[rt-users] Search hangs RT

[Kenneth Marshall]

On Tue, Feb 10, 2009 at 04:19:27PM +0100, Anne-Marie Achrenius wrote:
> Kenneth Marshall skrev:
> > 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
> >   
> 
> Thanks for the help, unfortunately the problem doesn't seem to lie there:
> 
> mysql> SELECT COUNT(*) FROM sessions;
> +----------+
> | COUNT(*) |
> +----------+
> |      323 |
> +----------+
> 1 row in set (0.00 sec)
> 
> and deleting anything older than 30/1 left 11. Still the same problem,
> search keeps hanging.
> How do I optimize the table? (I used to work with Oracle db:s around 10
> years ago, I'm pretty rusty!)
> 
> Depressed,
> 
> /Anne-Marie
> 

Anne-Marie,

It is more drastic, but since your RT administrator is out, maybe you
could change to Session logging to a file and not the database. In
3.8 the lines in RT_Config.pm are:

=item C<$WebSessionClass>

C<$WebSessionClass> is the class you wish to use for managing Sessions.
It defaults to use your SQL database, but if you are using MySQL 3.x and
plans to use non-ascii Queue names, uncomment and add this line to
F<RT_SiteConfig.pm> will prevent session corruption.

=cut

# Set($WebSessionClass , 'Apache::Session::File');

You should be able to add this line to your RT_SiteConfig.pm and then
restart RT to use the file version of session storage. That should
get you working until your admin returns.

Good luck,
Ken