[horde] horde + apache 2.2.x + mod_proxy?

[Michael M Slusarz]

Quoting "Liam Hoekenga" <liamr at umich.edu>:

> So... since we installed 3.2, the load on our servers is  
> significantly higher.
> Kevin's made some very helpful suggestions as to the use of openBSD's
> PF and CARP.. but ideally I'd like a solution that wouldn't involve a
> new OS.

Still wondering where the load is coming from on your server.  The  
large installations I have worked with have all seen decreased load  
(some quite dramatically) using 3.2.

> I'm looking at mod_proxy and mod_proxy_balancer as a possible
> solution.. but I've not got it working.
>
> Every time I hit the front end, the browser is redirected to backend,
> and the user sees the backend's IP address.
>
> My front end conf looks like this..
>
>      ProxyPass / balancer://webmail/
>      ProxyPassReverse / balancer://webmail/
>      SSLProxyEngine      on
>      <Proxy balancer://webmail>
>          BalancerMember https://xxx.xxx.xxx.xxx
>      </Proxy>
>
> I found a suggestion in some old mail via marc, that I might want to
> add some stuff to horde/config/conf.php, so the horde installation on
> the backend server had information for the front end.
>
>      $conf['server']['name'] = 'web-test.mail.umich.edu';
>      $conf['cookie']['domain'] = 'web-test.mail.umich.edu';
>
>
> I can access our cache statistics and cgi on the backend via the front
> end, and the URL never changes in the browser... but as soon as I
> point it at horde, the IP address of the backend server is revealed to
> the user (shown in the browser's location bar)/
>
> Anyone have suggestions?

My suggestion is moving to a FastCGI architecture using something like  
lighttpd as the front end and using a distributed session handler -  
e.g. memcache, SQL.  From my experiences, without serious tweaking,  
Apache's performance is terrible with PHP - the Apache processes get  
so large (each process being 60-80MB+) that you reach a point where  
most of the server load has to deal with swapping those processes  
from/to memory - in other words, adding new Apache processes does  
nothing to improve performance.  With FastCGI, you can serve the  
front-end with a single box (welll... more likely several boxes for  
redundancy) and then add as many FastCGI servers in the backend that  
you need to handle the load.

michael

-- 
___________________________________
Michael Slusarz [slusarz at horde.org]