| [66] | 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat Configuration Reference - The Cluster object</title><meta value="Filip Hanik" name="author"><meta value="fhanik@apache.org" name="email"></head><body vlink="#525D76" alink="#525D76" link="#525D76" text="#000000" bgcolor="#ffffff"><table cellspacing="0" width="100%" border="0"><!--PAGE HEADER--><tr><td><!--PROJECT LOGO--><a href="http://tomcat.apache.org/"><img border="0" alt=" | 
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|  | 2 | The Apache Tomcat Servlet/JSP Container | 
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|  | 3 | " align="right" src="../../images/tomcat.gif"></a></td><td><font face="arial,helvetica,sanserif"><h1>Apache Tomcat 6.0</h1></font></td><td><!--APACHE LOGO--><a href="http://www.apache.org/"><img border="0" alt="Apache Logo" align="right" src="../../images/asf-logo.gif"></a></td></tr></table><table cellspacing="4" width="100%" border="0"><!--HEADER SEPARATOR--><tr><td colspan="2"><hr size="1" noshade></td></tr><tr><!--RIGHT SIDE MAIN BODY--><td align="left" valign="top" width="80%"><table cellspacing="4" width="100%" border="0"><tr><td valign="top" align="left"><h1>Apache Tomcat Configuration Reference</h1><h2>The Cluster object</h2></td><td nowrap="true" valign="top" align="right"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 4 | <p> | 
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|  | 5 | The tomcat cluster implementation provides session replication, context attribute replication and | 
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|  | 6 | cluster wide WAR file deployment. | 
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|  | 7 | While the <code>Cluster</code> configuration is fairly complex, the default configuration will work | 
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|  | 8 | for most people out of the box. </p><p> | 
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|  | 9 | The Tomcat Cluster implementation is very extensible, and hence we have exposed a myriad of options, | 
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|  | 10 | making the configuration seem like a lot, but don't lose faith, instead you have a tremendous control | 
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|  | 11 | over what is going on.</p> | 
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|  | 12 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Engine vs Host placement"><strong>Engine vs Host placement</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 13 | <p> | 
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|  | 14 | You can place the <code><Cluster></code> element inside either the <code><Engine></code> | 
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|  | 15 | container or the <code><Host></code> container.<br> | 
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|  | 16 | Placing it in the engine, means that you will support clustering in all virtual hosts of Tomcat, | 
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|  | 17 | and share the messaging component. When you place the <code><Cluster></code> inside the <code><Engine></code> | 
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|  | 18 | element, the cluster will append the host name of each session manager to the managers name so that two contexts with | 
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|  | 19 | the same name but sitting inside two different hosts will be distinguishable. | 
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|  | 20 | </p> | 
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|  | 21 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Context Attribute Replication"><strong>Context Attribute Replication</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 22 | <p>To configure context attribute replication, simply do this by swapping out the context implementation | 
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|  | 23 | used for your application context. | 
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|  | 24 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre><Context className="org.apache.catalina.ha.context.ReplicatedContext"/></pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr></table></div> | 
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|  | 25 | This context extends the Tomcat <code><a href="context.html">StandardContext</a></code> | 
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|  | 26 | so all the options from the <a href="context.html">base implementation</a> are valid. | 
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|  | 27 | </p> | 
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|  | 28 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Nested Components"><strong>Nested Components</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 29 | <p><b><a href="cluster-manager.html">Manager</a>:</b> <br> | 
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|  | 30 | The session manager element identifies what kind of session manager is used in this cluster implementation. | 
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|  | 31 | This manager configuration is identical to the one you would use in a regular <code><a href="context.html#Nested%20xComponents"><Context></a></code> configuration. | 
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|  | 32 | <br>The default value is the <code>org.apache.catalina.ha.session.DeltaManager</code> that is closely coupled with | 
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|  | 33 | the <code>SimpleTcpCluster</code> implementation. Other managers like the <code>org.apache.catalina.ha.session.BackupManager</code> | 
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|  | 34 | are/could be loosely coupled and don't rely on the <code>SimpleTcpCluster</code> for its data replication. | 
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|  | 35 | </p> | 
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|  | 36 | <p><b><a href="cluster-channel.html">Channel</a>:</b> <br> | 
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|  | 37 | The Channel and its sub components are all part of the IO layer | 
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|  | 38 | for the cluster group, and is a module in it's own that we have nick named "Tribes" | 
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|  | 39 | <br> | 
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|  | 40 | Any configuring and tuning of the network layer, the messaging and the membership logic | 
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|  | 41 | will be done in the channel and its nested components. | 
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|  | 42 | You can always find out more about <a href="../../tribes/introduction.html">Apache Tribes</a> | 
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|  | 43 | </p> | 
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|  | 44 | <p><b><a href="cluster-valve.html">Valve</a>:</b> <br> | 
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|  | 45 | The Tomcat Cluster implementation uses <code>Tomcat <a href="valve.html">Valves</a></code> to | 
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|  | 46 | track when requests enter and exit the servlet container. It uses these valves to be able to make | 
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|  | 47 | intelligent decisions on when to replicate data, which is always at the end of a request. | 
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|  | 48 | </p> | 
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|  | 49 | <p><b><a href="cluster-deployer.html">Deployer</a>:</b> <br> | 
