| <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat 7 Configuration Reference (7.0.77) - The Cluster Receiver 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="http://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 7.0.77, Mar 28 2017</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="http://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 Receiver 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="#Blocking_vs_Non-Blocking_Receiver">Blocking vs Non-Blocking Receiver</a></li><li><a href="#Attributes">Attributes</a><ol><li><a href="#Common_Attributes">Common Attributes</a></li><li><a href="#NioReceiver">NioReceiver</a></li><li><a href="#BioReceiver">BioReceiver</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> | |
| <p> | |
| The receiver component is responsible for receiving cluster messages. | |
| As you might notice through the configuration, is that the receiving of messages | |
| and sending of messages are two different components, this is different from many other | |
| frameworks, but there is a good reason for it, to decouple the logic for how messages are sent from | |
| how messages are received.<br> | |
| The receiver is very much like the Tomcat Connector, its the base of the thread pool | |
| for incoming cluster messages. The receiver is straight forward, but all the socket settings | |
| for incoming traffic are managed here. | |
| </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="Blocking vs Non-Blocking Receiver"><!--()--></a><a name="Blocking_vs_Non-Blocking_Receiver"><strong>Blocking vs Non-Blocking Receiver</strong></a></font></td></tr><tr><td><blockquote> | |
| <p> | |
| The receiver supports both a non blocking, <code>org.apache.catalina.tribes.transport.nio.NioReceiver</code>, and a | |
| blocking, <code>org.apache.catalina.tribes.transport.bio.BioReceiver</code>. It is preferred to use the non blocking receiver | |
| to be able to grow your cluster without running into thread starvation.<br> | |
| Using the non blocking receiver allows you to with a very limited thread count to serve a large number of messages. | |
| Usually the rule is to use 1 thread per node in the cluster for small clusters, and then depending on your message frequency | |
| and your hardware, you'll find an optimal number of threads peak out at a certain number. | |
| </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 implementation of the receiver component. Two implementations available, | |
| <code>org.apache.catalina.tribes.transport.nio.NioReceiver</code> and | |
| <code>org.apache.catalina.tribes.transport.bio.BioReceiver</code>.<br> | |
| The <code>org.apache.catalina.tribes.transport.nio.NioReceiver</code> is the | |
| preferred implementation | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">address</code></td><td align="left" valign="center"> | |
| The address (network interface) to listen for incoming traffic. | |
| Same as the bind address. The default value is <code>auto</code> and translates to | |
| <code>java.net.InetAddress.getLocalHost().getHostAddress()</code>. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">direct</code></td><td align="left" valign="center"> | |
| Possible values are <code>true</code> or <code>false</code>. | |
| Set to true if you want the receiver to use direct bytebuffers when reading data | |
| from the sockets. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">port</code></td><td align="left" valign="center"> | |
| The listen port for incoming data. The default value is <code>4000</code>. | |
| To avoid port conflicts the receiver will automatically bind to a free port within the range of | |
| <code> port <= bindPort < port+autoBind</code> | |
| So for example, if port is 4000, and autoBind is set to 10, then the receiver will open up | |
| a server socket on the first available port in the range 4000-4009. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">autoBind</code></td><td align="left" valign="center"> | |
| Default value is <code>100</code>. | |
| Use this value if you wish to automatically avoid port conflicts the cluster receiver will try to open a | |
| server socket on the <code>port</code> attribute port, and then work up <code>autoBind</code> number of times. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">securePort</code></td><td align="left" valign="center"> | |
| The secure listen port. This port is SSL enabled. If this attribute is omitted no SSL port is opened up. | |
| There default value is unset, meaning there is no SSL socket available. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">udpPort</code></td><td align="left" valign="center"> | |
| The UDP listen port. If this attribute is omitted no UDP port is opened up. | |
| There default value is unset, meaning there is no UDP listener available. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">selectorTimeout</code></td><td align="left" valign="center"> | |
| The value in milliseconds for the polling timeout in the <code>NioReceiver</code>. On older versions of the JDK | |
| there have been bugs, that should all now be cleared out where the selector never woke up. | |
| The default value is a very high <code>5000</code> milliseconds. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxThreads</code></td><td align="left" valign="center"> | |
| The maximum number of threads in the receiver thread pool. The default value is <code>6</code> | |
| Adjust this value relative to the number of nodes in the cluster, the number of messages being exchanged and | |
| the hardware you are running on. A higher value doesn't mean more efficiency, tune this value according to your | |
| own test results. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">minThreads</code></td><td align="left" valign="center"> | |
