From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
cc: Andrew Dunstan <andrew@dunslane.net>,
        Alexander Lakhin <exclusion@gmail.com>,
        pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Why is src/test/modules/committs/t/002_standby.pl flaky?
In-reply-to: <1600941.1641685316@sss.pgh.pa.us>
References: <CA+hUKG+OeoETZQ=Qw5Ub5h3tmwQhBmDA=nuNO3KG=zWfUypFAw@mail.gmail.com> <e4ddf83b-b399-aea4-498d-eb8e35e055e9@dunslane.net> <1600941.1641685316@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Sat, 08 Jan 2022 18:41:56 -0500"
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Date: Sat, 08 Jan 2022 20:17:16 -0500
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I wrote:
> So for some reason, on these machines detection of walsender-initiated
> connection close is unreliable ... or maybe, the walsender didn't close
> the connection, but is somehow still hanging around?  Don't have much id=
ea
> where to dig beyond that, but maybe someone else will.  I wonder in
> particular if this could be related to our recent discussions about
> whether to use shutdown(2) on Windows --- could we need to do the
> equivalent of 6051857fc/ed52c3707 on walsender connections?

... wait a minute.  After some more study of the buildfarm logs,
it was brought home to me that these failures started happening
just after 6051857fc went in:

https://buildfarm.postgresql.org/cgi-bin/show_failures.pl?max_days=3D90&br=
anch=3D&member=3D&stage=3Dmodule-commit_tsCheck&filter=3DSubmit

The oldest matching failure is jacana's on 2021-12-03.
(The above sweep finds an unrelated-looking failure on 2021-11-11,
but no others before 6051857fc went in on 2021-12-02.  Also, it
looks likely that ed52c3707 on 2021-12-07 made the failure more
probable, because jacana's is the only matching failure before 12-07.)

So I'm now thinking it's highly likely that those commits are
causing it somehow, but how?

			regards, tom lane