[pgpool-general: 1544] Re: Mysterious Load Spikes

[Quentin Hartman]

Yeah, I just finished reading through those threads and they are
interesting, but their conclusions seem to be that the root issue is
related to IO problems, particular with regard to checkpoints. Since I'm
not running postgres on the pgpool2 boxes at all, I really don't think it's
directly related to the problem I'm seeing. My pgpool2 boxes have virtually
no IO load on them at all.

QH

On Thu, Mar 28, 2013 at 9:47 AM, Lonni J Friedman <netllama at gmail.com>wrote:

> Ah, that thread looks interesting, although the original poster seems
> to have fixed his issues with a kernel upgrade to some 3.4.x kernel.
> I'm using 3.6.6, so I'm not sure whether its the same thing at all.
>
> On Thu, Mar 28, 2013 at 8:40 AM, Tatsuo Ishii <ishii at postgresql.org>
> wrote:
> > Maybe this one?
> >
> > http://www.postgresql.org/message-id/512D4548.2000502@agliodbs.com
> > --
> > Tatsuo Ishii
> > SRA OSS, Inc. Japan
> > English: http://www.sraoss.co.jp/index_en.php
> > Japanese: http://www.sraoss.co.jp
> >
> >> Did you have a particular thread in mind?  I scanned the list
> >> archives, and honestly didn't see anything relevant.  The closest
> >> thing was this very recent off-topic post:
> >> http://www.postgresql.org/message-id/51519CE9.1070409@opinioni.net
> >>
> >> On Thu, Mar 28, 2013 at 2:27 AM, Will Ferguson
> >> <wferguson at northplains.com> wrote:
> >>>
> >>> Have a look in the postgres performance mailing lists. There's been a
> lot of chatter recently about performance problems regarding 3.x kernels.
> >>>
> >>> Will
> >>>
> >>>
> >>> On 27/03/13 15:24, Quentin Hartman wrote:
> >>>
> >>> On Wed, Mar 27, 2013 at 9:15 AM, Lonni J Friedman <netllama at gmail.com>
> wrote:
> >>>>
> >>>> FWIW, I also see roughly the same behavior, although my environment is
> >>>> somewhat different than yours.  Previously my pgpool server was
> >>>> running on RHEL6, however it was migrated to Fedora17 (without
> >>>> changing the pgpool version).  Before the migration the load on the
> >>>> server was typically less than 1.00.  Since migrating the load average
> >>>> is 30+ (with spikes up to 60 quite often).  Yet there's nothing
> >>>> obvious causing the load.  I'm certain something in pgpool is causing
> >>>> this behavior, because the load drops to 0 during the rare times when
> >>>> we need to stop pgpool for maintenance.
> >>>
> >>>
> >>> Thanks for the quick reply Lonni. I'm glad to hear that it's not a
> problem limited to Ubuntu. Like you I suspect it has something to do with
> the 3.x kernel series. I'm going to be doing some experimentation soon to
> try to isolate and eliminate this problem. I'll update this thread with my
> findings.
> >>>
> >>> If anyone else is interested in coordinating efforts, I'd be glad for
> the help.
> >>>
> >>> QH
> >>>
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