MINI

files >> C:/xampp/tomcat/webapps/docs/config/cluster-channel.html
 <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat 7 Configuration Reference (7.0.103) - The Cluster Channel object</title><meta name="author" content="Filip Hanik"><style type="text/css" media="print">
    .noPrint {display: none;}
    td#mainBody {width: 100%;}
</style><style type="text/css">
code {background-color:rgb(224,255,255);padding:0 0.1em;}
code.attributeName, code.propertyName {background-color:transparent;}


table {
  border-collapse: collapse;
  text-align: left;
}
table *:not(table) {
  /* Prevent border-collapsing for table child elements like <div> */
  border-collapse: separate;
}

th {
  text-align: left;
}


div.codeBox pre code, code.attributeName, code.propertyName, code.noHighlight, .noHighlight code {
  background-color: transparent;
}
div.codeBox {
  overflow: auto;
  margin: 1em 0;
}
div.codeBox pre {
  margin: 0;
  padding: 4px;
  border: 1px solid #999;
  border-radius: 5px;
  background-color: #eff8ff;
  display: table; /* To prevent <pre>s from taking the complete available width. */
  /*
  When it is officially supported, use the following CSS instead of display: table
  to prevent big <pre>s from exceeding the browser window:
  max-width: available;
  width: min-content;
  */
}

div.codeBox pre.wrap {
  white-space: pre-wrap;
}


table.defaultTable tr, table.detail-table tr {
    border: 1px solid #CCC;
}

table.defaultTable tr:nth-child(even), table.detail-table tr:nth-child(even) {
    background-color: #FAFBFF;
}

table.defaultTable tr:nth-child(odd), table.detail-table tr:nth-child(odd) {
    background-color: #EEEFFF;
}

table.defaultTable th, table.detail-table th {
  background-color: #88b;
  color: #fff;
}

table.defaultTable th, table.defaultTable td, table.detail-table th, table.detail-table td {
  padding: 5px 8px;
}


p.notice {
    border: 1px solid rgb(255, 0, 0);
    background-color: rgb(238, 238, 238);
    color: rgb(0, 51, 102);
    padding: 0.5em;
    margin: 1em 2em 1em 1em;
}
</style></head><body bgcolor="#ffffff" text="#000000" link="#525D76" alink="#525D76" vlink="#525D76"><table border="0" width="100%" cellspacing="0"><!--PAGE HEADER--><tr><td><!--PROJECT LOGO--><a href="https://tomcat.apache.org/"><img src="../images/tomcat.gif" align="right" alt="
    The Apache Tomcat Servlet/JSP Container
  " border="0"></a></td><td><h1><font face="arial,helvetica,sanserif">Apache Tomcat 7</font></h1><font face="arial,helvetica,sanserif">Version 7.0.103, Mar 16 2020</font></td><td><!--APACHE LOGO--><a href="http://www.apache.org/"><img src="../images/asf-logo.svg" align="right" alt="Apache Logo" border="0" style="width: 266px;height: 83px;"></a></td></tr></table><table border="0" width="100%" cellspacing="4"><!--HEADER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><tr><!--LEFT SIDE NAVIGATION--><td width="20%" valign="top" nowrap class="noPrint"><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><li><a href="https://wiki.apache.org/tomcat/FAQ">FAQ</a></li><li><a href="#comments_section">User Comments</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="jar-scanner.html">JarScanner</a></li><li><a href="listeners.html">Listeners</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="sessionidgenerator.html">SessionIdGenerator</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>web.xml</strong></p><ul><li><a href="filter.html">Filter</a></li></ul><p><strong>Other</strong></p><ul><li><a href="systemprops.html">System properties</a></li></ul></td><!--RIGHT SIDE MAIN BODY--><td width="80%" valign="top" align="left" id="mainBody"><h1>The Cluster Channel object</h1><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Table of Contents"><!--()--></a><a name="Table_of_Contents"><strong>Table of Contents</strong></a></font></td></tr><tr><td><blockquote>
<ul><li><a href="#Introduction">Introduction</a></li><li><a href="#Nested_Components">Nested Components</a></li><li><a href="#Attributes">Attributes</a><ol><li><a href="#Common_Attributes">Common Attributes</a></li><li><a href="#org.apache.catalina.tribes.group.GroupChannel_Attributes">org.apache.catalina.tribes.group.GroupChannel Attributes</a></li></ol></li></ul>
</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Introduction"><strong>Introduction</strong></a></font></td></tr><tr><td><blockquote>
  The cluster channel is the main component of a small framework we've nicknamed Apache Tribes.<br>
  The channel manages a set of sub components and together they create a group communication framework.<br>
  This framework is then used internally by the components that need to send messages between different Tomcat instances.
  <br>
  A few examples of these components would be the SimpleTcpCluster that does the messaging for the DeltaManager,
  or the BackupManager that uses a different replication strategy. The ReplicatedContext object does also
  use the channel object to communicate context attribute changes.
</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Nested Components"><!--()--></a><a name="Nested_Components"><strong>Nested Components</strong></a></font></td></tr><tr><td><blockquote>
  <p><b><a href="cluster-membership.html">Channel/Membership</a>:</b> <br>
    The Membership component is responsible for auto discovering new nodes in the cluster
    and also to provide for notifications for any nodes that have not responded with a heartbeat.
    The default implementation uses multicast.<br>
    In the membership component you configure how your nodes, aka. members, are to be discovered and/or
    divided up.
    You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a>
  </p>
  <p><b><a href="cluster-sender.html">Channel/Sender</a>:</b> <br>
    The Sender component manages all outbound connections and data messages that are sent
    over the network from one node to another.
    This component allows messages to be sent in parallel.
    The default implementation uses TCP client sockets, and socket tuning for outgoing messages are
    configured here.<br>
    You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a>
  </p>
  <p><b><a href="cluster-sender.html#transport">Channel/Sender/Transport</a>:</b> <br>
    The Transport component is the bottom IO layer for the sender component.
    The default implementation uses non-blocking TCP client sockets.<br>
    You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a>
  </p>
  <p><b><a href="cluster-receiver.html">Channel/Receiver</a>:</b> <br>
    The receiver component listens for messages from other nodes.
    Here you will configure the cluster thread pool, as it will dispatch incoming
    messages to a thread pool for faster processing.
    The default implementation uses non-blocking TCP server sockets.<br>
    You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a>
  </p>
  <p><b><a href="cluster-interceptor.html">Channel/Interceptor</a>:</b> <br>
    The channel will send messages through an interceptor stack. Because of this, you have the ability to
    customize the way messages are sent and received, and even how membership is handled.<br>
    You can always find out more about <a href="../tribes/introduction.html">Apache Tribes</a>
  </p>
</blockquote></td></tr></table><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Attributes"><strong>Attributes</strong></a></font></td></tr><tr><td><blockquote>

