| <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 Sender 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 Sender 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="#Concurrent_Parallel_Delivery">Concurrent Parallel Delivery</a></li><li><a href="#Nested_Elements">Nested Elements</a></li><li><a href="#Attributes">Attributes</a><ol><li><a href="#Common_Sender_Attributes">Common Sender Attributes</a></li><li><a href="#Common_Transport_Attributes">Common Transport Attributes</a></li><li><a href="#Common_PooledSender_Attributes">Common PooledSender 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> | |
| <p> | |
| The channel sender component is responsible for delivering outgoing cluster messages over the network. | |
| In the default implementation, <code>org.apache.catalina.tribes.transport.ReplicationTransmitter</code>, | |
| the sender is a fairly empty shell with not much logic around a fairly complex <code><Transport></code> | |
| component the implements the actual delivery mechanism. | |
| </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="Concurrent Parallel Delivery"><!--()--></a><a name="Concurrent_Parallel_Delivery"><strong>Concurrent Parallel Delivery</strong></a></font></td></tr><tr><td><blockquote> | |
| <p> | |
| In the default <code>transport</code> implementation, <code>org.apache.catalina.tribes.transport.nio.PooledParallelSender</code>, | |
| Apache Tribes implements what we like to call "Concurrent Parallel Delivery". | |
| This means that we can send a message to more than one destination at the same time(parallel), and | |
| deliver two messages to the same destination at the same time(concurrent). Combine these two and we have | |
| "Concurrent Parallel Delivery". | |
| </p> | |
| <p> | |
| When is this useful? The simplest example we can think of is when part of your code is sending a 10MB message, | |
| like a war file being deployed, and you need to push through a small 10KB message, say a session being replicated, | |
| you don't have to wait for the 10MB message to finish, as a separate thread will push in the small message | |
| transmission at the same time. Currently there is no interrupt, pause or priority mechanism available, but check back soon. | |
| </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="Nested Elements"><!--()--></a><a name="Nested_Elements"><strong>Nested Elements</strong></a></font></td></tr><tr><td><blockquote> | |
| <p> | |
| The nested element <code><Transport></code> is not required, but encouraged, as this is where | |
| you would set all the socket options for the outgoing messages. Please see its attributes below. | |
| There are two implementations, in a similar manner to the <a href="cluster-receiver.html">receiver</a>, one is non-blocking | |
| based and the other is built using blocking IO. <br> | |
| <code>org.apache.catalina.tribes.transport.bio.PooledMultiSender</code> is the blocking implementation and | |
| <code>org.apache.catalina.tribes.transport.nio.PooledParallelSender</code>. | |
| Parallel delivery is not available for the blocking implementation due to the fact that it is blocking a thread on sending data. | |
| </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 Sender Attributes"><!--()--></a><a name="Common_Sender_Attributes"><strong>Common Sender 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"> | |
| Required, only available implementation is <code>org.apache.catalina.tribes.transport.ReplicationTransmitter</code> | |
| </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="Common Transport Attributes"><!--()--></a><a name="Common_Transport_Attributes"><strong>Common Transport 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"> | |
| Required, an implementation of the <code>org.apache.catalina.tribes.transport.MultiPointSender</code>.<br> | |
| Non-blocking implementation is <code>org.apache.catalina.tribes.transport.nio.PooledParallelSender</code><br> | |
| Blocking implementation is <code>org.apache.catalina.tribes.transport.bio.PooledMultiSender</code> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">rxBufSize</code></td><td align="left" valign="center"> | |
| The receive buffer size on the socket. | |
| Default value is <code>25188</code> bytes. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">txBufSize</code></td><td align="left" valign="center"> | |
| The send buffer size on the socket. | |
| Default value is <code>43800</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">directBuffer</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 writing data | |
| to the sockets. Default value is <code>false</code> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">keepAliveCount</code></td><td align="left" valign="center"> | |
| The number of requests that can go through the socket before the socket is closed, and reopened | |
| for the next request. The default value is <code>-1</code>, which is unlimited. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">keepAliveTime</code></td><td align="left" valign="center"> | |
| The number of milliseconds a connection is kept open after its been opened. | |
| The default value is <code>-1</code>, which is unlimited. | |
| </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.(3 seconds) This timeout starts when a message send attempt is starting, until the transfer has been completed. | |
| For the NIO sockets, this will mean, that the caller can guarantee that we will not attempt sending the message | |
| longer than this timeout value. For the blocking IO implementation, this translated directly to the soTimeout.<br> | |
| A timeout will not spawn a retry attempt, in order to guarantee the return of the application thread. | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxRetryAttempts</code></td><td align="left" valign="center"> | |
| How many times do we retry a failed message, that received a IOException at the socket level. | |
| The default value is <code>1</code>, meaning we will retry a message that has failed once. | |
| In other words, we will attempt a message send no more than twice. One is the original send, and one is the | |
| <code>maxRetryAttempts</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">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">soTrafficClass</code></td><td align="left" valign="center"> | |
| Sets the traffic class level for the socket, the value is between 0 and 255. | |
| Default value is <code>int soTrafficClass = 0x04 | 0x08 | 0x010;</code> | |
| Different values are defined in <a href="http://docs.oracle.com/javase/6/docs/api/java/net/Socket.html#setTrafficClass(int)"> | |
| java.net.Socket#setTrafficClass(int)</a>. | |
| </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">throwOnFailedAck</code></td><td align="left" valign="center"> | |
| Boolean value, default value is <code>true</code>. | |
| If set to true, the sender will throw a <code>org.apache.catalina.tribes.RemoteProcessException</code> | |
| when we receive a negative ack from the remote member. | |
| Set to false, and Tribes will treat a positive ack the same way as a negative ack, that the message was received. | |
| </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="Common PooledSender Attributes"><!--()--></a><a name="Common_PooledSender_Attributes"><strong>Common PooledSender 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">poolSize</code></td><td align="left" valign="center"> | |
| The maximum number of concurrent connections from A to B. | |
| The value is based on a per-destination count. | |
| The default value is <code>25</code> | |
| </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxWait</code></td><td align="left" valign="center"> | |
| The maximum number of milliseconds that the senderPool will wait when | |
| there are no available senders. The default value is <code>3000</code> | |
| milliseconds.(3 seconds). | |
| </td></tr></table> | |
| </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-sender.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> |