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|  | 50 | The Deployer component is the Tomcat Farm Deployer. It allows you to deploy and undeploy applications | 
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|  | 51 | cluster wide. | 
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|  | 52 | </p> | 
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|  | 53 | <p><b><a href="cluster-listener.html">ClusterListener</a>:</b> <br> | 
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|  | 54 | ClusterListener's are used to track messages sent and received using the <code>SimpleTcpCluster</code>. | 
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|  | 55 | If you wish to track messages, you can add a listener here, or you can add a valve to the channel object. | 
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|  | 56 | </p> | 
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|  | 57 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Deprecated configuration options"><strong>Deprecated configuration options</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 58 | <p> | 
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|  | 59 | <b>Deprecated settings:</b> In the previous version of Tomcat you were able to control session | 
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|  | 60 | manager settings using manager.<property>=value. | 
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|  | 61 | This has been discontinued, as the way it was written interfers with | 
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|  | 62 | the ability to support multiple different manager classes under one cluster implementation, | 
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|  | 63 | as the same properties might have the different effect on different managers. | 
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|  | 64 | </p> | 
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|  | 65 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 66 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="SimpleTcpCluster Attributes"><strong>SimpleTcpCluster Attributes</strong></a></font></td></tr><tr><td><blockquote> | 
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|  | 67 | <table cellpadding="5" border="1"><tr><th bgcolor="#023264" width="15%"><font color="#ffffff">Attribute</font></th><th bgcolor="#023264" width="85%"><font color="#ffffff">Description</font></th></tr><tr><td valign="center" align="left"><strong><code>className</code></strong></td><td valign="center" align="left"> | 
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|  | 68 | <p>The main cluster class, currently only one is available, | 
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|  | 69 | <code>org.apache.catalina.ha.tcp.SimpleTcpCluster</code> | 
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|  | 70 | </p> | 
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|  | 71 | </td></tr><tr><td valign="center" align="left"><strong><code>channelSendOptions</code></strong></td><td valign="center" align="left"> | 
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|  | 72 | <p>The Tribes channel send options, default is <code>8</code>.<br> | 
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|  | 73 | This option is used to set the flag that all messages sent through the | 
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|  | 74 | SimpleTcpCluster uses. The flag decides how the messages are sent, and is a simple logical OR.<br> | 
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|  | 75 |  | 
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|  | 76 | <div align="left"><table border="0" cellpadding="0" cellspacing="4"><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr><tr><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" bgcolor="#ffffff"><pre> | 
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|  | 77 | int options= Channel.SEND_OPTIONS_ASYNCHRONOUS | | 
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|  | 78 | Channel.SEND_OPTIONS_SYNCHRONIZED_ACK | | 
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|  | 79 | Channel.SEND_OPTIONS_USE_ACK; | 
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|  | 80 | </pre></td><td width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr><tr><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td><td height="1" width="1" bgcolor="#023264"><img border="0" hspace="0" vspace="0" height="1" width="1" src="../../images/void.gif"></td></tr></table></div> | 
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|  | 81 | Some of the values are:<br> | 
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|  | 82 | <code>Channel.SEND_OPTIONS_SYNCHRONIZED_ACK = 0x0004</code><br> | 
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|  | 83 | <code>Channel.SEND_OPTIONS_ASYNCHRONOUS = 0x0008</code><br> | 
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|  | 84 | <code>Channel.SEND_OPTIONS_USE_ACK = 0x0002</code><br> | 
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|  | 85 | So to use ACK and ASYNC messaging, the flag would be <code>10 (8+2) or 0x000B</code><br> | 
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|  | 86 | </p> | 
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|  | 87 | </td></tr><tr><td valign="center" align="left"><code>heartbeatBackgroundEnabled</code></td><td valign="center" align="left"> | 
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|  | 88 | <p>Enable this flag don't forget to disable the channel heartbeat thread. | 
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|  | 89 | </p> | 
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|  | 90 | </td></tr><tr><td valign="center" align="left"><code>doClusterLog</code></td><td valign="center" align="left"> | 
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|  | 91 | <p><b>Deprecated since 6.0.0</b></p> | 
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|  | 92 | <p>Possible values are <code>true</code> or <code>false</code><br> | 
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|  | 93 | Value is inherited from Tomcat 5.5 and has no official meaning. | 
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|  | 94 | to configure logging, use the standard tomcat logging configuration. | 
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|  | 95 | </p> | 
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|  | 96 | </td></tr><tr><td valign="center" align="left"><code>clusterLogName</code></td><td valign="center" align="left"> | 
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|  | 97 | <p><b>Deprecated since 6.0.0</b></p> | 
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|  | 98 | <p> | 
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|  | 99 | Value is inherited from Tomcat 5.5 and has no official meaning. | 
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|  | 100 | to configure logging, use the standard tomcat logging configuration. | 
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|  | 101 | </p> | 
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|  | 102 | </td></tr></table> | 
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|  | 103 | </blockquote></td></tr></table> | 
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|  | 104 | </blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr size="1" noshade></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font size="-1" color="#525D76"><em> | 
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|  | 105 | Copyright © 1999-2008, Apache Software Foundation | 
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|  | 106 | </em></font></div></td></tr></table></body></html> | 
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