Thread
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[PATCH v7 5/5] Move code to apply one WAL record to a subroutine.
Heikki Linnakangas <heikki.linnakangas@iki.fi> — 2021-09-16T08:07:45Z
--- src/backend/access/transam/xlogrecovery.c | 284 +++++++++++----------- 1 file changed, 147 insertions(+), 137 deletions(-) diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c index 5b9d928a8ab..fe6b215b9c5 100644 --- a/src/backend/access/transam/xlogrecovery.c +++ b/src/backend/access/transam/xlogrecovery.c @@ -367,6 +367,7 @@ static char recoveryStopName[MAXFNAMELEN]; static bool recoveryStopAfter; /* prototypes for local functions */ +static void ApplyWalRecord(XLogReaderState *xlogreader, XLogRecord *record, TimeLineID *replayTLI); static void xlog_block_info(StringInfo buf, XLogReaderState *record); static void readRecoverySignalFile(void); @@ -1396,11 +1397,8 @@ PerformWalRecovery(void) if (record != NULL) { - ErrorContextCallback errcallback; TimestampTz xtime; PGRUsage ru0; - XLogRecPtr ReadRecPtr; - XLogRecPtr EndRecPtr; pg_rusage_init(&ru0); @@ -1426,14 +1424,9 @@ PerformWalRecovery(void) */ do { - bool switchedTLI = false; - - ReadRecPtr = xlogreader->ReadRecPtr; - EndRecPtr = xlogreader->EndRecPtr; - if (!StandbyMode) ereport_startup_progress("redo in progress, elapsed time: %ld.%02d s, current LSN: %X/%X", - LSN_FORMAT_ARGS(ReadRecPtr)); + LSN_FORMAT_ARGS(xlogreader->ReadRecPtr)); #ifdef WAL_DEBUG if (XLOG_DEBUG || @@ -1444,8 +1437,8 @@ PerformWalRecovery(void) initStringInfo(&buf); appendStringInfo(&buf, "REDO @ %X/%X; LSN %X/%X: ", - LSN_FORMAT_ARGS(ReadRecPtr), - LSN_FORMAT_ARGS(EndRecPtr)); + LSN_FORMAT_ARGS(xlogreader->ReadRecPtr), + LSN_FORMAT_ARGS(xlogreader->EndRecPtr)); xlog_outrec(&buf, xlogreader); appendStringInfoString(&buf, " - "); xlog_outdesc(&buf, xlogreader); @@ -1500,133 +1493,10 @@ PerformWalRecovery(void) recoveryPausesHere(false); } - /* Setup error traceback support for ereport() */ - errcallback.callback = rm_redo_error_callback; - errcallback.arg = (void *) xlogreader; - errcallback.previous = error_context_stack; - error_context_stack = &errcallback; - - /* - * ShmemVariableCache->nextXid must be beyond record's xid. - */ - AdvanceNextFullTransactionIdPastXid(record->xl_xid); - - /* - * Before replaying this record, check if this record causes the - * current timeline to change. The record is already considered to - * be part of the new timeline, so we update ThisTimeLineID before - * replaying it. That's important so that replayEndTLI, which is - * recorded as the minimum recovery point's TLI if recovery stops - * after this record, is set correctly. - */ - if (record->xl_rmid == RM_XLOG_ID) - { - TimeLineID newReplayTLI = replayTLI; - TimeLineID prevReplayTLI = replayTLI; - uint8 info = record->xl_info & ~XLR_INFO_MASK; - - if (info == XLOG_CHECKPOINT_SHUTDOWN) - { - CheckPoint checkPoint; - - memcpy(&checkPoint, XLogRecGetData(xlogreader), sizeof(CheckPoint)); - newReplayTLI = checkPoint.ThisTimeLineID; - prevReplayTLI = checkPoint.PrevTimeLineID; - } - else if (info == XLOG_END_OF_RECOVERY) - { - xl_end_of_recovery xlrec; - - memcpy(&xlrec, XLogRecGetData(xlogreader), sizeof(xl_end_of_recovery)); - newReplayTLI = xlrec.ThisTimeLineID; - prevReplayTLI = xlrec.PrevTimeLineID; - } - - if (newReplayTLI != replayTLI) - { - /* Check that it's OK to switch to this TLI */ - checkTimeLineSwitch(EndRecPtr, newReplayTLI, - prevReplayTLI, replayTLI); - - /* Following WAL records should be run with new TLI */ - replayTLI = newReplayTLI; - switchedTLI = true; - } - } - - /* - * Update shared replayEndRecPtr before replaying this record, so - * that XLogFlush will update minRecoveryPoint correctly. - */ - SpinLockAcquire(&XLogRecoveryCtl->info_lck); - XLogRecoveryCtl->replayEndRecPtr = EndRecPtr; - XLogRecoveryCtl->replayEndTLI = replayTLI; - SpinLockRelease(&XLogRecoveryCtl->info_lck); - - /* - * If we are attempting to enter Hot Standby mode, process XIDs we - * see - */ - if (standbyState >= STANDBY_INITIALIZED && - TransactionIdIsValid(record->xl_xid)) - RecordKnownAssignedTransactionIds(record->xl_xid); - - /* Now apply the WAL record itself */ - RmgrTable[record->xl_rmid].rm_redo(xlogreader); - - /* - * After redo, check whether the backup pages associated with the - * WAL record are consistent with the existing pages. This check - * is done only if consistency check is enabled for this record. - */ - if ((record->xl_info & XLR_CHECK_CONSISTENCY) != 0) - checkXLogConsistency(xlogreader); - - /* Pop the error context stack */ - error_context_stack = errcallback.previous; - - /* - * Update lastReplayedEndRecPtr after this record has been - * successfully replayed. - */ - SpinLockAcquire(&XLogRecoveryCtl->info_lck); - XLogRecoveryCtl->lastReplayedEndRecPtr = EndRecPtr; - XLogRecoveryCtl->lastReplayedTLI = replayTLI; - SpinLockRelease(&XLogRecoveryCtl->info_lck); - - /* Also remember its starting position. */ - LastReplayedReadRecPtr = ReadRecPtr; - /* - * If rm_redo called XLogRequestWalReceiverReply, then we wake up - * the receiver so that it notices the updated - * lastReplayedEndRecPtr and sends a reply to the primary. + * Apply the record */ - if (doRequestWalReceiverReply) - { - doRequestWalReceiverReply = false; - WalRcvForceReply(); - } - - /* Allow read-only connections if we're consistent now */ - CheckRecoveryConsistency(); - - /* Is this a timeline switch? */ - if (switchedTLI) - { - /* - * Before we continue on the new timeline, clean up any - * (possibly bogus) future WAL segments on the old timeline. - */ - RemoveNonParentXlogFiles(EndRecPtr, replayTLI); - - /* - * Wake up any walsenders to notice that we are on a new - * timeline. - */ - if (AllowCascadeReplication()) - WalSndWakeup(); - } + ApplyWalRecord(xlogreader, record, &replayTLI); /* Exit loop if we reached inclusive recovery target */ if (recoveryStopsAfter(xlogreader)) @@ -1685,7 +1555,7 @@ PerformWalRecovery(void) ereport(LOG, (errmsg("redo done at %X/%X system usage: %s", - LSN_FORMAT_ARGS(ReadRecPtr), + LSN_FORMAT_ARGS(xlogreader->ReadRecPtr), pg_rusage_show(&ru0)))); xtime = GetLatestXTime(); if (xtime) @@ -1714,6 +1584,146 @@ PerformWalRecovery(void) (errmsg("recovery ended before configured recovery target was reached"))); } +/* + * Subroutine of PerformWalRecovery, to apply one WAL record. + */ +static void +ApplyWalRecord(XLogReaderState *xlogreader, XLogRecord *record, TimeLineID *replayTLI) +{ + XLogRecPtr ReadRecPtr; + XLogRecPtr EndRecPtr; + ErrorContextCallback errcallback; + bool switchedTLI = false; + + ReadRecPtr = xlogreader->ReadRecPtr; + EndRecPtr = xlogreader->EndRecPtr; + + /* Setup error traceback support for ereport() */ + errcallback.callback = rm_redo_error_callback; + errcallback.arg = (void *) xlogreader; + errcallback.previous = error_context_stack; + error_context_stack = &errcallback; + + /* + * ShmemVariableCache->nextXid must be beyond record's xid. + */ + AdvanceNextFullTransactionIdPastXid(record->xl_xid); + + /* + * Before replaying this record, check if this record causes