Re: cpu bound postgresql setup.

Benjamin Krajmalnik wrote:
> > -----Original Message-----
> > From: Bruce Momjian [mailto:bruce(at)momjian(dot)us]
> > Sent: Monday, June 28, 2010 3:45 PM
> > To: Benjamin Krajmalnik
> > Cc: Rajesh Kumar Mallah; Kevin Grittner; pgsql-
> > performance(at)postgresql(dot)org
> > Subject: Re: [PERFORM] cpu bound postgresql setup.
> >
> > Benjamin Krajmalnik wrote:
> > > Rajesh,
> > >
> > > I had a similar situation a few weeks ago whereby performance all of
> > a
> > > sudden decreased.
> > > The one tunable which resolved the problem in my case was increasing
> > the
> > > number of checkpoint segments.
> > > After increasing them, everything went back to its normal state.
> >
> > Did you get a db server log message suggesting in increasing that
> > setting? I hope so.

> Unfortunately not. The behavior I had was ebbs and flows. On FreeBSD,
> I was seeing a lot of kernel wait states in top. So every few minutes,
> responsiveness of the db was pretty bad. 8.4.4/amd64 on FreeBSD 7.2

Bummer. What is supposed to happen is if you are checkpointing too
frequently ( < 30 seconds), you get the suggestion about increasing
checkpoint_segments. I have not heard of cases where you are not
checkpointing too frequently, and increasing checkpoint_segments helps.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ None of us is going to be here forever. +