diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 135 |
1 files changed, 112 insertions, 23 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 4164a4097d9..d47d0d916bf 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -188,7 +188,18 @@ static bool LocalHotStandbyActive = false; */ static int LocalXLogInsertAllowed = -1; -/* Are we recovering using offline XLOG archives? */ +/* + * When ArchiveRecoveryRequested is set, archive recovery was requested, + * ie. recovery.conf file was present. When InArchiveRecovery is set, we are + * currently recovering using offline XLOG archives. These variables are only + * valid in the startup process. + * + * When ArchiveRecoveryRequested is true, but InArchiveRecovery is false, we're + * currently performing crash recovery using only XLOG files in pg_xlog, but + * will switch to using offline XLOG archives as soon as we reach the end of + * WAL in pg_xlog. +*/ +static bool ArchiveRecoveryRequested = false; static bool InArchiveRecovery = false; /* Was the last xlog file restored from archive, or local? */ @@ -206,10 +217,13 @@ static TimestampTz recoveryTargetTime; static char *recoveryTargetName; /* options taken from recovery.conf for XLOG streaming */ -static bool StandbyMode = false; +static bool StandbyModeRequested = false; static char *PrimaryConnInfo = NULL; static char *TriggerFile = NULL; +/* are we currently in standby mode? */ +bool StandbyMode = false; + /* if recoveryStopsHere returns true, it saves actual stop xid/time/name here */ static TransactionId recoveryStopXid; static TimestampTz recoveryStopTime; @@ -4236,6 +4250,43 @@ next_record_is_invalid: readFile = -1; } + /* + * If archive recovery was requested, but we were still doing crash + * recovery, switch to archive recovery and retry using the offline + * archive. We have now replayed all the valid WAL in pg_xlog, so + * we are presumably now consistent. + * + * We require that there's at least some valid WAL present in + * pg_xlog, however (!fetch_ckpt). We could recover using the WAL + * from the archive, even if pg_xlog is completely empty, but we'd + * have no idea how far we'd have to replay to reach consistency. + * So err on the safe side and give up. + */ + if (!InArchiveRecovery && ArchiveRecoveryRequested && !fetching_ckpt) + { + ereport(DEBUG1, + (errmsg_internal("reached end of WAL in pg_xlog, entering archive recovery"))); + InArchiveRecovery = true; + if (StandbyModeRequested) + StandbyMode = true; + + /* initialize minRecoveryPoint to this record */ + LWLockAcquire(ControlFileLock, LW_EXCLUSIVE); + ControlFile->state = DB_IN_ARCHIVE_RECOVERY; + if (XLByteLT(ControlFile->minRecoveryPoint, EndRecPtr)) + ControlFile->minRecoveryPoint = EndRecPtr; + + /* update local copy */ + minRecoveryPoint = ControlFile->minRecoveryPoint; + + UpdateControlFile(); + LWLockRelease(ControlFileLock); + + CheckRecoveryConsistency(); + + goto retry; + } + /* In standby-mode, keep trying */ if (StandbyMode) goto retry; @@ -5631,7 +5682,7 @@ readRecoveryCommandFile(void) } else if (strcmp(item->name, "standby_mode") == 0) { - if (!parse_bool(item->value, &StandbyMode)) + if (!parse_bool(item->value, &StandbyModeRequested)) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("parameter \"%s\" requires a Boolean value", @@ -5662,7 +5713,7 @@ readRecoveryCommandFile(void) /* * Check for compulsory parameters */ - if (StandbyMode) + if (StandbyModeRequested) { if (PrimaryConnInfo == NULL && recoveryRestoreCommand == NULL) ereport(WARNING, @@ -5679,7 +5730,7 @@ readRecoveryCommandFile(void) } /* Enable fetching from archive recovery area */ - InArchiveRecovery = true; + ArchiveRecoveryRequested = true; /* * If user specified recovery_target_timeline, validate it or compute the @@ -5689,6 +5740,11 @@ readRecoveryCommandFile(void) */ if (rtliGiven) { + /* + * Temporarily set InArchiveRecovery, so that existsTimeLineHistory + * or findNewestTimeLine below will check the archive. + */ + InArchiveRecovery = true; if (rtli) { /* Timeline 1 does not have a history file, all else should */ @@ -5705,6 +5761,7 @@ readRecoveryCommandFile(void) recoveryTargetTLI = findNewestTimeLine(recoveryTargetTLI); recoveryTargetIsLatest = true; } + InArchiveRecovery = false; } FreeConfigVariables(head); @@ -6283,9 +6340,9 @@ StartupXLOG(void) archiveCleanupCommand ? archiveCleanupCommand : "", sizeof(XLogCtl->archiveCleanupCommand)); - if (InArchiveRecovery) + if (ArchiveRecoveryRequested) { - if (StandbyMode) + if (StandbyModeRequested) ereport(LOG, (errmsg("entering standby mode"))); else if (recoveryTarget == RECOVERY_TARGET_XID) @@ -6309,13 +6366,22 @@ StartupXLOG(void) * Take ownership of the wakeup latch if we're going to sleep during * recovery. */ - if (StandbyMode) + if (StandbyModeRequested) OwnLatch(&XLogCtl->recoveryWakeupLatch); if (read_backup_label(&checkPointLoc, &backupEndRequired, &backupFromStandby)) { /* + * Archive