Re: Wake up backends immediately when sync standbys decrease

Shinya Kato <shinya11.kato@gmail.com>

From: Shinya Kato <shinya11.kato@gmail.com>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: Chao Li <li.evan.chao@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-02-01T06:24:45Z
Lists: pgsql-hackers

Attachments

Thank you for the reviews!

On Sat, Jan 31, 2026 at 12:28 AM Fujii Masao <masao.fujii@gmail.com> wrote:
> This issue can occur not only when the number of sync standbys is reduced,
> but also when the configured standby names change. For example, if the config
> changes from "FIRST 2 (sby1, sby2)" to "FIRST 2 (sby1, sby3)",
> waiters on sby2 should be released immediately. But, currently, there can
> a delay before that happens. Right?

Yes, you're right, so I revised the comments and commit message.

> > My main concern is code duplication. The same block is added in three places. While the existing reload handling is already duplicated there, adding more logic on top makes the situation a bit worse from a maintenance perspective.
> >
> > Would it make sense to factor the reload handling into a small helper, for example:
>
> +1

I've updated it in the v2 patch.


-- 
Best regards,
Shinya Kato
NTT OSS Center

Commits

  1. Release synchronous replication waiters immediately on configuration changes.