sds aof_filename = getTempIncrAofName();
sds aof_filepath = makePath(server.aof_dirname, aof_filename);
serverLog(LL_NOTICE, "Removing the temp incr aof file %s in the background", aof_filename);
bg_unlink(aof_filepath);
sdsfree(aof_filepath);
sdsfree(aof_filename);
return;
}
/* Called after `loadDataFromDisk` when redis start. If `server.aof_state` is
* 'AOF_ON', It will do three things:
* 1. Force create a BASE file when redis starts with an empty dataset
* 2. Open the last opened INCR type AOF for writing, If not, create a new one
* 3. Synchronously update the manifest file to the disk
*
* If any of the above steps fails, the redis process will exit.
*/
void aofOpenIfNeededOnServerStart(void) {
if (server.aof_state != AOF_ON) {
return;
}
serverAssert(server.aof_manifest != NULL);
serverAssert(server.aof_fd == -1);
if (dirCreateIfMissing(server.aof_dirname) == -1) {
serverLog(LL_WARNING, "Can't open or create append-only dir %s: %s",
server.aof_dirname, strerror(errno));
exit(1);
}
/* If we start with an empty dataset, we will force create a BASE file. */
size_t incr_aof_len = listLength(server.aof_manifest->incr_aof_list);
if (!server.aof_manifest->base_aof_info && !incr_aof_len) {
sds base_name = getNewBaseFileNameAndMarkPreAsHistory(server.aof_manifest);
sds base_filepath = makePath(server.aof_dirname, base_name);
if (rewriteAppendOnlyFile(base_filepath) != C_OK) {
exit(1);
}
sdsfree(base_filepath);
serverLog(LL_NOTICE, "Creating AOF base file %s on server start",
base_name);
}
/* Because we will 'exit(1)' if open AOF or persistent manifest fails, so
* we don't need atomic modification here. */
sds aof_name = getLastIncrAofName(server.aof_manifest);
/* Here we should use 'O_APPEND' flag. */
sds aof_filepath = makePath(server.aof_dirname, aof_name);
server.aof_fd = open(aof_filepath, O_WRONLY|O_APPEND|O_CREAT, 0644);
sdsfree(aof_filepath);
if (server.aof_fd == -1) {
serverLog(LL_WARNING, "Can't open the append-only file %s: %s",
aof_name, strerror(errno));
exit(1);
}
/* Persist our changes. */
int ret = persistAofManifest(server.aof_manifest);
if (ret != C_OK) {
exit(1);
}
server.aof_last_incr_size = getAppendOnlyFileSize(aof_name, NULL);
server.aof_last_incr_fsync_offset = server.aof_last_incr_size;
if (incr_aof_len) {
serverLog(LL_NOTICE, "Opening AOF incr file %s on server start", aof_name);
} else {
serverLog(LL_NOTICE, "Creating AOF incr file %s on server start", aof_name);
}
}
int aofFileExist(char *filename) {
sds file_path = makePath(server.aof_dirname, filename);
int ret = fileExist(file_path);
sdsfree(file_path);
return ret;
}
/* Called in `rewriteAppendOnlyFileBackground`. If `server.aof_state`
* is 'AOF_ON', It will do two things:
* 1. Open a new INCR type AOF for writing
* 2. Synchronously update the manifest file to the disk
*
* The above two steps of modification are atomic, that is, if
* any step fails, the entire operation will rollback and returns
* C_ERR, and if all succeeds, it returns C_OK.
*
* If `server.aof_state` is 'AOF_WAIT_REWRITE', It will open a temporary INCR AOF
* file to accumulate data during AOF_WAIT_REWRITE, and it will eventually be
* renamed in the `backgroundRewriteDoneHandler` and written to the manifest file.
* */
int openNewIncrAofForAppend(void) {
serverAssert(server.aof_manifest != NULL);
int newfd = -1;
aofManifest *temp_am = NULL;
sds new_aof_name = NULL;
/* Only open new INCR AOF when AOF enabled. */
if (server.aof_state == AOF_OFF) return C_OK;
/* Open new AOF. */
if (server.aof_state == AOF_WAIT_REWRITE) {
/* Use a temporary INCR AOF file to accumulate data during AOF_WAIT_REWRITE. */
new_aof_name = getTempIncrAofName();
tempIncAofStartReplOffset = server.master_repl_offset;
} else {
/* Dup a temp aof_manifest to modify. */
temp_am = aofManifestDup(server.aof_manifest);
new_aof_name = sdsdup(getNewIncrAofName(temp_am, server.master_repl_offset));
}
sds new_aof_filepath = makePath(server.aof_dirname, new_aof_name);
newfd = open(new_aof_filepath, O_WRONLY|O_TRUNC|O_CREAT, 0644);
sdsfree(new_aof_filepath);
if (newfd == -1) {
serverLog(LL_WARNING, "Can't open the append-only file %s: %s",
new_aof_name, strerror(errno));
goto cleanup;
}
if (temp_am) {
/* Persist AOF Manifest. */
if (persistAofManifest(temp_am) == C_ERR) {
goto cleanup;
}
}
serverLog(LL_NOTICE, "Creating AOF incr file %s on background rewrite",
new_aof_name);
sdsfree(new_aof_name);
/* If reaches here, we can safely modify the `server.aof_manifest`
* and `server.aof_fd`. */
/* fsync and close old aof_fd if needed. In fsync everysec it's ok to delay
* the fsync as long as we grantee it happens, and in fsync always the file
* is already synced at this point so fsync doesn't matter. */
if (server.aof_fd != -1) {
aof_background_fsync_and_close(server.aof_fd);
server.aof_last_fsync = server.mstime;
}
server.aof_fd = newfd;
/* Reset the aof_last_incr_size. */
server.aof_last_incr_size = 0;
/* Reset the aof_last_incr_fsync_offset. */
server.aof_last_incr_fsync_offset = 0;
/* Update `server.aof_manifest`. */
if (temp_am) aofManifestFreeAndUpdate(temp_am);
return C_OK;
cleanup:
if (new_aof_name) sdsfree(new_aof_name);
if (newfd != -1) close(newfd);
if (temp_am) aofManifestFree(temp_am);
return C_ERR;
}
/* When we close gracefully the AOF file, we have the chance to persist the
* end replication offset of current INCR AOF. */
void updateCurIncrAofEndOffset(void) {
if (server.aof_state != AOF_ON) return;
serverAssert(server.aof_manifest != NULL);
if (listLength(server.aof_manifest->incr_aof_list) == 0) return;
aofInfo *ai = listNodeValue(listLast(server.aof_manifest->incr_aof_list));
ai->end_offset = server.master_repl_offset;
server.aof_manifest->dirty = 1;
/* It doesn't matter if the persistence fails since this information is not
* critical, we can get an approximate value by start offset plus file size. */
persistAofManifest(server.aof_manifest);
}
/* After loading AOF data, we need to update the `server.master_repl_offset`
* based on the information of the last INCR AOF, to avoid the rollback of
* the start offset of new INCR AOF. */
void updateReplOffsetAndResetEndOffset(void) {
if (server.aof_state != AOF_ON) return;
serverAssert(server.aof_manifest != NULL);
/* If the INCR file has an end offset, we directly use it, and clear it
* to avoid the next time we load the manifest file, we will use the same
* offset, but the real offset may have advanced. */
if (listLength(server.aof_manifest->incr_aof_list) == 0) return;
aofInfo *ai = listNodeValue(listLast(server.aof_manifest->incr_aof_list));
if (ai->end_offset != -1) {
server.master_repl_offset = ai->end_offset;
ai->end_offset = -1;
server.aof_manifest->dirty = 1;
/* We must update the end offset of INCR file correctly, otherwise we
* may keep wrong information in the manifest file, since we continue
* to append data to the same INCR file. */
if (persistAofManifest(server.aof_manifest) != AOF_OK)
exit(1);
} else {
/* If the INCR file doesn't have an end offset, we need to calculate
* the replication offset by the start offset plus the file size. */
server.master_repl_offset = (ai->start_offset == -1 ? 0 : ai->start_offset) +
getAppendOnlyFileSize(ai->file_name, NULL);
}
}
/* Whether to limit the execution of Background AOF rewrite.
*
* At present, if AOFRW fails, redis will automatically retry. If it continues
* to fail, we may get a lot of very small INCR files. so we need an AOFRW
* limiting measure.
*
* We can't directly use `server.aof_current_size` and `server.aof_last_incr_size`,
* because there may be no new writes after AOFRW fails.
*
* So, we use time delay to achieve our goal. When AOFRW fails, we delay the execution
* of the next AOFRW by 1 minute. If the next AOFRW also fails, it will be delayed by 2
* minutes. The next is 4, 8, 16, the maximum delay is 60 minutes (1 hour).
*
* During the limit period, we can still use the 'bgrewriteaof' command to execute AOFRW
* immediately.
*
* Return 1 means that AOFRW is limited and cannot be executed. 0 means that we can execute
* AOFRW, which may be that we have reached the 'next_rewrite_time' or the number of INCR
* AOFs has not reached the limit threshold.
