Optimizing Apache performance: KeepAlive Off/On and mpm-prefork/mpm-worker

[janny_buh]

I'm using OXSE 6.20.1.0 with Apache 2.2 on RHEL 5.5 in a clustered setup.
Default installation of Apache comes with KeepAlive Off and mpm-prefork.
I would like to optimize Apache performance, but OXSE installation guides there is no mention on those options...

For example, what about turning KeepAlive On and changing to mpm-worker thread model?
Are those changes "compatible" with OXSE usage pattern?

What about changing Apache configuration as follows?

KeepAlive On
KeepAliveTimeout ??? (less than default 15, it is too much I think, so I guess 2 or 3 will be more appropriate)
MaxKeepAliveRequests 100

<IfModule worker.c>
ServerLimit         40
ThreadLimit         25

StartServers         4
MaxClients        1000
MinSpareThreads     50
MaxSpareThreads    150
ThreadsPerChild     25
MaxRequestsPerChild  4000
</IfModule>