[rt-users] Search hangs RT

[Kenneth Marshall]

On Tue, Feb 10, 2009 at 02:21:15PM +0100, Anne-Marie Achrenius wrote:
> Hello!
> 
> I'm new to the list and I'm in a bit of a pickle, our RT-guru is on
> paternity leave and we've started having problems with our RT-installation.
> I've tried searching the list archives for something similar, but
> nothing fits exactly:
> 
> The problem: Often (not every time, maybe 8 out of 10) when I perform a
> Search in RT, the search hangs.
> The mysqld process is at 100 % cpu. When reading the log files, this
> jumps out:
> 
> /var/lib/mysql/blaha.log:
> 
> SELECT GET_LOCK('Apache-Session-ed5bea237ae21873fecd13ade9cb3f63', 3600)
> 
> and after a few minutes the web-interface returns with "500 Internal
> Server Error"
> 
> I've so far tried to decrease the LOCK time in
> /usr/lib/perl5/site_perl/5.8.5/Apache/Session/Lock/MySQL.pm
> but that doesn't seem to help at all.
> I've enabled logging of slow mysql queries, but so far no log entries
> 
> We're running RT 3.7.5
>                      mysql 14.7
>                      apache 2.0.52
> 
> Does anyone have any suggestions or similar problems?
> I can't pinpoint when we started having problems, 2-3 weeks ago, and the
> problem seems to slowly escalate.
> 
> /Anne-Marie
> 
> 
Maybe your session table needs to be cleaned up. Try deleting any
sessions over a couple of days old and then optimize the table. I
cannot help with the specific commands since we use PostgreSQL for
our RT instance but in SQL I run a command like:

DELETE FROM sessions WHERE lastupdated < '2009-1-30';

or even

TRUNCATE TABLE sessions;

to get them all. You may just have a bloat problem. Try a

SELECT COUNT(*) FROM sessions;

Hope this helps.

Cheers,
Ken