[Koha] Regular performance problems

[LAURENT Henri-Damien]

Le 14/03/2011 18:09, Chris Hobbs a écrit :
>  Our koha server regularly grinds to a halt, preventing use of the web
> gui and even making it near impossible to log into via ssh. One minute
> load average on the server has spiked into at least the 80s, where it
> normally hovers around 1.
> 
> If I'm patient, after about 15 minutes the system becomes usable again.
> 
> Where should I begin looking for the trouble?
> 
> The system is running on a VMWare ESX host. It's been given two vCPUs
> and 6GB of RAM. The host is not starved for resources, so I think I can
> exclude it from the equation. Other VMs running on the same host are not
> affected.
> 
> Koha is version 3.01.00.140 (last beta before 3.2). The server is Ubuntu
> 9.10. We have ~200,000 items and ~100,000 biblios.
> 
> I was able to capture a process list during the last event (this AM),
> and saw that I had 95 instances of apache started. At the moment, with
> things working smoothly, I have only 14.
> 
> I've also run mysqltuner.pl in order to locate potential bottlenecks
> with the db, and the only glaring issues I have are:
> 
> 1) Lots of joins without indexes (811 since db restart this morning)
> 2)  Temporary tables created on disk: 45% (6K on disk / 15K total)
>   I've set innodb_buffer_pool_size = 1G in my.cnf, but still the system
> keeps creating these tables on disk, which certainly can't be helping
> anything.
> 
> OK, any ideas? Other troubleshooting info I can provide? It's gotten to
> the point that we're losing a decent amount of time every day to this issue.
> 
> Thanks so much in advance!
>  
> -- 
> Chris Hobbs
> Director, Technology
> New Haven Unified School District
Hi
Innodb file management is quite important for performance.
We wrote a performance blog post
http://www.biblibre.com/en/blog/entry/mysql-default-config-and-very-large-koha-database
you might find it interesting.
Also, you should check that your kernel is at least bigmem enabled.
Last but not least, check that you are not sending too many queries at
once. We had that problem once. Solution could be to use a firewall to
block more than 10 requests of the same page from same ip in a short
amount of time (say less than 3 second for instance)
There also has been an interesting discussion on performance tweeking on
apache on list
http://www.mail-archive.com/koha-devel@lists.koha-community.org/msg00074.html
Hope that helps
-- 
Henri-Damien LAURENT