mirror of
https://git.postgresql.org/git/postgresql.git
synced 2025-02-05 19:09:58 +08:00
Split off functions related to timeline history files and XLOG archiving.
This is just refactoring, to make the functions accessible outside xlog.c. A followup patch will make use of that, to allow fetching timeline history files over streaming replication.
This commit is contained in:
Heikki Linnakangas
parent
0899556e92
commit
d5497b95f3
@ -13,7 +13,8 @@ top_builddir = ../../../..
|
||||
include $(top_builddir)/src/Makefile.global
|
||||
|
||||
OBJS = clog.o transam.o varsup.o xact.o rmgr.o slru.o subtrans.o multixact.o \
|
||||
twophase.o twophase_rmgr.o xlog.o xlogfuncs.o xlogutils.o
|
||||
timeline.o twophase.o twophase_rmgr.o xlog.o xlogarchive.o xlogfuncs.o \
|
||||
xlogutils.o
|
||||
|
||||
include $(top_srcdir)/src/backend/common.mk
|
||||
|
||||
|
||||
378
src/backend/access/transam/timeline.c
Normal file
378
src/backend/access/transam/timeline.c
Normal file
@ -0,0 +1,378 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* timeline.c
|
||||
* Functions for reading and writing timeline history files.
|
||||
*
|
||||
* A timeline history file lists the timeline changes of the timeline, in
|
||||
* a simple text format. They are archived along with the WAL segments.
|
||||
*
|
||||
* The files are named like "<WAL segment>.history". For example, if the
|
||||
* database starts up and switches to timeline 5, while processing WAL
|
||||
* segment 000000030000002A00000006 (the old timeline was 3), the timeline
|
||||
* history file would be called "000000050000002A00000006.history".
|
||||
*
|
||||
* Each line in the file represents a timeline switch:
|
||||
*
|
||||
* <parentTLI> <xlogfname> <reason>
|
||||
*
|
||||
* parentTLI ID of the parent timeline
|
||||
* xlogfname filename of the WAL segment where the switch happened
|
||||
* reason human-readable explanation of why the timeline was changed
|
||||
*
|
||||
* The fields are separated by tabs. Lines beginning with # are comments, and
|
||||
* are ignored. Empty lines are also ignored.
|
||||
*
|
||||
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* src/backend/access/transam/timeline.c
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
||||
#include "postgres.h"
|
||||
|
||||
#include <stdio.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include "access/timeline.h"
|
||||
#include "access/xlog_internal.h"
|
||||
#include "access/xlogdefs.h"
|
||||
#include "storage/fd.h"
|
||||
|
||||
/*
|
||||
* Try to read a timeline's history file.
|
||||
*
|
||||
* If successful, return the list of component TLIs (the given TLI followed by
|
||||
* its ancestor TLIs). If we can't find the history file, assume that the
|
||||
* timeline has no parents, and return a list of just the specified timeline
|
||||
* ID.
|
||||
*/
|
||||
List *
|
||||
readTimeLineHistory(TimeLineID targetTLI)
|
||||
{
|
||||
List *result;
|
||||
char path[MAXPGPATH];
|
||||
char histfname[MAXFNAMELEN];
|
||||
char fline[MAXPGPATH];
|
||||
FILE *fd;
|
||||
|
||||
/* Timeline 1 does not have a history file, so no need to check */
|
||||
if (targetTLI == 1)
|
||||
return list_make1_int((int) targetTLI);
|
||||
|
||||
if (InArchiveRecovery)
|
||||
{
|
||||
TLHistoryFileName(histfname, targetTLI);
|
||||
RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0);
|
||||
}
|
||||
else
|
||||
TLHistoryFilePath(path, targetTLI);
|
||||
|
||||
fd = AllocateFile(path, "r");
|
||||
if (fd == NULL)
|
||||
{
|
||||
if (errno != ENOENT)
|
||||
ereport(FATAL,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not open file \"%s\": %m", path)));
|
||||
/* Not there, so assume no parents */
|
||||
return list_make1_int((int) targetTLI);
|
||||
}
|
||||
|
||||
result = NIL;
|
||||
|
||||
/*
|
||||
* Parse the file...
