Re: [HACKERS] make async slave to wait for lsn to be replayed

Michael Paquier <michael@paquier.xyz>

From: Michael Paquier <michael@paquier.xyz>
To: Alexander Korotkov <aekorotkov@gmail.com>
Cc: Kevin Hale Boyes <kcboyes@gmail.com>, Kartyshov Ivan <i.kartyshov@postgrespro.ru>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, hlinnaka@iki.fi, alvherre@alvh.no-ip.org, pashkin.elfe@gmail.com, bharath.rupireddyforpostgres@gmail.com, euler@eulerto.com, thomas.munro@gmail.com, peter@eisentraut.org, amit.kapila16@gmail.com, dilipbalaut@gmail.com, smithpb2250@gmail.com, pgsql-hackers@lists.postgresql.org
Date: 2024-08-06T05:36:03Z
Lists: pgsql-hackers
On Tue, Aug 06, 2024 at 05:17:10AM +0300, Alexander Korotkov wrote:
> The 0001 patch is intended to improve this situation.  Actually, it's
> not right to just put RecoveryInProgress() after
> GetXLogReplayRecPtr(), because more wal could be replayed between
> these calls.  Instead we need to recheck GetXLogReplayRecPtr() after
> getting negative result of RecoveryInProgress() because WAL replay
> position couldn't get updated after.
> 0002 patch comprises fix for the header comment of WaitLSNSetLatches() function
> 0003 patch comprises tests for pg_wal_replay_wait() errors.

Before adding more tests, could it be possible to stabilize what's in
the tree?  drongo has reported one failure with the recovery test
043_wal_replay_wait.pl introduced recently by 3c5db1d6b016:
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=drongo&dt=2024-08-05%2004%3A24%3A54
--
Michael

Commits

  1. Ensure standby promotion point in 043_wal_replay_wait.pl

  2. Minor cleanup related to pg_wal_replay_wait() procedure

  3. Adjust pg_wal_replay_wait() procedure behavior on promoted standby

  4. pg_wal_replay_wait(): Fix typo in the doc

  5. Implement pg_wal_replay_wait() stored procedure

  6. Revert: Implement pg_wal_replay_wait() stored procedure

  7. Call WaitLSNCleanup() in AbortTransaction()

  8. Clarify what is protected by WaitLSNLock

  9. Use an LWLock instead of a spinlock in waitlsn.c

  10. Use the pairing heap instead of a flat array for LSN replay waiters

  11. Minor improvements for waitlsn.c

  12. Make the order of the header file includes consistent