public inbox for [email protected]  

help / color / mirror / Atom feed

From: Jakub Wartak <[email protected]>
To: Anthonin Bonnefoy <[email protected]>
Cc: Srinath Reddy Sadipiralla <[email protected]>
Cc: Jeremy Schneider <[email protected]>
Cc: PostgreSQL mailing lists <[email protected]>
Subject: Re: hang during shutdown
Date: Mon, 6 Jul 2026 14:42:10 +0200
Message-ID: <CAKZiRmxxD5y2hArj3p4Ueq2jvQoTUsUr7tjeK44OnSqxAD1ZmA@mail.gmail.com> (raw)
In-Reply-To: <CAO6_Xqpzj_V1gF0ikPCVkA3Q2K5YqRnAdHiV5TqpLNAZsdwWbQ@mail.gmail.com>
References: <CA+fnDAa8Kbbx3KkqpfxutTx41RchJsT3Lykqwcedm0CVr5Tw=A@mail.gmail.com>
	<CAFC+b6pQXYMks5f4XJ-QX4QpxnYnrNz9Zrkg8EiJ5-O+PxKxBQ@mail.gmail.com>
	<CAO6_Xqpzj_V1gF0ikPCVkA3Q2K5YqRnAdHiV5TqpLNAZsdwWbQ@mail.gmail.com>

On Mon, Jul 6, 2026 at 8:30 AM Anthonin Bonnefoy
<[email protected]> wrote:
>
> Hi,
>
> On Sun, Jul 5, 2026 at 11:55 PM Jeremy Schneider
> <[email protected]> wrote:
> > so far, it all started with this postgres hang during a shutdown. we didnt capture enough diagnostics to root-cause the domino before the hang, but the data i do have about this postgres hang is very peculiar. i'm working on some automation to gather more diagnostics if there is a recurrence. in the meantime i wanted to share what i do know, in case anyone else has seen something similar.
> >
> > postgres version 16.13
> > Ubuntu 22.04.5 LTS
> > kernel 5.15.0-1110-azure
> >
> > between log messages and wal contents, it appears PostmasterStateMachine transitioned into PM_WAIT_BACKENDS but never progressed beyond this for a full 30 minutes until external automation finally killed the processes.
>
> Did you have an active logical replication stream at the time of the
> shutdown? If so, it's very likely due to a bug in the logical
> walsender[..]

Aren't walsenders in general problematic for shutdowns? (not just logical, of
course it might be this). The PG 19 is going to have
wal_sender_shutdown_timeout, and from description it seems to match [0] to
something like that. 'netstat -ntpo' would help to see from such hanged
system (if walsenders running there at this point at all).

-J.

[0] - https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=a8f45dee91768cf1447ffaf2527e499e7...

view thread (6+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: hang during shutdown
  In-Reply-To: <CAKZiRmxxD5y2hArj3p4Ueq2jvQoTUsUr7tjeK44OnSqxAD1ZmA@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox