From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: Alvaro Herrera <alvherre@2ndquadrant.com>,
        Kyotaro Horiguchi <horikyota.ntt@gmail.com>, michael@paquier.xyz,
        thomas.munro@gmail.com, tomas.vondra@2ndquadrant.com,
        a.zakirov@postgrespro.ru, ah@cybertec.at, magnus@hagander.net,
        robertmhaas@gmail.com, pgsql-hackers@postgresql.org
Subject: Re: shared-memory based stats collector
In-reply-to: <20200309184754.yvrgzqpzs3iynszq@alap3.anarazel.de>
References: <15888.1583770875@sss.pgh.pa.us>
 <20200309183705.GA10363@alvherre.pgsql>
 <20200309184754.yvrgzqpzs3iynszq@alap3.anarazel.de>
Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Mon, 09 Mar 2020 11:47:54 -0700"
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Date: Mon, 09 Mar 2020 15:04:23 -0400
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Andres Freund <andres@anarazel.de> writes:
> On 2020-03-09 15:37:05 -0300, Alvaro Herrera wrote:
>> I'm worried that we're causing all processes to terminate when an
>> archiver dies in some ugly way; but in the current coding, it's pretty
>> harmless and we'd just start a new one.  I think this needs to be
>> reconsidered.  As far as I know, pgarchiver remains unconnected to
>> shared memory so a crash-restart cycle is not necessary.  We should
>> continue to just log the error message and move on.

> Why is it worth having the archiver be "robust" that way?

I'd ask a different question: what the heck is this patchset doing
touching the archiver in the first place?  I can see no plausible
reason for that doing anything related to stats collection.  If we
now need some new background processing for stats, let's make a
new postmaster child process to do that, not overload the archiver
with unrelated responsibilities.

			regards, tom lane