Horton

Re: Implement waiting for wal lsn replay: reloaded

Andres Freund <andres@anarazel.de>

View thread
From: Andres Freund <andres@anarazel.de>
To: Álvaro Herrera <alvherre@kurilemu.de>
Cc: Alexander Korotkov <aekorotkov@gmail.com>, Xuneng Zhou <xunengzhou@gmail.com>, pgsql-hackers <pgsql-hackers@lists.postgresql.org>, Michael Paquier <michael@paquier.xyz>, jian he <jian.universality@gmail.com>, Tomas Vondra <tomas@vondra.me>, Yura Sokolov <y.sokolov@postgrespro.ru>
Date: 2025-11-03T15:13:02Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Clean up 019_replslot_limit.pl comments

  2. Stabilize 019_replslot_limit.pl: wait on slot restart_lsn

  3. Use WAIT FOR LSN in PostgreSQL::Test::Cluster::wait_for_catchup()

  4. Add tab completion for the WAIT FOR LSN MODE option

  5. Add the MODE option to the WAIT FOR LSN command

  6. Extend xlogwait infrastructure with write and flush wait types

  7. Unify error messages

  8. Optimize shared memory usage for WaitLSNProcInfo

  9. Fix WaitLSNWakeup() fast-path check for InvalidXLogRecPtr

  10. Fix incorrect function name in comments

  11. Add infrastructure for efficient LSN waiting

  12. Add pairingheap_initialize() for shared memory usage

  13. Implement WAIT FOR command

Hi,

On 2025-11-03 16:06:58 +0100, Álvaro Herrera wrote:
> On 2025-Nov-03, Alexander Korotkov wrote:
> 
> > I'd like to give this subject another chance for pg19.  I'm going to
> > push this if no objections.
> 
> Sure.  I don't understand why patches 0002 and 0003 are separate though.

FWIW, I appreciate such splits. Even if the functionality isn't usable
independently, it's still different type of code that's affected. And the
patches are each big enough to make that worthwhile for easier review.

One thing that'd be nice to do once we have WAIT FOR is to make the common
case of wait_for_catchup() use this facility, instead of polling...

Greetings,

Andres Freund