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| 771 | blopes | 1 | <!DOCTYPE html SYSTEM "about:legacy-compat"> |
| 2 | <html lang="en"><head><META http-equiv="Content-Type" content="text/html; charset=UTF-8"><link href="./images/docs-stylesheet.css" rel="stylesheet" type="text/css"><title>Apache Tomcat 9 (9.0.112) - Proxy Support How-To</title></head><body><div id="wrapper"><header><div id="header"><div><div><div class="logo noPrint"><a href="https://tomcat.apache.org/"><img alt="Tomcat Home" src="./images/tomcat.png"></a></div><div style="height: 1px;"></div><div class="asfLogo noPrint"><a href="https://www.apache.org/" target="_blank"><img src="./images/asf-logo.svg" alt="The Apache Software Foundation" style="width: 266px; height: 83px;"></a></div><h1>Apache Tomcat 9</h1><div class="versionInfo"> |
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| 3 | Version 9.0.112, |
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| 4 | <time datetime="2025-11-06">Nov 6 2025</time></div><div style="height: 1px;"></div><div style="clear: left;"></div></div></div></div></header><div id="middle"><div><div id="mainLeft" class="noprint"><div><nav><div><h2>Links</h2><ul><li><a href="index.html">Docs Home</a></li><li><a href="https://cwiki.apache.org/confluence/display/TOMCAT/FAQ">FAQ</a></li></ul></div><div><h2>User Guide</h2><ul><li><a href="introduction.html">1) Introduction</a></li><li><a href="setup.html">2) Setup</a></li><li><a href="appdev/index.html">3) First webapp</a></li><li><a href="deployer-howto.html">4) Deployer</a></li><li><a href="manager-howto.html">5) Manager</a></li><li><a href="host-manager-howto.html">6) Host Manager</a></li><li><a href="realm-howto.html">7) Realms and AAA</a></li><li><a href="security-manager-howto.html">8) Security Manager</a></li><li><a href="jndi-resources-howto.html">9) JNDI Resources</a></li><li><a href="jndi-datasource-examples-howto.html">10) JDBC DataSources</a></li><li><a href="class-loader-howto.html">11) Classloading</a></li><li><a href="jasper-howto.html">12) JSPs</a></li><li><a href="ssl-howto.html">13) SSL/TLS</a></li><li><a href="ssi-howto.html">14) SSI</a></li><li><a href="cgi-howto.html">15) CGI</a></li><li><a href="proxy-howto.html">16) Proxy Support</a></li><li><a href="mbeans-descriptors-howto.html">17) MBeans Descriptors</a></li><li><a href="default-servlet.html">18) Default Servlet</a></li><li><a href="cluster-howto.html">19) Clustering</a></li><li><a href="balancer-howto.html">20) Load Balancer</a></li><li><a href="connectors.html">21) Connectors</a></li><li><a href="monitoring.html">22) Monitoring and Management</a></li><li><a href="logging.html">23) Logging</a></li><li><a href="apr.html">24) APR/Native</a></li><li><a href="virtual-hosting-howto.html">25) Virtual Hosting</a></li><li><a href="aio.html">26) Advanced IO</a></li><li><a href="maven-jars.html">27) Mavenized</a></li><li><a href="security-howto.html">28) Security Considerations</a></li><li><a href="windows-service-howto.html">29) Windows Service</a></li><li><a href="windows-auth-howto.html">30) Windows Authentication</a></li><li><a href="jdbc-pool.html">31) Tomcat's JDBC Pool</a></li><li><a href="web-socket-howto.html">32) WebSocket</a></li><li><a href="rewrite.html">33) Rewrite</a></li><li><a href="cdi.html">34) CDI 2 and JAX-RS</a></li><li><a href="graal.html">35) AOT/GraalVM Support</a></li></ul></div><div><h2>Reference</h2><ul><li><a href="RELEASE-NOTES.txt">Release Notes</a></li><li><a href="config/index.html">Configuration</a></li><li><a href="api/index.html">Tomcat Javadocs</a></li><li><a href="servletapi/index.html">Servlet 4.0 Javadocs</a></li><li><a href="jspapi/index.html">JSP 2.3 Javadocs</a></li><li><a href="elapi/index.html">EL 3.0 Javadocs</a></li><li><a href="websocketapi/index.html">WebSocket 1.1 Javadocs</a></li><li><a href="jaspicapi/index.html">JASPIC 1.1 Javadocs</a></li><li><a href="annotationapi/index.html">Common Annotations 1.3 Javadocs</a></li><li><a href="https://tomcat.apache.org/connectors-doc/">JK 1.2 Documentation</a></li></ul></div><div><h2>Apache Tomcat Development</h2><ul><li><a href="building.html">Building</a></li><li><a href="changelog.html">Changelog</a></li><li><a href="https://cwiki.apache.org/confluence/display/TOMCAT/Tomcat+Versions">Status</a></li><li><a href="developers.html">Developers</a></li><li><a href="architecture/index.html">Architecture</a></li><li><a href="tribes/introduction.html">Tribes</a></li></ul></div></nav></div></div><div id="mainRight"><div id="content"><h2>Proxy Support How-To</h2><h3 id="Table_of_Contents">Table of Contents</h3><div class="text"> |
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| 5 | <ul><li><a href="#Introduction">Introduction</a></li><li><a href="#Apache_httpd_Proxy_Support">Apache httpd Proxy Support</a></li></ul> |
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| 6 | </div><h3 id="Introduction">Introduction</h3><div class="text"> |
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| 7 | |||
| 8 | <p>Using standard configurations of Tomcat, web applications can ask for |
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| 9 | the server name and port number to which the request was directed for |
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| 10 | processing. When Tomcat is running standalone with the |
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| 11 | <a href="config/http.html">HTTP/1.1 Connector</a>, it will generally |
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| 12 | report the server name specified in the request, and the port number on |
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| 13 | which the <strong>Connector</strong> is listening. The servlet API |
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| 14 | calls of interest, for this purpose, are:</p> |
