Re: [HACKERS] Re: PD_ALL_VISIBLE flag was incorrectly set happend during repeatable vacuum

On Wed, Mar 02, 2011 at 04:20:24PM -0800, bricklen wrote:
> On Wed, Mar 2, 2011 at 3:53 PM, daveg <daveg(at)sonic(dot)net> wrote:
> >> > Postgresql version is 8.4.4.
> >>
> >> I don't see how this could be related, but since you're running on NFS,
> >> maybe it is, somehow:
> >> http://archives.postgresql.org/message-id/4D40DDB7.1010000@credativ.com
> >> (for example what if the visibility map fork's last page is overwritten?)
> >
> > Running on ISCSI, not nfs. But it is still a Netapp, so who knows. I'll look.
> > Also, we are not seeing any of the "unexpected data beyond EOF" errors,
> > just thousands per day of the PD_ALL_VISIBLE error.
> >
> > -dg
>
> FWIW, we had a couple occurrences of that message about a month ago on 9.0.2
>
> http://archives.postgresql.org/pgsql-general/2011-01/msg00887.php
>
> Haven't seen it since we ran a cluster-wide vacuum.

We did a shutdown and restart to clear the buffer cache (but did not reboot
the host) and a vacuum on all dbs in the cluster last night. That cleared it
up for a couple hours, but we are still getting lots of these messages.

Most of them are pg_statistic and we create and drop hundreds of thousands of
temp tables daily, so there is a good chance there is a concurrancy issue.

-dg

--
David Gould daveg(at)sonic(dot)net 510 536 1443 510 282 0869
If simplicity worked, the world would be overrun with insects.