From 6abc5026f92b99d704bff527d1306eb8588635e9 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Tue, 31 Aug 2021 20:55:10 -0400 Subject: [PATCH v3 1/5] Revert "Avoid creating archive status ".ready" files too early" This reverts commit 515e3d84a0b58b58eb30194209d2bc47ed349f5b. --- src/backend/access/transam/timeline.c | 2 +- src/backend/access/transam/xlog.c | 220 ++--------------------- src/backend/access/transam/xlogarchive.c | 17 +- src/backend/postmaster/walwriter.c | 7 - src/backend/replication/walreceiver.c | 6 +- src/include/access/xlog.h | 1 - src/include/access/xlogarchive.h | 4 +- src/include/access/xlogdefs.h | 1 - 8 files changed, 24 insertions(+), 234 deletions(-) diff --git a/src/backend/access/transam/timeline.c b/src/backend/access/transam/timeline.c index acd5c2431d..8d0903c175 100644 --- a/src/backend/access/transam/timeline.c +++ b/src/backend/access/transam/timeline.c @@ -452,7 +452,7 @@ writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI, if (XLogArchivingActive()) { TLHistoryFileName(histfname, newTLI); - XLogArchiveNotify(histfname, true); + XLogArchiveNotify(histfname); } } diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 24165ab03e..e51a7a749d 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -724,18 +724,6 @@ typedef struct XLogCtlData XLogRecPtr lastFpwDisableRecPtr; slock_t info_lck; /* locks shared variables shown above */ - - /* - * Variables used to track segment-boundary-crossing WAL records. See - * RegisterSegmentBoundary. Protected by segtrack_lck. - */ - XLogSegNo lastNotifiedSeg; - XLogSegNo earliestSegBoundary; - XLogRecPtr earliestSegBoundaryEndPtr; - XLogSegNo latestSegBoundary; - XLogRecPtr latestSegBoundaryEndPtr; - - slock_t segtrack_lck; /* locks shared variables shown above */ } XLogCtlData; static XLogCtlData *XLogCtl = NULL; @@ -932,7 +920,6 @@ static void RemoveXlogFile(const char *segname, XLogSegNo recycleSegNo, XLogSegNo *endlogSegNo); static void UpdateLastRemovedPtr(char *filename); static void ValidateXLOGDirectoryStructure(void); -static void RegisterSegmentBoundary(XLogSegNo seg, XLogRecPtr pos); static void CleanupBackupHistory(void); static void UpdateMinRecoveryPoint(XLogRecPtr lsn, bool force); static XLogRecord *ReadRecord(XLogReaderState *xlogreader, @@ -1167,56 +1154,23 @@ XLogInsertRecord(XLogRecData *rdata, END_CRIT_SECTION(); /* - * If we crossed page boundary, update LogwrtRqst.Write; if we crossed - * segment boundary, register that and wake up walwriter. + * Update shared LogwrtRqst.Write, if we crossed page boundary. */ if (StartPos / XLOG_BLCKSZ != EndPos / XLOG_BLCKSZ) { - XLogSegNo StartSeg; - XLogSegNo EndSeg; - - XLByteToSeg(StartPos, StartSeg, wal_segment_size); - XLByteToSeg(EndPos, EndSeg, wal_segment_size); - - /* - * Register our crossing the segment boundary if that occurred. - * - * Note that we did not use XLByteToPrevSeg() for determining the - * ending segment. This is so that a record that fits perfectly into - * the end of the segment causes the latter to get marked ready for - * archival immediately. - */ - if (StartSeg != EndSeg && XLogArchivingActive()) - RegisterSegmentBoundary(EndSeg, EndPos); - - /* - * Advance LogwrtRqst.Write so that it includes new block(s). - * - * We do this after registering the segment boundary so that the - * comparison with the flushed pointer below can use the latest value - * known globally. - */ SpinLockAcquire(&XLogCtl->info_lck); + /* advance global request to include new block(s) */ if (XLogCtl->LogwrtRqst.Write < EndPos) XLogCtl->LogwrtRqst.Write = EndPos; /* update local result copy while I have the chance */ LogwrtResult = XLogCtl->LogwrtResult; SpinLockRelease(&XLogCtl->info_lck); - - /* - * There's a chance that the record was already flushed to disk and we - * missed marking segments as ready for archive. If this happens, we - * nudge the WALWriter, which will take care of notifying segments as - * needed. - */ - if (StartSeg != EndSeg && XLogArchivingActive() && - LogwrtResult.Flush >= EndPos && ProcGlobal->walwriterLatch) - SetLatch(ProcGlobal->walwriterLatch); } /* * If this was an XLOG_SWITCH record, flush the record and