recovery was requested, and thanks to the backup label file, + * we know how far we need to replay to reach consistency. Enter + * archive recovery directly. + */ + InArchiveRecovery = true; + if (StandbyModeRequested) + StandbyMode = true; + + /* * When a backup_label file is present, we want to roll forward from * the checkpoint it identifies, rather than using pg_control. */ @@ -6356,6 +6422,33 @@ StartupXLOG(void) else { /* + * It's possible that archive recovery was requested, but we don't + * know how far we need to replay the WAL before we reach consistency. + * This can happen for example if a base backup is taken from a running + * server using an atomic filesystem snapshot, without calling + * pg_start/stop_backup. Or if you just kill a running master server + * and put it into archive recovery by creating a recovery.conf file. + * + * Our strategy in that case is to perform crash recovery first, + * replaying all the WAL present in pg_xlog, and only enter archive + * recovery after that. + * + * But usually we already know how far we need to replay the WAL (up to + * minRecoveryPoint, up to backupEndPoint, or until we see an + * end-of-backup record), and we can enter archive recovery directly. + */ + if (ArchiveRecoveryRequested && + (!XLByteEQ(ControlFile->minRecoveryPoint, InvalidXLogRecPtr) || + ControlFile->backupEndRequired || + !XLByteEQ(ControlFile->backupEndPoint, InvalidXLogRecPtr) || + ControlFile->state == DB_SHUTDOWNED)) + { + InArchiveRecovery = true; + if (StandbyModeRequested) + StandbyMode = true; + } + + /* * Get the last valid checkpoint record. If the latest one according * to pg_control is broken, try the next-to-last one. */ @@ -6454,7 +6547,7 @@ StartupXLOG(void) } else if (ControlFile->state != DB_SHUTDOWNED) InRecovery = true; - else if (InArchiveRecovery) + else if (ArchiveRecoveryRequested) { /* force recovery due to presence of recovery.conf */ InRecovery = true; @@ -6487,12 +6580,6 @@ StartupXLOG(void) ControlFile->prevCheckPoint = ControlFile->checkPoint; ControlFile->checkPoint = checkPointLoc; ControlFile->checkPointCopy = checkPoint; - if (InArchiveRecovery) - { - /* initialize minRecoveryPoint if not set yet */ - if (XLByteLT(ControlFile->minRecoveryPoint, checkPoint.redo)) - ControlFile->minRecoveryPoint = checkPoint.redo; - } /* * Set backupStartPoint if we're starting recovery from a base backup. @@ -6571,7 +6658,7 @@ StartupXLOG(void) * control file and we've established a recovery snapshot from a * running-xacts WAL record. */ - if (InArchiveRecovery && EnableHotStandby) + if (ArchiveRecoveryRequested && EnableHotStandby) { TransactionId *xids; int nxids; @@ -6669,7 +6756,7 @@ StartupXLOG(void) * process in addition to postmaster! Also, fsync requests are * subsequently to be handled by the checkpointer, not locally. */ - if (InArchiveRecovery && IsUnderPostmaster) + if (ArchiveRecoveryRequested && IsUnderPostmaster) { PublishStartupProcessInformation(); SetForwardFsyncRequests(); @@ -6873,7 +6960,7 @@ StartupXLOG(void) * We don't need the latch anymore. It's not strictly necessary to disown * it, but let's do it for the sake of tidiness. */ - if (StandbyMode) + if (StandbyModeRequested) DisownLatch(&XLogCtl->recoveryWakeupLatch); /* @@ -6918,7 +7005,7 @@ StartupXLOG(void) * crashes while an online backup is in progress. We must not treat * that as an error, or the database will refuse to start up. */ - if (InArchiveRecovery || ControlFile->backupEndRequired) + if (ArchiveRecoveryRequested || ControlFile->backupEndRequired) { if (ControlFile->backupEndRequired) ereport(FATAL, @@ -6948,8 +7035,10 @@ StartupXLOG(void) * * In a normal crash recovery, we can just extend the timeline we were in. */ - if (InArchiveRecovery) + if (ArchiveRecoveryRequested) { + Assert(InArchiveRecovery); + ThisTimeLineID = findNewestTimeLine(recoveryTargetTLI) + 1; ereport(LOG, (errmsg("selected new timeline ID: %u", ThisTimeLineID))); @@ -6966,7 +7055,7 @@ StartupXLOG(void) * that we also have a copy of the last block of the old WAL in readBuf; * we will use that below.) */ - if (InArchiveRecovery) + if (ArchiveRecoveryRequested) exitArchiveRecovery(curFileTLI, endLogId, endLogSeg); /* @@ -8799,7 +8888,7 @@ xlog_redo(XLogRecPtr lsn, XLogRecord *record) * record, the backup was canceled and the end-of-backup record will * never arrive. */ - if (InArchiveRecovery && + if (ArchiveRecoveryRequested && !XLogRecPtrIsInvalid(ControlFile->backupStartPoint) && XLogRecPtrIsInvalid(ControlFile->backupEndPoint)) ereport(PANIC, @@ -10263,7 +10352,7 @@ XLogPageRead(XLogRecPtr *RecPtr, int emode, bool fetching_ckpt, * Request a restartpoint if we've replayed too much xlog since the * last one. */ - if (StandbyMode && bgwriterLaunched) + if (StandbyModeRequested && bgwriterLaunched) { if (XLogCheckpointNeeded(readId, readSeg)) { |