|
||||
*/
|
||||
while (fgets(fline, sizeof(fline), fd) != NULL)
|
||||
{
|
||||
/* skip leading whitespace and check for # comment */
|
||||
char *ptr;
|
||||
char *endptr;
|
||||
TimeLineID tli;
|
||||
|
||||
for (ptr = fline; *ptr; ptr++)
|
||||
{
|
||||
if (!isspace((unsigned char) *ptr))
|
||||
break;
|
||||
}
|
||||
if (*ptr == '\0' || *ptr == '#')
|
||||
continue;
|
||||
|
||||
/* expect a numeric timeline ID as first field of line */
|
||||
tli = (TimeLineID) strtoul(ptr, &endptr, 0);
|
||||
if (endptr == ptr)
|
||||
ereport(FATAL,
|
||||
(errmsg("syntax error in history file: %s", fline),
|
||||
errhint("Expected a numeric timeline ID.")));
|
||||
|
||||
if (result &&
|
||||
tli <= (TimeLineID) linitial_int(result))
|
||||
ereport(FATAL,
|
||||
(errmsg("invalid data in history file: %s", fline),
|
||||
errhint("Timeline IDs must be in increasing sequence.")));
|
||||
|
||||
/* Build list with newest item first */
|
||||
result = lcons_int((int) tli, result);
|
||||
|
||||
/* we ignore the remainder of each line */
|
||||
}
|
||||
|
||||
FreeFile(fd);
|
||||
|
||||
if (result &&
|
||||
targetTLI <= (TimeLineID) linitial_int(result))
|
||||
ereport(FATAL,
|
||||
(errmsg("invalid data in history file \"%s\"", path),
|
||||
errhint("Timeline IDs must be less than child timeline's ID.")));
|
||||
|
||||
result = lcons_int((int) targetTLI, result);
|
||||
|
||||
ereport(DEBUG3,
|
||||
(errmsg_internal("history of timeline %u is %s",
|
||||
targetTLI, nodeToString(result))));
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/*
|
||||
* Probe whether a timeline history file exists for the given timeline ID
|
||||
*/
|
||||
bool
|
||||
existsTimeLineHistory(TimeLineID probeTLI)
|
||||
{
|
||||
char path[MAXPGPATH];
|
||||
char histfname[MAXFNAMELEN];
|
||||
FILE *fd;
|
||||
|
||||
/* Timeline 1 does not have a history file, so no need to check */
|
||||
if (probeTLI == 1)
|
||||
return false;
|
||||
|
||||
if (InArchiveRecovery)
|
||||
{
|
||||
TLHistoryFileName(histfname, probeTLI);
|
||||
RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0);
|
||||
}
|
||||
else
|
||||
TLHistoryFilePath(path, probeTLI);
|
||||
|
||||
fd = AllocateFile(path, "r");
|
||||
if (fd != NULL)
|
||||
{
|
||||
FreeFile(fd);
|
||||
return true;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (errno != ENOENT)
|
||||
ereport(FATAL,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not open file \"%s\": %m", path)));
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Find the newest existing timeline, assuming that startTLI exists.
|
||||
*
|
||||
* Note: while this is somewhat heuristic, it does positively guarantee
|
||||
* that (result + 1) is not a known timeline, and therefore it should
|
||||
* be safe to assign that ID to a new timeline.
|
||||
*/
|
||||
TimeLineID
|
||||
findNewestTimeLine(TimeLineID startTLI)
|
||||
{
|
||||
TimeLineID newestTLI;
|
||||
TimeLineID probeTLI;
|
||||
|
||||
/*
|
||||
* The algorithm is just to probe for the existence of timeline history
|
||||
* files. XXX is it useful to allow gaps in the sequence?
|
||||
*/
|
||||
newestTLI = startTLI;
|
||||
|
||||
for (probeTLI = startTLI + 1;; probeTLI++)
|
||||
{
|
||||
if (existsTimeLineHistory(probeTLI))
|
||||
{
|
||||
newestTLI = probeTLI; /* probeTLI exists */
|
||||
}
|
||||
else
|
||||
{
|
||||
/* doesn't exist, assume we're done */
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
return newestTLI;
|
||||
}
|
||||
|
||||
/*
|
||||
* Create a new timeline history file.
|
||||
*
|
||||
* newTLI: ID of the new timeline
|
||||
* parentTLI: ID of its immediate parent
|
||||
* endTLI et al: ID of the last used WAL file, for annotation purposes
|
||||
* reason: human-readable explanation of why the timeline was switched
|
||||
*
|
||||
* Currently this is only used at the end recovery, and so there are no locking
|
||||
* considerations. But we should be just as tense as XLogFileInit to avoid
|
||||
* emplacing a bogus file.
|
||||
*/
|
||||
void
|
||||
writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
|
||||
TimeLineID endTLI, XLogSegNo endLogSegNo, char *reason)
|
||||
{
|
||||
char path[MAXPGPATH];
|
||||
char tmppath[MAXPGPATH];
|
||||
char histfname[MAXFNAMELEN];
|
||||
char xlogfname[MAXFNAMELEN];
|
||||
char buffer[BLCKSZ];
|
||||
int srcfd;
|
||||
int fd;
|
||||
int nbytes;
|
||||
|
||||
Assert(newTLI > parentTLI); /* else bad selection of newTLI */
|
||||
|
||||
/*
|
||||
* Write into a temp file name.
