| 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat Configuration Reference - The Cluster Receiver 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 Receiver 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 | <p> |
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| 5 | The receiver component is responsible for receiving cluster messages. |
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| 6 | As you might notice through the configuration, is that the receiving of messages |
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| 7 | and sending of messages are two different components, this is different from many other |
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| 8 | frameworks, but there is a good reason for it, to decouple the logic for how messages are sent from |
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| 9 | how messages are received.<br> |
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| 10 | The receiver is very much like the Tomcat Connector, its the base of the thread pool |
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| 11 | for incoming cluster messages. The receiver is straight forward, but all the socket settings |
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| 12 | for incoming traffic are managed here. |
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| 13 | </p> |
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| 14 | </blockquote></td></tr></table><table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#525D76"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="Blocking vs Non-Blocking Receiver"><strong>Blocking vs Non-Blocking Receiver</strong></a></font></td></tr><tr><td><blockquote> |
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| 15 | <p> |
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| 16 | The receiver supports both a non blocking, <code>org.apache.catalina.tribes.transport.nio.NioReceiver</code>, and a |
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| 17 | blocking, <code>org.apache.catalina.tribes.transport.bio.BioReceiver</code>. It is preferred to use the non blocking receiver |
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| 18 | to be able to grow your cluster without running into thread starvation.<br> |
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| 19 | Using the non blocking receiver allows you to with a very limited thread count to serve a large number of messages. |
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| 20 | Usually the rule is to use 1 thread per node in the cluster for small clusters, and then depending on your message frequency |
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| 21 | and your hardware, you'll find an optimal number of threads peak out at a certain number. |
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| 22 | </p> |
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| 23 | </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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| 24 | <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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| 25 | <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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| 26 | The implementation of the receiver component. Two implementations available, |
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| 27 | <code>org.apache.catalina.tribes.transport.nio.NioReceiver</code> and |
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| 28 | <code>org.apache.catalina.tribes.transport.bio.BioReceiver</code>.<br> |
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| 29 | The <code>org.apache.catalina.tribes.transport.nio.NioReceiver</code> is the |
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| 30 | preferred implementation |
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| 31 | </td></tr><tr><td valign="center" align="left"><code>address</code></td><td valign="center" align="left"> |
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| 32 | The address (network interface) to listen for incoming traffic. |
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| 33 | Same as the bind address. The default value is <code>auto</code> and translates to |
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| 34 | <code>java.net.InetAddress.getLocalHost().getHostAddress()</code>. |
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| 35 | </td></tr><tr><td valign="center" align="left"><code>direct</code></td><td valign="center" align="left"> |
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| 36 | Possible values are <code>true</code> or <code>false</code>. |
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| 37 | Set to true if you want the receiver to use direct bytebuffers when reading data |
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| 38 | from the sockets. |
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| 39 | </td></tr><tr><td valign="center" align="left"><code>port</code></td><td valign="center" align="left"> |
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| 40 | The listen port for incoming data. The default value is <code>4000</code>. |
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| 41 | To avoid port conflicts the receiver will automatically bind to a free port within the range of |
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| 42 | <code> port <= bindPort <= port+autoBind</code> |
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| 43 | So for example, if port is 4000, and autoBind is set to 10, then the receiver will open up |
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| 44 | a server socket on the first available port in the range 4000-4100. |
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| 45 | </td></tr><tr><td valign="center" align="left"><code>autoBind</code></td><td valign="center" align="left"> |
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| 46 | Default value is <code>100</code>. |
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| 47 | Use this value if you wish to automatically avoid port conflicts the cluster receiver will try to open a |
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| 48 | server socket on the <code>port</code> attribute port, and then work up <code>autoBind</code> number of times. |
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| 49 | </td></tr><tr><td valign="center" align="left"><code>securePort</code></td><td valign="center" align="left"> |
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| 50 | The secure listen port. This port is SSL enabled. If this attribute is omitted no SSL port is opened up. |
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| 51 | There default value is unset, meaning there is no SSL socket available. |
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| 52 | </td></tr><tr><td valign="center" align="left"><code>selectorTimeout</code></td><td valign="center" align="left"> |
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| 53 | The value in milliseconds for the polling timeout in the <code>NioReceiver</code>. On older versions of the JDK |
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| 54 | there have been bugs, that should all now be cleared out where the selector never woke up. |
