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Chapter 14. Apache HTTP Server

14.2.1.2. Server pool Size Regulation

In Apache HTTP Server 2.0, the responsibility for accepting requests and dispatching child processes

to handle them has been abstracted into a group of modules called Multi Processing Modules (MPMs).

Unlike other modules, only one module from the MPM group can be loaded by the Apache HTTP

Server because an MPM module is responsible for basic request handling and dispatching. There are

three MPM modules that ship with version 2.0: prefork, worker, and perchild.

The original Apache HTTP Server 1.3 behavior has been moved into the prefork MPM. Currently

only the prefork MPM is available on Red Hat Linux, although other MPMs may be made available

at some later date.

The MPM supplied by default on Red Hat Linux is prefork which accepts the same directives as

Apache HTTP Server 1.3. The following directives may be migrated directly:

  StartServers

  MinSpareServers

  MaxSpareServers

  MaxClients

  MaxRequestsPerChild

For more on this topic, refer to the following documentation on the Apache Software Foundation's

website:

http://httpd.apache.org/docs 2.0/mpm.html

14.2.1.3. Dynamic Shared Object (DSO) Support

There are many changes required here and it is highly recommended that anyone trying to modify an

Apache 1.3 configuration to suit Apache 2.0 (as opposed to migrating your changes into the Apache

2.0 configuration) copy this section from the stock Red Hat Linux Apache HTTP Server 2.0 configu 

ration file.

Important

If you do decide to try and modify your original file, please note that it is of paramount importance

that your httpd.conf contains the following directive:

Include conf.d/*.conf

Omission of this directive will result in the failure of all modules packaged in their own RPMs (such

as mod_perl, php, and mod_ssl).

Those who still do not want to copy the section from the stock Apache HTTP Server 2.0 configuration

should note the following:

The

AddModule

and

ClearModuleList

directives no longer exist. These directives where used

to ensure that modules could be enabled in the correct order. The Apache 2.0 API allows modules

to specify their ordering, eliminating the need for these two directives.

The order of the

LoadModule

lines is no longer relevant.

Many modules have been added, removed, renamed, split up, or incorporated with each other.