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

Alvaro Herrera <alvherre@commandprompt.com>

From: Alvaro Herrera <alvherre@commandprompt.com>

To: daveg <daveg@sonic.net>

Cc: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Maxim Boguk <maxim.boguk@gmail.com>, Fujii Masao <masao.fujii@gmail.com>, pgsql-admin <pgsql-admin@postgresql.org>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2011-03-02T21:45:13Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Fix a violation of WAL coding rules in the recent patch to include an
- 7fc7a7c4d082 9.0.0 cited

Excerpts from daveg's message of mié mar 02 18:30:34 -0300 2011:

> After a restart and vacuum of all dbs with no other activity things were
> quiet for a couple hours and then we started seeing these PD_ALL_VISIBLE
> messages again. 
> 
> Going back through the logs we have been getting these since at least before
> mid January. Oddly, this only happens on four systems which are all new Dell
> 32 core Nehalem 512GB machines using iscsi partitions served off a Netapp.
> Our older 8 core 64GB hosts have never logged any of these errors. I'm not
> saying it is related to the hw, as these hosts are doing a lot more work than
> the old hosts so it may be a concurrency problem that just never came up at
> lower levels before.
> 
> 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?)

-- 
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
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