[Kolab-devel] Kolab troubles under high load

[Steffen Hansen]

On Monday 09 May 2005 11:18, Matt Douhan wrote:
> On Sunday 08 May 2005 18.46, Steffen Hansen wrote:
> > On Friday 06 May 2005 11:55, Matt Douhan wrote:
> > > I am not convinced that several instances of the filter is
> > > actually in use, how can I check that?
> > >
> > > SHould I see several kolabfilter and kolabmailboxfilter in ps
> > > output ?
> >
> > Yes, you should see several instances of php when looking with top
> > or ps. I see over 10 instances running when I "mailbomb" my
> > test-server.
>
> 11:16am mdouhan @ (removed hostname) ~ > ps -auxw | grep filter | wc
> -l 72
>
> ok I 'd say this is working nicely as far as the number of filters
> not being one.
>
> the load increased dramatically on the server though, and I guess
> this is due to the invokation of PHP for every filter. This is not
> hurting in any way yet but I guess if the load increases further then
> launching more filters might eventually exhaust the box.
>
> Is the no way to keep the PHP interpreter started at all time to save
> the startup cost?

That would require a partial rewrite of the filter code. I have made a 
few experiments, and it seems that the way to go would be to make the 
filter speak LMTP and invoke it through the the postfix spawn(8) 
service.

Alternatively it should be made into a real SMTP server with pre-forked 
children to take care of clients -- but that is asking a bit much from 
a PHP script imho :-)

regards
-- 
Steffen Hansen          |       Klarälvdalens Datakonsult AB
Senior Software Engineer|       http://www.klaralvdalens-datakonsult.se
                        |
                        |       Platform-independent
                        |       software solutions