|
||||
*/
|
||||
snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
|
||||
|
||||
unlink(tmppath);
|
||||
|
||||
/* do not use get_sync_bit() here --- want to fsync only at end of fill */
|
||||
fd = BasicOpenFile(tmppath, O_RDWR | O_CREAT | O_EXCL,
|
||||
S_IRUSR | S_IWUSR);
|
||||
if (fd < 0)
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not create file \"%s\": %m", tmppath)));
|
||||
|
||||
/*
|
||||
* If a history file exists for the parent, copy it verbatim
|
||||
*/
|
||||
if (InArchiveRecovery)
|
||||
{
|
||||
TLHistoryFileName(histfname, parentTLI);
|
||||
RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0);
|
||||
}
|
||||
else
|
||||
TLHistoryFilePath(path, parentTLI);
|
||||
|
||||
srcfd = BasicOpenFile(path, O_RDONLY, 0);
|
||||
if (srcfd < 0)
|
||||
{
|
||||
if (errno != ENOENT)
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not open file \"%s\": %m", path)));
|
||||
/* Not there, so assume parent has no parents */
|
||||
}
|
||||
else
|
||||
{
|
||||
for (;;)
|
||||
{
|
||||
errno = 0;
|
||||
nbytes = (int) read(srcfd, buffer, sizeof(buffer));
|
||||
if (nbytes < 0 || errno != 0)
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not read file \"%s\": %m", path)));
|
||||
if (nbytes == 0)
|
||||
break;
|
||||
errno = 0;
|
||||
if ((int) write(fd, buffer, nbytes) != nbytes)
|
||||
{
|
||||
int save_errno = errno;
|
||||
|
||||
/*
|
||||
* If we fail to make the file, delete it to release disk
|
||||
* space
|
||||
*/
|
||||
unlink(tmppath);
|
||||
|
||||
/*
|
||||
* if write didn't set errno, assume problem is no disk space
|
||||
*/
|
||||
errno = save_errno ? save_errno : ENOSPC;
|
||||
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not write to file \"%s\": %m", tmppath)));
|
||||
}
|
||||
}
|
||||
close(srcfd);
|
||||
}
|
||||
|
||||
/*
|
||||
* Append one line with the details of this timeline split.
|
||||
*
|
||||
* If we did have a parent file, insert an extra newline just in case the
|
||||
* parent file failed to end with one.
|
||||
*/
|
||||
XLogFileName(xlogfname, endTLI, endLogSegNo);
|
||||
|
||||
snprintf(buffer, sizeof(buffer),
|
||||
"%s%u\t%s\t%s\n",
|
||||
(srcfd < 0) ? "" : "\n",
|
||||
parentTLI,
|
||||
xlogfname,
|
||||
reason);
|
||||
|
||||
nbytes = strlen(buffer);
|
||||
errno = 0;
|
||||
if ((int) write(fd, buffer, nbytes) != nbytes)
|
||||
{
|
||||
int save_errno = errno;
|
||||
|
||||
/*
|
||||
* If we fail to make the file, delete it to release disk space
|
||||
*/
|
||||
unlink(tmppath);
|
||||
/* if write didn't set errno, assume problem is no disk space */
|
||||
errno = save_errno ? save_errno : ENOSPC;
|
||||
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not write to file \"%s\": %m", tmppath)));
|
||||
}
|
||||
|
||||
if (pg_fsync(fd) != 0)
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not fsync file \"%s\": %m", tmppath)));
|
||||
|
||||
if (close(fd))
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not close file \"%s\": %m", tmppath)));
|
||||
|
||||
|
||||
/*
|
||||
* Now move the completed history file into place with its final name.
|
||||
*/
|
||||
TLHistoryFilePath(path, newTLI);
|
||||
|
||||
/*
|
||||
* Prefer link() to rename() here just to be really sure that we don't
|
||||
* overwrite an existing logfile. However, there shouldn't be one, so
|
||||
* rename() is an acceptable substitute except for the truly paranoid.
|
||||
*/
|
||||
#if HAVE_WORKING_LINK
|
||||
if (link(tmppath, path) < 0)
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not link file \"%s\" to \"%s\": %m",
|
||||
tmppath, path)));
|
||||
unlink(tmppath);
|
||||
#else
|
||||
if (rename(tmppath, path) < 0)
|
||||
ereport(ERROR,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not rename file \"%s\" to \"%s\": %m",
|
||||
tmppath, path)));
|
||||
#endif
|
||||
}
|
||||
File diff suppressed because it is too large
Load Diff
572
src/backend/access/transam/xlogarchive.c
Normal file
572
src/backend/access/transam/xlogarchive.c
Normal file
@ -0,0 +1,572 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* xlogarchive.c
|
||||
* Functions for archiving WAL files and restoring from the archive.
