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Fix some serious bugs in archive recovery, now that bgwriter is active

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during it:

When bgwriter is active, the startup process can't perform mdsync() correctly
because it won't see the fsync requests accumulated in bgwriter's private
pendingOpsTable. Therefore make bgwriter responsible for the end-of-recovery
checkpoint as well, when it's active.

When bgwriter is active (= archive recovery), the startup process must not
accumulate fsync requests to its own pendingOpsTable, since bgwriter won't
see them there when it performs restartpoints. Make startup process drop its
pendingOpsTable when bgwriter is launched to avoid that.

Update minimum recovery point one last time when leaving archive recovery.
It won't be updated by the end-of-recovery checkpoint because XLogFlush()
sees us as out of recovery already.

This fixes bug #4879 reported by Fujii Masao.
This commit is contained in:
Heikki Linnakangas
2009-06-25 21:36:00 +00:00
parent e6b8f47047
commit 7e48b77b1c
5 changed files with 104 additions and 42 deletions
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109
src/backend/access/transam/xlog.c
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.343 2009/06/11 14:48:54 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.344 2009/06/25 21:36:00 heikki Exp $
*
*-------------------------------------------------------------------------
*/
@ -4912,12 +4912,18 @@ exitArchiveRecovery(TimeLineID endTLI, uint32 endLogId, uint32 endLogSeg)
{
char recoveryPath[MAXPGPATH];
char xlogpath[MAXPGPATH];
XLogRecPtr InvalidXLogRecPtr = {0, 0};
/*
* We are no longer in archive recovery state.
*/
InArchiveRecovery = false;
/*
* Update min recovery point one last time.
*/
UpdateMinRecoveryPoint(InvalidXLogRecPtr, true);
/*
* We should have the ending log segment currently open. Verify, and then
* close it (to avoid problems on Windows with trying to rename or delete
@ -5156,6 +5162,7 @@ StartupXLOG(void)
XLogRecord *record;
uint32 freespace;
TransactionId oldestActiveXID;
bool bgwriterLaunched = false;
XLogCtl->SharedRecoveryInProgress = true;
@ -5472,7 +5479,11 @@ StartupXLOG(void)
* process in addition to postmaster!
*/
if (InArchiveRecovery && IsUnderPostmaster)
{
SetForwardFsyncRequests();
SendPostmasterSignal(PMSIGNAL_RECOVERY_STARTED);
bgwriterLaunched = true;
}
/*
* main redo apply loop
@ -5709,12 +5720,6 @@ StartupXLOG(void)
/* Pre-scan prepared transactions to find out the range of XIDs present */
oldestActiveXID = PrescanPreparedTransactions();
/*
* Allow writing WAL for us, so that we can create a checkpoint record.
* But not yet for other backends!
*/
LocalRecoveryInProgress = false;
if (InRecovery)
{
int rmid;
@ -5743,7 +5748,12 @@ StartupXLOG(void)
* the rule that TLI only changes in shutdown checkpoints, which
* allows some extra error checking in xlog_redo.
*/
CreateCheckPoint(CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_IMMEDIATE);
if (bgwriterLaunched)
RequestCheckpoint(CHECKPOINT_END_OF_RECOVERY |
CHECKPOINT_IMMEDIATE |
CHECKPOINT_WAIT);
else
CreateCheckPoint(CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IMMEDIATE);
/*
* And finally, execute the recovery_end_command, if any.
@ -5806,7 +5816,7 @@ StartupXLOG(void)
}
/*
* All done. Allow others to write WAL.
* All done. Allow backends to write WAL.
*/
XLogCtl->SharedRecoveryInProgress = false;
}
@ -6123,12 +6133,13 @@ LogCheckpointStart(int flags, bool restartpoint)
* the main message, but what about all the flags?
*/
if (restartpoint)
msg = "restartpoint starting:%s%s%s%s%s%s";
msg = "restartpoint starting:%s%s%s%s%s%s%s";
else
msg = "checkpoint starting:%s%s%s%s%s%s";
msg = "checkpoint starting:%s%s%s%s%s%s%s";
elog(LOG, msg,
(flags & CHECKPOINT_IS_SHUTDOWN) ? " shutdown" : "",
(flags & CHECKPOINT_END_OF_RECOVERY) ? " end-of-recovery" : "",
(flags & CHECKPOINT_IMMEDIATE) ? " immediate" : "",