the current + * timeline to change. The record is already considered to be part of the + * new timeline, so we update replayTLI before replaying it. That's + * important so that replayEndTLI, which is recorded as the minimum + * recovery point's TLI if recovery stops after this record, is set + * correctly. + */ + if (record->xl_rmid == RM_XLOG_ID) + { + TimeLineID newReplayTLI = *replayTLI; + TimeLineID prevReplayTLI = *replayTLI; + uint8 info = record->xl_info & ~XLR_INFO_MASK; + + if (info == XLOG_CHECKPOINT_SHUTDOWN) + { + CheckPoint checkPoint; + + memcpy(&checkPoint, XLogRecGetData(xlogreader), sizeof(CheckPoint)); + newReplayTLI = checkPoint.ThisTimeLineID; + prevReplayTLI = checkPoint.PrevTimeLineID; + } + else if (info == XLOG_END_OF_RECOVERY) + { + xl_end_of_recovery xlrec; + + memcpy(&xlrec, XLogRecGetData(xlogreader), sizeof(xl_end_of_recovery)); + newReplayTLI = xlrec.ThisTimeLineID; + prevReplayTLI = xlrec.PrevTimeLineID; + } + + if (newReplayTLI != *replayTLI) + { + /* Check that it's OK to switch to this TLI */ + checkTimeLineSwitch(EndRecPtr, newReplayTLI, prevReplayTLI, *replayTLI); + + /* Following WAL records should be run with new TLI */ + *replayTLI = newReplayTLI; + switchedTLI = true; + } + } + + /* + * Update shared replayEndRecPtr before replaying this record, so that + * XLogFlush will update minRecoveryPoint correctly. + */ + SpinLockAcquire(&XLogRecoveryCtl->info_lck); + XLogRecoveryCtl->replayEndRecPtr = EndRecPtr; + XLogRecoveryCtl->replayEndTLI = *replayTLI; + SpinLockRelease(&XLogRecoveryCtl->info_lck); + + /* + * If we are attempting to enter Hot Standby mode, process XIDs we see + */ + if (standbyState >= STANDBY_INITIALIZED && + TransactionIdIsValid(record->xl_xid)) + RecordKnownAssignedTransactionIds(record->xl_xid); + + /* Now apply the WAL record itself */ + RmgrTable[record->xl_rmid].rm_redo(xlogreader); + + /* + * After redo, check whether the backup pages associated with the WAL + * record are consistent with the existing pages. This check is done only + * if consistency check is enabled for this record. + */ + if ((record->xl_info & XLR_CHECK_CONSISTENCY) != 0) + checkXLogConsistency(xlogreader); + + /* Pop the error context stack */ + error_context_stack = errcallback.previous; + + /* + * Update lastReplayedEndRecPtr after this record has been successfully + * replayed. + */ + SpinLockAcquire(&XLogRecoveryCtl->info_lck); + XLogRecoveryCtl->lastReplayedEndRecPtr = EndRecPtr; + XLogRecoveryCtl->lastReplayedTLI = *replayTLI; + SpinLockRelease(&XLogRecoveryCtl->info_lck); + + /* Also remember its starting position. */ + LastReplayedReadRecPtr = ReadRecPtr; + + /* + * If rm_redo called XLogRequestWalReceiverReply, then we wake up the + * receiver so that it notices the updated lastReplayedEndRecPtr and sends + * a reply to the primary. + */ + if (doRequestWalReceiverReply) + { + doRequestWalReceiverReply = false; + WalRcvForceReply(); + } + + /* Allow read-only connections if we're consistent now */ + CheckRecoveryConsistency(); + + /* Is this a timeline switch? */ + if (switchedTLI) + { + /* + * Before we continue on the new timeline, clean up any (possibly + * bogus) future WAL segments on the old timeline. + */ + RemoveNonParentXlogFiles(EndRecPtr, *replayTLI); + + /* + * Wake up any walsenders to notice that we are on a new timeline. + */ + if (AllowCascadeReplication()) + WalSndWakeup(); + } +} + /* * Error context callback for errors occurring during rm_redo(). */ -- 2.30.2 --------------3904592D294EBE853403D5C1--