| 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat Configuration Reference - The Cluster Channel 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><!--LEFT SIDE NAVIGATION--><td nowrap="true" valign="top" width="20%"><p><strong>Links</strong></p><ul><li><a href="../index.html">Docs Home</a></li><li><a href="index.html">Config Ref. Home</a></li></ul><p><strong>Top Level Elements</strong></p><ul><li><a href="server.html">Server</a></li><li><a href="service.html">Service</a></li></ul><p><strong>Executors</strong></p><ul><li><a href="executor.html">Executor</a></li></ul><p><strong>Connectors</strong></p><ul><li><a href="http.html">HTTP</a></li><li><a href="ajp.html">AJP</a></li></ul><p><strong>Containers</strong></p><ul><li><a href="context.html">Context</a></li><li><a href="engine.html">Engine</a></li><li><a href="host.html">Host</a></li><li><a href="cluster.html">Cluster</a></li></ul><p><strong>Nested Components</strong></p><ul><li><a href="globalresources.html">Global Resources</a></li><li><a href="loader.html">Loader</a></li><li><a href="manager.html">Manager</a></li><li><a href="realm.html">Realm</a></li><li><a href="resources.html">Resources</a></li><li><a href="valve.html">Valve</a></li></ul><p><strong>Cluster Elements</strong></p><ul><li><a href="cluster.html">Cluster</a></li><li><a href="cluster-manager.html">Manager</a></li><li><a href="cluster-channel.html">Channel</a></li><li><a href="cluster-membership.html">Channel/Membership</a></li><li><a href="cluster-sender.html">Channel/Sender</a></li><li><a href="cluster-receiver.html">Channel/Receiver</a></li><li><a href="cluster-interceptor.html">Channel/Interceptor</a></li><li><a href="cluster-valve.html">Valve</a></li><li><a href="cluster-deployer.html">Deployer</a></li><li><a href="cluster-listener.html">ClusterListener</a></li></ul><p><strong>Global Settings</strong></p><ul><li><a href="systemprops.html">System properties</a></li></ul></td><!--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 Channel object</h2></td><td nowrap="true" valign="top" align="right"><small><a href="printer/cluster-channel.html"><img alt="Printer Friendly Version" border="0" src="../images/printer.gif"><br>print-friendly<br>version |
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| 4 | </a></small></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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| 5 | The cluster channel is the main component of a small framework we've nicknamed Apache Tribes.<br> |
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| 6 | The channel manages a set of sub components and together they create a group communication framework.<br> |
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| 7 | This framework is then used internally by the components that need to send messages between different Tomcat instances. |
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| 8 | <br> |
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| 9 | A few examples of these components would be the SimpleTcpCluster that does the messaging for the DeltaManager, |
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| 10 | or the BackupManager that uses a different replication strategy. The ReplicatedContext object does also |
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| 11 | use the channel object to communicate context attribute changes. |
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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="Nested Components"><strong>Nested Components</strong></a></font></td></tr><tr><td><blockquote> |
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| 13 | <p><b><a href="cluster-membership.html">Channel/Membership</a>:</b> <br> |
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| 14 | The Membership component is responsible for auto discovering new nodes in the cluster |
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| 15 | and also to provide for notifications for any nodes that have not responded with a heartbeat. |
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| 16 | The default implementation uses multicast.<br> |
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| 17 | In the membership component you configure how your nodes, aka. members, are to be discovered and/or |
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| 18 | divided up. |
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| 19 | You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a> |
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| 20 | </p> |
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| 21 | <p><b><a href="cluster-sender.html">Channel/Sender</a>:</b> <br> |
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| 22 | The Sender component manages all outbound connections and data messages that are sent |
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| 23 | over the network from one node to another. |
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| 24 | This component allows messages to be sent in parallel. |
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| 25 | The default implementation uses TCP client sockets, and socket tuning for outgoing messages are |
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| 26 | configured here.<br> |
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| 27 | You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a> |
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| 28 | </p> |
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| 29 | <p><b><a href="cluster-sender.html#transport">Channel/Sender/Transport</a>:</b> <br> |
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| 30 | The Transport component is the bottom IO layer for the sender component. |
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| 31 | The default implementation uses non-blocking TCP client sockets.<br> |
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| 32 | You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a> |
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| 33 | </p> |
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| 34 | <p><b><a href="cluster-receiver.html">Channel/Receiver</a>:</b> <br> |
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| 35 | The receiver component listens for messages from other nodes. |
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| 36 | Here you will configure the cluster thread pool, as it will dispatch incoming |
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| 37 | messages to a thread pool for faster processing. |
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| 38 | The default implementation uses non-blocking TCP server sockets.<br> |
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| 39 | You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a> |
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| 40 | </p> |
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| 41 | <p><b><a href="cluster-interceptor.html">Channel/Interceptor</a>:</b> <br> |
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| 42 | The channel will send messages through an interceptor stack. Because of this, you have the ability to |
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| 43 | customize the way messages are sent and received, and even how membership is handled.<br> |
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| 44 | You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a> |
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| 45 | </p> |
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| 46 | </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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| 47 | |
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| 48 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Common Attributes"><strong>Common Attributes</strong></a></font></td></tr><tr><td><blockquote> |
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| 49 | |
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| 50 | <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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| 51 | The default value here is <code>org.apache.catalina.tribes.group.GroupChannel</code> and is |
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| 52 | currently the only implementation available. |
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| 53 | </td></tr></table> |
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| 54 | |
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| 55 | |
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| 56 | </blockquote></td></tr></table> |
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| 57 | |
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| 58 | |
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| 59 | </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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| 60 | Copyright © 1999-2008, Apache Software Foundation |
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| 61 | </em></font></div></td></tr></table></body></html> |
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