* */
#define AOF_REWRITE_LIMITE_THRESHOLD 3
#define AOF_REWRITE_LIMITE_MAX_MINUTES 60 /* 1 hour */
int aofRewriteLimited(void) {
static int next_delay_minutes = 0;
static time_t next_rewrite_time = 0;
if (server.stat_aofrw_consecutive_failures < AOF_REWRITE_LIMITE_THRESHOLD) {
/* We may be recovering from limited state, so reset all states. */
next_delay_minutes = 0;
next_rewrite_time = 0;
return 0;
}
/* if it is in the limiting state, then check if the next_rewrite_time is reached */
if (next_rewrite_time != 0) {
if (server.unixtime < next_rewrite_time) {
return 1;
} else {
next_rewrite_time = 0;
return 0;
}
}
next_delay_minutes = (next_delay_minutes == 0) ? 1 : (next_delay_minutes * 2);
if (next_delay_minutes > AOF_REWRITE_LIMITE_MAX_MINUTES) {
next_delay_minutes = AOF_REWRITE_LIMITE_MAX_MINUTES;
}
next_rewrite_time = server.unixtime + next_delay_minutes * 60;
serverLog(LL_WARNING,
"Background AOF rewrite has repeatedly failed and triggered the limit, will retry in %d minutes", next_delay_minutes);
return 1;
}
/* ----------------------------------------------------------------------------
* AOF file implementation
* ------------------------------------------------------------------------- */
/* Return true if an AOf fsync is currently already in progress in a
* BIO thread. */
int aofFsyncInProgress(void) {
/* Note that we don't care about aof_background_fsync_and_close because
* server.aof_fd has been replaced by the new INCR AOF file fd,
* see openNewIncrAofForAppend. */
return bioPendingJobsOfType(BIO_AOF_FSYNC) != 0;
}
/* 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) {
bioCreateFsyncJob(fd, server.master_repl_offset, 1);
}
/* Close the fd on the basis of aof_background_fsync. */
void aof_background_fsync_and_close(int fd) {
bioCreateCloseAofJob(fd, server.master_repl_offset, 1);
}
/* Kills an AOFRW child process if exists */
void killAppendOnlyChild(void) {
int statloc;
/* No AOFRW child? return. */
if (server.child_type != CHILD_TYPE_AOF) return;
/* Kill AOFRW child, wait for child exit. */
serverLog(LL_NOTICE,"Killing running AOF rewrite child: %ld",
(long) server.child_pid);
if (kill(server.child_pid,SIGUSR1) != -1) {
while(waitpid(-1, &statloc, 0) != server.child_pid);
}
aofRemoveTempFile(server.child_pid);
resetChildState();
server.aof_rewrite_time_start = -1;
}
/* Called when the user switches from "appendonly yes" to "appendonly no"
* at runtime using the CONFIG command. */
void stopAppendOnly(void) {
serverAssert(server.aof_state != AOF_OFF);
flushAppendOnlyFile(1);
if (redis_fsync(server.aof_fd) == -1) {
serverLog(LL_WARNING,"Fail to fsync the AOF file: %s",strerror(errno));
} else {
server.aof_last_fsync = server.mstime;
}
close(server.aof_fd);
updateCurIncrAofEndOffset();
server.aof_fd = -1;
server.aof_selected_db = -1;
server.aof_state = AOF_OFF;
server.aof_rewrite_scheduled = 0;
server.aof_last_incr_size = 0;
server.aof_last_incr_fsync_offset = 0;
server.fsynced_reploff = -1;
atomicSet(server.fsynced_reploff_pending, 0);
killAppendOnlyChild();
sdsfree(server.aof_buf);
server.aof_buf = sdsempty();
}
/* Called when the user switches from "appendonly no" to "appendonly yes"
* at runtime using the CONFIG command. */
int startAppendOnly(void) {
serverAssert(server.aof_state == AOF_OFF);
server.aof_state = AOF_WAIT_REWRITE;
if (hasActiveChildProcess() && server.child_type != CHILD_TYPE_AOF) {
server.aof_rewrite_scheduled = 1;
serverLog(LL_NOTICE,"AOF was enabled but there is already another background operation. An AOF background was scheduled to start when possible.");
} else if (server.in_exec){
server.aof_rewrite_scheduled = 1;
serverLog(LL_NOTICE,"AOF was enabled during a transaction. An AOF background was scheduled to start when possible.");
} else {
/* If there is a pending AOF rewrite, we need to switch it off and
* start a new one: the old one cannot be reused because it is not
* accumulating the AOF buffer. */
if (server.child_type == CHILD_TYPE_AOF) {
serverLog(LL_NOTICE,"AOF was enabled but there is already an AOF rewriting in background. Stopping background AOF and starting a rewrite now.");
killAppendOnlyChild();
}
if (rewriteAppendOnlyFileBackground() == C_ERR) {
server.aof_state = AOF_OFF;
serverLog(LL_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 C_ERR;
}
}
server.aof_last_fsync = server.mstime;
/* If AOF fsync error in bio job, we just ignore it and log the event. */
int aof_bio_fsync_status;
atomicGet(server.aof_bio_fsync_status, aof_bio_fsync_status);
if (aof_bio_fsync_status == C_ERR) {
serverLog(LL_WARNING,
"AOF reopen, just ignore the AOF fsync error in bio job");
atomicSet(server.aof_bio_fsync_status,C_OK);
}
/* If AOF was in error state, we just ignore it and log the event. */
if (server.aof_last_write_status == C_ERR) {
serverLog(LL_WARNING,"AOF reopen, just ignore the last error.");
server.aof_last_write_status = C_OK;
}
return C_OK;
}
void startAppendOnlyWithRetry(void) {
unsigned int tries, max_tries = 10;
for (tries = 0; tries < max_tries; ++tries) {
if (startAppendOnly() == C_OK)
break;
serverLog(LL_WARNING, "Failed to enable AOF! Trying it again in one second.");
sleep(1);
}
if (tries == max_tries) {
serverLog(LL_WARNING, "FATAL: AOF can't be turned on. Exiting now.");
exit(1);
}
}
/* Called after "appendonly" config is changed. */
void applyAppendOnlyConfig(void) {
if (!server.aof_enabled && server.aof_state != AOF_OFF) {
stopAppendOnly();
} else if (server.aof_enabled && server.aof_state == AOF_OFF) {
startAppendOnlyWithRetry();
}
}
/* This is a wrapper to the write syscall in order to retry on short writes
* or if the syscall gets interrupted. It could look strange that we retry
* on short writes given that we are writing to a block device: normally if
* the first call is short, there is a end-of-space condition, so the next
* is likely to fail. However apparently in modern systems this is no longer
* true, and in general it looks just more resilient to retry the write. If
* there is an actual error condition we'll get it at the next try. */
ssize_t aofWrite(int fd, const char *buf, size_t len) {
ssize_t nwritten = 0, totwritten = 0;
while(len) {
nwritten = write(fd, buf, len);
if (nwritten < 0) {
if (errno == EINTR) continue;
return totwritten ? totwritten : -1;
}
len -= nwritten;
buf += nwritten;
totwritten += nwritten;
}
return totwritten;
}
/* Write the append only file buffer on disk.
*
* Since we are required to write the AOF before replying to the client,
* and the only way the client socket can get a write is entering when
* the 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.
*
* 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. */
#define AOF_WRITE_LOG_ERROR_RATE 30 /* Seconds between errors logging. */
void flushAppendOnlyFile(int force) {
ssize_t nwritten;
int sync_in_progress = 0;
mstime_t latency;
if (sdslen(server.aof_buf) == 0) {
if (server.aof_last_incr_fsync_offset == server.aof_last_incr_size) {
/* All data is fsync'd already: Update fsynced_reploff_pending just in case.
* This is needed to avoid a WAITAOF hang in case a module used RM_Call
* with the NO_AOF flag, in which case master_repl_offset will increase but
* fsynced_reploff_pending won't be updated (because there's no reason, from
* the AOF POV, to call fsync) and then WAITAOF may wait on the higher offset
* (which contains data that was only propagated to replicas, and not to AOF) */
if (!aofFsyncInProgress())
atomicSet(server.fsynced_reploff_pending, server.master_repl_offset);
} else {
/* Check if we need to do fsync even the aof buffer is empty,
* because previously in AOF_FSYNC_EVERYSEC mode, fsync is
* called only when aof buffer is not empty, so if users
* stop write commands before fsync called in one second,
* the data in page cache cannot be flushed in time. */
if (server.aof_fsync == AOF_FSYNC_EVERYSEC &&
server.mstime - server.aof_last_fsync >= 1000 &&
!(sync_in_progress = aofFsyncInProgress()))
goto try_fsync;
/* Check if we need to do fsync even the aof buffer is empty,
* the reason is described in the previous AOF_FSYNC_EVERYSEC block,
* and AOF_FSYNC_ALWAYS is also checked here to handle a case where
* aof_fsync is changed from everysec to always. */
if (server.aof_fsync == AOF_FSYNC_ALWAYS)
goto try_fsync;
}
return;
}
if (server.aof_fsync == AOF_FSYNC_EVERYSEC)
sync_in_progress = aofFsyncInProgress();
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 postponing, remember that we are
* postponing the flush and return. */
server.aof_flush_postponed_start = server.mstime;
return;
} else if (server.mstime - server.aof_flush_postponed_start < 2000) {
/* We were already waiting for fsync to finish, but for less
* than two seconds this is still ok. Postpone again. */
return;
}
/* Otherwise fall through, and go write since we can't wait
* over two seconds. */
server.aof_delayed_fsync++;
serverLog(LL_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.");
}
}
/* 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 */
if (server.aof_flush_sleep && sdslen(server.aof_buf)) {
usleep(server.aof_flush_sleep);
}
latencyStartMonitor(latency);
nwritten = aofWrite(server.aof_fd,server.aof_buf,sdslen(server.aof_buf));
latencyEndMonitor(latency);
/* We want to capture different events for delayed writes:
* when the delay happens with a pending fsync, or with a saving child
* active, and when the above two conditions are missing.