the empty - * padding space that fills the rest of the segment. + * padding space that fills the rest of the segment, and perform + * end-of-segment actions (eg, notifying archiver). */ if (isLogSwitch) { @@ -2467,7 +2421,6 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible) /* We should always be inside a critical section here */ Assert(CritSectionCount > 0); - Assert(LWLockHeldByMe(WALWriteLock)); /* * Update local LogwrtResult (caller probably did this already, but...) @@ -2633,12 +2586,11 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible) * later. Doing it here ensures that one and only one backend will * perform this fsync. * - * If WAL archiving is active, we attempt to notify the archiver - * of any segments that are now ready for archival. - * - * This is also the right place to update the timer for - * archive_timeout and to signal for a checkpoint if too many - * logfile segments have been used since the last checkpoint. + * This is also the right place to notify the Archiver that the + * segment is ready to copy to archival storage, and to update the + * timer for archive_timeout, and to signal for a checkpoint if + * too many logfile segments have been used since the last + * checkpoint. */ if (finishing_seg) { @@ -2650,7 +2602,7 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible) LogwrtResult.Flush = LogwrtResult.Write; /* end of page */ if (XLogArchivingActive()) - NotifySegmentsReadyForArchive(LogwrtResult.Flush); + XLogArchiveNotifySeg(openLogSegNo); XLogCtl->lastSegSwitchTime = (pg_time_t) time(NULL); XLogCtl->lastSegSwitchLSN = LogwrtResult.Flush; @@ -2738,9 +2690,6 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible) XLogCtl->LogwrtRqst.Flush = LogwrtResult.Flush; SpinLockRelease(&XLogCtl->info_lck); } - - if (XLogArchivingActive()) - NotifySegmentsReadyForArchive(LogwrtResult.Flush); } /* @@ -4379,131 +4328,6 @@ ValidateXLOGDirectoryStructure(void) } } -/* - * RegisterSegmentBoundary - * - * WAL records that are split across a segment boundary require special - * treatment for archiving: the initial segment must not be archived until - * the end segment has been flushed, in case we crash before we have - * the chance to flush the end segment (because after recovery we would - * overwrite that WAL record with a different one, and so the file we - * archived no longer represents truth.) This also applies to streaming - * physical replication. - * - * To handle this, we keep track of the LSN of WAL records that cross - * segment boundaries. Two such are sufficient: the ones with the - * earliest and the latest end pointers we know about, since the flush - * position advances monotonically. WAL record writers register - * boundary-crossing records here, which is used by .ready file creation - * to delay until the end segment is known flushed. - */ -static void -RegisterSegmentBoundary(XLogSegNo seg, XLogRecPtr endpos) -{ - XLogSegNo segno PG_USED_FOR_ASSERTS_ONLY; - - /* verify caller computed segment number correctly */ - AssertArg((XLByteToSeg(endpos, segno, wal_segment_size), segno == seg)); - - SpinLockAcquire(&XLogCtl->segtrack_lck); - - /* - * If no segment boundaries are registered, store the new segment boundary - * in earliestSegBoundary. Otherwise, store the greater segment - * boundaries in latestSegBoundary. - */ - if (XLogCtl->earliestSegBoundary == MaxXLogSegNo) - { - XLogCtl->earliestSegBoundary = seg; - XLogCtl->earliestSegBoundaryEndPtr = endpos; - } - else if (seg > XLogCtl->earliestSegBoundary && - (XLogCtl->latestSegBoundary == MaxXLogSegNo || - seg > XLogCtl->latestSegBoundary)) - { - XLogCtl->latestSegBoundary = seg; - XLogCtl->latestSegBoundaryEndPtr = endpos; - } - - SpinLockRelease(&XLogCtl->segtrack_lck); -} - -/* - * NotifySegmentsReadyForArchive - * - * Mark segments as ready for archival, given that it is safe to do so. - * This function is idempotent. - */ -void -NotifySegmentsReadyForArchive(XLogRecPtr flushRecPtr) -{ - XLogSegNo latest_boundary_seg; - XLogSegNo last_notified; - XLogSegNo flushed_seg; - XLogSegNo seg; - bool keep_latest; - - XLByteToSeg(flushRecPtr, flushed_seg, wal_segment_size); - - SpinLockAcquire(&XLogCtl->segtrack_lck); - - if (XLogCtl->latestSegBoundary <= flushed_seg && - XLogCtl->latestSegBoundaryEndPtr <= flushRecPtr) - { - latest_boundary_seg = XLogCtl->latestSegBoundary; - keep_latest = false; - } - else if (XLogCtl->earliestSegBoundary <= flushed_seg && - XLogCtl->earliestSegBoundaryEndPtr <= flushRecPtr) - { - latest_boundary_seg = XLogCtl->earliestSegBoundary; - keep_latest = true; - } - else - { - SpinLockRelease(&XLogCtl->segtrack_lck); - return; - } - - last_notified = XLogCtl->lastNotifiedSeg; - - /* - * Update shared memory and discard segment boundaries that are no longer - * needed. - * - * It is safe to update shared memory before we attempt to create the - * .ready files. If our calls to XLogArchiveNotifySeg() fail, - * RemoveOldXlogFiles() will retry it as needed. - */ - if (last_notified < latest_boundary_seg - 1) - XLogCtl->lastNotifiedSeg = latest_boundary_seg - 1; - - if (keep_latest) - { - XLogCtl->earliestSegBoundary = XLogCtl->latestSegBoundary; - XLogCtl->earliestSegBoundaryEndPtr = XLogCtl->latestSegBoundaryEndPtr; - } - else - { - XLogCtl->earliestSegBoundary = MaxXLogSegNo; - XLogCtl->earliestSegBoundaryEndPtr = InvalidXLogRecPtr; - } - - XLogCtl->latestSegBoundary = MaxXLogSegNo; - XLogCtl->latestSegBoundaryEndPtr = InvalidXLogRecPtr; - - SpinLockRelease(&XLogCtl->segtrack_lck); - - /* - * Notify archiver about segments that are ready for archival (by creating - * the corresponding .ready files). - */ - for (seg = last_notified + 1; seg < latest_boundary_seg; seg++) - XLogArchiveNotifySeg(seg, false); - - PgArchWakeup(); -} - /* * Remove previous backup history files. This also retries creation of * .ready files for any backup history files for which XLogArchiveNotify @@ -5406,17 +5230,9 @@ XLOGShmemInit(void) SpinLockInit(&XLogCtl->Insert.insertpos_lck); SpinLockInit(&XLogCtl->info_lck); - SpinLockInit(&XLogCtl->segtrack_lck); SpinLockInit(&XLogCtl->ulsn_lck); InitSharedLatch(&XLogCtl->recoveryWakeupLatch); ConditionVariableInit(&XLogCtl->recoveryNotPausedCV); - - /* Initialize stuff for marking segments as ready for archival. */ - XLogCtl->lastNotifiedSeg = MaxXLogSegNo; - XLogCtl->earliestSegBoundary = MaxXLogSegNo; - XLogCtl->earliestSegBoundaryEndPtr = InvalidXLogRecPtr; - XLogCtl->latestSegBoundary = MaxXLogSegNo; - XLogCtl->latestSegBoundaryEndPtr = InvalidXLogRecPtr; } /* @@ -8057,20 +7873,6 @@ StartupXLOG(void) XLogCtl->LogwrtRqst.Write = EndOfLog; XLogCtl->LogwrtRqst.Flush = EndOfLog; - /* - * Initialize XLogCtl->lastNotifiedSeg to the previous WAL file. - */ - if (XLogArchivingActive()) - { - XLogSegNo EndOfLogSeg; - - XLByteToSeg(EndOfLog, EndOfLogSeg, wal_segment_size); - - SpinLockAcquire(&XLogCtl->segtrack_lck); - XLogCtl->lastNotifiedSeg = EndOfLogSeg - 1; - SpinLockRelease(&XLogCtl->segtrack_lck); - } - /* * Update full_page_writes in shared memory and write an XLOG_FPW_CHANGE * record before resource manager writes cleanup WAL records or checkpoint @@ -8198,7 +8000,7 @@ StartupXLOG(void) XLogArchiveCleanup(partialfname); durable_rename(origpath, partialpath, ERROR); - XLogArchiveNotify(partialfname, true); + XLogArchiveNotify(partialfname); } } } diff --git a/src/backend/access/transam/xlogarchive.c b/src/backend/access/transam/xlogarchive.c index b9c19b2085..26b023e754 100644 --- a/src/backend/access/transam/xlogarchive.c +++ b/src/backend/access/transam/xlogarchive.c @@ -433,7 +433,7 @@ KeepFileRestoredFromArchive(const char *path, const char *xlogfname) if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS) XLogArchiveForceDone(xlogfname); else - XLogArchiveNotify(xlogfname, true); + XLogArchiveNotify(xlogfname); /* * If the existing file was replaced, since walsenders might have it open, @@ -462,12 +462,9 @@ KeepFileRestoredFromArchive(const char *path, const char *xlogfname) * 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 - * - * Optionally, nudge the archiver process so that it'll notice the file we - * create. */ void -XLogArchiveNotify(const char *xlog, bool nudge) +XLogArchiveNotify(const char *xlog) { char archiveStatusPath[MAXPGPATH]; FILE *fd; @@ -492,8 +489,8 @@ XLogArchiveNotify(const char *xlog, bool nudge) return; } - /* If caller requested, let archiver know it's got work to do */ - if (nudge) + /* Notify archiver that it's got something to do */ + if (IsUnderPostmaster) PgArchWakeup(); } @@ -501,12 +498,12 @@ XLogArchiveNotify(const char *xlog, bool nudge) * Convenience routine to notify using segment number representation of filename */ void -XLogArchiveNotifySeg(XLogSegNo segno, bool nudge) +XLogArchiveNotifySeg(XLogSegNo segno) { char xlog[MAXFNAMELEN]; XLogFileName(xlog, ThisTimeLineID, segno, wal_segment_size); - XLogArchiveNotify(xlog, nudge); + XLogArchiveNotify(xlog); } /* @@ -611,7 +608,7 @@ XLogArchiveCheckDone(const char *xlog) return true; /* Retry creation of the .ready file */ - XLogArchiveNotify(xlog, true); + XLogArchiveNotify(xlog); return false; } diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c index 6a1e16edc2..626fae8454 100644 --- a/src/backend/postmaster/walwriter.c +++ b/src/backend/postmaster/walwriter.c @@ -248,13 +248,6 @@ WalWriterMain(void) /* Process any signals received recently */ HandleWalWriterInterrupts(); - /* - * Notify the archiver of any WAL segments that are ready. We do this - * here to handle a race condition where WAL is flushed to disk prior - * to registering the segment boundary. - */ - NotifySegmentsReadyForArchive(GetFlushRecPtr()); - /* * Do what we're here for; then, if XLogBackgroundFlush() found useful * work to do, reset hibernation counter. diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c index 60de3be92c..9a2bc37fd7 100644 --- a/src/backend/replication/walreceiver.c +++ b/src/backend/replication/walreceiver.c @@ -622,7 +622,7 @@ WalReceiverMain(void) if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS) XLogArchiveForceDone(xlogfname); else - XLogArchiveNotify(xlogfname, true); + XLogArchiveNotify(xlogfname); } recvFile = -1; @@ -760,7 +760,7 @@ WalRcvFetchTimeLineHistoryFiles(TimeLineID first, TimeLineID last) if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS) XLogArchiveForceDone(fname); else - XLogArchiveNotify(fname, true); + XLogArchiveNotify(fname); pfree(fname); pfree(content); @@ -915,7 +915,7 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr) if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS) XLogArchiveForceDone(xlogfname); else - XLogArchiveNotify(xlogfname, true); + XLogArchiveNotify(xlogfname); } recvFile = -1; diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 6b6ae81c2d..0a8ede700d 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -315,7 +315,6 @@ extern XLogRecPtr GetInsertRecPtr(void); extern XLogRecPtr GetFlushRecPtr(void); extern XLogRecPtr GetLastImportantRecPtr(void); extern void RemovePromoteSignalFiles(void); -extern void NotifySegmentsReadyForArchive(XLogRecPtr flushRecPtr); extern bool PromoteIsTriggered(void); extern bool CheckPromoteSignal(void); diff --git a/src/include/access/xlogarchive.h b/src/include/access/xlogarchive.h index 935b4cb02d..3edd1a976c 100644 --- a/src/include/access/xlogarchive.h +++ b/src/include/access/xlogarchive.h @@ -23,8 +23,8 @@ extern bool RestoreArchivedFile(char *path, const char *xlogfname, extern void ExecuteRecoveryCommand(const char *command, const char *commandName, bool failOnSignal); extern void KeepFileRestoredFromArchive(const char *path, const char *xlogfname); -extern void XLogArchiveNotify(const char *xlog, bool nudge); -extern void XLogArchiveNotifySeg(XLogSegNo segno, bool nudge); +extern void XLogArchiveNotify(const char *xlog); +extern void XLogArchiveNotifySeg(XLogSegNo segno); extern void XLogArchiveForceDone(const char *xlog); extern bool XLogArchiveCheckDone(const char *xlog); extern bool XLogArchiveIsBusy(const char *xlog); diff --git a/src/include/access/xlogdefs.h b/src/include/access/xlogdefs.h index 9b455e88e3..60348d1850 100644 --- a/src/include/access/xlogdefs.h +++ b/src/include/access/xlogdefs.h @@ -46,7 +46,6 @@ typedef uint64 XLogRecPtr; * XLogSegNo - physical log file sequence number. */ typedef uint64 XLogSegNo; -#define MaxXLogSegNo ((XLogSegNo) 0xFFFFFFFFFFFFFFFF) /* * TimeLineID (TLI) - identifies different database histories to prevent -- 2.30.2