| 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><!--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"><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 |   The cluster channel is the main component of a small framework we've nicknamed Apache Tribes.<br> | 
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| 5 |   The channel manages a set of sub components and together they create a group communication framework.<br> | 
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| 6 |   This framework is then used internally by the components that need to send messages between different Tomcat instances. | 
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| 7 |   <br> | 
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| 8 |   A few examples of these components would be the SimpleTcpCluster that does the messaging for the DeltaManager, | 
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| 9 |   or the BackupManager that uses a different replication strategy. The ReplicatedContext object does also  | 
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| 10 |   use the channel object to communicate context attribute changes. | 
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| 11 | </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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| 12 |   <p><b><a href="cluster-membership.html">Channel/Membership</a>:</b> <br> | 
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| 13 |     The Membership component is responsible for auto discovering new nodes in the cluster | 
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| 14 |     and also to provide for notifications for any nodes that have not responded with a heartbeat. | 
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| 15 |     The default implementation uses multicast.<br> | 
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| 16 |     In the membership component you configure how your nodes, aka. members, are to be discovered and/or  | 
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| 17 |     divided up.  | 
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| 18 |     You can always find out more about <a href="../../tribes/introduction.html">Apache Tribes</a> | 
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| 19 |   </p> | 
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| 20 |   <p><b><a href="cluster-sender.html">Channel/Sender</a>:</b> <br> | 
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| 21 |     The Sender component manages all outbound connections and data messages that are sent  | 
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| 22 |     over the network from one node to another. | 
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| 23 |     This component allows messages to be sent in parallel. | 
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| 24 |     The default implementation uses TCP client sockets, and socket tuning for outgoing messages are | 
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| 25 |     configured here.<br> | 
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| 26 |     You can always find out more about <a href="../../tribes/introduction.html">Apache Tribes</a> | 
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| 27 |   </p> | 
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| 28 |   <p><b><a href="cluster-sender.html#transport">Channel/Sender/Transport</a>:</b> <br> | 
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| 29 |     The Transport component is the bottom IO layer for the sender component. | 
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| 30 |     The default implementation uses non-blocking TCP client sockets.<br> | 
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| 31 |     You can always find out more about <a href="../../tribes/introduction.html">Apache Tribes</a> | 
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| 32 |   </p> | 
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| 33 |   <p><b><a href="cluster-receiver.html">Channel/Receiver</a>:</b> <br> | 
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| 34 |     The receiver component listens for messages from other nodes. | 
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| 35 |     Here you will configure the cluster thread pool, as it will dispatch incoming | 
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| 36 |     messages to a thread pool for faster processing. | 
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| 37 |     The default implementation uses non-blocking TCP server sockets.<br> | 
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| 38 |     You can always find out more about <a href="../../tribes/introduction.html">Apache Tribes</a> | 
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| 39 |   </p> | 
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| 40 |   <p><b><a href="cluster-interceptor.html">Channel/Interceptor</a>:</b> <br> | 
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| 41 |     The channel will send messages through an interceptor stack. Because of this, you have the ability to  | 
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| 42 |     customize the way messages are sent and received, and even how membership is handled.<br> | 
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| 43 |     You can always find out more about <a href="../../tribes/introduction.html">Apache Tribes</a> | 
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| 44 |   </p> | 
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| 45 | </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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| 46 |  | 
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| 47 |   <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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| 48 |  | 
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| 49 |   <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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| 50 |        The default value here is <code>org.apache.catalina.tribes.group.GroupChannel</code> and is | 
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| 51 |        currently the only implementation available. | 
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| 52 |     </td></tr></table> | 
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| 53 |  | 
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| 54 |  | 
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| 55 |   </blockquote></td></tr></table> | 
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| 56 |  | 
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| 57 |  | 
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| 58 | </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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| 59 |         Copyright © 1999-2008, Apache Software Foundation | 
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| 60 |         </em></font></div></td></tr></table></body></html> | 
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