Horton
Menu

Re: synchronized_standby_slots behavior inconsistent with quorum-based synchronous replication

Alexander Kukushkin <cyberdemn@gmail.com>

View thread
From: Alexander Kukushkin <cyberdemn@gmail.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-02-26T09:29:29Z
Lists: pgsql-hackers 
Hi,

On Thu, 26 Feb 2026 at 09:45, shveta malik <shveta.malik@gmail.com> wrote:

>
> As suggested in [1], IMO, it is a reasonably good idea for
> 'synchronized_standby_slots' to DEFAULT to the value of
> 'synchronous_standby_names'. That way, even if the user missed to
> configure 'synchronized_standby_slots' explicitly, we would still have
> reasonable protection in place.


Hmm.
synchronous_standby_names contains application_names,
while synchronized_standby_slots contains names of physical replication
slots.
These are two different things, and in fact sync replication doesn't even
require to use replication slots.
What is worse, even when all standbys use physical replication slots there
is no guarantee that values in synchronous_standby_names will match
physical slot names.

Regards,
--
Alexander Kukushkin