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| 15 | <ul> |
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| 16 | <li><code>ServletRequest.getServerName()</code>: Returns the host name of the server to which the request was sent.</li> |
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| 17 | <li><code>ServletRequest.getServerPort()</code>: Returns the port number of the server to which the request was sent.</li> |
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| 18 | <li><code>ServletRequest.getLocalName()</code>: Returns the host name of the Internet Protocol (IP) interface on which the request was received.</li> |
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| 19 | <li><code>ServletRequest.getLocalPort()</code>: Returns the Internet Protocol (IP) port number of the interface on which the request was received.</li> |
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| 20 | </ul> |
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| 21 | |||
| 22 | <p>When you are running behind a proxy server (or a web server that is |
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| 23 | configured to behave like a proxy server), you will sometimes prefer to |
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| 24 | manage the values returned by these calls. In particular, you will |
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| 25 | generally want the port number to reflect that specified in the original |
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| 26 | request, not the one on which the <strong>Connector</strong> itself is |
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| 27 | listening. You can use the <code>proxyName</code> and <code>proxyPort</code> |
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| 28 | attributes on the <code><Connector></code> element to configure |
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| 29 | these values.</p> |
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| 30 | |||
| 31 | <p>Proxy support can take many forms. The following sections describe |
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| 32 | proxy configurations for several common cases.</p> |
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| 33 | |||
| 34 | </div><h3 id="Apache_httpd_Proxy_Support">Apache httpd Proxy Support</h3><div class="text"> |
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| 35 | |||
| 36 | <p>Apache httpd 1.3 and later versions support an optional module |
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| 37 | (<code>mod_proxy</code>) that configures the web server to act as a proxy |
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| 38 | server. This can be used to forward requests for a particular web application |
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| 39 | to a Tomcat instance, without having to configure a web connector such as |
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| 40 | <code>mod_jk</code>. To accomplish this, you need to perform the following |
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| 41 | tasks:</p> |
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| 42 | <ol> |
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| 43 | <li><p>Configure your copy of Apache so that it includes the |
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| 44 | <code>mod_proxy</code> module. If you are building from source, |
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| 45 | the easiest way to do this is to include the |
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| 46 | <code>--enable-module=proxy</code> directive on the |
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| 47 | <code>./configure</code> command line.</p></li> |
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| 48 | <li><p>If not already added for you, make sure that you are loading the |
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| 49 | <code>mod_proxy</code> module at Apache startup time, by using the |
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| 50 | following directives in your <code>httpd.conf</code> file:</p> |
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| 51 | <div class="codeBox"><pre><code>LoadModule proxy_module {path-to-modules}/mod_proxy.so |
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| 52 | </code></pre></div></li> |
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| 53 | <li><p>Include two directives in your <code>httpd.conf</code> file for |
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| 54 | each web application that you wish to forward to Tomcat. For |
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| 55 | example, to forward an application at context path <code>/myapp</code>:</p> |
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| 56 | <div class="codeBox"><pre><code>ProxyPass /myapp http://localhost:8081/myapp |
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| 57 | ProxyPassReverse /myapp http://localhost:8081/myapp</code></pre></div> |
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| 58 | <p>which tells Apache to forward URLs of the form |
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| 59 | <code>http://localhost/myapp/*</code> to the Tomcat connector |
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| 60 | listening on port 8081.</p></li> |
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| 61 | <li><p>Configure your copy of Tomcat to include a special |
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| 62 | <code><Connector></code> element, with appropriate |
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| 63 | proxy settings, for example:</p> |