* We also use an additional event name to save all samples which is
* useful for graphing / monitoring purposes. */
if (sync_in_progress) {
latencyAddSampleIfNeeded("aof-write-pending-fsync",latency);
} else if (hasActiveChildProcess()) {
latencyAddSampleIfNeeded("aof-write-active-child",latency);
} else {
latencyAddSampleIfNeeded("aof-write-alone",latency);
}
latencyAddSampleIfNeeded("aof-write",latency);
/* We performed the write so reset the postponed flush sentinel to zero. */
server.aof_flush_postponed_start = 0;
if (nwritten != (ssize_t)sdslen(server.aof_buf)) {
static time_t last_write_error_log = 0;
int can_log = 0;
/* Limit logging rate to 1 line per AOF_WRITE_LOG_ERROR_RATE seconds. */
if ((server.unixtime - last_write_error_log) > AOF_WRITE_LOG_ERROR_RATE) {
can_log = 1;
last_write_error_log = server.unixtime;
}
/* Log the AOF write error and record the error code. */
if (nwritten == -1) {
if (can_log) {
serverLog(LL_WARNING,"Error writing to the AOF file: %s",
strerror(errno));
}
server.aof_last_write_errno = errno;
} else {
if (can_log) {
serverLog(LL_WARNING,"Short write while writing to "
"the AOF file: (nwritten=%lld, "
"expected=%lld)",
(long long)nwritten,
(long long)sdslen(server.aof_buf));
}
if (ftruncate(server.aof_fd, server.aof_last_incr_size) == -1) {
if (can_log) {
serverLog(LL_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));
}
} else {
/* If the ftruncate() succeeded we can set nwritten to
* -1 since there is no longer partial data into the AOF. */
nwritten = -1;
}
server.aof_last_write_errno = ENOSPC;
}
/* Handle the AOF write error. */
if (server.aof_fsync == AOF_FSYNC_ALWAYS) {
/* We can't recover when the fsync policy is ALWAYS since the reply
* for the client is already in the output buffers (both writes and
* reads), and the changes to the db can't be rolled back. Since we
* have a contract with the user that on acknowledged or observed
* writes are is synced on disk, we must exit. */
serverLog(LL_WARNING,"Can't recover from AOF write error when the AOF fsync policy is 'always'. Exiting...");
exit(1);
} else {
/* Recover from failed write leaving data into the buffer. However
* set an error to stop accepting writes as long as the error
* condition is not cleared. */
server.aof_last_write_status = C_ERR;
/* Trim the sds buffer if there was a partial write, and there
* was no way to undo it with ftruncate(2). */
if (nwritten > 0) {
server.aof_current_size += nwritten;
server.aof_last_incr_size += nwritten;
sdsrange(server.aof_buf,nwritten,-1);
}
return; /* We'll try again on the next call... */
}
} else {
/* Successful write(2). If AOF was in error state, restore the
* OK state and log the event. */
if (server.aof_last_write_status == C_ERR) {
serverLog(LL_NOTICE,
"AOF write error looks solved, Redis can write again.");
server.aof_last_write_status = C_OK;
}
}
server.aof_current_size += nwritten;
server.aof_last_incr_size += nwritten;
/* 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();
}
try_fsync:
/* 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 && hasActiveChildProcess())
return;
/* Perform the fsync if needed. */
if (server.aof_fsync == AOF_FSYNC_ALWAYS) {
/* redis_fsync is defined as fdatasync() for Linux in order to avoid
* flushing metadata. */
latencyStartMonitor(latency);
/* Let's try to get this data on the disk. To guarantee data safe when
* the AOF fsync policy is 'always', we should exit if failed to fsync
* AOF (see comment next to the exit(1) after write error above). */
if (redis_fsync(server.aof_fd) == -1) {
serverLog(LL_WARNING,"Can't persist AOF for fsync error when the "
"AOF fsync policy is 'always': %s. Exiting...", strerror(errno));
exit(1);
}
latencyEndMonitor(latency);
latencyAddSampleIfNeeded("aof-fsync-always",latency);
server.aof_last_incr_fsync_offset = server.aof_last_incr_size;
server.aof_last_fsync = server.mstime;
atomicSet(server.fsynced_reploff_pending, server.master_repl_offset);
} else if (server.aof_fsync == AOF_FSYNC_EVERYSEC &&
server.mstime - server.aof_last_fsync >= 1000) {
if (!sync_in_progress) {
aof_background_fsync(server.aof_fd);
server.aof_last_incr_fsync_offset = server.aof_last_incr_size;
}
server.aof_last_fsync = server.mstime;
}
}
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++) {
o = getDecodedObject(argv[j]);
buf[0] = '$';
len = 1+ll2string(buf+1,sizeof(buf)-1,sdslen(o->ptr));
buf[len++] = '\r';
buf[len++] = '\n';
dst = sdscatlen(dst,buf,len);
dst = sdscatlen(dst,o->ptr,sdslen(o->ptr));
dst = sdscatlen(dst,"\r\n",2);
decrRefCount(o);
}
return dst;
}
/* Generate a piece of timestamp annotation for AOF if current record timestamp
* in AOF is not equal server unix time. If we specify 'force' argument to 1,
* we would generate one without check, currently, it is useful in AOF rewriting
* child process which always needs to record one timestamp at the beginning of
* rewriting AOF.
*
* Timestamp annotation format is "#TS:${timestamp}\r\n". "TS" is short of
* timestamp and this method could save extra bytes in AOF. */
sds genAofTimestampAnnotationIfNeeded(int force) {
sds ts = NULL;
if (force || server.aof_cur_timestamp < server.unixtime) {
server.aof_cur_timestamp = force ? time(NULL) : server.unixtime;
ts = sdscatfmt(sdsempty(), "#TS:%I\r\n", server.aof_cur_timestamp);
serverAssert(sdslen(ts) <= AOF_ANNOTATION_LINE_MAX_LEN);
}
return ts;
}
/* Write the given command to the aof file.
* dictid - dictionary id the command should be applied to,
* this is used in order to decide if a `select` command
* should also be written to the aof. Value of -1 means
* to avoid writing `select` command in any case.
* argv - The command to write to the aof.
* argc - Number of values in argv
*/
void feedAppendOnlyFile(int dictid, robj **argv, int argc) {
sds buf = sdsempty();
serverAssert(dictid == -1 || (dictid >= 0 && dictid < server.dbnum));
/* Feed timestamp if needed */
if (server.aof_timestamp_enabled) {
sds ts = genAofTimestampAnnotationIfNeeded(0);
if (ts != NULL) {
buf = sdscatsds(buf, ts);
sdsfree(ts);
}
}
/* The DB this command was targeting is not the same as the last command
* we appended. To issue a SELECT command is needed. */
if (dictid != -1 && 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.aof_selected_db = dictid;
}
/* All commands should be propagated the same way in AOF as in replication.
* No need for AOF-specific translation. */
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. */
if (server.aof_state == AOF_ON ||
(server.aof_state == AOF_WAIT_REWRITE && server.child_type == CHILD_TYPE_AOF))
{
server.aof_buf = sdscatlen(server.aof_buf, 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 client *createAOFClient(void) {
struct client *c = createClient(NULL);
c->id = CLIENT_ID_AOF; /* So modules can identify it's the AOF client. */
/*
* The AOF client should never be blocked (unlike master
* replication connection).
* This is because blocking the AOF client might cause
* deadlock (because potentially no one will unblock it).
* Also, if the AOF client will be blocked just for
* background processing there is a chance that the
* command execution order will be violated.
*/
c->flags = CLIENT_DENY_BLOCKING;
/* We set the fake client as a slave waiting for the synchronization
* so that Redis will not try to send replies to this client. */
c->replstate = SLAVE_STATE_WAIT_BGSAVE_START;
return c;
}
/* Replay an append log file. On success AOF_OK or AOF_TRUNCATED is returned,
* otherwise, one of the following is returned:
* AOF_OPEN_ERR: Failed to open the AOF file.
* AOF_NOT_EXIST: AOF file doesn't exist.
* AOF_EMPTY: The AOF file is empty (nothing to load).
