From: Merlin Moncure <mmoncure@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Benjamin Minshall <minshall@intellicon.biz>
Cc: pgsql-performance@postgresql.org
Subject: Re: stats collector process high CPU utilization
Date: Thu, 1 Mar 2007 16:58:20 -0500
Message-ID: <b42b73150703011358p7dfe77dft85ba7f3cdd3ce160@mail.gmail.com> (raw)
In-Reply-To: <16282.1172779976@sss.pgh.pa.us>
References: <45CB5D06.7090004@intellicon.biz>
<62089.75.14.32.120.1170994418.squirrel@intellicon.biz>
<14668.1170995218@sss.pgh.pa.us>
<20070209142459.GB4253@alvh.no-ip.org>
<24717.1171033699@sss.pgh.pa.us>
<29832.1171036557@sss.pgh.pa.us>
<45CCA0DB.2010903@intellicon.biz>
<1116.1171038786@sss.pgh.pa.us>
<45CCBF13.2000707@intellicon.biz>
<16282.1172779976@sss.pgh.pa.us>
On 3/1/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Benjamin Minshall <minshall@intellicon.biz> writes:
> > Tom Lane wrote:
> >> It's sounding like what you had was just transient bloat, in which case
> >> it might be useful to inquire whether anything out-of-the-ordinary had
> >> been done to the database right before the excessive-CPU-usage problem
> >> started.
>
> > I don't believe that there was any unusual activity on the server, but I
> > have set up some more detailed logging to hopefully identify a pattern
> > if the problem resurfaces.
>
> A further report led us to realize that 8.2.x in fact has a nasty bug
> here: the stats collector is supposed to dump its stats to a file at
> most every 500 milliseconds, but the code was actually waiting only
> 500 microseconds :-(. The larger the stats file, the more obvious
> this problem gets.
I think this explains the trigger that was blowing up my FC4 box.
merlin
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To: pgsql-performance@postgresql.org
Cc: mmoncure@gmail.com, tgl@sss.pgh.pa.us, minshall@intellicon.biz
Subject: Re: stats collector process high CPU utilization
In-Reply-To: <b42b73150703011358p7dfe77dft85ba7f3cdd3ce160@mail.gmail.com>
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