Performance Tuning - Red Hat ENTERPRISE LINUX 4 System Administration Manual

Chapter 24. Apache HTTP Server Configuration
The PID File value corresponds to the
server records its process ID (pid). This file should only be readable by root. In most cases, it should
be left to the default value.
The Core Dump Directory value corresponds to the
HTTP Server tries to switch to this directory before executing a core dump. The default value is the
ServerRoot. However, if the user that the server runs as can not write to this directory, the core
dump can not be written. Change this value to a directory writable by the user the server runs as, if
you want to write the core dumps to disk for debugging purposes.
The User value corresponds to the
requests. This user's settings determine the server's access. Any files inaccessible to this user are
also inaccessible to your website's visitors. The default for User is apache.
The user should only have privileges so that it can access files which are supposed to be visible to
the outside world. The user is also the owner of any CGI processes spawned by the server. The user
should not be allowed to execute any code which is not intended to be in response to HTTP requests.
Warning
Unless you know exactly what you are doing, do not set the User directive to root. Using
root as the User creates large security holes for your Web server.
The parent httpd process first runs as root during normal operations, but is then immediately handed
off to the apache user. The server must start as root because it needs to bind to a port below 1024.
Ports below 1024 are reserved for system use, so they can not be used by anyone but root. Once the
server has attached itself to its port, however, it hands the process off to the apache user before it
accepts any connection requests.
The Group value corresponds to the
directive. Group sets the group under which the server answers requests. The default group is also
apache.

24.5. Performance Tuning

Click on the Performance Tuning tab to configure the maximum number of child server processes
you want and to configure the Apache HTTP Server options for client connections. The default settings
for these options are appropriate for most situations. Altering these settings may affect the overall
performance of your Web server.
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http://httpd.apache.org/docs-2.0/mod/mpm_common.html#pidfile
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http://httpd.apache.org/docs-2.0/mod/mpm_common.html#coredumpdirectory
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http://httpd.apache.org/docs-2.0/mod/mpm_common.html#user
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http://httpd.apache.org/docs-2.0/mod/mpm_common.html#group
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directive. This directive sets the file in which the
PidFile
CoreDumpDirectory
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directive. It sets the userid used by the server to answer
User
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directive. The Group directive is similar to the User
Group
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directive. The Apache