postgres.git / summary / log / commit / refs

commit    94b18c60c7a52452356bb49a04c1495083ea67f6
Author:   Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date:     Fri Dec 09 12:32:42 2011 +0000

    Don't set reachedMinRecoveryPoint during crash recovery. In crash recovery,
    we don't reach consistency before replaying all of the WAL. Rename the
    variable to reachedConsistency, to make its intention clearer.
    
    In master, that was an active bug because of the recent patch to
    immediately PANIC if a reference to a missing page is found in WAL after
    reaching consistency, as Tom Lane's test case demonstrated. In 9.1 and 9.0,
    the only consequence was a misleading "consistent recovery state reached at
    %X/%X" message in the log at the beginning of crash recovery (the database
    is not consistent at that point yet). In 8.4, the log message was not
    printed in crash recovery, even though there was a similar
    reachedMinRecoveryPoint local variable that was also set early. So,
    backpatch to 9.1 and 9.0.


 src/backend/access/transam/xlog.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 1612acd1409..d2c5841d741 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -514,7 +514,13 @@ static TimeLineID lastPageTLI = 0;
 static XLogRecPtr minRecoveryPoint;		/* local copy of
 										 * ControlFile->minRecoveryPoint */
 static bool updateMinRecoveryPoint = true;
-static bool reachedMinRecoveryPoint = false;
+
+/*
+ * Have we reached a consistent database state? In crash recovery, we have
+ * to replay all the WAL, so reachedConsistency is never set. During archive
+ * recovery, the database is consistent once minRecoveryPoint is reached.
+ */
+static bool reachedConsistency = false;
 
 static bool InRedo = false;
 
@@ -6608,14 +6614,21 @@ CheckRecoveryConsistency(void)
 {
 	static bool backendsAllowed = false;
 
+	/*
+	 * During crash recovery, we don't reach a consistent state until we've
+	 * replayed all the WAL.
+	 */
+	if (XLogRecPtrIsInvalid(minRecoveryPoint))
+		return;
+
 	/*
 	 * Have we passed our safe starting point?
 	 */
-	if (!reachedMinRecoveryPoint &&
+	if (!reachedConsistency &&
 		XLByteLE(minRecoveryPoint, EndRecPtr) &&
 		XLogRecPtrIsInvalid(ControlFile->backupStartPoint))
 	{
-		reachedMinRecoveryPoint = true;
+		reachedConsistency = true;
 		ereport(LOG,
 				(errmsg("consistent recovery state reached at %X/%X",
 						EndRecPtr.xlogid, EndRecPtr.xrecoff)));
@@ -6628,7 +6641,7 @@ CheckRecoveryConsistency(void)
 	 */
 	if (standbyState == STANDBY_SNAPSHOT_READY &&
 		!backendsAllowed &&
-		reachedMinRecoveryPoint &&
+		reachedConsistency &&
 		IsUnderPostmaster)
 	{
 		backendsAllowed = true;


[parent: ec218056feb4]