|
||||
*
|
||||
*
|
||||
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* src/backend/access/transam/xlogarchive.c
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
||||
#include "postgres.h"
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <sys/stat.h>
|
||||
#include <signal.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include "access/xlog_internal.h"
|
||||
#include "miscadmin.h"
|
||||
#include "postmaster/startup.h"
|
||||
#include "storage/fd.h"
|
||||
#include "storage/ipc.h"
|
||||
#include "storage/lwlock.h"
|
||||
#include "storage/pmsignal.h"
|
||||
|
||||
/*
|
||||
* Attempt to retrieve the specified file from off-line archival storage.
|
||||
* If successful, fill "path" with its complete path (note that this will be
|
||||
* a temp file name that doesn't follow the normal naming convention), and
|
||||
* return TRUE.
|
||||
*
|
||||
* If not successful, fill "path" with the name of the normal on-line file
|
||||
* (which may or may not actually exist, but we'll try to use it), and return
|
||||
* FALSE.
|
||||
*
|
||||
* For fixed-size files, the caller may pass the expected size as an
|
||||
* additional crosscheck on successful recovery. If the file size is not
|
||||
* known, set expectedSize = 0.
|
||||
*/
|
||||
bool
|
||||
RestoreArchivedFile(char *path, const char *xlogfname,
|
||||
const char *recovername, off_t expectedSize)
|
||||
{
|
||||
char xlogpath[MAXPGPATH];
|
||||
char xlogRestoreCmd[MAXPGPATH];
|
||||
char lastRestartPointFname[MAXPGPATH];
|
||||
char *dp;
|
||||
char *endp;
|
||||
const char *sp;
|
||||
int rc;
|
||||
bool signaled;
|
||||
struct stat stat_buf;
|
||||
XLogSegNo restartSegNo;
|
||||
XLogRecPtr restartRedoPtr;
|
||||
TimeLineID restartTli;
|
||||
|
||||
/* In standby mode, restore_command might not be supplied */
|
||||
if (recoveryRestoreCommand == NULL)
|
||||
goto not_available;
|
||||
|
||||
/*
|
||||
* When doing archive recovery, we always prefer an archived log file even
|
||||
* if a file of the same name exists in XLOGDIR. The reason is that the
|
||||
* file in XLOGDIR could be an old, un-filled or partly-filled version
|
||||
* that was copied and restored as part of backing up $PGDATA.
|
||||
*
|
||||
* We could try to optimize this slightly by checking the local copy
|
||||
* lastchange timestamp against the archived copy, but we have no API to
|
||||
* do this, nor can we guarantee that the lastchange timestamp was
|
||||
* preserved correctly when we copied to archive. Our aim is robustness,
|
||||
* so we elect not to do this.
|
||||
*
|
||||
* If we cannot obtain the log file from the archive, however, we will try
|
||||
* to use the XLOGDIR file if it exists. This is so that we can make use
|
||||
* of log segments that weren't yet transferred to the archive.
|
||||
*
|
||||
* Notice that we don't actually overwrite any files when we copy back
|
||||
* from archive because the restore_command may inadvertently
|
||||
* restore inappropriate xlogs, or they may be corrupt, so we may wish to
|
||||
* fallback to the segments remaining in current XLOGDIR later. The
|
||||
* copy-from-archive filename is always the same, ensuring that we don't
|
||||
* run out of disk space on long recoveries.
|
||||
*/
|
||||
snprintf(xlogpath, MAXPGPATH, XLOGDIR "/%s", recovername);
|
||||
|
||||
/*
|
||||
* Make sure there is no existing file named recovername.
|
||||
*/
|
||||
if (stat(xlogpath, &stat_buf) != 0)
|
||||
{
|
||||
if (errno != ENOENT)
|
||||
ereport(FATAL,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not stat file \"%s\": %m",
|
||||
xlogpath)));
|
||||
}
|
||||
else
|
||||
{
|
||||
if (unlink(xlogpath) != 0)
|
||||
ereport(FATAL,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not remove file \"%s\": %m",
|
||||
xlogpath)));
|
||||
}
|
||||
|
||||
/*
|
||||
* Calculate the archive file cutoff point for use during log shipping
|
||||
* replication. All files earlier than this point can be deleted from the
|
||||
* archive, though there is no requirement to do so.
|
||||
*
|
||||
* We initialise this with the filename of an InvalidXLogRecPtr, which
|
||||
* will prevent the deletion of any WAL files from the archive because of
|
||||
* the alphabetic sorting property of WAL filenames.
|
||||
*
|
||||
* Once we have successfully located the redo pointer of the checkpoint
|
||||
* from which we start recovery we never request a file prior to the redo
|
||||
* pointer of the last restartpoint. When redo begins we know that we have
|
||||
* successfully located it, so there is no need for additional status
|
||||
* flags to signify the point when we can begin deleting WAL files from
|
||||
* the archive.
