Scenario:
SLES 9
Apache2
ZfD 7 MiddleTier (SP1 IR3a HP3)

Issue:
How to optimize the SLES 9 Apache2 for MiddleTier performance

Details:
Earlier we had the MiddleTier service (XTIER) running in a NetWare 6.5 server.
Now the XTIER runs in a SLES 9 server.

In NetWare we changed the following line in the Apache2 httpd.conf file for max MiddleTier performance:
ThreadsPerChild 512 (default 50)

But how should this be applied to the Apache2 conf-files in a SLES9?
Instead of the httpd.conf, tuning are done in a file called server-tuning.conf,
which seems to act as an "add-on" to the httpd.conf.

But in the server-tuning.conf file there are 5 consecutive chapters looking almost alike,
that may be eligible for the wanted line "ThreadsPerChild 512".

Where shall I put the line "ThreadsPerChild 512" ?

These chapters are (cut and paste from server-tuning.conf):
***********************
# prefork MPM
<IfModule prefork.c>
# number of server processes to start
StartServers 5
# minimum number of server processes which are kept spare
MinSpareServers 5
# maximum number of server processes which are kept spare
MaxSpareServers 10
# highest possible MaxClients setting for the lifetime of the Apache process.
ServerLimit 150
# maximum number of server processes allowed to start
MaxClients 150
# maximum number of requests a server process serves
MaxRequestsPerChild 0
</IfModule>

# worker MPM
<IfModule worker.c>
# initial number of server processes to start
StartServers 2
# minimum number of worker threads which are kept spare
MinSpareThreads 25
# maximum number of worker threads which are kept spare
MaxSpareThreads 1024
# maximum number of simultaneous client connections
MaxClients 8192
ServerLimit 128
# constant number of worker threads in each server process
ThreadsPerChild 64
# maximum number of requests a server process serves
MaxRequestsPerChild 0
</IfModule>

# leader MPM
<IfModule leader.c>
# initial number of server processes to start
StartServers 2
# minimum number of worker threads which are kept spare
MinSpareThreads 25
# maximum number of worker threads which are kept spare
MaxSpareThreads 75
# maximum number of simultaneous client connections
MaxClients 150
# constant number of worker threads in each server process
ThreadsPerChild 25
# maximum number of requests a server process serves
MaxRequestsPerChild 0
</IfModule>

# perchild MPM
<IfModule perchild.c>
# constant number of server processes
NumServers 5
# initial number of worker threads in each server process
StartThreads 5
# minimum number of worker threads which are kept spare
MinSpareThreads 5
# maximum number of worker threads which are kept spare
MaxSpareThreads 10
# maximum number of worker threads in each server process
MaxThreadsPerChild 20
# maximum number of connections per server process
MaxRequestsPerChild 0

AcceptMutex fcntl
</IfModule>

# metux MPM
<IfModule metuxmpm.c>
# initial number of worker threads in each server process
StartThreads 5
# minimum number of worker threads which are kept spare
MinSpareThreads 5
# maximum number of worker threads which are kept spare
MaxSpareThreads 10
# maximum number of connections per server process
MaxRequestsPerChild 0
***********************