| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 1 | <html><head><META http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><title>Apache Tomcat 7 Configuration Reference (7.0.77) - The Executor (thread pool)</title><meta name="author" content="Filip Hanik"><style type="text/css" media="print">
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 | 79 | </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="
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 80 |     The Apache Tomcat Servlet/JSP Container
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 81 |   " 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 Executor (thread pool)</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>
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 82 | <ul><li><a href="#Introduction">Introduction</a></li><li><a href="#Attributes">Attributes</a><ol><li><a href="#Common_Attributes">Common Attributes</a></li><li><a href="#Standard_Implementation">Standard Implementation</a></li></ol></li></ul>
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 | 83 | </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>
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 | 84 | 
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 85 |   <p>The <strong>Executor</strong> represents a thread pool that can be shared
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 86 |      between components in Tomcat. Historically there has been a thread pool per
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 87 |      connector created but this allows you to share a thread pool, between (primarily) connector
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 88 |      but also other components when those get configured to support executors</p>
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 | 89 | 
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 | 90 | 
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 | 91 |   <p>The executor has to implement the <code>org.apache.catalina.Executor</code> interface.</p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 92 | 
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 93 |   <p>The executor is a nested element to the <a href="service.html">Service</a> element.
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 | 94 |      And in order for it to be picked up by the connectors, the Executor element has to appear
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 | 95 |      prior to the Connector element in server.xml</p>
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 | 96 | </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>
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 | 97 | 
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 | 98 |   <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>
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 | 99 | 
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 | 100 |   <p>All implementations of <strong>Executor</strong>
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 | 101 |   support the following attributes:</p>
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 | 102 | 
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 103 |   <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">className</code></td><td align="left" valign="center">
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 | 104 |       <p>The class of the implementation. The implementation has to implement the
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 105 |          <code>org.apache.catalina.Executor</code> interface.
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 | 106 |          This interface ensures that the object can be referenced through its <code>name</code> attribute
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 | 107 |          and that implements Lifecycle, so that it can be started and stopped with the container.
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 | 108 |          The default value for the className is <code>org.apache.catalina.core.StandardThreadExecutor</code></p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 109 |     </td></tr><tr><td align="left" valign="center"><strong><code class="attributeName">name</code></strong></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 110 |       <p>The name used to reference this pool in other places in server.xml.
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 | 111 |          The name is required and must be unique.</p>
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 | 112 |     </td></tr></table>
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 | 113 | 
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 | 114 |   </blockquote></td></tr></table>
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 | 115 | 
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 | 116 |   <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#828DA6"><font color="#ffffff" face="arial,helvetica.sanserif"><a name="Standard Implementation"><!--()--></a><a name="Standard_Implementation"><strong>Standard Implementation</strong></a></font></td></tr><tr><td><blockquote>
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 | 117 | 
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 | 118 |   <p>
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 | 119 |   The default implementation supports the following attributes:</p>
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 | 120 | 
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 121 |   <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">threadPriority</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 122 |       <p>(int) The thread priority for threads in the executor, the default is
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 | 123 |       <code>5</code> (the value of the <code>Thread.NORM_PRIORITY</code> constant)</p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 124 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">daemon</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 125 |       <p>(boolean) Whether the threads should be daemon threads or not, the default is <code>true</code></p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 126 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">namePrefix</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 127 |       <p>(String) The name prefix for each thread created by the executor.
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 | 128 |          The thread name for an individual thread will be <code>namePrefix+threadNumber</code></p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 129 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxThreads</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 130 |       <p>(int) The max number of active threads in this pool, default is <code>200</code></p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 131 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">minSpareThreads</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 132 |       <p>(int) The minimum number of threads always kept alive, default is <code>25</code></p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 133 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxIdleTime</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 134 |       <p>(int) The number of milliseconds before an idle thread shutsdown, unless the number of active threads are less
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 | 135 |          or equal to minSpareThreads. Default value is <code>60000</code>(1 minute)</p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 136 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">maxQueueSize</code></td><td align="left" valign="center">
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 137 |       <p>(int) The maximum number of runnable tasks that can queue up awaiting
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 | 138 |         execution before we reject them. Default value is <code>Integer.MAX_VALUE</code></p>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 139 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">prestartminSpareThreads</code></td><td align="left" valign="center">
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 | 140 |       <p>(boolean) Whether minSpareThreads should be started when starting the Executor or not,
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 | 141 |           the default is <code>false</code></p>
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 | 142 |     </td></tr><tr><td align="left" valign="center"><code class="attributeName">threadRenewalDelay</code></td><td align="left" valign="center">
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 | 143 |       <p>(long) If a <a href="listeners.html">ThreadLocalLeakPreventionListener</a> is configured,
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 | 144 |         it will notify this executor about stopped contexts.
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 | 145 |         After a context is stopped, threads in the pool are renewed. To avoid renewing all threads at the same time,
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 | 146 |         this option sets a delay between renewal of any 2 threads. The value is in ms,
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 | 147 |         default value is <code>1000</code> ms. If value is negative, threads are not renewed.</p>
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 148 |     </td></tr></table>
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 | 149 | 
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 | 150 | 
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 | 151 |   </blockquote></td></tr></table>
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| 刘洪青 | 6266f99 | 2017-05-15 21:21:03 +0800 | [diff] [blame^] | 152 | </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
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 | 153 |               on improving documentation for Apache Tomcat.<br><br>
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 | 178 |         Copyright © 1999-2017, Apache Software Foundation
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| Hongqing Liu | fd5ee81 | 2014-05-10 16:32:51 +0800 | [diff] [blame] | 179 |         </em></font></div></td></tr></table></body></html> |