Re: "pgstat wait timeout" warnings

On Thu, Aug 11, 2011 at 10:30 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
>>> --On 10. August 2011 21:54:06 +0300 Heikki Linnakangas
>>> <heikki(dot)linnakangas(at)enterprisedb(dot)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
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