Maybe this can contribute
When I run a query over this table XXX, and immediately try to cancel the
query, the cancel never completes.
I found that this situation was fixed in last release (9.0.8)
· Ensure sequential scans check for query cancel reasonably often
(Merlin Moncure)
A scan encountering many consecutive pages that contain no live tuples would
not respond to interrupts meanwhile
Maybe in the autovacuum happen something similar?
De: Anibal David Acosta [mailto:***@devshock.com]
Enviado el: jueves, 02 de agosto de 2012 10:52 a.m.
Para: 'Craig Ringer'
CC: 'pgsql-***@postgresql.org'
Asunto: RE: [ADMIN] Timeout error on pgstat
Craig, those lines appear between pgstat timeout
ERROR: canceling autovacuum task
CONTEXT: automatic vacuum of table "XXX"
The table XXX is a table with about 200 insert p/ second. No update or
delete.
The problem apparently is just with this table because there are others
autovacuum running and working fin over others tables
The only difference is that this table XXX has about 5millions of insert
daily and all those 5millons are deleted in the night (cleanup process).
De: Craig Ringer [mailto:***@ringerc.id.au]
Enviado el: miércoles, 01 de agosto de 2012 10:01 p.m.
Para: Anibal David Acosta
CC: pgsql-***@postgresql.org
Asunto: Re: [ADMIN] Timeout error on pgstat
On 08/02/2012 04:27 AM, Anibal David Acosta wrote:
I have a lot (maybe 1 every 10 seconds) of this error WARNING: pgstat wait
timeout
A quick search suggests this can be due to excessive I/O. However, this
thread:
http://postgresql.1045698.n5.nabble.com/pgstat-wait-timeout-td5078125.html
sounds very similar to your issue. I'm wondering if there's a bug lurking in
there somewhere.
In the pg_stat_activity show an autovacuum process over a very used table
that runs about 1 hour and then this vacuum is cancelled (according to log)
Was there any context to the `cancelling autovacuum task' message?
I have Postgres 9.0.3 on a windows 2008 R2 running for about 1 year in same
conditions, but this error is occurring about 1 week ago.
The current 9.0 release is 9.0.8, so you're missing a bunch of bug fixes.
http://www.postgresql.org/docs/current/static/release-9-0-8.html
Consider updating. You don't need to do a dump and reload or use pg_upgrade,
since it's only a minor version update. Stop the DB, install the new
binaries, start the DB.
However, I don't see any fixes related to the stats writer in the relnotes
from the 9.0 series.
--
Craig Ringer