summaryrefslogtreecommitdiff
path: root/docs/manual/mpm.html.en
blob: b6977c360c23e2a877817cb40cfeedb5d5cde699 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
              This file is generated from xml source: DO NOT EDIT
        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
      -->
<title>Multi-Processing Modules (MPMs) - Apache HTTP Server</title>
<link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
<link href="./style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
<link href="./images/favicon.ico" rel="shortcut icon" /></head>
<body id="manual-page"><div id="page-header">
<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>
<p class="apache">Apache HTTP Server Version 2.0</p>
<img alt="" src="./images/feather.gif" /></div>
<div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="./images/left.gif" /></a></div>
<div id="path">
<a href="http://www.apache.org/">Apache</a> &gt; <a href="http://httpd.apache.org/">HTTP Server</a> &gt; <a href="http://httpd.apache.org/docs-project/">Documentation</a> &gt; <a href="./">Version 2.0</a></div><div id="page-content"><div id="preamble"><h1>Multi-Processing Modules (MPMs)</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="./de/mpm.html" hreflang="de" rel="alternate" title="Deutsch">&nbsp;de&nbsp;</a> |
<a href="./en/mpm.html" title="English">&nbsp;en&nbsp;</a> |
<a href="./es/mpm.html" hreflang="es" rel="alternate" title="Espaņol">&nbsp;es&nbsp;</a> |
<a href="./ja/mpm.html" hreflang="ja" rel="alternate" title="Japanese">&nbsp;ja&nbsp;</a> |
<a href="./ko/mpm.html" hreflang="ko" rel="alternate" title="Korean">&nbsp;ko&nbsp;</a> |
<a href="./ru/mpm.html" hreflang="ru" rel="alternate" title="Russian">&nbsp;ru&nbsp;</a></p>
</div>

<p>This document describes what a Multi-Processing Module is and
how they are used by the Apache HTTP Server.</p>
</div>
<div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#introduction">Introduction</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#choosing">Choosing an MPM</a></li>
<li><img alt="" src="./images/down.gif" /> <a href="#defaults">MPM Defaults</a></li>
</ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
<div class="section">
<h2><a name="introduction" id="introduction">Introduction</a></h2>

    <p>The Apache HTTP Server is designed to be a powerful and
    flexible web server that can work on a very wide variety of
    platforms in a range of different environments. Different
    platforms and different environments often require different
    features, or may have different ways of implementing the same
    feature most efficiently. Apache has always accommodated a wide
    variety of environments through its modular design. This design
    allows the webmaster to choose which features will be included
    in the server by selecting which modules to load either at
    compile-time or at run-time.</p>

    <p>Apache 2.0 extends this modular design to the most basic
    functions of a web server. The server ships with a selection of
    Multi-Processing Modules (MPMs) which are responsible for
    binding to network ports on the machine, accepting requests,
    and dispatching children to handle the requests.</p>

    <p>Extending the modular design to this level of the server
    allows two important benefits:</p>

    <ul>
      <li>Apache can more cleanly and efficiently support a wide
      variety of operating systems. In particular, the Windows
      version of Apache is now much more efficient, since
      <code class="module"><a href="./mod/mpm_winnt.html">mpm_winnt</a></code> can use native
      networking features in place of the POSIX layer used in
      Apache 1.3. This benefit also extends to other operating
      systems that implement specialized MPMs.</li>

      <li>The server can be better customized for the needs of the
      particular site. For example, sites that need a great deal of
      scalability can choose to use a threaded MPM like 
      <code class="module"><a href="./mod/worker.html">worker</a></code>, while sites requiring
      stability or compatibility with older software can use a
      <code class="module"><a href="./mod/prefork.html">prefork</a></code>. In addition,
      special features like serving different hosts under different
      userids (<code class="module"><a href="./mod/perchild.html">perchild</a></code>) can be
      provided.</li>
    </ul>

    <p>At the user level, MPMs appear much like other Apache
    modules. The main difference is that one and only one MPM must
    be loaded into the server at any time. The list of available
    MPMs appears on the <a href="mod/">module index page</a>.</p>

</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
<div class="section">
<h2><a name="choosing" id="choosing">Choosing an MPM</a></h2>

    <p>MPMs must be chosen during configuration, and compiled into
    the server. Compilers are capable of optimizing a lot of
    functions if threads are used, but only if they know that
    threads are being used.</p>

    <p>To actually choose the desired MPM, use the argument
      <code>--with-mpm=<em>NAME</em></code> with the
      <code class="program"><a href="./programs/configure.html">configure</a></code> script. <em>NAME</em> is the name of the
      desired MPM.</p>

    <p>Once the server has been compiled, it is possible to
    determine which MPM was chosen by using <code>./httpd
    -l</code>. This command will list every module that is compiled
    into the server, including the MPM.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
<div class="section">
<h2><a name="defaults" id="defaults">MPM Defaults</a></h2>

<p>The following table lists the default MPMs for various operating
systems.  This will be the MPM selected if you do not make another
choice at compile-time.</p>

<table>

<tr><td>BeOS</td><td><code class="module"><a href="./mod/beos.html">beos</a></code></td></tr>
<tr><td>Netware</td><td><code class="module"><a href="./mod/mpm_netware.html">mpm_netware</a></code></td></tr>
<tr><td>OS/2</td><td><code class="module"><a href="./mod/mpmt_os2.html">mpmt_os2</a></code></td></tr>
<tr><td>Unix</td><td><code class="module"><a href="./mod/prefork.html">prefork</a></code></td></tr>
<tr><td>Windows</td><td><code class="module"><a href="./mod/mpm_winnt.html">mpm_winnt</a></code></td></tr>
</table>
</div></div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="./de/mpm.html" hreflang="de" rel="alternate" title="Deutsch">&nbsp;de&nbsp;</a> |
<a href="./en/mpm.html" title="English">&nbsp;en&nbsp;</a> |
<a href="./es/mpm.html" hreflang="es" rel="alternate" title="Espaņol">&nbsp;es&nbsp;</a> |
<a href="./ja/mpm.html" hreflang="ja" rel="alternate" title="Japanese">&nbsp;ja&nbsp;</a> |
<a href="./ko/mpm.html" hreflang="ko" rel="alternate" title="Korean">&nbsp;ko&nbsp;</a> |
<a href="./ru/mpm.html" hreflang="ru" rel="alternate" title="Russian">&nbsp;ru&nbsp;</a></p>
</div><div id="footer">
<p class="apache">Copyright 1995-2005 The Apache Software Foundation or its licensors, as applicable.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
<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>
</body></html>