Re: [GENERAL] postmaster deadlock while logging after syslogger exited - Mailing list pgsql-general

From Tom Lane
Subject Re: [GENERAL] postmaster deadlock while logging after syslogger exited
Date
Msg-id 23680.1510887983@sss.pgh.pa.us
Whole thread Raw
In response to Re: [GENERAL] postmaster deadlock while logging after sysloggerexited  (Andres Freund <andres@anarazel.de>)
Responses Re: [GENERAL] postmaster deadlock while logging after syslogger exited
List pgsql-general
Andres Freund <andres@anarazel.de> writes:
> On 2017-11-16 21:39:49 -0500, Tom Lane wrote:
>> What might be worth thinking about is allowing the syslogger process to
>> inherit the postmaster's OOM-kill-proofness setting, instead of dropping
>> down to the same vulnerability as the postmaster's other child processes.

> Hm. I'm a bit scared about that - it doesn't seem that inconceivable
> that various backends log humongous multi-line messages, leading to
> syslogger *actually* taking up a fair amount of memory. Note that we're
> using plain stringinfos that ereport(ERROR) out of memory situations,
> rather than failing more gracefully.

True, but there's no hard limits on the postmaster's memory consumption
either ... and if the syslogger does get killed on such a basis, we have
at the least lost a bunch of log output.  On the whole I think we'd be
better off trying to prevent OOM kills on the syslogger.  (That doesn't
preclude other mitigation measures.)
        regards, tom lane


-- 
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

pgsql-general by date:

Previous
From: Andres Freund
Date:
Subject: Re: [GENERAL] postmaster deadlock while logging after sysloggerexited
Next
From: Andres Freund
Date:
Subject: Re: [GENERAL] postmaster deadlock while logging after syslogger exited