mod_heartbeat.html.en revision 4645afc7dbc233218e8f05053ee2aa1751d94fc4
<?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>mod_heartbeat - 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 2.5</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/">Documentation</a> &gt; <a href="../">Version 2.5</a> &gt; <a href="./">Modules</a></div>
<div id="page-content">
<div id="preamble"><h1>Apache Module mod_heartbeat</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="/en/mod/mod_heartbeat.html" title="English">&nbsp;en&nbsp;</a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>sends messages with server status to frontend proxy</td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Experimental</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">Module�Identifier:</a></th><td>heartbeat_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">Source�File:</a></th><td>mod_heartbeat</td></tr>
<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.3 and later</td></tr></table>
<h3>Summary</h3>
<p> <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code> sends multicast messages to a <code class="module"><a href="/mod/mod_heartmonitor.html">mod_heartmonitor</a></code> listener
that advertises the servers current connection count. Usually, <code class="module"><a href="/mod/mod_heartmonitor.html">mod_heartmonitor</a></code>
will be running on a proxy server with <code class="module"><a href="/mod/mod_lbmethod_heartbeat.html">mod_lbmethod_heartbeat</a></code> loaded, which allows
<code class="directive"><a href="/mod/mod_proxy.html#proxypass">ProxyPass</a></code> to use the "heartbeat" <em>lbmethod</em> inside
of <code class="directive"><a href="/mod/mod_proxy.html#proxypass">ProxyPass</a></code>.</p>
<p>
<code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code> itself is loaded on the origin server(s) that serve requests
through the proxy server(s).
</p>
<div class="warning">
To use <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code>,
<code class="module"><a href="/mod/mod_status.html">mod_status</a></code> and <code class="module"><a href="/mod/mod_watchdog.html">mod_watchdog</a></code>
must be either a static modules or, if a dynamic module, must
be loaded before <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code>.
</div>
</div>
<div id="quickview"><h3 class="directives">Directives</h3>
<ul id="toc">
<li><img alt="" src="/images/down.gif" /> <a href="#heartbeataddress">HeartbeatAddress</a></li>
</ul>
<h3>Topics</h3>
<ul id="topics">
<li><img alt="" src="/images/down.gif" /> <a href="#consuming">Consuming mod_heartbeat Output</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="consuming" id="consuming">Consuming mod_heartbeat Output</a></h2>
<p>
Every 1 second, this module generates a single multicast UDP
packet, containing the number of busy and idle workers. The
packet is a simple ASCII format, similar to GET query parameters
in HTTP.
</p>
<div class="example"><h3>An Example Packet</h3><p><code>
v=1&amp;ready=75&amp;busy=0
</code></p></div>
<p>
Consumers should handle new variables besides busy and ready,
separated by '&amp;', being added in the future.
</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="HeartbeatAddress" id="HeartbeatAddress">HeartbeatAddress</a> <a name="heartbeataddress" id="heartbeataddress">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Multicast address for heartbeat packets</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HeartbeatAddress <var>addr:port</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>disabled</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>Experimental</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_heartbeat</td></tr>
</table>
<p>The <code class="directive">HeartbeatAddress</code> directive specifies the
multicast address to which <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code> will send
status information. This address will usually correspond to a configured
<code class="directive"><a href="/mod/mod_heartmonitor.html#heartbeatlisten">HeartbeatListen</a></code> on a
frontend proxy system.</p>
<div class="example"><p><code>
HeartbeatAddress 239.0.0.1:27999
</code></p></div>
</div>
</div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="/en/mod/mod_heartbeat.html" title="English">&nbsp;en&nbsp;</a></p>
</div><div id="footer">
<p class="apache">Copyright 2012 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>