mirror of
https://github.com/apache/httpd.git
synced 2025-05-30 01:07:09 +03:00
5347b4715f
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@421086 13f79535-47bb-0310-9956-ffa450edef68
266 lines
17 KiB
XML
266 lines
17 KiB
XML
<?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>perchild - 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>
|
||
<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 2.3</p>
|
||
<img alt="" src="../images/feather.gif" /></div>
|
||
<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
|
||
<div id="path">
|
||
<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 2.3</a> > <a href="./">Modules</a></div>
|
||
<div id="page-content">
|
||
<div id="preamble"><h1>Apache MPM perchild</h1>
|
||
<div class="toplang">
|
||
<p><span>Available Languages: </span><a href="../en/mod/perchild.html" title="English"> en </a></p>
|
||
</div>
|
||
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Multi-Processing Module allowing for daemon processes serving
|
||
requests to be assigned a variety of different userids</td></tr>
|
||
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>MPM</td></tr>
|
||
<tr><th><a href="module-dict.html#ModuleIdentifier">Module<EFBFBD>Identifier:</a></th><td>mpm_perchild_module</td></tr>
|
||
<tr><th><a href="module-dict.html#SourceFile">Source<EFBFBD>File:</a></th><td>perchild.c</td></tr></table>
|
||
<h3>Summary</h3>
|
||
|
||
<div class="warning">
|
||
This module is not functional. Development of this module is not
|
||
complete and is not currently active. Do not use
|
||
<code class="module"><a href="../mod/perchild.html">perchild</a></code> unless you are a programmer willing to
|
||
help fix it.
|
||
</div>
|
||
|
||
<p>This Multi-Processing Module (MPM) implements a hybrid
|
||
multi-process, multi-threaded web server. A fixed number of
|
||
processes create threads to handle requests. Fluctuations in
|
||
load are handled by increasing or decreasing the number of
|
||
threads in each process.</p>
|
||
</div>
|
||
<div id="quickview"><h3 class="directives">Directives</h3>
|
||
<ul id="toc">
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#acceptmutex">AcceptMutex</a></li>
|
||
<li><img alt="" src="../images/down.gif" /> <a href="#assignuserid">AssignUserID</a></li>
|
||
<li><img alt="" src="../images/down.gif" /> <a href="#childperuserid">ChildPerUserID</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#enableexceptionhook">EnableExceptionHook</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#group">Group</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listen">Listen</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listenbacklog">ListenBacklog</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#lockfile">LockFile</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li>
|
||
<li><img alt="" src="../images/down.gif" /> <a href="#maxthreadsperchild">MaxThreadsPerChild</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#minsparethreads">MinSpareThreads</a></li>
|
||
<li><img alt="" src="../images/down.gif" /> <a href="#numservers">NumServers</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#pidfile">PidFile</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#receivebuffersize">ReceiveBufferSize</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#sendbuffersize">SendBufferSize</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#serverlimit">ServerLimit</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#startthreads">StartThreads</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadlimit">ThreadLimit</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadstacksize">ThreadStackSize</a></li>
|
||
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#user">User</a></li>
|
||
</ul>
|
||
<h3>Topics</h3>
|
||
<ul id="topics">
|
||
<li><img alt="" src="../images/down.gif" /> <a href="#how-it-works">How it works</a></li>
|
||
</ul><h3>See also</h3>
|
||
<ul class="seealso">
|
||
<li><a href="../bind.html">Setting which addresses and ports Apache
|
||
uses</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="how-it-works" id="how-it-works">How it works</a></h2>
|
||
<p>A single control process launches the number of child processes
|
||
indicated by the <code class="directive"><a href="#numservers">NumServers</a></code>
|
||
directive at server startup. Each child process creates threads as
|
||
specified in the <code class="directive"><a href="../mod/mpm_common.html#startthreads">StartThreads</a></code> directive.
|
||
The individual threads then
|
||
listen for connections and serve them when they arrive.</p>
|
||
|
||
<p>Apache always tries to maintain a pool of <dfn>spare</dfn> or
|
||
idle server threads, which stand ready to serve incoming
|
||
requests. In this way, clients do not need to wait for new
|
||
threads to be created. For each child process, Apache assesses
|
||
the number of idle threads and creates or destroys threads to
|
||
keep this number within the boundaries specified by
|
||
<code class="directive"><a href="../mod/mpm_common.html#minsparethreads">MinSpareThreads</a></code>
|
||
and <code class="directive"><a href="../mod/mpm_common.html#maxsparethreads">MaxSpareThreads</a></code>.