* AOF_FAILED: Failed to load the AOF file. */
int loadSingleAppendOnlyFile(char *filename) {
struct client *fakeClient;
struct redis_stat sb;
int old_aof_state = server.aof_state;
long loops = 0;
off_t valid_up_to = 0; /* Offset of latest well-formed command loaded. */
off_t valid_before_multi = 0; /* Offset before MULTI command loaded. */
off_t last_progress_report_size = 0;
int ret = AOF_OK;
sds aof_filepath = makePath(server.aof_dirname, filename);
FILE *fp = fopen(aof_filepath, "r");
if (fp == NULL) {
int en = errno;
if (redis_stat(aof_filepath, &sb) == 0 || errno != ENOENT) {
serverLog(LL_WARNING,"Fatal error: can't open the append log file %s for reading: %s", filename, strerror(en));
sdsfree(aof_filepath);
return AOF_OPEN_ERR;
} else {
serverLog(LL_WARNING,"The append log file %s doesn't exist: %s", filename, strerror(errno));
sdsfree(aof_filepath);
return AOF_NOT_EXIST;
}
}
if (fp && redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) {
fclose(fp);
sdsfree(aof_filepath);
return AOF_EMPTY;
}
/* Temporarily disable AOF, to prevent EXEC from feeding a MULTI
* to the same file we're about to read. */
server.aof_state = AOF_OFF;
client *old_cur_client = server.current_client;
client *old_exec_client = server.executing_client;
fakeClient = createAOFClient();
server.current_client = server.executing_client = fakeClient;
/* Check if the AOF file is in RDB format (it may be RDB encoded base AOF
* or old style RDB-preamble AOF). In that case we need to load the RDB file
* and later continue loading the AOF tail if it is an old style RDB-preamble AOF. */
char sig[5]; /* "REDIS" */
if (fread(sig,1,5,fp) != 5 || memcmp(sig,"REDIS",5) != 0) {
/* Not in RDB format, seek back at 0 offset. */
if (fseek(fp,0,SEEK_SET) == -1) goto readerr;
} else {
/* RDB format. Pass loading the RDB functions. */
rio rdb;
int old_style = !strcmp(filename, server.aof_filename);
if (old_style)
serverLog(LL_NOTICE, "Reading RDB preamble from AOF file...");
else
serverLog(LL_NOTICE, "Reading RDB base file on AOF loading...");
if (fseek(fp,0,SEEK_SET) == -1) goto readerr;
rioInitWithFile(&rdb,fp);
if (rdbLoadRio(&rdb,RDBFLAGS_AOF_PREAMBLE,NULL) != C_OK) {
if (old_style)
serverLog(LL_WARNING, "Error reading the RDB preamble of the AOF file %s, AOF loading aborted", filename);
else
serverLog(LL_WARNING, "Error reading the RDB base file %s, AOF loading aborted", filename);
ret = AOF_FAILED;
goto cleanup;
} else {
loadingAbsProgress(ftello(fp));
last_progress_report_size = ftello(fp);
if (old_style) serverLog(LL_NOTICE, "Reading the remaining AOF tail...");
}
}
/* Read the actual AOF file, in REPL format, command by command. */
while(1) {
int argc, j;
unsigned long len;
robj **argv;
char buf[AOF_ANNOTATION_LINE_MAX_LEN];
sds argsds;
struct redisCommand *cmd;
/* Serve the clients from time to time */
if (!(loops++ % 1024)) {
off_t progress_delta = ftello(fp) - last_progress_report_size;
loadingIncrProgress(progress_delta);
last_progress_report_size += progress_delta;
processEventsWhileBlocked();
processModuleLoadingProgressEvent(1);
}
if (fgets(buf,sizeof(buf),fp) == NULL) {
if (feof(fp)) {
break;
} else {
goto readerr;
}
}
if (buf[0] == '#') continue; /* Skip annotations */
if (buf[0] != '*') goto fmterr;
if (buf[1] == '\0') goto readerr;
argc = atoi(buf+1);
if (argc < 1) goto fmterr;
if ((size_t)argc > SIZE_MAX / sizeof(robj*)) goto fmterr;
/* Load the next command in the AOF as our fake client
* argv. */
argv = zmalloc(sizeof(robj*)*argc);
fakeClient->argc = argc;
fakeClient->argv = argv;
fakeClient->argv_len = argc;
for (j = 0; j < argc; j++) {
/* Parse the argument len. */
char *readres = fgets(buf,sizeof(buf),fp);
if (readres == NULL || buf[0] != '$') {
fakeClient->argc = j; /* Free up to j-1. */
freeClientArgv(fakeClient);
if (readres == NULL)
goto readerr;
else
goto fmterr;
}
len = strtol(buf+1,NULL,10);
/* Read it into a string object. */
argsds = sdsnewlen(SDS_NOINIT,len);
if (len && fread(argsds,len,1,fp) == 0) {
sdsfree(argsds);
fakeClient->argc = j; /* Free up to j-1. */
freeClientArgv(fakeClient);
goto readerr;
}
argv[j] = createObject(OBJ_STRING,argsds);
/* Discard CRLF. */
if (fread(buf,2,1,fp) == 0) {
fakeClient->argc = j+1; /* Free up to j. */
freeClientArgv(fakeClient);
goto readerr;
}
}
/* Command lookup */
cmd = lookupCommand(argv,argc);
if (!cmd) {
serverLog(LL_WARNING,
"Unknown command '%s' reading the append only file %s",
(char*)argv[0]->ptr, filename);
freeClientArgv(fakeClient);
ret = AOF_FAILED;
goto cleanup;
}
if (cmd->proc == multiCommand) valid_before_multi = valid_up_to;
/* Run the command in the context of a fake client */
fakeClient->cmd = fakeClient->lastcmd = cmd;
if (fakeClient->flags & CLIENT_MULTI &&
fakeClient->cmd->proc != execCommand)
{
/* Note: we don't have to attempt calling evalGetCommandFlags,
* since this is AOF, the checks in processCommand are not made
* anyway.*/
queueMultiCommand(fakeClient, cmd->flags);
} else {
cmd->proc(fakeClient);
}
/* The fake client should not have a reply */
serverAssert(fakeClient->bufpos == 0 &&
listLength(fakeClient->reply) == 0);
/* The fake client should never get blocked */
serverAssert((fakeClient->flags & CLIENT_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. */
freeClientArgv(fakeClient);
if (server.aof_load_truncated) valid_up_to = ftello(fp);
if (server.key_load_delay)
debugDelay(server.key_load_delay);
}
/* This point can only be reached when EOF is reached without errors.
* If the client is in the middle of a MULTI/EXEC, handle it as it was
* a short read, even if technically the protocol is correct: we want
* to remove the unprocessed tail and continue. */
if (fakeClient->flags & CLIENT_MULTI) {
serverLog(LL_WARNING,
"Revert incomplete MULTI/EXEC transaction in AOF file %s", filename);
valid_up_to = valid_before_multi;
goto uxeof;
}
loaded_ok: /* DB loaded, cleanup and return success (AOF_OK or AOF_TRUNCATED). */
loadingIncrProgress(ftello(fp) - last_progress_report_size);
server.aof_state = old_aof_state;
goto cleanup;
readerr: /* Read error. If feof(fp) is true, fall through to unexpected EOF. */
if (!feof(fp)) {
serverLog(LL_WARNING,"Unrecoverable error reading the append only file %s: %s", filename, strerror(errno));
ret = AOF_FAILED;
goto cleanup;
}
uxeof: /* Unexpected AOF end of file. */
if (server.aof_load_truncated) {
serverLog(LL_WARNING,"!!! Warning: short read while loading the AOF file %s!!!", filename);
serverLog(LL_WARNING,"!!! Truncating the AOF %s at offset %llu !!!",
filename, (unsigned long long) valid_up_to);
if (valid_up_to == -1 || truncate(aof_filepath,valid_up_to) == -1) {
if (valid_up_to == -1) {
serverLog(LL_WARNING,"Last valid command offset is invalid");
} else {
serverLog(LL_WARNING,"Error truncating the AOF file %s: %s",
filename, strerror(errno));
}
} else {
/* Make sure the AOF file descriptor points to the end of the
* file after the truncate call. */
if (server.aof_fd != -1 && lseek(server.aof_fd,0,SEEK_END) == -1) {
serverLog(LL_WARNING,"Can't seek the end of the AOF file %s: %s",
filename, strerror(errno));
} else {
serverLog(LL_WARNING,
"AOF %s loaded anyway because aof-load-truncated is enabled", filename);
ret = AOF_TRUNCATED;
goto loaded_ok;
}
}
}
serverLog(LL_WARNING, "Unexpected end of file reading the append only file %s. You can: "
"1) Make a backup of your AOF file, then use ./redis-check-aof --fix <filename.manifest>. "
"2) Alternatively you can set the 'aof-load-truncated' configuration option to yes and restart the server.", filename);
ret = AOF_FAILED;
goto cleanup;
fmterr: /* Format error. */
serverLog(LL_WARNING, "Bad file format reading the append only file %s: "
"make a backup of your AOF file, then use ./redis-check-aof --fix <filename.manifest>", filename);
ret = AOF_FAILED;
/* fall through to cleanup. */
cleanup:
if (fakeClient) freeClient(fakeClient);
server.current_client = old_cur_client;
server.executing_client = old_exec_client;
fclose(fp);
sdsfree(aof_filepath);
return ret;
}
/* Load the AOF files according the aofManifest pointed by am. */
int loadAppendOnlyFiles(aofManifest *am) {
serverAssert(am != NULL);
int status, ret = AOF_OK;
long long start;
off_t total_size = 0, base_size = 0;
sds aof_name;
int total_num, aof_num = 0, last_file;
/* If the 'server.aof_filename' file exists in dir, we may be starting
* from an old redis version. We will use enter upgrade mode in three situations.
