Re: Postgres entering zombie state once a week in production evnvironment

On Tue, Apr 14, 2009 at 12:25 AM, Bryce Nesbitt <bryce2@obviously.com> wrote:
> We have a medium scale installation of Postgres 8.3 that is freezing about
> once a week.  I'm looking for any hints on how to diagnose the situation, as
> nothing is logged.
>
> The system is matched pair of Sunfire servers, running Debian Etch with a
> 2.6.18-6-amd64 kernel, PostgreSQL 8.3.4, and DRBD 8.0.13.
>
> During a failed state, pg_stat_activity will show hundreds of statements
> pending.  query_start will show the statements arriving at a normal rate (a
> few per second), but clearly they never complete.  The bulk of these
> statement are a simple select that starts each web session, a statement that
> generally completes in tenths of milliseconds.  Restarting postgres restores
> normal operation, at the loss of all chance of figuring out what was wrong.

What does pg_locks say during this time?  Specifically about locks
that aren't granted?