Date: Thu, 9 Jul 2026 22:19:55 -0700
From: Jeremy Schneider <schneider@ardentperf.com>
To: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Cc: Jakub Wartak <jakub.wartak@enterprisedb.com>, Srinath Reddy Sadipiralla
 <srinath2133@gmail.com>, PostgreSQL mailing lists
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Subject: Re: hang during shutdown
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On Thu, 9 Jul 2026 09:09:25 +0200
Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com> wrote:

> As you didn't have a shutdown checkpoint, the symptoms look very
> similar (though you didn't confirm whether you were using logical
> replication, so I'm gonna assume you do).

No logical replication. Are we sure this only impacts logical and not
physical? Thanks for the pointer - interesting one.

We do use physical replication. Replicas were shut down and they closed
their connections to this writer instance around 04:25 just before
pg_ctl stop was executed on the writer itself.

Something was on the writer DB's CPU before shutdown; metrics show total
CPU for that linux namespace (k8s pod) around 0.86 cores until 04:24 and
then the CPU starts dropping when the database shuts down. Bu 04:28 the
CPU is under 0.01 cores and the CPU remains effectively zero until the
processes are SIGKILL'd 30 minutes later.

-Jeremy


-- 
To know the thoughts and deeds that have marked man's progress is to
feel the great heart throbs of humanity through the centuries; and if
one does not feel in these pulsations a heavenward striving, one must
indeed be deaf to the harmonies of life.

Helen Keller, The Story Of My Life, 1902, 1903, 1905, introduction by
Ralph Barton Perry (Garden City, NY: Doubleday & Company, 1954), p90.