*
* 1. If the 'server.aof_dirname' directory not exist
* 2. If the 'server.aof_dirname' directory exists but the manifest file is missing
* 3. If the 'server.aof_dirname' directory exists and the manifest file it contains
* has only one base AOF record, and the file name of this base AOF is 'server.aof_filename',
* and the 'server.aof_filename' file not exist in 'server.aof_dirname' directory
* */
if (fileExist(server.aof_filename)) {
if (!dirExists(server.aof_dirname) ||
(am->base_aof_info == NULL && listLength(am->incr_aof_list) == 0) ||
(am->base_aof_info != NULL && listLength(am->incr_aof_list) == 0 &&
!strcmp(am->base_aof_info->file_name, server.aof_filename) && !aofFileExist(server.aof_filename)))
{
aofUpgradePrepare(am);
}
}
if (am->base_aof_info == NULL && listLength(am->incr_aof_list) == 0) {
return AOF_NOT_EXIST;
}
total_num = getBaseAndIncrAppendOnlyFilesNum(am);
serverAssert(total_num > 0);
/* Here we calculate the total size of all BASE and INCR files in
* advance, it will be set to `server.loading_total_bytes`. */
total_size = getBaseAndIncrAppendOnlyFilesSize(am, &status);
if (status != AOF_OK) {
/* If an AOF exists in the manifest but not on the disk, we consider this to be a fatal error. */
if (status == AOF_NOT_EXIST) status = AOF_FAILED;
return status;
} else if (total_size == 0) {
return AOF_EMPTY;
}
startLoading(total_size, RDBFLAGS_AOF_PREAMBLE, 0);
/* Load BASE AOF if needed. */
if (am->base_aof_info) {
serverAssert(am->base_aof_info->file_type == AOF_FILE_TYPE_BASE);
aof_name = (char*)am->base_aof_info->file_name;
updateLoadingFileName(aof_name);
base_size = getAppendOnlyFileSize(aof_name, NULL);
last_file = ++aof_num == total_num;
start = ustime();
ret = loadSingleAppendOnlyFile(aof_name);
if (ret == AOF_OK || (ret == AOF_TRUNCATED && last_file)) {
serverLog(LL_NOTICE, "DB loaded from base file %s: %.3f seconds",
aof_name, (float)(ustime()-start)/1000000);
}
/* If the truncated file is not the last file, we consider this to be a fatal error. */
if (ret == AOF_TRUNCATED && !last_file) {
ret = AOF_FAILED;
serverLog(LL_WARNING, "Fatal error: the truncated file is not the last file");
}
if (ret == AOF_OPEN_ERR || ret == AOF_FAILED) {
goto cleanup;
}
}
/* Load INCR AOFs if needed. */
if (listLength(am->incr_aof_list)) {
listNode *ln;
listIter li;
listRewind(am->incr_aof_list, &li);
while ((ln = listNext(&li)) != NULL) {
aofInfo *ai = (aofInfo*)ln->value;
serverAssert(ai->file_type == AOF_FILE_TYPE_INCR);
aof_name = (char*)ai->file_name;
updateLoadingFileName(aof_name);
last_file = ++aof_num == total_num;
start = ustime();
ret = loadSingleAppendOnlyFile(aof_name);
if (ret == AOF_OK || (ret == AOF_TRUNCATED && last_file)) {
serverLog(LL_NOTICE, "DB loaded from incr file %s: %.3f seconds",
aof_name, (float)(ustime()-start)/1000000);
}
/* We know that (at least) one of the AOF files has data (total_size > 0),
* so empty incr AOF file doesn't count as a AOF_EMPTY result */
if (ret == AOF_EMPTY) ret = AOF_OK;
/* If the truncated file is not the last file, we consider this to be a fatal error. */
if (ret == AOF_TRUNCATED && !last_file) {
ret = AOF_FAILED;
serverLog(LL_WARNING, "Fatal error: the truncated file is not the last file");
}
if (ret == AOF_OPEN_ERR || ret == AOF_FAILED) {
goto cleanup;
}
}
}
server.aof_current_size = total_size;
/* Ideally, the aof_rewrite_base_size variable should hold the size of the
* AOF when the last rewrite ended, this should include the size of the
* incremental file that was created during the rewrite since otherwise we
* risk the next automatic rewrite to happen too soon (or immediately if
* auto-aof-rewrite-percentage is low). However, since we do not persist
* aof_rewrite_base_size information anywhere, we initialize it on restart
* to the size of BASE AOF file. This might cause the first AOFRW to be
* executed early, but that shouldn't be a problem since everything will be
* fine after the first AOFRW. */
server.aof_rewrite_base_size = base_size;
cleanup:
stopLoading(ret == AOF_OK || ret == AOF_TRUNCATED);
return ret;
}
/* ----------------------------------------------------------------------------
* 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 server.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 == OBJ_ENCODING_INT) {
return rioWriteBulkLongLong(r,(long)obj->ptr);
} else if (sdsEncodedObject(obj)) {
return rioWriteBulkString(r,obj->ptr,sdslen(obj->ptr));
} else {
serverPanic("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);
listTypeIterator *li = listTypeInitIterator(o,0,LIST_TAIL);
listTypeEntry entry;
while (listTypeNext(li,&entry)) {
if (count == 0) {
int cmd_items = (items > AOF_REWRITE_ITEMS_PER_CMD) ?
AOF_REWRITE_ITEMS_PER_CMD : items;
if (!rioWriteBulkCount(r,'*',2+cmd_items) ||
!rioWriteBulkString(r,"RPUSH",5) ||
!rioWriteBulkObject(r,key))
{
listTypeReleaseIterator(li);
return 0;
}
}
unsigned char *vstr;
size_t vlen;
long long lval;
vstr = listTypeGetValue(&entry,&vlen,&lval);
if (vstr) {
if (!rioWriteBulkString(r,(char*)vstr,vlen)) {
listTypeReleaseIterator(li);
return 0;
}
} else {
if (!rioWriteBulkLongLong(r,lval)) {
listTypeReleaseIterator(li);
return 0;
}
}
if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
listTypeReleaseIterator(li);
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);
setTypeIterator *si = setTypeInitIterator(o);
char *str;
size_t len;
int64_t llval;
while (setTypeNext(si, &str, &len, &llval) != -1) {
if (count == 0) {
int cmd_items = (items > AOF_REWRITE_ITEMS_PER_CMD) ?
AOF_REWRITE_ITEMS_PER_CMD : items;
if (!rioWriteBulkCount(r,'*',2+cmd_items) ||
!rioWriteBulkString(r,"SADD",4) ||
!rioWriteBulkObject(r,key))
{
setTypeReleaseIterator(si);
return 0;
}
}
size_t written = str ?
rioWriteBulkString(r, str, len) : rioWriteBulkLongLong(r, llval);
if (!written) {
setTypeReleaseIterator(si);
return 0;
}
if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
setTypeReleaseIterator(si);
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 == OBJ_ENCODING_LISTPACK) {
unsigned char *zl = o->ptr;
unsigned char *eptr, *sptr;
unsigned char *vstr;
unsigned int vlen;
long long vll;
double score;
eptr = lpSeek(zl,0);
serverAssert(eptr != NULL);
sptr = lpNext(zl,eptr);
serverAssert(sptr != NULL);
while (eptr != NULL) {
vstr = lpGetValue(eptr,&vlen,&vll);
score = zzlGetScore(sptr);
if (count == 0) {
int cmd_items = (items > AOF_REWRITE_ITEMS_PER_CMD) ?
AOF_REWRITE_ITEMS_PER_CMD : items;
if (!rioWriteBulkCount(r,'*',2+cmd_items*2) ||
!rioWriteBulkString(r,"ZADD",4) ||
!rioWriteBulkObject(r,key))
{
return 0;
}
}
if (!rioWriteBulkDouble(r,score)) return 0;
if (vstr != NULL) {
if (!rioWriteBulkString(r,(char*)vstr,vlen)) return 0;
} else {
if (!rioWriteBulkLongLong(r,vll)) return 0;
}
zzlNext(zl,&eptr,&sptr);
if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
} else if (o->encoding == OBJ_ENCODING_SKIPLIST) {
zset *zs = o->ptr;
dictIterator *di = dictGetIterator(zs->dict);
dictEntry *de;
while((de = dictNext(di)) != NULL) {
sds ele = dictGetKey(de);
double *score = dictGetVal(de);
if (count == 0) {
int cmd_items = (items > AOF_REWRITE_ITEMS_PER_CMD) ?
AOF_REWRITE_ITEMS_PER_CMD : items;
if (!rioWriteBulkCount(r,'*',2+cmd_items*2) ||
!rioWriteBulkString(r,"ZADD",4) ||
!rioWriteBulkObject(r,key))
{
dictReleaseIterator(di);
return 0;
}
}
if (!rioWriteBulkDouble(r,*score) ||
!rioWriteBulkString(r,ele,sdslen(ele)))
{
dictReleaseIterator(di);
return 0;
}
if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
dictReleaseIterator(di);
} else {
serverPanic("Unknown sorted zset encoding");
}
return 1;
}
/* Write either the key or the value of the currently selected item of a 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 OBJ_HASH_KEY or OBJ_HASH_VALUE.
*
* The function returns 0 on error, non-zero on success. */
static int rioWriteHashIteratorCursor(rio *r, hashTypeIterator *hi, int what) {
if ((hi->encoding == OBJ_ENCODING_LISTPACK) || (hi->encoding == OBJ_ENCODING_LISTPACK_EX)) {
unsigned char *vstr = NULL;
unsigned int vlen = UINT_MAX;
long long vll = LLONG_MAX;
hashTypeCurrentFromListpack(hi, what, &vstr, &vlen, &vll, NULL);
if (vstr)
return rioWriteBulkString(r, (char*)vstr, vlen);
else
return rioWriteBulkLongLong(r, vll);
} else if (hi->encoding == OBJ_ENCODING_HT) {
char *str;
size_t len;
hashTypeCurrentFromHashTable(hi, what, &str, &len, NULL);
return rioWriteBulkString(r, str, len);
}
serverPanic("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) {
int res = 0; /*fail*/
hashTypeIterator *hi;
long long count = 0, items = hashTypeLength(o, 0);
int isHFE = hashTypeGetMinExpire(o, 0) != EB_EXPIRE_TIME_INVALID;
hi = hashTypeInitIterator(o);
if (!isHFE) {
while (hashTypeNext(hi, 0) != C_ERR) {
if (count == 0) {
int cmd_items = (items > AOF_REWRITE_ITEMS_PER_CMD) ?
