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<h1 align="CENTER">Multi-Processing Module perchild</h1>
<p>This Multi-Processing Module allows for daemon processes
serving requests to be assigned a variety of different
userids.</p>
rel="Help"><strong>Status:</strong></a> MPM<br />
<a href="module-dict.html#SourceFile"
<a href="module-dict.html#ModuleIdentifier"
rel="Help"><strong>Module Identifier:</strong></a>
mpm_perchild_module</p>
<h2>Summary</h2>
<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>
<p>A single control process launches the number of child
processes indicated by the <code>NumServers</code> directive at
server startup. Each child process creates threads as specified
in the <code>StartThreads</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 <em>spare</em> 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>MinSpareThreads</code> and <code>MaxSpareThreads</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>NumServers</code>) by the maximum
number of threads created in each process
(<code>MaxThreadsPerChild</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>User</code> and <code>Group</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 <a
href="/suexec.html">suexec</a> is used, these directives also
set the privileges which will be inherited by CGI scripts.</p>
<p><code>MaxRequestsPerChild</code> controls how frequently the
server recycles processes by killing old ones and launching new
ones.</p>
ports Apache uses</a>.</p>
<p>In addition it adds the extra ability to specify that
specific processes should serve requests under different
userids. These processes can then be associated with specific
virtual hosts.</p>
<!-- XXX: This desperately needs more explanation. -->
<h2>Directives</h2>
<ul>
<li><a href="#assignuserid">AssignUserID</a></li>
<li><a href="#childperuserid">ChildPerUserID</a></li>
<li><a
<li><a
<li><a
<li><a
<li><a
<li><a
<li><a
<li><a
<li><a
<li><a
</ul>
<hr />
<h2><a id="assignuserid" name="assignuserid">AssignUserID
directive</a></h2>
rel="Help"><strong>Syntax:</strong></a><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> MPM<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> perchild</p>
<p>Tie a virtual host to a specific child process.</p>
<hr />
<h2><a id="childperuserid" name="childperuserid">ChildPerUserID
directive</a></h2>
rel="Help"><strong>Syntax:</strong></a><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config<br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> MPM<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> perchild</p>
<p>Specify a User and Group for a specific child process.</p>
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