|
||||
*/
|
||||
GetOldestRestartPoint(&restartRedoPtr, &restartTli);
|
||||
if (!XLogRecPtrIsInvalid(restartRedoPtr))
|
||||
{
|
||||
XLByteToSeg(restartRedoPtr, restartSegNo);
|
||||
XLogFileName(lastRestartPointFname, restartTli, restartSegNo);
|
||||
/* we shouldn't need anything earlier than last restart point */
|
||||
Assert(strcmp(lastRestartPointFname, xlogfname) <= 0);
|
||||
}
|
||||
else
|
||||
XLogFileName(lastRestartPointFname, 0, 0L);
|
||||
|
||||
/*
|
||||
* construct the command to be executed
|
||||
*/
|
||||
dp = xlogRestoreCmd;
|
||||
endp = xlogRestoreCmd + MAXPGPATH - 1;
|
||||
*endp = '\0';
|
||||
|
||||
for (sp = recoveryRestoreCommand; *sp; sp++)
|
||||
{
|
||||
if (*sp == '%')
|
||||
{
|
||||
switch (sp[1])
|
||||
{
|
||||
case 'p':
|
||||
/* %p: relative path of target file */
|
||||
sp++;
|
||||
StrNCpy(dp, xlogpath, endp - dp);
|
||||
make_native_path(dp);
|
||||
dp += strlen(dp);
|
||||
break;
|
||||
case 'f':
|
||||
/* %f: filename of desired file */
|
||||
sp++;
|
||||
StrNCpy(dp, xlogfname, endp - dp);
|
||||
dp += strlen(dp);
|
||||
break;
|
||||
case 'r':
|
||||
/* %r: filename of last restartpoint */
|
||||
sp++;
|
||||
StrNCpy(dp, lastRestartPointFname, endp - dp);
|
||||
dp += strlen(dp);
|
||||
break;
|
||||
case '%':
|
||||
/* convert %% to a single % */
|
||||
sp++;
|
||||
if (dp < endp)
|
||||
*dp++ = *sp;
|
||||
break;
|
||||
default:
|
||||
/* otherwise treat the % as not special */
|
||||
if (dp < endp)
|
||||
*dp++ = *sp;
|
||||
break;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
if (dp < endp)
|
||||
*dp++ = *sp;
|
||||
}
|
||||
}
|
||||
*dp = '\0';
|
||||
|
||||
ereport(DEBUG3,
|
||||
(errmsg_internal("executing restore command \"%s\"",
|
||||
xlogRestoreCmd)));
|
||||
|
||||
/*
|
||||
* Check signals before restore command and reset afterwards.
|
||||
*/
|
||||
PreRestoreCommand();
|
||||
|
||||
/*
|
||||
* Copy xlog from archival storage to XLOGDIR
|
||||
*/
|
||||
rc = system(xlogRestoreCmd);
|
||||
|
||||
PostRestoreCommand();
|
||||
|
||||
if (rc == 0)
|
||||
{
|
||||
/*
|
||||
* command apparently succeeded, but let's make sure the file is
|
||||
* really there now and has the correct size.
|
||||
*/
|
||||
if (stat(xlogpath, &stat_buf) == 0)
|
||||
{
|
||||
if (expectedSize > 0 && stat_buf.st_size != expectedSize)
|
||||
{
|
||||
int elevel;
|
||||
|
||||
/*
|
||||
* If we find a partial file in standby mode, we assume it's
|
||||
* because it's just being copied to the archive, and keep
|
||||
* trying.
|
||||
*
|
||||
* Otherwise treat a wrong-sized file as FATAL to ensure the
|
||||
* DBA would notice it, but is that too strong? We could try
|
||||
* to plow ahead with a local copy of the file ... but the
|
||||
* problem is that there probably isn't one, and we'd
|
||||
* incorrectly conclude we've reached the end of WAL and we're
|
||||
* done recovering ...
|
||||
*/
|
||||
if (StandbyMode && stat_buf.st_size < expectedSize)
|
||||
elevel = DEBUG1;
|
||||
else
|
||||
elevel = FATAL;
|
||||
ereport(elevel,
|
||||
(errmsg("archive file \"%s\" has wrong size: %lu instead of %lu",
|
||||
xlogfname,
|
||||
(unsigned long) stat_buf.st_size,
|
||||
(unsigned long) expectedSize)));
|
||||
return false;
|
||||
}
|
||||
else
|
||||
{
|
||||
ereport(LOG,
|
||||
(errmsg("restored log file \"%s\" from archive",
|
||||
xlogfname)));
|
||||
strcpy(path, xlogpath);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* stat failed */
|
||||
if (errno != ENOENT)
|
||||
ereport(FATAL,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not stat file \"%s\": %m",
|
||||
xlogpath)));
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Remember, we rollforward UNTIL the restore fails so failure here is
|
||||
* just part of the process... that makes it difficult to determine
|
||||
* whether the restore failed because there isn't an archive to restore,
|
||||
* or because the administrator has specified the restore program
|
||||
* incorrectly. We have to assume the former.
