Re: Implement waiting for wal lsn replay: reloaded

Alexander Korotkov <aekorotkov@gmail.com>

From: Alexander Korotkov <aekorotkov@gmail.com>
To: Xuneng Zhou <xunengzhou@gmail.com>
Cc: Alexander Lakhin <exclusion@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Peter Eisentraut <peter@eisentraut.org>, Andres Freund <andres@anarazel.de>, Thomas Munro <thomas.munro@gmail.com>, Álvaro Herrera <alvherre@kurilemu.de>, Chao Li <li.evan.chao@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: 2026-05-25T09:00:20Z
Lists: pgsql-hackers
On Sat, May 23, 2026 at 9:40 PM Xuneng Zhou <xunengzhou@gmail.com> wrote:
>> > I agree with you.  But do we actually need a
>> > wait_for_standby_and_slot_catchup() wrapper.  I think we can call
>> > $node->wait_for_slot_catchup() directly and simplify the fix.  Check
>> > the attached patch.
>> >
>>
>> The patch looks good to me. I agree that the wait_for_slot_catchup is
>> not needed and could be misleading. This change would make the exact
>> synchronization point and its intention clearer. The only price we
>> need to pay here is bringing back the polling. But it seems acceptable
>> since the cost was there in the pre-wait-for-lsn era. And thanks for
>> writing the great commit message!
>
>
> Sorry for copy-pasting the wrong function name. It should be wait_for_catchup().

Good, thank you.  I'll push it if no objections.

------
Regards,
Alexander Korotkov
Supabase