[rt-users] Performance Issues

[Cliff Flood]

Kevin Sonney wrote:
> I had this same problem and unpgraded MySQL to 4.0 and all has been
> well.

What we see when a ticket is being served is an Apache CPU spike for the 
duration of the serve and a small MySQL spike just after the request is 
made. This leads me to believe the poor performance is the fault of 
Apache+mod_perl
Also, I would have expected the change to InnoDB tables to have given a 
performance boost if a slow DB was at fault.

Can you suggest how MySQL 4 might produce better results? Does RT use 
different queries with the newer MySQL?

This also leads me to another question, does anyone have any suggestions 
  or tips on how to debug mod_perl or on general tips for improving 
mod_perl performance. I really would like to get to the bottom of this 
and all help is appreciated.


> -----Original Message-----
> From: Cliff Flood [mailto:cliff.flood at voxpilot.com] 
> Sent: Tuesday, October 19, 2004 9:38 AM
> To: rt-users at lists.bestpractical.com
> Subject: [rt-users] Performance Issues
> 
> 
> Hi Guys,
> 
> We have an RT install that is performing quite poorly. Tickets take 
> quite a few seconds to open, sometimes 20 or more, depending on the 
> number of replies/comments. Our system has 896 tickets at present.
> 
> We were running 3.0.11. I upgraded to 3.2.2 hoping I might see some 
> performance gains but unfortunately I didn't.
> 
> I changed my MySQL (3.23.49) tables from MyISAM to InnoDB with no 
> discernible performance gain.
> 
> Applied some (Kernel shared memory, MySQL buffers) of the suggestions 
> from the PerformanceTuning[1] section of the WiKi, again with no 
> noticeable increase in performance. Upgraded DBIx::SearchBuilder to 1.11
> 
> Other pertinent stats;
> 
> Apache 1.3.31
> Perl 5.8.4
> Linux 2.4.7-10smp
> Dual PIII 500Mhz
> 512MB RAM
> 2 reasonably fast 10,000rpm SCSI discs in RAID 1.
> 
> When a ticket is being served I can see Apache using 99% CPU time for 
> the duration of the serve.
> 
> I've done much reading of the available docs. and mailing list archives.
> 
> I'm not quite sure what I should look at next. I know this class of 
> problem seems to be common. I haven't seen any definitive answers. Any 
> pointers would be appreciated.
> 
> 1. http://wiki.bestpractical.com/index.cgi?PerformanceTuning

-- 
Cliff Flood
Systems Administrator
V O X P I L O T
+353 1 209 1924