Re: "pgstat wait timeout" warnings - Mailing list pgsql-hackers

From Robert Haas
Subject Re: "pgstat wait timeout" warnings
Date
Msg-id CA+TgmoZW-BAoL4J=UepBhR8gzpuB-qKm787PkeRYroxp8kuikg@mail.gmail.com
Whole thread Raw
In response to Re: "pgstat wait timeout" warnings  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Thu, Aug 11, 2011 at 10:30 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Andres Freund <andres@anarazel.de> writes:
>>> --On 10. August 2011 21:54:06 +0300 Heikki Linnakangas
>>> <heikki.linnakangas@enterprisedb.com> wrote:
>>>> So my theory is that if the I/O is really busy, write() on the stats file
>>>> blocks for more than 5 seconds, and you get the timeout.
>
>> Yes, I have seen it several times as well. I can actually reproduce it
>> without much problems, so if you have some idea to test...
>
> It doesn't surprise me that it's possible to reproduce it under extreme
> I/O load.  What I am wondering about is whether there's some bug/effect
> that allows it to happen without that.

I got it several times during a pgbench -i -s 5000 run this morning.
I guess that's a lot of I/O, but I'm not sure I'd refer to one process
filling a table with data as "extreme".

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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