(flags & CHECKPOINT_FORCE) ? " force" : "",
(flags & CHECKPOINT_WAIT) ? " wait" : "",
@ -6190,10 +6201,12 @@ LogCheckpointEnd(bool restartpoint)
*
* flags is a bitwise OR of the following:
* CHECKPOINT_IS_SHUTDOWN: checkpoint is for database shutdown.
* CHECKPOINT_END_OF_RECOVERY: checkpoint is for end of WAL recovery.
* CHECKPOINT_IMMEDIATE: finish the checkpoint ASAP,
* ignoring checkpoint_completion_target parameter.
* CHECKPOINT_FORCE: force a checkpoint even if no XLOG activity has occured
* since the last one (implied by CHECKPOINT_IS_SHUTDOWN).
* since the last one (implied by CHECKPOINT_IS_SHUTDOWN and
* CHECKPOINT_END_OF_RECOVERY).
*
* Note: flags contains other bits, of interest here only for logging purposes.
* In particular note that this routine is synchronous and does not pay
@ -6202,7 +6215,7 @@ LogCheckpointEnd(bool restartpoint)
void
CreateCheckPoint(int flags)
{
bool shutdown = (flags & CHECKPOINT_IS_SHUTDOWN) != 0;
bool shutdown;
CheckPoint checkPoint;
XLogRecPtr recptr;
XLogCtlInsert *Insert = &XLogCtl->Insert;
@ -6212,34 +6225,52 @@ CreateCheckPoint(int flags)
uint32 _logSeg;
TransactionId *inCommitXids;
int nInCommit;
bool OldInRecovery = InRecovery;
/* shouldn't happen */
if (RecoveryInProgress())
elog(ERROR, "can't create a checkpoint during recovery");
/*
* An end-of-recovery checkpoint is really a shutdown checkpoint, just
* issued at a different time.
*/
if (flags & ((CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY) != 0))
shutdown = true;
else
shutdown = false;
/*
* A startup checkpoint is created before anyone else is allowed to
* write WAL. To allow us to write the checkpoint record, set
* LocalRecoveryInProgress to false. This lets us write WAL, but others
* are still not allowed to do so.
*/
if (flags & CHECKPOINT_END_OF_RECOVERY)
{
Assert(RecoveryInProgress());
LocalRecoveryInProgress = false;
InitXLOGAccess();
/*
* Before 8.4, end-of-recovery checkpoints were always performed by
* the startup process, and InRecovery was set true. InRecovery is not
* normally set in bgwriter, but we set it here temporarily to avoid
* confusing old code in the end-of-recovery checkpoint code path that
* rely on it.
*/
InRecovery = true;
}
else
{
/* shouldn't happen */
if (RecoveryInProgress())
elog(ERROR, "can't create a checkpoint during recovery");
}
/*
* Acquire CheckpointLock to ensure only one checkpoint happens at a time.
* During normal operation, bgwriter is the only process that creates
* checkpoints, but at the end of archive recovery, the bgwriter can be
* busy creating a restartpoint while the startup process tries to perform
* the startup checkpoint.
* (This is just pro forma, since in the present system structure there is
* only one process that is allowed to issue checkpoints at any given
* time.)
*/
if (!LWLockConditionalAcquire(CheckpointLock, LW_EXCLUSIVE))
{
Assert(InRecovery);
/*
* A restartpoint is in progress. Wait until it finishes. This can
* cause an extra restartpoint to be performed, but that's OK because
* we're just about to perform a checkpoint anyway. Flushing the
* buffers in this restartpoint can take some time, but that time is
* saved from the upcoming checkpoint so the net effect is zero.
*/
ereport(DEBUG2, (errmsg("hurrying in-progress restartpoint")));
RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_WAIT);
LWLockAcquire(CheckpointLock, LW_EXCLUSIVE);
}
LWLockAcquire(CheckpointLock, LW_EXCLUSIVE);
/*
* Prepare to accumulate statistics.
@ -6298,7 +6329,8 @@ CreateCheckPoint(int flags)
* the end of the last checkpoint record, and its redo pointer must point
* to itself.
*/
if ((flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_FORCE)) == 0)
if ((flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY |
CHECKPOINT_FORCE)) == 0)
{
XLogRecPtr curInsert;
@ -6542,6 +6574,9 @@ CreateCheckPoint(int flags)
CheckpointStats.ckpt_segs_recycled);
LWLockRelease(CheckpointLock);
/* Restore old value */
InRecovery = OldInRecovery;
}
/*