From b669f416cee77ef9025b80f9c4201688578447d1 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon, 11 Feb 2013 22:16:56 +0200
Subject: [PATCH] Fix checkpoint after fast promotion.
The intention was to request a regular online checkpoint immediately after
end of recovery, when performing "fast promotion". However, because the
checkpoint was requested before other backends were allowed to write WAL,
the checkpointer process performed a restartpoint rather than a checkpoint.
Delay the RequestCheckPoint call until after recovery has truly ended, so
that you get a real checkpoint.
---
src/backend/access/transam/xlog.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 3155238c58d..140f9109a6f 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4731,6 +4731,7 @@ StartupXLOG(void)
DBState dbstate_at_startup;
XLogReaderState *xlogreader;
XLogPageReadPrivate private;
+ bool fast_promoted = false;
/*
* Read control file and check XLOG status looks valid.
@@ -5781,15 +5782,13 @@ StartupXLOG(void)
* assigning a new TLI, using a shutdown checkpoint allows us to have
* the rule that TLI only changes in shutdown checkpoints, which
* allows some extra error checking in xlog_redo.
+ *
+ * In fast promotion, only create a lightweight end-of-recovery record
+ * instead of a full checkpoint. A checkpoint is requested later, after
+ * we're fully out of recovery mode and already accepting queries.
*/
if (bgwriterLaunched)
{
- bool checkpoint_wait = true;
-
- /*
- * If we've been explicitly promoted with fast option,
- * end of recovery without a checkpoint if possible.
- */
if (fast_promote)
{
checkPointLoc = ControlFile->prevCheckPoint;
@@ -5802,22 +5801,15 @@ StartupXLOG(void)
record = ReadCheckpointRecord(xlogreader, checkPointLoc, 1, false);
if (record != NULL)
{
- checkpoint_wait = false;
+ fast_promoted = true;
CreateEndOfRecoveryRecord();
}
}
- /*
- * In most cases we will wait for a full checkpoint to complete.
- *
- * If not, issue a normal, non-immediate checkpoint but don't wait.
- */
- if (checkpoint_wait)
+ if (!fast_promoted)
RequestCheckpoint(CHECKPOINT_END_OF_RECOVERY |
CHECKPOINT_IMMEDIATE |
CHECKPOINT_WAIT);
- else
- RequestCheckpoint(0); /* No flags */
}
else
CreateCheckPoint(CHECKPOINT_END_OF_RECOVERY | CHECKPOINT_IMMEDIATE);
@@ -5925,6 +5917,15 @@ StartupXLOG(void)
* wal sender processes to notice that we've been promoted.
*/
WalSndWakeup();
+
+ /*
+ * If this was a fast promotion, request an (online) checkpoint now. This
+ * isn't required for consistency, but the last restartpoint might be far
+ * back, and in case of a crash, recovering from it might take a longer
+ * than is appropriate now that we're not in standby mode anymore.
+ */
+ if (fast_promoted)
+ RequestCheckpoint(0);
}
/*
--
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