[SOGo] Re: question about /etc/init.d script

[Helge Hess]

On 01.04.2008, at 00:14, Ernersto Revilla wrote:
> About load balancing: I'll have a look later on. snsd can forward
> request to the load balancer.

The snsd is irrelevant for ScalableOGo, since it does not use  
sessions. (it can also balance non-session requests, but there are way  
better solutions for this).

> I don't know the interface, but I can read
> the source code to see what really happens there (and why I can't use
> just mod_proxy proxy-balancer, pound or a hardware load balancer).

You can use all of those as a frontend. Be sure to configure them to  
stick requests to an instance (probably using some cookie).
Originally we used Pound, but mod_proxy has gotten quite good in the  
last years too.

Note that this does not remove the need to use Apache in front of a  
SOPE application (since the SOPE app is not a full HTTP server). The  
load balancer is to be used as an Apache load balancer.

> FastCGI would also be a nice thing as lighttpd may do load balancing  
> at
> this level with no external code.

I fail to see what FastCGI has to do with this or why it would be any  
better than implementing the necessary HTTP (why another protocol?).
Anyways, you could certainly write an WOFastCGIAdaptor if you wanted to.

> Of course, this depends of what data
> is NOT shared between instances (like session data, etc.).

ScalableOGo is stateless, thats the core of the idea. Stateful servers  
do not scale (as well). *However* to have good cache usage, requests  
of course should stay at their origin instance if possible (most load  
balancers support this).

Helge
-- 
Helge Hess
http://www.helgehess.eu/