granicus.if.org Git - apache/blob - docs/manual/mod/event.html.en

   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
   7       -->
   8 <title>event - 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>
  14 <div id="page-header">
  15 <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>
  16 <p class="apache">Apache HTTP Server Version 2.3</p>
  17 <img alt="" src="../images/feather.gif" /></div>
  18 <div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="../images/left.gif" /></a></div>
  19 <div id="path">
  20 <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/">Documentation</a> &gt; <a href="../">Version 2.3</a> &gt; <a href="./">Modules</a></div>
  21 <div id="page-content">
  22 <div id="preamble"><h1>Apache MPM event</h1>
  23 <div class="toplang">
  24 <p><span>Available Languages: </span><a href="../en/mod/event.html" title="English">&nbsp;en&nbsp;</a> |
  25 <a href="../fr/mod/event.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
  26 </div>
  27 <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
  28 of consuming threads only for connections with active processing</td></tr>
  29 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>MPM</td></tr>
  30 <tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>mpm_event_module</td></tr>
  31 <tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>event.c</td></tr></table>
  32 <h3>Summary</h3>
  33
  34     <p>The <code class="module"><a href="../mod/event.html">event</a></code> Multi-Processing Module (MPM) is
  35     designed to allow more requests to be served simultaneously by
  36     passing off some processing work to supporting threads, freeing up
  37     the main threads to work on new requests.  It is based on the
  38     <code class="module"><a href="../mod/worker.html">worker</a></code> MPM, which implements a hybrid
  39     multi-process multi-threaded server.  Run-time configuration
  40     directives are identical to those provided by
  41     <code class="module"><a href="../mod/worker.html">worker</a></code>.</p>
  42
  43     <p>To use the <code class="module"><a href="../mod/event.html">event</a></code> MPM, add
  44       <code>--with-mpm=event</code> to the <code class="program"><a href="../programs/configure.html">configure</a></code>
  45       script's arguments when building the <code class="program"><a href="../programs/httpd.html">httpd</a></code>.</p>
  46
  47 </div>
  48 <div id="quickview"><h3 class="directives">Directives</h3>
  49 <ul id="toc">
  50 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li>
  51 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#enableexceptionhook">EnableExceptionHook</a></li>
  52 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#group">Group</a></li>
  53 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listen">Listen</a></li>
  54 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listenbacklog">ListenBacklog</a></li>
  55 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxclients">MaxClients</a></li>
  56 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxconnectionsperchild">MaxConnectionsPerChild</a></li>
  57 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxmemfree">MaxMemFree</a></li>
  58 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li>
  59 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#minsparethreads">MinSpareThreads</a></li>
  60 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#pidfile">PidFile</a></li>
  61 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li>
  62 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#sendbuffersize">SendBufferSize</a></li>
  63 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#serverlimit">ServerLimit</a></li>
  64 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#startservers">StartServers</a></li>
  65 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadlimit">ThreadLimit</a></li>
  66 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadsperchild">ThreadsPerChild</a></li>
  67 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadstacksize">ThreadStackSize</a></li>
  68 <li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#user">User</a></li>
  69 </ul>
  70 <h3>Topics</h3>
  71 <ul id="topics">
  72 <li><img alt="" src="../images/down.gif" /> <a href="#how-it-works">How it Works</a></li>
  73 <li><img alt="" src="../images/down.gif" /> <a href="#requirements">Requirements</a></li>
  74 </ul><h3>See also</h3>
  75 <ul class="seealso">
  76 <li><a href="worker.html">The worker MPM</a></li>
  77 </ul></div>
  78 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  79 <div class="section">
  80 <h2><a name="how-it-works" id="how-it-works">How it Works</a></h2>
  81     <p>This MPM tries to fix the 'keep alive problem' in HTTP. After a client
  82     completes the first request, the client can keep the connection
  83     open, and send further requests using the same socket. This can
  84     save signifigant overhead in creating TCP connections. However,
  85     Apache HTTP Server traditionally keeps an entire child process/thread waiting
  86     for data from the client, which brings its own disadvantages. To
  87     solve this problem, this MPM uses a dedicated thread to handle both
  88     the Listening sockets, and all sockets that are in a Keep Alive
  89     state.</p>
  90
  91     <p>The MPM assumes that the underlying <code>apr_pollset</code>
  92     implementation is reasonably threadsafe. This enables the MPM to
  93     avoid excessive high level locking, or having to wake up the listener
  94     thread in order to send it a keep-alive socket. This is currently
  95     only compatible with KQueue and EPoll.</p>
  96
  97 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
  98 <div class="section">
  99 <h2><a name="requirements" id="requirements">Requirements</a></h2>
 100     <p>This MPM depends on <a class="glossarylink" href="../glossary.html#apr" title="see glossary">APR</a>'s atomic
 101     compare-and-swap operations for thread synchronization. If you are
 102     compiling for an x86 target and you don't need to support 386s, or
 103     you are compiling for a SPARC and you don't need to run on
 104     pre-UltraSPARC chips, add
 105     <code>--enable-nonportable-atomics=yes</code> to the
 106     <code class="program"><a href="../programs/configure.html">configure</a></code> script's arguments. This will cause
 107     APR to implement atomic operations using efficient opcodes not
 108     available in older CPUs.</p>
 109
 110     <p>This MPM does not perform well on older platforms which lack good
 111     threading, but the requirement for EPoll or KQueue makes this
 112     moot.</p>
 113
 114     <ul>
 115
 116       <li>To use this MPM on FreeBSD, FreeBSD 5.3 or higher is recommended.
 117       However, it is possible to run this MPM on FreeBSD 5.2.1, if you
 118       use <code>libkse</code> (see <code>man libmap.conf</code>).</li>
 119
 120       <li>For NetBSD, at least version 2.0 is recommended.</li>
 121
 122       <li>For Linux, a 2.6 kernel is recommended. It is also necessary to
 123       ensure that your version of <code>glibc</code> has been compiled
 124       with support for EPoll.</li>
 125
 126     </ul>
 127 </div>
 128 </div>
 129 <div class="bottomlang">
 130 <p><span>Available Languages: </span><a href="../en/mod/event.html" title="English">&nbsp;en&nbsp;</a> |
 131 <a href="../fr/mod/event.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
 132 </div><div id="footer">
 133 <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>
 134 <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>
 135 </body></html>