Date: Sun, 20 Apr 2025 14:53:39 -0700
From: Noah Misch <noah@leadboat.com>
To: Andres Freund <andres@anarazel.de>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Nathan Bossart <nathandbossart@gmail.com>,
	Michael Paquier <michael@paquier.xyz>,
	Robert Pang <robertpang@google.com>,
	Kyotaro Horiguchi <horikyota.ntt@gmail.com>, robertmhaas@gmail.com,
	pgsql-hackers@postgresql.org
Subject: Re: Back-patch of: avoid multiple hard links to same WAL file after
 a crash
Message-ID: <20250420215339.e8.nmisch@google.com>
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On Mon, Apr 14, 2025 at 09:19:35AM +0900, Michael Paquier wrote:
> On Sun, Apr 13, 2025 at 11:51:57AM -0400, Tom Lane wrote:
> > Noah Misch <noah@leadboat.com> writes:
> > > Tom and Michael, do you still object to the test addition, or not?  If there
> > > are no new or renewed objections by 2025-04-20, I'll proceed to add the test.

Pushed as commit 714bd9e.  The failure so far is
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=skink&dt=2025-04-20%2015%3A36%3A35
with these highlights:

pg_ctl: server does not shut down

2025-04-20 17:27:35.735 UTC [1576688][postmaster][:0] LOG:  received immediate shutdown request
2025-04-20 17:27:35.969 UTC [1577386][archiver][:0] FATAL:  archive command was terminated by signal 3: Quit
2025-04-20 17:27:35.969 UTC [1577386][archiver][:0] DETAIL:  The failed archive command was: cp "pg_wal/00000001000000000000006D" "/home/bf/bf-build/skink-master/HEAD/pgsql.build/testrun/recovery/045_archive_restartpoint/data/t_045_archive_restartpoint_primary_data/archives/00000001000000000000006D"

The checkpoints and WAL creation took 30s, but archiving was only 20% done
(based on file name 00000001000000000000006D) at the 360s PGCTLTIMEOUT.  I can
reproduce this if I test with valgrind --trace-children=yes.  With my normal
valgrind settings, the whole test file takes only 18s.  I recommend one of
these changes to skink:

- Add --trace-children-skip='/bin/*,/usr/bin/*' so valgrind doesn't instrument
  "sh" and "cp" commands.
- Remove --trace-children=yes

Andres, what do you think about making one of those skink configuration
changes?  Alternatively, I could make the test poll until archiving catches
up.  However, that would take skink about 30min, and I expect little value
from 30min of valgrind instrumenting the "cp" command.