Re: Lots of stuck queries after upgrade to 9.4 - Mailing list pgsql-general

From Andres Freund
Subject Re: Lots of stuck queries after upgrade to 9.4
Date
Msg-id 20150720112242.GZ5520@alap3.anarazel.de
Whole thread Raw
In response to Re: Lots of stuck queries after upgrade to 9.4  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: Lots of stuck queries after upgrade to 9.4  (Andres Freund <andres@anarazel.de>)
List pgsql-general
On 2015-07-20 13:06:51 +0200, Alvaro Herrera wrote:
> Spiros Ioannou wrote:
> > Hi Tom,
> > thank you for your input. The DB was stuck again, I attach all logs and
> > stack traces.
> >
> > A stack trace from a COMMIT, an INSERT, an UPDATE, the wal writer, the
> > writer, and a sequence.
> >
> > Stracing the commit was stuck at: semop(3145761, {{12, -1, 0}}, 1
>
> Hmm, isn't this an indication of problems in the WAL insertion logic?
> Looks to me like there are deadlocks using lwlocks.

Hm. The problem seems to be the WaitXLogInsertionsToFinish() call in
XLogFlush().

Spiros, I guess you have commit_delay enabled? If so, does disabling it
"fix" the issue?

Regards,

Andres


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