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| 55 | The default value is a very high <code>5000</code> milliseconds. |
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| 56 | </td></tr><tr><td valign="center" align="left"><code>maxThreads</code></td><td valign="center" align="left"> |
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| 57 | The maximum number of threads in the receiver thread pool. The default value is <code>6</code> |
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| 58 | Adjust this value relative to the number of nodes in the cluster, the number of messages being exchanged and |
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| 59 | the hardware you are running on. A higher value doesn't mean more effiecency, tune this value according to your |
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| 60 | own test results. |
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| 61 | </td></tr><tr><td valign="center" align="left"><code>minThreads</code></td><td valign="center" align="left"> |
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| 62 | Minimum number of threads to be created when the receiver is started up. Default value is <code>6</code> |
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| 63 | </td></tr><tr><td valign="center" align="left"><code>ooBInline</code></td><td valign="center" align="left"> |
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| 64 | Boolean value for the socket OOBINLINE option. Possible values are <code>true</code> or <code>false</code>. |
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| 65 | </td></tr><tr><td valign="center" align="left"><code>rxBufSize</code></td><td valign="center" align="left"> |
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| 66 | The receiver buffer size on the receiving sockets. Value is in bytes, the default value is <code>43800</code> bytes. |
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| 67 | </td></tr><tr><td valign="center" align="left"><code>txBufSize</code></td><td valign="center" align="left"> |
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| 68 | The sending buffer size on the receiving sockets. Value is in bytes, the default value is <code>25188</code> bytes. |
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| 69 | </td></tr><tr><td valign="center" align="left"><code>soKeepAlive</code></td><td valign="center" align="left"> |
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| 70 | Boolean value for the socket SO_KEEPALIVE option. Possible values are <code>true</code> or <code>false</code>. |
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| 71 | </td></tr><tr><td valign="center" align="left"><code>soLingerOn</code></td><td valign="center" align="left"> |
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| 72 | Boolean value to determine whether to use the SO_LINGER socket option. |
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| 73 | Possible values are <code>true</code> or <code>false</code>. Default value is <code>true</code>. |
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| 74 | </td></tr><tr><td valign="center" align="left"><code>soLingerTime</code></td><td valign="center" align="left"> |
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| 75 | Sets the SO_LINGER socket option time value. The value is in seconds. |
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| 76 | The default value is <code>3</code> seconds. |
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| 77 | </td></tr><tr><td valign="center" align="left"><code>soReuseAddress</code></td><td valign="center" align="left"> |
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| 78 | Boolean value for the socket SO_REUSEADDR option. Possible values are <code>true</code> or <code>false</code>. |
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| 79 | </td></tr><tr><td valign="center" align="left"><code>soTrafficClass</code></td><td valign="center" align="left"> |
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| 80 | Sets the traffic class level for the socket, the value is between 0 and 255. |
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| 81 | Different values are defined in <a href="http://java.sun.com/j2se/1.5.0/docs/api/java/net/Socket.html#setTrafficClass(int)"> |
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| 82 | java.net.Socket#setTrafficClass(int)</a>. |
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| 83 | </td></tr><tr><td valign="center" align="left"><code>tcpNoDelay</code></td><td valign="center" align="left"> |
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| 84 | Boolean value for the socket TCP_NODELAY option. Possible values are <code>true</code> or <code>false</code>. |
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| 85 | The default value is <code>true</code> |
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| 86 | </td></tr><tr><td valign="center" align="left"><code>timeout</code></td><td valign="center" align="left"> |
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| 87 | Sets the SO_TIMEOUT option on the socket. The value is in milliseconds and the default value is <code>3000</code> |
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| 88 | milliseconds. |
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| 89 | </td></tr><tr><td valign="center" align="left"><code>useBufferPool</code></td><td valign="center" align="left"> |
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| 90 | Boolean value whether to use a shared buffer pool of cached <code>org.apache.catalina.tribes.io.XByteBuffer</code> |
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| 91 | objects. If set to true, the XByteBuffer that is used to pass a message up the channel, will be recycled at the end |
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| 92 | of the requests. This means that interceptors in the channel must not maintain a reference to the object |
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| 93 | after the <code>org.apache.catalina.tribes.ChannelInterceptor#messageReceived</code> method has exited. |
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| 94 | </td></tr></table> |
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| 95 | </blockquote></td></tr></table> |
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| 96 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="NioReceiver"><strong>NioReceiver</strong></a></font></td></tr><tr><td><blockquote> |
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| 97 | </blockquote></td></tr></table> |
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| 98 | <table cellpadding="2" cellspacing="0" border="0"><tr><td bgcolor="#828DA6"><font face="arial,helvetica.sanserif" color="#ffffff"><a name="BioReceiver"><strong>BioReceiver</strong></a></font></td></tr><tr><td><blockquote> |
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| 99 | </blockquote></td></tr></table> |
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| 100 | |
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| 101 | </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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| 102 | Copyright © 1999-2008, Apache Software Foundation |
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| 103 | </em></font></div></td></tr></table></body></html> |
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