AOF_REWRITE_ITEMS_PER_CMD : items;
if (!rioWriteBulkCount(r, '*', 2 + cmd_items * 2) ||
!rioWriteBulkString(r, "HMSET", 5) ||
!rioWriteBulkObject(r, key))
goto reHashEnd;
}
if (!rioWriteHashIteratorCursor(r, hi, OBJ_HASH_KEY) ||
!rioWriteHashIteratorCursor(r, hi, OBJ_HASH_VALUE))
goto reHashEnd;
if (++count == AOF_REWRITE_ITEMS_PER_CMD) count = 0;
items--;
}
} else {
while (hashTypeNext(hi, 0) != C_ERR) {
char hmsetCmd[] = "*4\r\n$5\r\nHMSET\r\n";
if ( (!rioWrite(r, hmsetCmd, sizeof(hmsetCmd) - 1)) ||
(!rioWriteBulkObject(r, key)) ||
(!rioWriteHashIteratorCursor(r, hi, OBJ_HASH_KEY)) ||
(!rioWriteHashIteratorCursor(r, hi, OBJ_HASH_VALUE)) )
goto reHashEnd;
if (hi->expire_time != EB_EXPIRE_TIME_INVALID) {
char cmd[] = "*6\r\n$10\r\nHPEXPIREAT\r\n";
if ( (!rioWrite(r, cmd, sizeof(cmd) - 1)) ||
(!rioWriteBulkObject(r, key)) ||
(!rioWriteBulkLongLong(r, hi->expire_time)) ||
(!rioWriteBulkString(r, "FIELDS", 6)) ||
(!rioWriteBulkString(r, "1", 1)) ||
(!rioWriteHashIteratorCursor(r, hi, OBJ_HASH_KEY)) )
goto reHashEnd;
}
}
}
res = 1; /* success */
reHashEnd:
hashTypeReleaseIterator(hi);
return res;
}
/* Helper for rewriteStreamObject() that generates a bulk string into the
* AOF representing the ID 'id'. */
int rioWriteBulkStreamID(rio *r,streamID *id) {
int retval;
sds replyid = sdscatfmt(sdsempty(),"%U-%U",id->ms,id->seq);
retval = rioWriteBulkString(r,replyid,sdslen(replyid));
sdsfree(replyid);
return retval;
}
/* Helper for rewriteStreamObject(): emit the XCLAIM needed in order to
* add the message described by 'nack' having the id 'rawid', into the pending
* list of the specified consumer. All this in the context of the specified
* key and group. */
int rioWriteStreamPendingEntry(rio *r, robj *key, const char *groupname, size_t groupname_len, streamConsumer *consumer, unsigned char *rawid, streamNACK *nack) {
/* XCLAIM <key> <group> <consumer> 0 <id> TIME <milliseconds-unix-time>
RETRYCOUNT <count> JUSTID FORCE. */
streamID id;
streamDecodeID(rawid,&id);
if (rioWriteBulkCount(r,'*',12) == 0) return 0;
if (rioWriteBulkString(r,"XCLAIM",6) == 0) return 0;
if (rioWriteBulkObject(r,key) == 0) return 0;
if (rioWriteBulkString(r,groupname,groupname_len) == 0) return 0;
if (rioWriteBulkString(r,consumer->name,sdslen(consumer->name)) == 0) return 0;
if (rioWriteBulkString(r,"0",1) == 0) return 0;
if (rioWriteBulkStreamID(r,&id) == 0) return 0;
if (rioWriteBulkString(r,"TIME",4) == 0) return 0;
if (rioWriteBulkLongLong(r,nack->delivery_time) == 0) return 0;
if (rioWriteBulkString(r,"RETRYCOUNT",10) == 0) return 0;
if (rioWriteBulkLongLong(r,nack->delivery_count) == 0) return 0;
if (rioWriteBulkString(r,"JUSTID",6) == 0) return 0;
if (rioWriteBulkString(r,"FORCE",5) == 0) return 0;
return 1;
}
/* Helper for rewriteStreamObject(): emit the XGROUP CREATECONSUMER is
* needed in order to create consumers that do not have any pending entries.
* All this in the context of the specified key and group. */
int rioWriteStreamEmptyConsumer(rio *r, robj *key, const char *groupname, size_t groupname_len, streamConsumer *consumer) {
/* XGROUP CREATECONSUMER <key> <group> <consumer> */
if (rioWriteBulkCount(r,'*',5) == 0) return 0;
if (rioWriteBulkString(r,"XGROUP",6) == 0) return 0;
if (rioWriteBulkString(r,"CREATECONSUMER",14) == 0) return 0;
if (rioWriteBulkObject(r,key) == 0) return 0;
if (rioWriteBulkString(r,groupname,groupname_len) == 0) return 0;
if (rioWriteBulkString(r,consumer->name,sdslen(consumer->name)) == 0) return 0;
return 1;
}
/* Emit the commands needed to rebuild a stream object.
* The function returns 0 on error, 1 on success. */
int rewriteStreamObject(rio *r, robj *key, robj *o) {
stream *s = o->ptr;
streamIterator si;
streamIteratorStart(&si,s,NULL,NULL,0);
streamID id;
int64_t numfields;
if (s->length) {
/* Reconstruct the stream data using XADD commands. */
while(streamIteratorGetID(&si,&id,&numfields)) {
/* Emit a two elements array for each item. The first is
* the ID, the second is an array of field-value pairs. */
/* Emit the XADD <key> <id> ...fields... command. */
if (!rioWriteBulkCount(r,'*',3+numfields*2) ||
!rioWriteBulkString(r,"XADD",4) ||
!rioWriteBulkObject(r,key) ||
!rioWriteBulkStreamID(r,&id))
{
streamIteratorStop(&si);
return 0;
}
while(numfields--) {
unsigned char *field, *value;
int64_t field_len, value_len;
streamIteratorGetField(&si,&field,&value,&field_len,&value_len);
if (!rioWriteBulkString(r,(char*)field,field_len) ||
!rioWriteBulkString(r,(char*)value,value_len))
{
streamIteratorStop(&si);
return 0;
}
}
}
} else {
/* Use the XADD MAXLEN 0 trick to generate an empty stream if
* the key we are serializing is an empty string, which is possible
* for the Stream type. */
id.ms = 0; id.seq = 1;
if (!rioWriteBulkCount(r,'*',7) ||
!rioWriteBulkString(r,"XADD",4) ||
!rioWriteBulkObject(r,key) ||
!rioWriteBulkString(r,"MAXLEN",6) ||
!rioWriteBulkString(r,"0",1) ||
!rioWriteBulkStreamID(r,&id) ||
!rioWriteBulkString(r,"x",1) ||
!rioWriteBulkString(r,"y",1))
{
streamIteratorStop(&si);
return 0;
}
}
/* Append XSETID after XADD, make sure lastid is correct,
* in case of XDEL lastid. */
if (!rioWriteBulkCount(r,'*',7) ||
!rioWriteBulkString(r,"XSETID",6) ||
!rioWriteBulkObject(r,key) ||
!rioWriteBulkStreamID(r,&s->last_id) ||
!rioWriteBulkString(r,"ENTRIESADDED",12) ||
!rioWriteBulkLongLong(r,s->entries_added) ||
!rioWriteBulkString(r,"MAXDELETEDID",12) ||
!rioWriteBulkStreamID(r,&s->max_deleted_entry_id))
{
streamIteratorStop(&si);
return 0;
}
/* Create all the stream consumer groups. */
if (s->cgroups) {
raxIterator ri;
raxStart(&ri,s->cgroups);
raxSeek(&ri,"^",NULL,0);
while(raxNext(&ri)) {
streamCG *group = ri.data;
/* Emit the XGROUP CREATE in order to create the group. */
if (!rioWriteBulkCount(r,'*',7) ||
!rioWriteBulkString(r,"XGROUP",6) ||
!rioWriteBulkString(r,"CREATE",6) ||
!rioWriteBulkObject(r,key) ||
!rioWriteBulkString(r,(char*)ri.key,ri.key_len) ||
!rioWriteBulkStreamID(r,&group->last_id) ||
!rioWriteBulkString(r,"ENTRIESREAD",11) ||
!rioWriteBulkLongLong(r,group->entries_read))
{
raxStop(&ri);
streamIteratorStop(&si);
return 0;
}
/* Generate XCLAIMs for each consumer that happens to
* have pending entries. Empty consumers would be generated with
* XGROUP CREATECONSUMER. */
raxIterator ri_cons;
raxStart(&ri_cons,group->consumers);
raxSeek(&ri_cons,"^",NULL,0);
while(raxNext(&ri_cons)) {
streamConsumer *consumer = ri_cons.data;
/* If there are no pending entries, just emit XGROUP CREATECONSUMER */
if (raxSize(consumer->pel) == 0) {
if (rioWriteStreamEmptyConsumer(r,key,(char*)ri.key,
ri.key_len,consumer) == 0)
{
raxStop(&ri_cons);
raxStop(&ri);
streamIteratorStop(&si);
return 0;
}
continue;
}
/* For the current consumer, iterate all the PEL entries
* to emit the XCLAIM protocol. */
raxIterator ri_pel;
raxStart(&ri_pel,consumer->pel);
raxSeek(&ri_pel,"^",NULL,0);
while(raxNext(&ri_pel)) {
streamNACK *nack = ri_pel.data;
if (rioWriteStreamPendingEntry(r,key,(char*)ri.key,
ri.key_len,consumer,
ri_pel.key,nack) == 0)
{
raxStop(&ri_pel);
raxStop(&ri_cons);
raxStop(&ri);
streamIteratorStop(&si);
return 0;
}
}
raxStop(&ri_pel);
}
raxStop(&ri_cons);
}
raxStop(&ri);
}
streamIteratorStop(&si);
return 1;
}
/* Call the module type callback in order to rewrite a data type
* that is exported by a module and is not handled by Redis itself.
