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authorHeikki Linnakangas <heikki.linnakangas@iki.fi>2010-11-01 09:56:45 +0200
committerHeikki Linnakangas <heikki.linnakangas@iki.fi>2010-11-01 10:04:45 +0200
commit268fecc62cde08c89952c26cb01db8f04a2dc88d (patch)
treef88b1caa5473a447600ffe3a0dbfffbbd82e8d4b /src
parent381d6a05aecbade0bf536325ace36f1507da042b (diff)
Fix corner-case bug in tracking of latest removed WAL segment during
streaming replication. We used log/seg 0/0 to indicate that no WAL segments have been removed since startup, but 0/0 is a valid value for the very first WAL segment after initdb. To make that disambiguous, store (latest removed WAL segment + 1) in the global variable. Per report from Matt Chesler, also reproduced by Greg Smith.
Diffstat (limited to 'src')
-rw-r--r--src/backend/access/transam/xlog.c9
-rw-r--r--src/backend/replication/walsender.c2
2 files changed, 7 insertions, 4 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index e3196e96d33..a55c2ffbcfe 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -363,7 +363,7 @@ typedef struct XLogCtlData
uint32 ckptXidEpoch; /* nextXID & epoch of latest checkpoint */
TransactionId ckptXid;
XLogRecPtr asyncXactLSN; /* LSN of newest async commit/abort */
- uint32 lastRemovedLog; /* latest removed/recycled XLOG segment */
+ uint32 lastRemovedLog; /* latest removed/recycled XLOG segment + 1 */
uint32 lastRemovedSeg;
/* Protected by WALWriteLock: */
@@ -3210,8 +3210,10 @@ PreallocXlogFiles(XLogRecPtr endptr)
}
/*
- * Get the log/seg of the latest removed or recycled WAL segment.
- * Returns 0 if no WAL segments have been removed since startup.
+ * Get the log/seg of the first WAL segment that has not been removed or
+ * recycled. In other words, the log/seg of the last removed/recycled WAL
+ * segment + 1.
+ * Returns 0/0 if no WAL segments have been removed since startup.
*/
void
XLogGetLastRemoved(uint32 *log, uint32 *seg)
@@ -3239,6 +3241,7 @@ UpdateLastRemovedPtr(char *filename)
seg;
XLogFromFileName(filename, &tli, &log, &seg);
+ NextLogSeg(log, seg);
SpinLockAcquire(&xlogctl->info_lck);
if (log > xlogctl->lastRemovedLog ||
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 2a16888b0ff..f3775ac72da 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -630,7 +630,7 @@ XLogRead(char *buf, XLogRecPtr recptr, Size nbytes)
XLogGetLastRemoved(&lastRemovedLog, &lastRemovedSeg);
XLByteToSeg(startRecPtr, log, seg);
if (log < lastRemovedLog ||
- (log == lastRemovedLog && seg <= lastRemovedSeg))
+ (log == lastRemovedLog && seg < lastRemovedSeg))
{
char filename[MAXFNAMELEN];