|
||
Since this process is very self-regulating, it is rarely
|
||
necessary to modify these directives from their default values.
|
||
The maximum number of clients that may be served simultaneously
|
||
is determined by multiplying the number of server processes
|
||
that will be created (<code class="directive"><a href="#numservers">NumServers</a></code>) by the maximum
|
||
number of threads created in each process
|
||
(<code class="directive"><a href="../mod/mpm_common.html#maxthreadsperchild">MaxThreadsPerChild</a></code>).</p>
|
||
|
||
<p>While the parent process is usually started as root under
|
||
Unix in order to bind to port 80, the child processes and
|
||
threads are launched by Apache as a less-privileged user. The
|
||
<code class="directive"><a href="../mod/mpm_common.html#user">User</a></code> and <code class="directive"><a href="../mod/mpm_common.html#group">Group</a></code> directives are used to
|
||
set the privileges of the Apache child processes. The child
|
||
processes must be able to read all the content that will be
|
||
served, but should have as few privileges beyond that as
|
||
possible. In addition, unless <code class="program"><a href="../programs/suexec.html">suexec</a></code> is used,
|
||
these directives also set the privileges which will be inherited
|
||
by CGI scripts.</p>
|
||
|
||
<p><code class="directive"><a href="../mod/mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></code>
|
||
controls how frequently the
|
||
server recycles processes by killing old ones and launching new
|
||
ones.</p>
|
||
|
||
<h3><a name="user-ids" id="user-ids">Working with different user-IDs</a></h3>
|
||
<p>The <code class="module"><a href="../mod/perchild.html">perchild</a></code> MPM adds the extra ability to
|
||
specify that particular processes should serve requests under
|
||
different user-IDs. These user-IDs can then be associated with
|
||
specific virtual hosts. You have to use one <code class="directive"><a href="#childperuserid">ChildPerUserID</a></code> directive for
|
||
every user/group combination you want to be run. Then you can tie
|
||
particular virtual hosts to that user and group IDs.</p>
|
||
|
||
<p>The following example runs 7 child processes. Two of them are run
|
||
under <code>user1</code>/<code>group1</code>. The next four are run
|
||
under <code>user2</code>/<code>group2</code> and the remaining
|
||
process uses the <code class="directive"><a href="../mod/mpm_common.html#user">User</a></code> and <code class="directive"><a href="../mod/mpm_common.html#group">Group</a></code>
|
||
of the main server:</p>
|
||
|
||
<div class="example"><h3>Global config</h3><p><code>
|
||
NumServers 7<br />
|
||
ChildPerUserID user1 group1 2<br />
|
||
ChildPerUserID user2 group2 4
|
||
</code></p></div>
|
||
|
||
<p>Using unbalanced numbers of processes as above is useful, if the
|
||
particular virtual hosts produce different load. The assignment to
|
||
the virtual hosts is easily done as in the example below. In
|
||
conclusion with the example above the following assumes, that
|
||
<code>server2</code> has to serve about twice of the hits of
|
||
<code>server1</code>.</p>
|
||
|
||
<div class="example"><h3>Example</h3><p><code>
|
||
NameVirtualHost *<br />
|
||
<br />
|
||
<VirtualHost *><br />
|
||
<span class="indent">
|
||
ServerName fallbackhost<br />
|
||
# no assignment; use fallback<br />
|
||
</span>
|
||
</VirtualHost><br />
|
||
<br />
|
||
<VirtualHost *><br />
|
||
<span class="indent">
|
||
ServerName server1<br />
|
||
AssignUserID user1 group1<br />
|
||
</span>
|
||
</VirtualHost><br />
|
||
<br />
|
||
<VirtualHost *><br />
|
||
<span class="indent">
|
||
ServerName server2<br />
|
||
AssignUserID user2 group2<br />
|
||
</span>
|
||
</VirtualHost>
|
||
</code></p></div>
|
||
|
||
</div>
|
||
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
|
||
<div class="directive-section"><h2><a name="AssignUserID" id="AssignUserID">AssignUserID</a> <a name="assignuserid" id="assignuserid">Directive</a></h2>
|
||
<table class="directive">
|
||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Tie a virtual host to a user and group ID</td></tr>
|
||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AssignUserID <var>user-id</var> <var>group-id</var></code></td></tr>
|
||
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>virtual host</td></tr>
|
||
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>MPM</td></tr>
|
||
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>perchild</td></tr>
|
||
</table>
|
||
<p>Tie a virtual host to a specific user/group combination. Requests
|
||
addressed to the virtual host where this directive appears will be
|
||
served by a process running with the specified user and group ID.</p>
|
||
|
||
<p>The user and group ID has to be assigned to a number of children
|
||
in the global server config using the <code class="directive"><a href="#childperuserid">ChildPerUserID</a></code> directive. See the section above for a
|
||
<a href="#user-ids">configuration example</a>.</p>
|
||
|
||
</div>
|
||
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
|
||
<div class="directive-section"><h2><a name="ChildPerUserID" id="ChildPerUserID">ChildPerUserID</a> <a name="childperuserid" id="childperuserid">Directive</a></h2>
|
||
<table class="directive">
|
||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Specify user ID and group ID for a number of child
|
||
processes</td></tr>
|
||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ChildPerUserID <var>user-id</var> <var>group-id</var>
|
||
<var>num-children</var></code></td></tr>
|
||
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
|
||
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>MPM</td></tr>
|
||
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>perchild</td></tr>
|
||
</table>
|
||
<p>Specify a user ID and group ID for a number of child processes.