* The function returns 0 on error, 1 on success. */
int rewriteModuleObject(rio *r, robj *key, robj *o, int dbid) {
RedisModuleIO io;
moduleValue *mv = o->ptr;
moduleType *mt = mv->type;
moduleInitIOContext(io,mt,r,key,dbid);
mt->aof_rewrite(&io,key,mv->value);
if (io.ctx) {
moduleFreeContext(io.ctx);
zfree(io.ctx);
}
return io.error ? 0 : 1;
}
static int rewriteFunctions(rio *aof) {
dict *functions = functionsLibGet();
dictIterator *iter = dictGetIterator(functions);
dictEntry *entry = NULL;
while ((entry = dictNext(iter))) {
functionLibInfo *li = dictGetVal(entry);
if (rioWrite(aof, "*3\r\n", 4) == 0) goto werr;
char function_load[] = "$8\r\nFUNCTION\r\n$4\r\nLOAD\r\n";
if (rioWrite(aof, function_load, sizeof(function_load) - 1) == 0) goto werr;
if (rioWriteBulkString(aof, li->code, sdslen(li->code)) == 0) goto werr;
}
dictReleaseIterator(iter);
return 1;
werr:
dictReleaseIterator(iter);
return 0;
}
int rewriteAppendOnlyFileRio(rio *aof) {
dictEntry *de;
int j;
long key_count = 0;
long long updated_time = 0;
kvstoreIterator *kvs_it = NULL;
/* Record timestamp at the beginning of rewriting AOF. */
if (server.aof_timestamp_enabled) {
sds ts = genAofTimestampAnnotationIfNeeded(1);
if (rioWrite(aof,ts,sdslen(ts)) == 0) { sdsfree(ts); goto werr; }
sdsfree(ts);
}
if (rewriteFunctions(aof) == 0) goto werr;
for (j = 0; j < server.dbnum; j++) {
char selectcmd[] = "*2\r\n$6\r\nSELECT\r\n";
redisDb *db = server.db + j;
if (kvstoreSize(db->keys) == 0) continue;
/* SELECT the new DB */
if (rioWrite(aof,selectcmd,sizeof(selectcmd)-1) == 0) goto werr;
if (rioWriteBulkLongLong(aof,j) == 0) goto werr;
kvs_it = kvstoreIteratorInit(db->keys);
/* Iterate this DB writing every entry */
while((de = kvstoreIteratorNext(kvs_it)) != NULL) {
sds keystr;
robj key, *o;
long long expiretime;
size_t aof_bytes_before_key = aof->processed_bytes;
keystr = dictGetKey(de);
o = dictGetVal(de);
initStaticStringObject(key,keystr);
expiretime = getExpire(db,&key);
/* Save the key and associated value */
if (o->type == OBJ_STRING) {
/* Emit a SET command */
char cmd[]="*3\r\n$3\r\nSET\r\n";
if (rioWrite(aof,cmd,sizeof(cmd)-1) == 0) goto werr;
/* Key and value */
if (rioWriteBulkObject(aof,&key) == 0) goto werr;
if (rioWriteBulkObject(aof,o) == 0) goto werr;
} else if (o->type == OBJ_LIST) {
if (rewriteListObject(aof,&key,o) == 0) goto werr;
} else if (o->type == OBJ_SET) {
if (rewriteSetObject(aof,&key,o) == 0) goto werr;
} else if (o->type == OBJ_ZSET) {
if (rewriteSortedSetObject(aof,&key,o) == 0) goto werr;
} else if (o->type == OBJ_HASH) {
if (rewriteHashObject(aof,&key,o) == 0) goto werr;
} else if (o->type == OBJ_STREAM) {
if (rewriteStreamObject(aof,&key,o) == 0) goto werr;
} else if (o->type == OBJ_MODULE) {
if (rewriteModuleObject(aof,&key,o,j) == 0) goto werr;
} else {
serverPanic("Unknown object type");
}
/* In fork child process, we can try to release memory back to the
* OS and possibly avoid or decrease COW. We give the dismiss
* mechanism a hint about an estimated size of the object we stored. */
size_t dump_size = aof->processed_bytes - aof_bytes_before_key;
if (server.in_fork_child) dismissObject(o, dump_size);
/* Save the expire time */
if (expiretime != -1) {
char cmd[]="*3\r\n$9\r\nPEXPIREAT\r\n";
if (rioWrite(aof,cmd,sizeof(cmd)-1) == 0) goto werr;
if (rioWriteBulkObject(aof,&key) == 0) goto werr;
if (rioWriteBulkLongLong(aof,expiretime) == 0) goto werr;
}
/* Update info every 1 second (approximately).
* in order to avoid calling mstime() on each iteration, we will
* check the diff every 1024 keys */
if ((key_count++ & 1023) == 0) {
long long now = mstime();
if (now - updated_time >= 1000) {
sendChildInfo(CHILD_INFO_TYPE_CURRENT_INFO, key_count, "AOF rewrite");
updated_time = now;
}
}
/* Delay before next key if required (for testing) */
if (server.rdb_key_save_delay)
debugDelay(server.rdb_key_save_delay);
}
kvstoreIteratorRelease(kvs_it);
}
return C_OK;
werr:
if (kvs_it) kvstoreIteratorRelease(kvs_it);
return C_ERR;
}
/* Write a sequence of commands able to fully rebuild the dataset into
* "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 AOF_REWRITE_ITEMS_PER_CMD items per time
* are inserted using a single command. */
int rewriteAppendOnlyFile(char *filename) {
rio aof;
FILE *fp = NULL;
char tmpfile[256];
/* 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) {
serverLog(LL_WARNING, "Opening the temp file for AOF rewrite in rewriteAppendOnlyFile(): %s", strerror(errno));
return C_ERR;
}
rioInitWithFile(&aof,fp);
if (server.aof_rewrite_incremental_fsync) {
rioSetAutoSync(&aof,REDIS_AUTOSYNC_BYTES);
rioSetReclaimCache(&aof,1);
}
startSaving(RDBFLAGS_AOF_PREAMBLE);
if (server.aof_use_rdb_preamble) {
int error;
if (rdbSaveRio(SLAVE_REQ_NONE,&aof,&error,RDBFLAGS_AOF_PREAMBLE,NULL) == C_ERR) {
errno = error;
goto werr;
}
} else {
if (rewriteAppendOnlyFileRio(&aof) == C_ERR) goto werr;
}
/* Make sure data will not remain on the OS's output buffers */
if (fflush(fp)) goto werr;
if (fsync(fileno(fp))) goto werr;
if (reclaimFilePageCache(fileno(fp), 0, 0) == -1) {
/* A minor error. Just log to know what happens */
serverLog(LL_NOTICE,"Unable to reclaim page cache: %s", strerror(errno));
}
if (fclose(fp)) { fp = NULL; goto werr; }
fp = NULL;
/* Use RENAME to make sure the DB file is changed atomically only
* if the generate DB file is ok. */
if (rename(tmpfile,filename) == -1) {
serverLog(LL_WARNING,"Error moving temp append only file on the final destination: %s", strerror(errno));
unlink(tmpfile);
stopSaving(0);
return C_ERR;
}
stopSaving(1);
return C_OK;
werr:
serverLog(LL_WARNING,"Write error writing append only file on disk: %s", strerror(errno));
if (fp) fclose(fp);
unlink(tmpfile);
stopSaving(0);
return C_ERR;
}
/* ----------------------------------------------------------------------------
* AOF background rewrite
* ------------------------------------------------------------------------- */
/* 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 open a new INCR AOF file to continue writing.
* 3) When the child finished '2a' exists.
* 4) The parent will trap the exit code, if it's OK, it will:
* 4a) get a new BASE file name and mark the previous (if we have) as the HISTORY type
* 4b) rename(2) the temp file in new BASE file name
* 4c) mark the rewritten INCR AOFs as history type
* 4d) persist AOF manifest file
* 4e) Delete the history files use bio
*/
int rewriteAppendOnlyFileBackground(void) {
pid_t childpid;
if (hasActiveChildProcess()) return C_ERR;
if (dirCreateIfMissing(server.aof_dirname) == -1) {
serverLog(LL_WARNING, "Can't open or create append-only dir %s: %s",
server.aof_dirname, strerror(errno));
server.aof_lastbgrewrite_status = C_ERR;
return C_ERR;
}
/* We set aof_selected_db to -1 in order to force the next call to the
* feedAppendOnlyFile() to issue a SELECT command. */
server.aof_selected_db = -1;
flushAppendOnlyFile(1);
if (openNewIncrAofForAppend() != C_OK) {
server.aof_lastbgrewrite_status = C_ERR;
return C_ERR;
}
if (server.aof_state == AOF_WAIT_REWRITE) {
/* Wait for all bio jobs related to AOF to drain. This prevents a race
* between updates to `fsynced_reploff_pending` of the worker thread, belonging
* to the previous AOF, and the new one. This concern is specific for a full
* sync scenario where we don't wanna risk the ACKed replication offset
* jumping backwards or forward when switching to a different master. */
bioDrainWorker(BIO_AOF_FSYNC);
/* Set the initial repl_offset, which will be applied to fsynced_reploff
* when AOFRW finishes (after possibly being updated by a bio thread) */
atomicSet(server.fsynced_reploff_pending, server.master_repl_offset);
server.fsynced_reploff = 0;
}
server.stat_aof_rewrites++;
if ((childpid = redisFork(CHILD_TYPE_AOF)) == 0) {
char tmpfile[256];
/* Child */
redisSetProcTitle("redis-aof-rewrite");
redisSetCpuAffinity(server.aof_rewrite_cpulist);
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) getpid());
if (rewriteAppendOnlyFile(tmpfile) == C_OK) {
serverLog(LL_NOTICE,
"Successfully created the temporary AOF base file %s", tmpfile);
sendChildCowInfo(CHILD_INFO_TYPE_AOF_COW_SIZE, "AOF rewrite");
exitFromChild(0);
} else {
exitFromChild(1);
}
} else {
/* Parent */
if (childpid == -1) {
server.aof_lastbgrewrite_status = C_ERR;
serverLog(LL_WARNING,
"Can't rewrite append only file in background: fork: %s",
strerror(errno));
return C_ERR;
}
serverLog(LL_NOTICE,
"Background append only file rewriting started by pid %ld",(long) childpid);
server.aof_rewrite_scheduled = 0;
server.aof_rewrite_time_start = time(NULL);
return C_OK;
}
return C_OK; /* unreached */
}
void bgrewriteaofCommand(client *c) {
if (server.child_type == CHILD_TYPE_AOF) {
addReplyError(c,"Background append only file rewriting already in progress");
} else if (hasActiveChildProcess() || server.in_exec) {
server.aof_rewrite_scheduled = 1;
/* When manually triggering AOFRW we reset the count
* so that it can be executed immediately. */
server.stat_aofrw_consecutive_failures = 0;
addReplyStatus(c,"Background append only file rewriting scheduled");
} else if (rewriteAppendOnlyFileBackground() == C_OK) {
addReplyStatus(c,"Background append only file rewriting started");
} else {
addReplyError(c,"Can't execute an AOF background rewriting. "
"Please check the server logs for more information.");
}
}
void aofRemoveTempFile(pid_t childpid) {
char tmpfile[256];
snprintf(tmpfile,256,"temp-rewriteaof-bg-%d.aof", (int) childpid);
bg_unlink(tmpfile);
snprintf(tmpfile,256,"temp-rewriteaof-%d.aof", (int) childpid);
bg_unlink(tmpfile);
}
/* Get size of an AOF file.
