Re: Fsync request queue

From: Peter Geoghegan <pg(at)bowt(dot)ie>
To: Andres Freund <andres(at)anarazel(dot)de>
Cc: Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Fsync request queue
Date: 2018-04-30 23:07:48
Message-ID: CAH2-Wzn+vxv4Ct2PveVhPqqRb65v1w5OzPm=8vA4=fM16A7dBA@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Mon, Apr 30, 2018 at 4:03 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>> Is this a problem in practice, though? I don't remember seeing any reports
>> of the fsync queue filling up, after we got the code to compact it. I don't
>> know if anyone has been looking for that, so that might also explain the
>> absence of reports, though.
>
> It's probably hard to diagnose that as the origin of slow IO from the
> outside. It's not exactly easy to diagnose that even if you know what's
> going on.

True, but has anyone ever actually observed a non-zero
pg_stat_bgwriter.buffers_backend_fsync in the wild after the
compaction queue stuff was added/backpatched?

--
Peter Geoghegan

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Yuriy Zhuravlev 2018-04-30 23:08:03 Re: Issues while building PG in MS Windows, using MSYS2 and MinGW-w64
Previous Message Andres Freund 2018-04-30 23:03:21 Re: Fsync request queue