|
||||
*
|
||||
* However, if the failure was due to any sort of signal, it's best to
|
||||
* punt and abort recovery. (If we "return false" here, upper levels will
|
||||
* assume that recovery is complete and start up the database!) It's
|
||||
* essential to abort on child SIGINT and SIGQUIT, because per spec
|
||||
* system() ignores SIGINT and SIGQUIT while waiting; if we see one of
|
||||
* those it's a good bet we should have gotten it too.
|
||||
*
|
||||
* On SIGTERM, assume we have received a fast shutdown request, and exit
|
||||
* cleanly. It's pure chance whether we receive the SIGTERM first, or the
|
||||
* child process. If we receive it first, the signal handler will call
|
||||
* proc_exit, otherwise we do it here. If we or the child process received
|
||||
* SIGTERM for any other reason than a fast shutdown request, postmaster
|
||||
* will perform an immediate shutdown when it sees us exiting
|
||||
* unexpectedly.
|
||||
*
|
||||
* Per the Single Unix Spec, shells report exit status > 128 when a called
|
||||
* command died on a signal. Also, 126 and 127 are used to report
|
||||
* problems such as an unfindable command; treat those as fatal errors
|
||||
* too.
|
||||
*/
|
||||
if (WIFSIGNALED(rc) && WTERMSIG(rc) == SIGTERM)
|
||||
proc_exit(1);
|
||||
|
||||
signaled = WIFSIGNALED(rc) || WEXITSTATUS(rc) > 125;
|
||||
|
||||
ereport(signaled ? FATAL : DEBUG2,
|
||||
(errmsg("could not restore file \"%s\" from archive: return code %d",
|
||||
xlogfname, rc)));
|
||||
|
||||
not_available:
|
||||
|
||||
/*
|
||||
* if an archived file is not available, there might still be a version of
|
||||
* this file in XLOGDIR, so return that as the filename to open.
|
||||
*
|
||||
* In many recovery scenarios we expect this to fail also, but if so that
|
||||
* just means we've reached the end of WAL.
|
||||
*/
|
||||
snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlogfname);
|
||||
return false;
|
||||
}
|
||||
|
||||
/*
|
||||
* Attempt to execute an external shell command during recovery.
|
||||
*
|
||||
* 'command' is the shell command to be executed, 'commandName' is a
|
||||
* human-readable name describing the command emitted in the logs. If
|
||||
* 'failOnSignal' is true and the command is killed by a signal, a FATAL
|
||||
* error is thrown. Otherwise a WARNING is emitted.
|
||||
*
|
||||
* This is currently used for recovery_end_command and archive_cleanup_command.
|
||||
*/
|
||||
void
|
||||
ExecuteRecoveryCommand(char *command, char *commandName, bool failOnSignal)
|
||||
{
|
||||
char xlogRecoveryCmd[MAXPGPATH];
|
||||
char lastRestartPointFname[MAXPGPATH];
|
||||
char *dp;
|
||||
char *endp;
|
||||
const char *sp;
|
||||
int rc;
|
||||
bool signaled;
|
||||
XLogSegNo restartSegNo;
|
||||
XLogRecPtr restartRedoPtr;
|
||||
TimeLineID restartTli;
|
||||
|
||||
Assert(command && commandName);
|
||||
|
||||
/*
|
||||
* Calculate the archive file cutoff point for use during log shipping
|
||||
* replication. All files earlier than this point can be deleted from the
|
||||
* archive, though there is no requirement to do so.
|
||||
*/
|
||||
GetOldestRestartPoint(&restartRedoPtr, &restartTli);
|
||||
XLByteToSeg(restartRedoPtr, restartSegNo);
|
||||
XLogFileName(lastRestartPointFname, restartTli, restartSegNo);
|
||||
LWLockRelease(ControlFileLock);
|
||||
|
||||
/*
|
||||
* construct the command to be executed
|
||||
*/
|
||||
dp = xlogRecoveryCmd;
|
||||
endp = xlogRecoveryCmd + MAXPGPATH - 1;
|
||||
*endp = '\0';
|
||||
|
||||
for (sp = command; *sp; sp++)
|
||||
{
|
||||
if (*sp == '%')
|
||||
{
|
||||
switch (sp[1])
|
||||
{
|
||||
case 'r':
|
||||
/* %r: filename of last restartpoint */
|
||||
sp++;
|
||||
StrNCpy(dp, lastRestartPointFname, endp - dp);
|
||||
dp += strlen(dp);
|
||||
break;
|
||||
case '%':
|
||||
/* convert %% to a single % */
|
||||
sp++;
|
||||
if (dp < endp)
|
||||
*dp++ = *sp;
|
||||
break;
|
||||
default:
|
||||
/* otherwise treat the % as not special */
|
||||
if (dp < endp)
|
||||
*dp++ = *sp;
|
||||
break;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
if (dp < endp)
|
||||
*dp++ = *sp;
|
||||
}
|
||||
}
|
||||
*dp = '\0';
|
||||
|
||||
ereport(DEBUG3,
|
||||
(errmsg_internal("executing %s \"%s\"", commandName, command)));
|
||||
|
||||
/*
|
||||
* execute the constructed command
|
||||
*/
|
||||
rc = system(xlogRecoveryCmd);
|
||||
if (rc != 0)
|
||||
{
|
||||
/*
|
||||
* If the failure was due to any sort of signal, it's best to punt and
|
||||
* abort recovery. See also detailed comments on signals in
|
||||
* RestoreArchivedFile().