  <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Common Attributes"><!--()--></a><a name="Common_Attributes"><strong>Common Attributes</strong></a></font></td></tr><tr><td><blockquote>

  <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><strong><code class="attributeName">className</code></strong></td><td align="left" valign="center">
       The default value here is <code>org.apache.catalina.tribes.group.GroupChannel</code> and is
       currently the only implementation available.
    </td></tr></table>


  </blockquote></td></tr></table>

  <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="org.apache.catalina.tribes.group.GroupChannel Attributes"><!--()--></a><a name="org.apache.catalina.tribes.group.GroupChannel_Attributes"><strong>org.apache.catalina.tribes.group.GroupChannel Attributes</strong></a></font></td></tr><tr><td><blockquote>

    <table border="1" cellpadding="5"><tr><th width="15%" bgcolor="#023264"><font color="#ffffff">Attribute</font></th><th width="85%" bgcolor="#023264"><font color="#ffffff">Description</font></th></tr><tr><td align="left" valign="center"><code class="attributeName">heartbeat</code></td><td align="left" valign="center">
         Flag whether the channel manages its own heartbeat.
         If set to true,  the channel start a local thread for the heart beat.
         If set this flag to false, you must set SimpleTcpCluster#heartbeatBackgroundEnabled
         to true. default value is true.
      </td></tr><tr><td align="left" valign="center"><code class="attributeName">heartbeatSleeptime</code></td><td align="left" valign="center">
        If heartbeat == true, specifies the interval of heartbeat thread in milliseconds.
        The default is 5000 (5 seconds).
      </td></tr><tr><td align="left" valign="center"><code class="attributeName">optionCheck</code></td><td align="left" valign="center">
        If set to true, the GroupChannel will check the option flags that each
        interceptor is using. Reports an error if two interceptor share the same
        flag. The default is false.
      </td></tr></table>

  </blockquote></td></tr></table>

</blockquote></td></tr></table></td></tr><!--FOOTER SEPARATOR--><tr><td colspan="2"><hr noshade size="1"></td></tr><!--PAGE FOOTER--><tr><td colspan="2"><div align="center"><font color="#525D76" size="-1"><em>
        Copyright &copy; 1999-2020, Apache Software Foundation
        </em></font></div></td></tr></table></body></html>