Performance Tuning for Content Manager

Chapter 9. Tuning WebSphere for Content Manager 265

Our recommendation

For optimum performance, specify the same value for the MaxSpareServers (see

above) and the StartServers parameters. Specifying similar values reduces the

CPU usage for creating and destroying httpd processes. It also preallocates and

maintains the specified number of processes so that few processes are created

and destroyed as the load approaches the specified number of processes (based

on MinSpareServers).

9.4.7 Maximum requests per child (MaxRequestPerChild)

Apache always creates one child process to handle requests. If it dies, another

child process is created automatically. Within the child process, multiple threads

handle incoming requests. The MaxRequestsPerChild directive sets the limit on

the number of requests that an individual child server process will handle. After

MaxRequestsPerChild requests, the child process will die. If

MaxRequestsPerChild is zero, then the process will never expire.

Setting MaxRequestsPerChild to a non-zero limit has two beneficial effects:

 It limits the amount of memory that process can consume by (accidental)

memory leakage.

 It helps to reduce the number of processes when the server load reduces by

giving the processes a finite life time.

However, on Win32®, It is recommended that this be set to zero. If it is set to a

non-zero value, when the request count is reached, the child process exits, and

is re-spawned, at which time it rereads the configuration files. This can lead to

unexpected behavior if you have modified a configuration file but are not

expecting the changes to be applied yet. See also (ThreadsPerChild).

Default values

0 for Windows platforms

0000 for AIX platforms

How to view or set

1. Edit the IBM HTTP server file httpd.conf, located in the directory

IBM_HTTP_Server_root_directory/conf.

2. Change the value of the MaxRequestPerChild parameter.

3. Save the changes and restart the IBM HTTP server.