* The status argument is an optional output argument to be filled with
* one of the AOF_ status values. */
off_t getAppendOnlyFileSize(sds filename, int *status) {
struct redis_stat sb;
off_t size;
mstime_t latency;
sds aof_filepath = makePath(server.aof_dirname, filename);
latencyStartMonitor(latency);
if (redis_stat(aof_filepath, &sb) == -1) {
if (status) *status = errno == ENOENT ? AOF_NOT_EXIST : AOF_OPEN_ERR;
serverLog(LL_WARNING, "Unable to obtain the AOF file %s length. stat: %s",
filename, strerror(errno));
size = 0;
} else {
if (status) *status = AOF_OK;
size = sb.st_size;
}
latencyEndMonitor(latency);
latencyAddSampleIfNeeded("aof-fstat", latency);
sdsfree(aof_filepath);
return size;
}
/* Get size of all AOF files referred by the manifest (excluding history).
* The status argument is an output argument to be filled with
* one of the AOF_ status values. */
off_t getBaseAndIncrAppendOnlyFilesSize(aofManifest *am, int *status) {
off_t size = 0;
listNode *ln;
listIter li;
if (am->base_aof_info) {
serverAssert(am->base_aof_info->file_type == AOF_FILE_TYPE_BASE);
size += getAppendOnlyFileSize(am->base_aof_info->file_name, status);
if (*status != AOF_OK) return 0;
}
listRewind(am->incr_aof_list, &li);
while ((ln = listNext(&li)) != NULL) {
aofInfo *ai = (aofInfo*)ln->value;
serverAssert(ai->file_type == AOF_FILE_TYPE_INCR);
size += getAppendOnlyFileSize(ai->file_name, status);
if (*status != AOF_OK) return 0;
}
return size;
}
int getBaseAndIncrAppendOnlyFilesNum(aofManifest *am) {
int num = 0;
if (am->base_aof_info) num++;
if (am->incr_aof_list) num += listLength(am->incr_aof_list);
return num;
}
/* A background append only file rewriting (BGREWRITEAOF) terminated its work.
* Handle this. */
void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
if (!bysignal && exitcode == 0) {
char tmpfile[256];
long long now = ustime();
sds new_base_filepath = NULL;
sds new_incr_filepath = NULL;
aofManifest *temp_am;
mstime_t latency;
serverLog(LL_NOTICE,
"Background AOF rewrite terminated with success");
snprintf(tmpfile, 256, "temp-rewriteaof-bg-%d.aof",
(int)server.child_pid);
serverAssert(server.aof_manifest != NULL);
/* Dup a temporary aof_manifest for subsequent modifications. */
temp_am = aofManifestDup(server.aof_manifest);
/* Get a new BASE file name and mark the previous (if we have)
* as the HISTORY type. */
sds new_base_filename = getNewBaseFileNameAndMarkPreAsHistory(temp_am);
serverAssert(new_base_filename != NULL);
new_base_filepath = makePath(server.aof_dirname, new_base_filename);
/* Rename the temporary aof file to 'new_base_filename'. */
latencyStartMonitor(latency);
if (rename(tmpfile, new_base_filepath) == -1) {
serverLog(LL_WARNING,
"Error trying to rename the temporary AOF base file %s into %s: %s",
tmpfile,
new_base_filepath,
strerror(errno));
aofManifestFree(temp_am);
sdsfree(new_base_filepath);
server.aof_lastbgrewrite_status = C_ERR;
server.stat_aofrw_consecutive_failures++;
goto cleanup;
}
latencyEndMonitor(latency);
latencyAddSampleIfNeeded("aof-rename", latency);
serverLog(LL_NOTICE,
"Successfully renamed the temporary AOF base file %s into %s", tmpfile, new_base_filename);
/* Rename the temporary incr aof file to 'new_incr_filename'. */
if (server.aof_state == AOF_WAIT_REWRITE) {
/* Get temporary incr aof name. */
sds temp_incr_aof_name = getTempIncrAofName();
sds temp_incr_filepath = makePath(server.aof_dirname, temp_incr_aof_name);
/* Get next new incr aof name. */
sds new_incr_filename = getNewIncrAofName(temp_am, tempIncAofStartReplOffset);
new_incr_filepath = makePath(server.aof_dirname, new_incr_filename);
latencyStartMonitor(latency);
if (rename(temp_incr_filepath, new_incr_filepath) == -1) {
serverLog(LL_WARNING,
"Error trying to rename the temporary AOF incr file %s into %s: %s",
temp_incr_filepath,
new_incr_filepath,
strerror(errno));
bg_unlink(new_base_filepath);
sdsfree(new_base_filepath);
aofManifestFree(temp_am);
sdsfree(temp_incr_filepath);
sdsfree(new_incr_filepath);
sdsfree(temp_incr_aof_name);
server.aof_lastbgrewrite_status = C_ERR;
server.stat_aofrw_consecutive_failures++;
goto cleanup;
}
latencyEndMonitor(latency);
latencyAddSampleIfNeeded("aof-rename", latency);
serverLog(LL_NOTICE,
"Successfully renamed the temporary AOF incr file %s into %s", temp_incr_aof_name, new_incr_filename);
sdsfree(temp_incr_filepath);
sdsfree(temp_incr_aof_name);
}
/* Change the AOF file type in 'incr_aof_list' from AOF_FILE_TYPE_INCR
* to AOF_FILE_TYPE_HIST, and move them to the 'history_aof_list'. */
markRewrittenIncrAofAsHistory(temp_am);
/* Persist our modifications. */
if (persistAofManifest(temp_am) == C_ERR) {
bg_unlink(new_base_filepath);
aofManifestFree(temp_am);
sdsfree(new_base_filepath);
if (new_incr_filepath) {
bg_unlink(new_incr_filepath);
sdsfree(new_incr_filepath);
}
server.aof_lastbgrewrite_status = C_ERR;
server.stat_aofrw_consecutive_failures++;
goto cleanup;
}
sdsfree(new_base_filepath);
if (new_incr_filepath) sdsfree(new_incr_filepath);
/* We can safely let `server.aof_manifest` point to 'temp_am' and free the previous one. */
aofManifestFreeAndUpdate(temp_am);
if (server.aof_state != AOF_OFF) {
/* AOF enabled. */
server.aof_current_size = getAppendOnlyFileSize(new_base_filename, NULL) + server.aof_last_incr_size;
server.aof_rewrite_base_size = server.aof_current_size;
}
/* We don't care about the return value of `aofDelHistoryFiles`, because the history
* deletion failure will not cause any problems. */
aofDelHistoryFiles();
server.aof_lastbgrewrite_status = C_OK;
server.stat_aofrw_consecutive_failures = 0;
serverLog(LL_NOTICE, "Background AOF rewrite finished successfully");
/* Change state from WAIT_REWRITE to ON if needed */
if (server.aof_state == AOF_WAIT_REWRITE) {
server.aof_state = AOF_ON;
/* Update the fsynced replication offset that just now become valid.
* This could either be the one we took in startAppendOnly, or a
* newer one set by the bio thread. */
long long fsynced_reploff_pending;
atomicGet(server.fsynced_reploff_pending, fsynced_reploff_pending);
server.fsynced_reploff = fsynced_reploff_pending;
}
serverLog(LL_VERBOSE,
"Background AOF rewrite signal handler took %lldus", ustime()-now);
} else if (!bysignal && exitcode != 0) {
server.aof_lastbgrewrite_status = C_ERR;
server.stat_aofrw_consecutive_failures++;
serverLog(LL_WARNING,
"Background AOF rewrite terminated with error");
} else {
/* SIGUSR1 is whitelisted, so we have a way to kill a child without
* triggering an error condition. */
if (bysignal != SIGUSR1) {
server.aof_lastbgrewrite_status = C_ERR;
server.stat_aofrw_consecutive_failures++;
}
serverLog(LL_WARNING,
"Background AOF rewrite terminated by signal %d", bysignal);
}
cleanup:
aofRemoveTempFile(server.child_pid);
/* Clear AOF buffer and delete temp incr aof for next rewrite. */
if (server.aof_state == AOF_WAIT_REWRITE) {
sdsfree(server.aof_buf);
server.aof_buf = sdsempty();
aofDelTempIncrAofFile();
}
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 == AOF_WAIT_REWRITE)
server.aof_rewrite_scheduled = 1;
}
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