| Minimum number of threads to be created when the receiver is started up. Default value is <code>6</code> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">ooBInline</code></td><td align="left" valign="center"> | |
| Boolean value for the socket OOBINLINE option. Possible values are <code>true</code> or <code>false</code>. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">rxBufSize</code></td><td align="left" valign="center"> | |
| The receiver buffer size on the receiving sockets. Value is in bytes, the default value is <code>43800</code> bytes. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">txBufSize</code></td><td align="left" valign="center"> | |
| The sending buffer size on the receiving sockets. Value is in bytes, the default value is <code>25188</code> bytes. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">udpRxBufSize</code></td><td align="left" valign="center"> | |
| The receive buffer size on the datagram socket. | |
| Default value is <code>25188</code> bytes. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">udpTxBufSize</code></td><td align="left" valign="center"> | |
| The send buffer size on the datagram socket. | |
| Default value is <code>43800</code> bytes. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">soKeepAlive</code></td><td align="left" valign="center"> | |
| Boolean value for the socket SO_KEEPALIVE option. Possible values are <code>true</code> or <code>false</code>. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">soLingerOn</code></td><td align="left" valign="center"> | |
| Boolean value to determine whether to use the SO_LINGER socket option. | |
| Possible values are <code>true</code> or <code>false</code>. Default value is <code>true</code>. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">soLingerTime</code></td><td align="left" valign="center"> | |
| Sets the SO_LINGER socket option time value. The value is in seconds. | |
| The default value is <code>3</code> seconds. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">soReuseAddress</code></td><td align="left" valign="center"> | |
| Boolean value for the socket SO_REUSEADDR option. Possible values are <code>true</code> or <code>false</code>. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">tcpNoDelay</code></td><td align="left" valign="center"> | |
| Boolean value for the socket TCP_NODELAY option. Possible values are <code>true</code> or <code>false</code>. | |
| The default value is <code>true</code> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">timeout</code></td><td align="left" valign="center"> | |
| Sets the SO_TIMEOUT option on the socket. The value is in milliseconds and the default value is <code>3000</code> | |
| milliseconds. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">useBufferPool</code></td><td align="left" valign="center"> | |
| Boolean value whether to use a shared buffer pool of cached <code>org.apache.catalina.tribes.io.XByteBuffer</code> | |
| objects. If set to true, the XByteBuffer that is used to pass a message up the channel, will be recycled at the end | |
| of the requests. This means that interceptors in the channel must not maintain a reference to the object | |
| after the <code>org.apache.catalina.tribes.ChannelInterceptor#messageReceived</code> method has exited. | |
| </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="NioReceiver"><strong>NioReceiver</strong></a></font></td></tr><tr><td><blockquote> | |
| </blockquote></td></tr></table> | |
| <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="BioReceiver"><strong>BioReceiver</strong></a></font></td></tr><tr><td><blockquote> | |
| </blockquote></td></tr></table> | |
| </blockquote></td></tr></table></td></tr><tr class="noPrint"><td width="20%" valign="top" nowrap class="noPrint"></td><td width="80%" valign="top" align="left"><table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#525D76"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="comments_section" id="comments_section"><strong>Comments</strong></a></font></td></tr><tr><td><blockquote><p class="notice"><strong>Notice: </strong>This comments section collects your suggestions | |
| on improving documentation for Apache Tomcat.<br><br> | |
| If you have trouble and need help, read | |
| <a href="http://tomcat.apache.org/findhelp.html">Find Help</a> page | |
| and ask your question on the tomcat-users | |
| <a href="http://tomcat.apache.org/lists.html">mailing list</a>. | |
| Do not ask such questions here. This is not a Q&A section.<br><br> | |
| The Apache Comments System is explained <a href="../comments.html">here</a>. | |
| Comments may be removed by our moderators if they are either | |
| implemented or considered invalid/off-topic.</p><script type="text/javascript"><!--//--><![CDATA[//><!-- | |
| var comments_shortname = 'tomcat'; | |
| var comments_identifier = 'http://tomcat.apache.org/tomcat-7.0-doc/config/cluster-receiver.html'; | |
| (function(w, d) { | |
| if (w.location.hostname.toLowerCase() == "tomcat.apache.org") { | |
| d.write('<div id="comments_thread"><\/div>'); | |
| var s = d.createElement('script'); | |
| s.type = 'text/javascript'; | |
| s.async = true; | |
| s.src = 'https://comments.apache.org/show_comments.lua?site=' + comments_shortname + '&page=' + comments_identifier; | |
| (d.getElementsByTagName('head')[0] || d.getElementsByTagName('body')[0]).appendChild(s); | |
| } | |
| else { | |
| d.write('<div id="comments_thread"><strong>Comments are disabled for this page at the moment.<\/strong><\/div>'); | |
| } | |
| })(window, document); | |
| //--><!]]></script></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 © 1999-2017, Apache Software Foundation | |
| </em></font></div></td></tr></table></body></html> |