public inbox for [email protected]
help / color / mirror / Atom feedFrom: Michael Paquier <[email protected]>
To: Aya Iwata (Fujitsu) <[email protected]>
Cc: Peter Smith <[email protected]>
Cc: Pavel Stehule <[email protected]>
Cc: Chao Li <[email protected]>
Cc: Hayato Kuroda (Fujitsu) <[email protected]>
Cc: pgsql-hackers <[email protected]>
Subject: Re: [PROPOSAL] Termination of Background Workers for ALTER/DROP DATABASE
Date: Mon, 16 Mar 2026 16:23:40 +0900
Message-ID: <[email protected]> (raw)
In-Reply-To: <OS3PR01MB8889505E2F3E443CCA4BD72EEA45A@OS3PR01MB8889.jpnprd01.prod.outlook.com>
References: <OS7PR01MB1196405302B700736580DEE49EAA8A@OS7PR01MB11964.jpnprd01.prod.outlook.com>
<CAFj8pRBk7zTKoxAAKAihNQuimztniWHPyRWHKp2iHq_2hH+dvQ@mail.gmail.com>
<OS7PR01MB11964C83E8E543743581250B0EAB3A@OS7PR01MB11964.jpnprd01.prod.outlook.com>
<CAHut+PvP6H2soK05c_0JZC8--=h4nWEtxYE_nJGjRkQr=25F1w@mail.gmail.com>
<[email protected]>
<CAHut+PtSVYKU4vfaRev4FMdbeZ3ukvxRy4X7uK05jv_9WMYafA@mail.gmail.com>
<OS7PR01MB1196426354C0294148A06AC65EA86A@OS7PR01MB11964.jpnprd01.prod.outlook.com>
<CAHut+PtZh+B_-z_TzmToUhL4-sBrf7dfH0uAb7VU-jkXFmHQSA@mail.gmail.com>
<[email protected]>
<OS3PR01MB8889505E2F3E443CCA4BD72EEA45A@OS3PR01MB8889.jpnprd01.prod.outlook.com>
On Fri, Mar 13, 2026 at 11:38:51AM +0000, Aya Iwata (Fujitsu) wrote:
> On March 10th, the bgworker test "t/002_worker_terminate.pl" failed on the Build Farm.
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=jay&dt=2026-03-10%2019%3A26%3A19
Indeed.
> We are currently attempting to reproduce this issue and are considering a fix.
>
> According to the log, the test failed because the bgworker cannot be terminated
> within the time frame (5 seconds) when ALTER DATABASE RENAME is executed.
>
> So I suspect that there is a lock conflict.
Aye, we have a timing issue here, and at first it seemed to me that
this was a bug in the backend logic. But actually I suspect that it
is simpler than that: we don't disable autovacuum so couldn't an
autovacuum worker connect to the database "testdb" that we are trying
to rename in this query? I cannot be 100% sure because we have
reduced the log activity for the sake of the tests, but that feels
possible to me. We could try to disable autovacuum entirely, then see
if the situation gets better in the buildfarm.
The failure rate is so low that it is likely going to take a few weeks
to check the stability of the situation. We could also lot more
things, of course, as a temporary solution.
What do you think?
--
Michael
Attachments:
[application/pgp-signature] signature.asc (833B, 2-signature.asc)
download
view thread (70+ 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], [email protected], [email protected]
Subject: Re: [PROPOSAL] Termination of Background Workers for ALTER/DROP DATABASE
In-Reply-To: <[email protected]>
* 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