On Fri, Dec 20, 2013 at 9:21 PM, MauMau <maumau...@gmail.com> wrote:
> From: "Fujii Masao" <masao.fu...@gmail.com>
>
>> ! if (source == XLOG_FROM_ARCHIVE && StandbyModeRequested)
>>
>> Even when standby_mode is not enabled, we can use cascade replication and
>> it needs the accumulated WAL files. So I think that
>> AllowCascadeReplication()
>> should be added into this condition.
>>
>> ! snprintf(recoveryPath, MAXPGPATH, XLOGDIR "/RECOVERYXLOG");
>> ! XLogFilePath(xlogpath, ThisTimeLineID, endLogSegNo);
>> !
>> ! if (restoredFromArchive)
>>
>> Don't we need to check !StandbyModeRequested and
>> !AllowCascadeReplication()
>> here?
>
>
> Oh, you are correct. Okay, done.
Thanks! The patch looks good to me. Attached is the updated version of
the patch. I added the comments.
Did you test whether this patch works properly in several recovery cases?
Regards,
--
Fujii Masao
*** a/src/backend/access/transam/xlog.c
--- b/src/backend/access/transam/xlog.c
***************
*** 3772,3781 **** XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli,
}
/*
! * If the segment was fetched from archival storage, replace the existing
! * xlog segment (if any) with the archival version.
*/
! if (source == XLOG_FROM_ARCHIVE)
{
KeepFileRestoredFromArchive(path, xlogfname);
--- 3772,3792 ----
}
/*
! * If the segment was fetched from archival storage and either cascading
! * replication or standby_mode is enabled, replace the existing xlog
! * segment (if any) with the archival version. Cascading replication needs
! * this replacement so that cascading walsender can send the xlog segment
! * which was restored from the archive. When standby_mode is enabled,
! * fast promotion is performed at the end of recovery, and also needs this
! * replacement so that the crash recovery just after fast promotion can
! * replay all the required segments from pg_xlog.
! *
! * If the replacement is not required, the segments are always restored onto
! * the same file named RECOVERYXLOG from the archive. This prevents the
! * large increase of segments in pg_xlog.
*/
! if (source == XLOG_FROM_ARCHIVE &&
! (AllowCascadeReplication() || StandbyModeRequested))
{
KeepFileRestoredFromArchive(path, xlogfname);
***************
*** 5572,5593 **** exitArchiveRecovery(TimeLineID endTLI, XLogSegNo endLogSegNo)
}
/*
! * If we are establishing a new timeline, we have to copy data from the
! * last WAL segment of the old timeline to create a starting WAL segment
! * for the new timeline.
*
! * Notify the archiver that the last WAL segment of the old timeline is
! * ready to copy to archival storage. Otherwise, it is not archived for a
! * while.
*/
! if (endTLI != ThisTimeLineID)
{
! XLogFileCopy(endLogSegNo, endTLI, endLogSegNo);
! if (XLogArchivingActive())
{
! XLogFileName(xlogpath, endTLI, endLogSegNo);
! XLogArchiveNotify(xlogpath);
}
}
--- 5583,5646 ----
}
/*
! * If the segment was fetched from archival storage and neither cascading
! * replication nor fast promotion is enabled, we replace the existing xlog
! * segment (if any) with the archival version named RECOVERYXLOG. This is
! * because whatever is in XLOGDIR is very possibly older than what we have
! * from the archives, since it could have come from restoring a PGDATA
! * backup. In any case, the archival version certainly is more
! * descriptive of what our current database state is, because that is what
! * we replayed from.
! *
! * Note that if we are establishing a new timeline, ThisTimeLineID is
! * already set to the new value, and so we will create a new file instead
! * of overwriting any existing file. (This is, in fact, always the case
! * at present.)
*
! * If either cascading replication or fast promotion is enabled, we don't
! * need the replacement here because it has already done just after the
! * segment was restored from the archive.
*/
! snprintf(recoveryPath, MAXPGPATH, XLOGDIR "/RECOVERYXLOG");
! XLogFilePath(xlogpath, ThisTimeLineID, endLogSegNo);
!
! if (restoredFromArchive &&
! !AllowCascadeReplication() && !StandbyModeRequested)
{
! unlink(xlogpath); /* might or might not exist */
! if (rename(recoveryPath, xlogpath) != 0)
! ereport(FATAL,
! (errcode_for_file_access(),
! errmsg("could not rename file \"%s\" to \"%s\": %m",
! recoveryPath, xlogpath)));
! /* XXX might we need to fix permissions on the file? */
! }
! else
! {
! /*
! * Since there might be a partial WAL segment named RECOVERYXLOG,
! * get rid of it.
! */
! unlink(recoveryPath); /* ignore any error */
! /*
! * If we are establishing a new timeline, we have to copy data from
! * the last WAL segment of the old timeline to create a starting WAL
! * segment for the new timeline.
! *
! * Notify the archiver that the last WAL segment of the old timeline
! * is ready to copy to archival storage. Otherwise, it is not archived
! * for a while.
! */
! if (endTLI != ThisTimeLineID)
{
! XLogFileCopy(endLogSegNo, endTLI, endLogSegNo);
!
! if (XLogArchivingActive())
! {
! XLogFileName(xlogpath, endTLI, endLogSegNo);
! XLogArchiveNotify(xlogpath);
! }
}
}
***************
*** 5598,5610 **** exitArchiveRecovery(TimeLineID endTLI, XLogSegNo endLogSegNo)
XLogFileName(xlogpath, ThisTimeLineID, endLogSegNo);
XLogArchiveCleanup(xlogpath);
- /*
- * Since there might be a partial WAL segment named RECOVERYXLOG, get rid
- * of it.
- */
- snprintf(recoveryPath, MAXPGPATH, XLOGDIR "/RECOVERYXLOG");
- unlink(recoveryPath); /* ignore any error */
-
/* Get rid of any remaining recovered timeline-history file, too */
snprintf(recoveryPath, MAXPGPATH, XLOGDIR "/RECOVERYHISTORY");
unlink(recoveryPath); /* ignore any error */
--- 5651,5656 ----
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