Re: [BUG] Panic due to incorrect missingContrecPtr after promotion

At Thu, 24 Feb 2022 16:26:42 +0900 (JST), Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> wrote in
> So, actually WAL did not ended in an incomplete record. I think
> FinishWalRecover is the last place to do that. (But it could be
> earlier.)

After some investigation, I finally concluded that we should reset
abortedRecPtr and missingContrecPtr at processing
XLOG_OVERWRITE_CONTRECORD.

--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -1953,6 +1953,11 @@ xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI)
LSN_FORMAT_ARGS(xlrec.overwritten_lsn),
timestamptz_to_str(xlrec.overwrite_time))));

+ /* We have safely skipped the aborted record */
+ abortedRecPtr = InvalidXLogRecPtr;
+ missingContrecPtr = InvalidXLogRecPtr;
+
/* Verifying the record should only happen once */
record->overwrittenRecPtr = InvalidXLogRecPtr;
}

The last check in the test against "resetting aborted record" is no
longer useful since it is already checked by
026_verwrite_contrecord.pl.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center