1 <?xml version="1.0" encoding="ISO-8859-1"?>
2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
3 <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
4 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
5 This file is generated from xml source: DO NOT EDIT
6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
8 <title>Multi-Processing Modules (MPMs) - Apache HTTP Server</title>
9 <link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
10 <link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
11 <link href="./style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
12 <link href="./images/favicon.ico" rel="shortcut icon" /></head>
13 <body id="manual-page"><div id="page-header">
14 <p class="menu"><a href="./mod/">Modules</a> | <a href="./mod/directives.html">Directives</a> | <a href="./faq/">FAQ</a> | <a href="./glossary.html">Glossary</a> | <a href="./sitemap.html">Sitemap</a></p>
15 <p class="apache">Apache HTTP Server Version 2.0</p>
16 <img alt="" src="./images/feather.gif" /></div>
17 <div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
19 <a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="./">Version 2.0</a></div><div id="page-content"><div id="preamble"><h1>Multi-Processing Modules (MPMs)</h1>
21 <p><span>Available Languages: </span><a href="./de/mpm.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
22 <a href="./en/mpm.html" title="English"> en </a> |
23 <a href="./es/mpm.html" hreflang="es" rel="alternate" title="Español"> es </a> |
24 <a href="./ja/mpm.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
25 <a href="./ko/mpm.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
26 <a href="./ru/mpm.html" hreflang="ru" rel="alternate" title="Russian"> ru </a> |
27 <a href="./tr/mpm.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
30 <p>This document describes what a Multi-Processing Module is and
31 how they are used by the Apache HTTP Server.</p>
33 <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#introduction">Introduction</a></li>
34 <li><img alt="" src="./images/down.gif" /> <a href="#choosing">Choosing an MPM</a></li>
35 <li><img alt="" src="./images/down.gif" /> <a href="#defaults">MPM Defaults</a></li>
37 <div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
39 <h2><a name="introduction" id="introduction">Introduction</a></h2>
41 <p>The Apache HTTP Server is designed to be a powerful and
42 flexible web server that can work on a very wide variety of
43 platforms in a range of different environments. Different
44 platforms and different environments often require different
45 features, or may have different ways of implementing the same
46 feature most efficiently. Apache has always accommodated a wide
47 variety of environments through its modular design. This design
48 allows the webmaster to choose which features will be included
49 in the server by selecting which modules to load either at
50 compile-time or at run-time.</p>
52 <p>Apache 2.0 extends this modular design to the most basic
53 functions of a web server. The server ships with a selection of
54 Multi-Processing Modules (MPMs) which are responsible for
55 binding to network ports on the machine, accepting requests,
56 and dispatching children to handle the requests.</p>
58 <p>Extending the modular design to this level of the server
59 allows two important benefits:</p>
62 <li>Apache can more cleanly and efficiently support a wide
63 variety of operating systems. In particular, the Windows
64 version of Apache is now much more efficient, since
65 <code class="module"><a href="./mod/mpm_winnt.html">mpm_winnt</a></code> can use native
66 networking features in place of the POSIX layer used in
67 Apache 1.3. This benefit also extends to other operating
68 systems that implement specialized MPMs.</li>
70 <li>The server can be better customized for the needs of the
71 particular site. For example, sites that need a great deal of
72 scalability can choose to use a threaded MPM like
73 <code class="module"><a href="./mod/worker.html">worker</a></code>, while sites requiring
74 stability or compatibility with older software can use a
75 <code class="module"><a href="./mod/prefork.html">prefork</a></code>. In addition,
76 special features like serving different hosts under different
77 userids (<code class="module"><a href="./mod/perchild.html">perchild</a></code>) can be
81 <p>At the user level, MPMs appear much like other Apache
82 modules. The main difference is that one and only one MPM must
83 be loaded into the server at any time. The list of available
84 MPMs appears on the <a href="mod/">module index page</a>.</p>
86 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
88 <h2><a name="choosing" id="choosing">Choosing an MPM</a></h2>
90 <p>MPMs must be chosen during configuration, and compiled into
91 the server. Compilers are capable of optimizing a lot of
92 functions if threads are used, but only if they know that
93 threads are being used.</p>
95 <p>To actually choose the desired MPM, use the argument
96 <code>--with-mpm=<em>NAME</em></code> with the
97 <code class="program"><a href="./programs/configure.html">configure</a></code> script. <em>NAME</em> is the name of the
100 <p>Once the server has been compiled, it is possible to
101 determine which MPM was chosen by using <code>./httpd
102 -l</code>. This command will list every module that is compiled
103 into the server, including the MPM.</p>
104 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
105 <div class="section">
106 <h2><a name="defaults" id="defaults">MPM Defaults</a></h2>
108 <p>The following table lists the default MPMs for various operating
109 systems. This will be the MPM selected if you do not make another
110 choice at compile-time.</p>
114 <tr><td>BeOS</td><td><code class="module"><a href="./mod/beos.html">beos</a></code></td></tr>
115 <tr><td>Netware</td><td><code class="module"><a href="./mod/mpm_netware.html">mpm_netware</a></code></td></tr>
116 <tr><td>OS/2</td><td><code class="module"><a href="./mod/mpmt_os2.html">mpmt_os2</a></code></td></tr>
117 <tr><td>Unix</td><td><code class="module"><a href="./mod/prefork.html">prefork</a></code></td></tr>
118 <tr><td>Windows</td><td><code class="module"><a href="./mod/mpm_winnt.html">mpm_winnt</a></code></td></tr>
121 <div class="bottomlang">
122 <p><span>Available Languages: </span><a href="./de/mpm.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
123 <a href="./en/mpm.html" title="English"> en </a> |
124 <a href="./es/mpm.html" hreflang="es" rel="alternate" title="Español"> es </a> |
125 <a href="./ja/mpm.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
126 <a href="./ko/mpm.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> |
127 <a href="./ru/mpm.html" hreflang="ru" rel="alternate" title="Russian"> ru </a> |
128 <a href="./tr/mpm.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
129 </div><div id="footer">
130 <p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
131 <p class="menu"><a href="./mod/">Modules</a> | <a href="./mod/directives.html">Directives</a> | <a href="./faq/">FAQ</a> | <a href="./glossary.html">Glossary</a> | <a href="./sitemap.html">Sitemap</a></p></div>