Обсуждение: unstable postgres on freebsd

Hi,

I seem to have an unstable/unreliable installation of postgresql, and I'm not sure how to troubleshoot it.

Symptoms:
$ psql postgres
psql: FATAL:  semctl(851974, 3, SETVAL, 0) failed: Invalid argument

(restart postgresql)
$ psql postgres
Welcome to psql 8.1.4, the PostgreSQL interactive terminal.
(rest of welcome message and psql prompt)

It will work fine for a while, but later it will stop accepting connections with the above error, until I restart postgresql again. It also happens when I call a ruby script that connects to postgres: fails with same error message sometimes, but works after restarting postgresql.

Versions/Environment:
Postgresql 8.1.4 (installed from ports on FreeBSD 6.1)

I've already tried reinstalling the postgresql81-server and postgresql81-client ports and their dependencies via portupgrade, but the symptoms persist. What else should I try?

--
Wes Sheldahl
wes.sheldahl@gmail.com

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Are you running this in a FreeBSD jail under 6.1?  It sounds like the problem
that I had where a second postmaster starts up and stomp's on the previous
postgresql's shared memory ...

To "fix", you have to make sure that both instances run as different UIDs, so
that one can't stomp on the other ...

- --On Friday, October 20, 2006 17:05:53 -0400 Wes Sheldahl
<wes.sheldahl@gmail.com> wrote:

> Hi,
>
> I seem to have an unstable/unreliable installation of postgresql, and I'm not
> sure how to troubleshoot it.
>
> Symptoms:
> $ psql postgres
> psql: FATAL:  semctl(851974, 3, SETVAL, 0) failed: Invalid argument
>
> (restart postgresql)
> $ psql postgres
> Welcome to psql 8.1.4, the PostgreSQL interactive terminal.
> (rest of welcome message and psql prompt)
>
> It will work fine for a while, but later it will stop accepting connections
> with the above error, until I restart postgresql again. It also happens when
> I call a ruby script that connects to postgres: fails with same error message
> sometimes, but works after restarting postgresql.
>
> Versions/Environment:
> Postgresql 8.1.4 (installed from ports on FreeBSD 6.1)
>
> I've already tried reinstalling the postgresql81-server and
> postgresql81-client ports and their dependencies via portupgrade, but the
> symptoms persist. What else should I try?
>
> --
> Wes Sheldahl
> wes.sheldahl@gmail.com



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"Wes Sheldahl" <wes.sheldahl@gmail.com> writes:
> I seem to have an unstable/unreliable installation of postgresql, and I'm
> not sure how to troubleshoot it.
> Symptoms:
> $ psql postgres
> psql: FATAL:  semctl(851974, 3, SETVAL, 0) failed: Invalid argument

AFAICS the only documented reason for that semctl to fail would be if
someone had removed the SysV semaphores that Postgres creates for itself
at startup.  Is it possible you've got some script on the loose that
periodically tries to clean out all the semaphores in the system?  Try
comparing the output of "ipcs -s" just after starting Postgres with the
output after this symptom appears.

It's probably worth asking if you've seen any other flaky behavior on
this box --- if so I'd kinda wonder about bad RAM or some such.

            regards, tom lane

Yes, it's a VPS running FreeBSD 6.1, so presumably it's in a FreeBSD jail. I'll verify that with my hosting provider and probably follow up along these lines. http://www.postgresql.org/docs/8.1/interactive/kernel-resources.html seems to recommend running as different uid's as well. Right now it's running as pgsql, UID 70, which I'm sure is the default. Thanks,

Wes Sheldahl





--
Wes Sheldahl
Sheldahl Consulting LLC
http://www.sheldahlconsulting.com
Phone: 859-338-3349
Fax: 866-387-4484
wes@sheldahlconsulting.com