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>mod_heartbeat - 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" /><link rel="stylesheet" type="text/css" href="/style/css/prettify.css" /> 12<script src="/style/scripts/prettify.min.js" type="text/javascript"> 13</script> 14 15<link href="/images/favicon.ico" rel="shortcut icon" /></head> 16<body> 17<div id="page-header"> 18<p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p> 19<p class="apache">Apache HTTP Server Version 2.4</p> 20<img alt="" src="/images/feather.gif" /></div> 21<div class="up"><a href="./"><img title="<-" alt="<-" src="/images/left.gif" /></a></div> 22<div id="path"> 23<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 2.4</a> > <a href="./">Modules</a></div> 24<div id="page-content"> 25<div id="preamble"><h1>Apache Module mod_heartbeat</h1> 26<div class="toplang"> 27<p><span>Available Languages: </span><a href="/en/mod/mod_heartbeat.html" title="English"> en </a> | 28<a href="/fr/mod/mod_heartbeat.html" hreflang="fr" rel="alternate" title="Fran�ais"> fr </a></p> 29</div> 30<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> 31<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Experimental</td></tr> 32<tr><th><a href="module-dict.html#ModuleIdentifier">Module�Identifier:</a></th><td>heartbeat_module</td></tr> 33<tr><th><a href="module-dict.html#SourceFile">Source�File:</a></th><td>mod_heartbeat</td></tr> 34<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.3 and later</td></tr></table> 35<h3>Summary</h3> 36 37<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 38that advertises the servers current connection count. Usually, <code class="module"><a href="/mod/mod_heartmonitor.html">mod_heartmonitor</a></code> 39will 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 40<code class="directive"><a href="/mod/mod_proxy.html#proxypass">ProxyPass</a></code> to use the "heartbeat" <em>lbmethod</em> inside 41of <code class="directive"><a href="/mod/mod_proxy.html#proxypass">ProxyPass</a></code>.</p> 42<p> 43 <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code> itself is loaded on the origin server(s) that serve requests 44 through the proxy server(s). 45</p> 46 47 <div class="warning"> 48 To use <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code>, 49 <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> 50 must be either a static modules or, if a dynamic module, must 51 be loaded before <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code>. 52 </div> 53 54</div> 55<div id="quickview"><h3 class="directives">Directives</h3> 56<ul id="toc"> 57<li><img alt="" src="/images/down.gif" /> <a href="#heartbeataddress">HeartbeatAddress</a></li> 58</ul> 59<h3>Topics</h3> 60<ul id="topics"> 61<li><img alt="" src="/images/down.gif" /> <a href="#consuming">Consuming mod_heartbeat Output</a></li> 62</ul><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div> 63<div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div> 64<div class="section"> 65<h2><a name="consuming" id="consuming">Consuming mod_heartbeat Output</a></h2> 66 67 <p> 68 Every 1 second, this module generates a single multicast UDP 69 packet, containing the number of busy and idle workers. The 70 packet is a simple ASCII format, similar to GET query parameters 71 in HTTP. 72 </p> 73 74<div class="example"><h3>An Example Packet</h3><p><code> 75v=1&ready=75&busy=0 76</code></p></div> 77 78 <p> 79 Consumers should handle new variables besides busy and ready, 80 separated by '&', being added in the future. 81 </p> 82 83</div> 84<div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div> 85<div class="directive-section"><h2><a name="HeartbeatAddress" id="HeartbeatAddress">HeartbeatAddress</a> <a name="heartbeataddress" id="heartbeataddress">Directive</a></h2> 86<table class="directive"> 87<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Multicast address for heartbeat packets</td></tr> 88<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>HeartbeatAddress <var>addr:port</var></code></td></tr> 89<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>disabled</code></td></tr> 90<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config</td></tr> 91<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Experimental</td></tr> 92<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_heartbeat</td></tr> 93</table> 94<p>The <code class="directive">HeartbeatAddress</code> directive specifies the 95multicast address to which <code class="module"><a href="/mod/mod_heartbeat.html">mod_heartbeat</a></code> will send 96status information. This address will usually correspond to a configured 97 <code class="directive"><a href="/mod/mod_heartmonitor.html#heartbeatlisten">HeartbeatListen</a></code> on a 98frontend proxy system.</p> 99<pre class="prettyprint lang-config">HeartbeatAddress 239.0.0.1:27999</pre> 100 101 102</div> 103</div> 104<div class="bottomlang"> 105<p><span>Available Languages: </span><a href="/en/mod/mod_heartbeat.html" title="English"> en </a> | 106<a href="/fr/mod/mod_heartbeat.html" hreflang="fr" rel="alternate" title="Fran�ais"> fr </a></p> 107</div><div class="top"><a href="#page-header"><img src="/images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. 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