[Koha-devel] memcached?

[LAURENT Henri-Damien]

Le 04/06/2010 18:40, Dobrica Pavlinusic a écrit :
> On Fri, Jun 04, 2010 at 04:35:51PM +0100, Colin Campbell wrote:
>> On 04/06/10 15:42, Cindy Murdock Ames wrote:
>>> Hi all,
>>>
>>> The good news: CCFLS went live with 3.2alpha2 on Tuesday! The bad news:
>>> our transactions are *really* slow at times. I suspect the culprit is
>>> probably a ton of simultaneous mysql activity.
>> Have you done any tuning of mysql? Out of the box it probably is
>> using less memory than it needs for efficient running. A lot of the
>> my.cnf parameters can be tuned to improve throughput.
>> Memcache can work wonders but it needs to be caching the data thats
>> causing you to thrash the db. I'm not sure we've reached that point
>> yet.
> 
> I documented my journy over mysql tuning for Koha at:
> 
> http://blog.rot13.org/2010/04/mysql_is_slow_did_you_tune_your_settings.html
> 
> Just running mysqltuner.pl or tuning-primer.sh will probably be enough
> :-)
> 
> I would highly recommend putting session files at filesystem as opposed
> to database, especially if you have semi-high load on your website (web
> crawlers and what not) because it cut down database load by 75% for us.
> 
> Testing current memcache in Koha, it seemed to be used only for
> localization caching, and it was a bit slower on our system after some
> basic profiling. YMMV.
> 
memcached is not really meant for speed but for scaling. Speed
improvement is a +.
So that compared to db access, it is not really faster.
But if you have many access and network slowness then it is really
interesting.
Chris Cormack also did some POCs on Caching whole pages. And not only
function results. And results were quite encouraging. But that never hit
code base for 3.2.
What is really strange is the way Context is evaluated multiple times.
And we come to thousands of SQL queries for a simple page.
-- 
Henri-Damien LAURENT
BibLibre