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			135 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			XML
		
	
	
	
	
	
<?xml version="1.0" encoding="ISO-8859-1"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
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        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
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              This file is generated from xml source: DO NOT EDIT
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        XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
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      -->
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<title>event - Apache HTTP Server</title>
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<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
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<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
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<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
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<link href="../images/favicon.ico" rel="shortcut icon" /></head>
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<body>
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<div id="page-header">
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<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>
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<p class="apache">Apache HTTP Server Version 2.3</p>
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<img alt="" src="../images/feather.gif" /></div>
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<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
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<div id="path">
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<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>
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<div id="page-content">
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<div id="preamble"><h1>Apache MPM event</h1>
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<div class="toplang">
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<p><span>Available Languages: </span><a href="../en/mod/event.html" title="English"> en </a> |
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<a href="../fr/mod/event.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p>
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</div>
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<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>A variant of the <code class="module"><a href="../mod/worker.html">worker</a></code> MPM with the goal
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of consuming threads only for connections with active processing</td></tr>
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<tr><th><a href="module-dict.html#Status">Status:</a></th><td>MPM</td></tr>
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<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>mpm_event_module</td></tr>
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<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>event.c</td></tr></table>
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<h3>Summary</h3>
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    <p>The <code class="module"><a href="../mod/event.html">event</a></code> Multi-Processing Module (MPM) is
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    designed to allow more requests to be served simultaneously by
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    passing off some processing work to supporting threads, freeing up
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    the main threads to work on new requests.  It is based on the
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    <code class="module"><a href="../mod/worker.html">worker</a></code> MPM, which implements a hybrid
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    multi-process multi-threaded server.  Run-time configuration
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    directives are identical to those provided by
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    <code class="module"><a href="../mod/worker.html">worker</a></code>.</p>
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    <p>To use the <code class="module"><a href="../mod/event.html">event</a></code> MPM, add
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      <code>--with-mpm=event</code> to the <code class="program"><a href="../programs/configure.html">configure</a></code>
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      script's arguments when building the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</p>
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</div>
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<div id="quickview"><h3 class="directives">Directives</h3>
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<ul id="toc">
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#enableexceptionhook">EnableExceptionHook</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#group">Group</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listen">Listen</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listenbacklog">ListenBacklog</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxclients">MaxClients</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxmemfree">MaxMemFree</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#minsparethreads">MinSpareThreads</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#pidfile">PidFile</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#sendbuffersize">SendBufferSize</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#serverlimit">ServerLimit</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#startservers">StartServers</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadlimit">ThreadLimit</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadsperchild">ThreadsPerChild</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadstacksize">ThreadStackSize</a></li>
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<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#user">User</a></li>
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</ul>
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<h3>Topics</h3>
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<ul id="topics">
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<li><img alt="" src="../images/down.gif" /> <a href="#how-it-works">How it Works</a></li>
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<li><img alt="" src="../images/down.gif" /> <a href="#requirements">Requirements</a></li>
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</ul><h3>See also</h3>
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<ul class="seealso">
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<li><a href="worker.html">The worker MPM</a></li>
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</ul></div>
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<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
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<div class="section">
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<h2><a name="how-it-works" id="how-it-works">How it Works</a></h2>
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    <p>This MPM tries to fix the 'keep alive problem' in HTTP. After a client
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    completes the first request, the client can keep the connection
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    open, and send further requests using the same socket. This can
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    save signifigant overhead in creating TCP connections. However,
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    Apache traditionally keeps an entire child process/thread waiting
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    for data from the client, which brings its own disadvantages. To
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    solve this problem, this MPM uses a dedicated thread to handle both
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    the Listening sockets, and all sockets that are in a Keep Alive
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    state.</p>
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    <p>The MPM assumes that the underlying <code>apr_pollset</code>
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    implementation is reasonably threadsafe. This enables the MPM to
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    avoid excessive high level locking, or having to wake up the listener
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    thread in order to send it a keep-alive socket. This is currently
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    only compatible with KQueue and EPoll.</p>
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</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
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<div class="section">
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<h2><a name="requirements" id="requirements">Requirements</a></h2>
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    <p>This MPM depends on <a class="glossarylink" href="../glossary.html#apr" title="see glossary">APR</a>'s atomic
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    compare-and-swap operations for thread synchronization. If you are
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    compiling for an x86 target and you don't need to support 386s, or
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    you are compiling for a SPARC and you don't need to run on
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    pre-UltraSPARC chips, add
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    <code>--enable-nonportable-atomics=yes</code> to the
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    <code class="program"><a href="../programs/configure.html">configure</a></code> script's arguments. This will cause
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    APR to implement atomic operations using efficient opcodes not
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    available in older CPUs.</p>
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    <p>This MPM does not perform well on older platforms which lack good
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    threading, but the requirement for EPoll or KQueue makes this
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    moot.</p>
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    <ul>
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      <li>To use this MPM on FreeBSD, FreeBSD 5.3 or higher is recommended.
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      However, it is possible to run this MPM on FreeBSD 5.2.1, if you
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      use <code>libkse</code> (see <code>man libmap.conf</code>).</li>
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      <li>For NetBSD, at least version 2.0 is recommended.</li>
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      <li>For Linux, a 2.6 kernel is recommended. It is also necessary to
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      ensure that your version of <code>glibc</code> has been compiled
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      with support for EPoll.</li>
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    </ul>
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</div>
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</div>
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<div class="bottomlang">
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<p><span>Available Languages: </span><a href="../en/mod/event.html" title="English"> en </a> |
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<a href="../fr/mod/event.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p>
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</div><div id="footer">
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<p class="apache">Copyright 2010 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>
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<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>
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