Sample Annotated Prefork and Worker MPM configurations

Further httpd Configuration example from a Well House Consultants training course
More on Further httpd Configuration [link]

This example is described in the following article(s):
• Tuning httpd / the supermarket checkout comparison - [link]
• Tuning Apache httpd and Tomcat to work well together - [link]

Source code: mpmsample.conf Module: A603

# Sample Annotated Prefork and Worker MPM configurations
# Apache 2.2.x ... from /usr/local/apache2/conf/extra/httpd-mpm.conf

# Prefork MPM example - for systems with one cpu

# Setting up with 35 memory slots for servers (that's the serverlimit)
# and all 35 of them may be used (the maxclients). If you change the
# serverlimit you have to stop and restart the apache daemon, but if
# you only change maxclients you can do a "graceful" and not put a
# blip in traffic

# four server are started when the server is started, and the number is
# increased to a maximum of 35 (maxclients) as required, with four spare
# servers being opened up ahead as traffic increases. As traffic drops
# away, the server leaves eight open servers available and waiting.

<IfModule mpm_prefork_module>
    ServerLimit 35
    StartServers 4
    MinSpareServers 4
    MaxSpareServers 8
    MaxClients 35
    MaxRequestsPerChild 2000
</IfModule>

# Worker MPM example - for systems with lots of cpus

# Initially, start two servers (startservers) each with a
# fixed number of threads (threadsperchild) - that's 25 each
# making an initial total of 50 thread. As traffic grows
# the pool of free threads will reduce; once it gets down
# to 25 (minsparethreads) start another server - that will
# add a further 25 threads because that's the size of blocks
# they come in. There's a maximum of 150 client threads, and
# they will be spread over six servers (thats calculated from
# maxclients / threadsperchild) so that in this example you
# mayt be service from six cpus.

<IfModule mpm_worker_module>
    StartServers 2
    MaxClients 150
    MinSpareThreads 25
    MaxSpareThreads 75
    ThreadsPerChild 25
    MaxRequestsPerChild 0
</IfModule>

# apachectl -l ... tells you which you are running:
#
# -bash-3.2$ ./apachectl -l
# Compiled in modules:
# core.c
# mod_authn_file.c
# [etc]
# prefork.c
# [etc]
# -bash-3.2$

Learn about this subject

This module and example are covered on the following public courses:
* Deploying Apache and Tomcat
* Deploying LAMP - Linux, Apache, MySQL, Perl/PHP
* Linux Web Server
* Deploying Java Applications on Linux / Unix
Also available on on site courses for larger groups

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Other Examples

This example comes from our "Further httpd Configuration" training module. You'll find a description of the topic and some other closely related examples on the "Further httpd Configuration" module index page.

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