|
||||
*/
|
||||
signaled = WIFSIGNALED(rc) || WEXITSTATUS(rc) > 125;
|
||||
|
||||
ereport((signaled && failOnSignal) ? FATAL : WARNING,
|
||||
/*------
|
||||
translator: First %s represents a recovery.conf parameter name like
|
||||
"recovery_end_command", and the 2nd is the value of that parameter. */
|
||||
(errmsg("%s \"%s\": return code %d", commandName,
|
||||
command, rc)));
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* XLogArchiveNotify
|
||||
*
|
||||
* Create an archive notification file
|
||||
*
|
||||
* The name of the notification file is the message that will be picked up
|
||||
* by the archiver, e.g. we write 0000000100000001000000C6.ready
|
||||
* and the archiver then knows to archive XLOGDIR/0000000100000001000000C6,
|
||||
* then when complete, rename it to 0000000100000001000000C6.done
|
||||
*/
|
||||
void
|
||||
XLogArchiveNotify(const char *xlog)
|
||||
{
|
||||
char archiveStatusPath[MAXPGPATH];
|
||||
FILE *fd;
|
||||
|
||||
/* insert an otherwise empty file called <XLOG>.ready */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
||||
fd = AllocateFile(archiveStatusPath, "w");
|
||||
if (fd == NULL)
|
||||
{
|
||||
ereport(LOG,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not create archive status file \"%s\": %m",
|
||||
archiveStatusPath)));
|
||||
return;
|
||||
}
|
||||
if (FreeFile(fd))
|
||||
{
|
||||
ereport(LOG,
|
||||
(errcode_for_file_access(),
|
||||
errmsg("could not write archive status file \"%s\": %m",
|
||||
archiveStatusPath)));
|
||||
return;
|
||||
}
|
||||
|
||||
/* Notify archiver that it's got something to do */
|
||||
if (IsUnderPostmaster)
|
||||
SendPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER);
|
||||
}
|
||||
|
||||
/*
|
||||
* Convenience routine to notify using segment number representation of filename
|
||||
*/
|
||||
void
|
||||
XLogArchiveNotifySeg(XLogSegNo segno)
|
||||
{
|
||||
char xlog[MAXFNAMELEN];
|
||||
|
||||
XLogFileName(xlog, ThisTimeLineID, segno);
|
||||
XLogArchiveNotify(xlog);
|
||||
}
|
||||
|
||||
/*
|
||||
* XLogArchiveCheckDone
|
||||
*
|
||||
* This is called when we are ready to delete or recycle an old XLOG segment
|
||||
* file or backup history file. If it is okay to delete it then return true.
|
||||
* If it is not time to delete it, make sure a .ready file exists, and return
|
||||
* false.
|
||||
*
|
||||
* If <XLOG>.done exists, then return true; else if <XLOG>.ready exists,
|
||||
* then return false; else create <XLOG>.ready and return false.
|
||||
*
|
||||
* The reason we do things this way is so that if the original attempt to
|
||||
* create <XLOG>.ready fails, we'll retry during subsequent checkpoints.
|
||||
*/
|
||||
bool
|
||||
XLogArchiveCheckDone(const char *xlog)
|
||||
{
|
||||
char archiveStatusPath[MAXPGPATH];
|
||||
struct stat stat_buf;
|
||||
|
||||
/* Always deletable if archiving is off */
|
||||
if (!XLogArchivingActive())
|
||||
return true;
|
||||
|
||||
/* First check for .done --- this means archiver is done with it */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".done");
|
||||
if (stat(archiveStatusPath, &stat_buf) == 0)
|
||||
return true;
|
||||
|
||||
/* check for .ready --- this means archiver is still busy with it */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
||||
if (stat(archiveStatusPath, &stat_buf) == 0)
|
||||
return false;
|
||||
|
||||
/* Race condition --- maybe archiver just finished, so recheck */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".done");
|
||||
if (stat(archiveStatusPath, &stat_buf) == 0)
|
||||
return true;
|
||||
|
||||
/* Retry creation of the .ready file */
|
||||
XLogArchiveNotify(xlog);
|
||||
return false;
|
||||
}
|
||||
|
||||
/*
|
||||
* XLogArchiveIsBusy
|
||||
*
|
||||
* Check to see if an XLOG segment file is still unarchived.