|
||
The third argument, <var>num-children</var>, is the number of child
|
||
processes to start with the specified user and group. It does
|
||
<em>not</em> represent a specific child number. In order to use this
|
||
directive, the server must be run initially as <code>root</code>.
|
||
If you start the server as a non-root user, it will fail to change
|
||
to the lesser privileged user.</p>
|
||
|
||
<p>If the total number of child processes, found by totaling all of the
|
||
third arguments to all <code class="directive">ChildPerUserID</code> directives
|
||
in the config file, is less than <code class="directive"><a href="#numservers">NumServers</a></code>, then all remaining children will inherit the
|
||
<code class="directive"><a href="../mod/mpm_common.html#user">User</a></code> and <code class="directive"><a href="../mod/mpm_common.html#group">Group</a></code> settings from the main server.
|
||
See the section above for a <a href="#user-ids">configuration
|
||
example</a>.</p>
|
||
|
||
<div class="warning"><h3>Security</h3>
|
||
<p>Don't set <var>user-id</var> (or <var>group-id</var>) to
|
||
<code>root</code> unless you know exactly what you are doing, and
|
||
what the dangers are.</p>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
|
||
<div class="directive-section"><h2><a name="MaxThreadsPerChild" id="MaxThreadsPerChild">MaxThreadsPerChild</a> <a name="maxthreadsperchild" id="maxthreadsperchild">Directive</a></h2>
|
||
<table class="directive">
|
||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maximum number of threads per child process</td></tr>
|
||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>MaxThreadsPerChild <var>number</var></code></td></tr>
|
||
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>MaxThreadsPerChild 64</code></td></tr>
|
||
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
|
||
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>MPM</td></tr>
|
||
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>perchild</td></tr>
|
||
</table>
|
||
<p>This directive sets the maximum number of threads that will be
|
||
created in each child process. To increase this value beyond its
|
||
default, it is necessary to change the value of the <code class="directive"><a href="../mod/mpm_common.html#threadlimit">ThreadLimit</a></code> directive and stop and
|
||
re-start the server.</p>
|
||
|
||
</div>
|
||
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
|
||
<div class="directive-section"><h2><a name="NumServers" id="NumServers">NumServers</a> <a name="numservers" id="numservers">Directive</a></h2>
|
||
<table class="directive">
|
||
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Total number of children alive at the same time</td></tr>
|
||
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NumServers <var>number</var></code></td></tr>
|
||
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>NumServers 2</code></td></tr>
|
||
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr>
|
||
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>MPM</td></tr>
|
||
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>perchild</td></tr>
|
||
</table>
|
||
<p>The <code class="directive">NumServers</code> directive determines the number
|
||
of children alive at the same time. This number should be large enough to
|
||
handle the requests for the entire site. To increase this value beyond the
|
||
value of <code>8</code>, it is necessary to change the value of the
|
||
<code class="directive"><a href="../mod/mpm_common.html#serverlimit">ServerLimit</a></code> directive and stop
|
||
and re-start the server. See the section above for a <a href="#user-ids">configuration example</a>.</p>
|
||
|
||
</div>
|
||
</div>
|
||
<div class="bottomlang">
|
||
<p><span>Available Languages: </span><a href="../en/mod/perchild.html" title="English"> en </a></p>
|
||
</div><div id="footer">
|
||
<p class="apache">Copyright 2006 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>
|
||
<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> |