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| 64 | <div class="codeBox"><pre><code><Connector port="8081" ... |
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| 65 | proxyName="www.mycompany.com" |
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| 66 | proxyPort="80"/></code></pre></div> |
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| 67 | <p>which will cause servlets inside this web application to think that |
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| 68 | all proxied requests were directed to <code>www.mycompany.com</code> |
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| 69 | on port 80.</p></li> |
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| 70 | <li><p>It is legal to omit the <code>proxyName</code> attribute from the |
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| 71 | <code><Connector></code> element. If you do so, the value |
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| 72 | returned by <code>request.getServerName()</code> will by the host |
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| 73 | name on which Tomcat is running. In the example above, it would be |
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| 74 | <code>localhost</code>.</p></li> |
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| 75 | <li><p>If you also have a <code><Connector></code> listening on port |
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| 76 | 8080 (nested within the same <a href="config/service.html">Service</a> |
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| 77 | element), the requests to either port will share the same set of |
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| 78 | virtual hosts and web applications.</p></li> |
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| 79 | <li><p>You might wish to use the IP filtering features of your operating |
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| 80 | system to restrict connections to port 8081 (in this example) to |
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| 81 | be allowed <strong>only</strong> from the server that is running |
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| 82 | Apache.</p></li> |
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| 83 | <li><p>Alternatively, you can set up a series of web applications that are |
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| 84 | only available via proxying, as follows:</p> |
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| 85 | <ul> |
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| 86 | <li>Configure another <code><Service></code> that contains |
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| 87 | only a <code><Connector></code> for the proxy port.</li> |
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| 88 | <li>Configure appropriate <a href="config/engine.html">Engine</a>, |
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| 89 | <a href="config/host.html">Host</a>, and |
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| 90 | <a href="config/context.html">Context</a> elements for the virtual hosts |
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| 91 | and web applications accessible via proxying.</li> |
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| 92 | <li>Optionally, protect port 8081 with IP filters as described |
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| 93 | earlier.</li> |
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| 94 | </ul></li> |
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| 95 | <li><p>When requests are proxied by Apache, the web server will be recording |
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| 96 | these requests in its access log. Therefore, you will generally want to |
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| 97 | disable any access logging performed by Tomcat itself.</p></li> |
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| 98 | </ol> |
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| 99 | |||
| 100 | <p>When requests are proxied in this manner, <strong>all</strong> requests |
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| 101 | for the configured web applications will be processed by Tomcat (including |
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| 102 | requests for static content). You can improve performance by using the |
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| 103 | <code>mod_jk</code> web connector instead of <code>mod_proxy</code>. |
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| 104 | <code>mod_jk</code> can be configured so that the web server serves static |
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| 105 | content that is not processed by filters or security constraints defined |
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| 106 | within the web application's deployment descriptor |
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| 107 | (<code>/WEB-INF/web.xml</code>).</p> |
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| 108 | |||
| 109 | </div></div></div></div></div><footer><div id="footer"> |
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| 110 | Copyright © 1999-2025, The Apache Software Foundation |
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| 111 | <br> |
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| 112 | Apache Tomcat, Tomcat, Apache, the Apache Tomcat logo and the Apache logo |
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| 113 | are either registered trademarks or trademarks of the Apache Software |
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| 114 | Foundation. |
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| 115 | </div></footer></div></body></html> |