|
||||
* This is almost but not quite the inverse of XLogArchiveCheckDone: in
|
||||
* the first place we aren't chartered to recreate the .ready file, and
|
||||
* in the second place we should consider that if the file is already gone
|
||||
* then it's not busy. (This check is needed to handle the race condition
|
||||
* that a checkpoint already deleted the no-longer-needed file.)
|
||||
*/
|
||||
bool
|
||||
XLogArchiveIsBusy(const char *xlog)
|
||||
{
|
||||
char archiveStatusPath[MAXPGPATH];
|
||||
struct stat stat_buf;
|
||||
|
||||
/* First check for .done --- this means archiver is done with it */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".done");
|
||||
if (stat(archiveStatusPath, &stat_buf) == 0)
|
||||
return false;
|
||||
|
||||
/* check for .ready --- this means archiver is still busy with it */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
||||
if (stat(archiveStatusPath, &stat_buf) == 0)
|
||||
return true;
|
||||
|
||||
/* Race condition --- maybe archiver just finished, so recheck */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".done");
|
||||
if (stat(archiveStatusPath, &stat_buf) == 0)
|
||||
return false;
|
||||
|
||||
/*
|
||||
* Check to see if the WAL file has been removed by checkpoint, which
|
||||
* implies it has already been archived, and explains why we can't see a
|
||||
* status file for it.
|
||||
*/
|
||||
snprintf(archiveStatusPath, MAXPGPATH, XLOGDIR "/%s", xlog);
|
||||
if (stat(archiveStatusPath, &stat_buf) != 0 &&
|
||||
errno == ENOENT)
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* XLogArchiveCleanup
|
||||
*
|
||||
* Cleanup archive notification file(s) for a particular xlog segment
|
||||
*/
|
||||
void
|
||||
XLogArchiveCleanup(const char *xlog)
|
||||
{
|
||||
char archiveStatusPath[MAXPGPATH];
|
||||
|
||||
/* Remove the .done file */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".done");
|
||||
unlink(archiveStatusPath);
|
||||
/* should we complain about failure? */
|
||||
|
||||
/* Remove the .ready file if present --- normally it shouldn't be */
|
||||
StatusFilePath(archiveStatusPath, xlog, ".ready");
|
||||
unlink(archiveStatusPath);
|
||||
/* should we complain about failure? */
|
||||
}
|
||||
23
src/include/access/timeline.h
Normal file
23
src/include/access/timeline.h
Normal file
@ -0,0 +1,23 @@
|
||||
/*
|
||||
* timeline.h
|
||||
*
|
||||
* Functions for reading and writing timeline history files.
|
||||
*
|
||||
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* src/include/access/timeline.h
|
||||
*/
|
||||
#ifndef TIMELINE_H
|
||||
#define TIMELINE_H
|
||||
|
||||
#include "access/xlogdefs.h"
|
||||
#include "nodes/pg_list.h"
|
||||
|
||||
extern List *readTimeLineHistory(TimeLineID targetTLI);
|
||||
extern bool existsTimeLineHistory(TimeLineID probeTLI);
|
||||
extern TimeLineID findNewestTimeLine(TimeLineID startTLI);
|
||||
extern void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
|
||||
TimeLineID endTLI, XLogSegNo endLogSegNo, char *reason);
|
||||
|
||||
#endif /* TIMELINE_H */
|
||||
@ -229,6 +229,29 @@ extern const RmgrData RmgrTable[];
|
||||
extern pg_time_t GetLastSegSwitchTime(void);
|
||||
extern XLogRecPtr RequestXLogSwitch(void);
|
||||
|
||||
extern void GetOldestRestartPoint(XLogRecPtr *oldrecptr, TimeLineID *oldtli);
|
||||
|
||||
/*
|
||||
* Exported for the functions in timeline.c and xlogarchive.c. Only valid
|
||||
* in the startup process.
|
||||
*/
|
||||
extern bool InArchiveRecovery;
|
||||
extern bool StandbyMode;
|
||||
extern char *recoveryRestoreCommand;
|
||||
|
||||
/*
|
||||
* Prototypes for functions in xlogarchive.c
|
||||
*/
|
||||
extern bool RestoreArchivedFile(char *path, const char *xlogfname,
|
||||
const char *recovername, off_t expectedSize);
|
||||
extern void ExecuteRecoveryCommand(char *command, char *commandName,
|
||||
bool failOnerror);
|
||||
extern void XLogArchiveNotify(const char *xlog);
|
||||
extern void XLogArchiveNotifySeg(XLogSegNo segno);
|
||||
extern bool XLogArchiveCheckDone(const char *xlog);
|
||||
extern bool XLogArchiveIsBusy(const char *xlog);
|
||||
extern void XLogArchiveCleanup(const char *xlog);
|
||||
|
||||
/*
|
||||
* These aren't in xlog.h because I'd rather not include fmgr.h there.
|
||||
*/
|
||||
|
||||
Loading…
Reference in New Issue
Block a user