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<div id="preamble"><h1>Apache Module mod_proxy_express</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../en/mod/mod_proxy_express.html" title="English">&nbsp;en&nbsp;</a> |
<a href="../fr/mod/mod_proxy_express.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
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<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Dynamic mass reverse proxy extension for
<code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code></td></tr>
<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>proxy_express_module</td></tr>
<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_proxy_express.c</td></tr>
<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.3.13 and later</td></tr></table>
<h3>Summary</h3>

    <p>This module creates dynamically configured mass reverse
    proxies, by mapping the <code>Host:</code> header of the HTTP request to
    a server name and backend URL stored in a DBM file.
    This allows for easy use of a huge number of reverse proxies
    with no configuration changes. It is much less feature-full
    than <code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code>, which also provides
    dynamic growth, but is intended to handle much, much
    larger numbers of backends. It is ideally suited as a
    front-end HTTP switch and for micro-services architectures.</p>

    <p>This module <em>requires</em> the service of <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>.</p>

    <div class="warning"><h3>Warning</h3>
      <p>Do not enable proxying until you have <a href="mod_proxy.html#access">secured your server</a>. Open proxy
      servers are dangerous both to your network and to the Internet at
      large.</p>
    </div>

<div class="note"><h3>Limitations</h3>
  <ul>
    <li>This module is not intended to replace the dynamic capability of
      <code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code>. Instead, it is intended to be mostly
      a lightweight and fast alternative to using <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
      with <code class="directive"><a href="../mod/mod_rewrite.html#rewritemap">RewriteMap</a></code> and the
      <code>[P]</code> flag for mapped reverse proxying.
    </li>
    <li>It does not support regex or pattern matching at all.
    </li>
    <li>It emulates:
      <pre class="prettyprint lang-config">&lt;VirtualHost *:80&gt;
   ServerName front.end.server
   ProxyPass        "/" "back.end.server:port"
   ProxyPassReverse "/" "back.end.server:port"
&lt;/VirtualHost&gt;</pre>

      That is, the entire URL is appended to the mapped backend
      URL. This is in keeping with the intent of being a simple
      but fast reverse proxy switch.
    </li>
  </ul>
</div>

</div>
<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><h3 class="directives">Directives</h3>
<ul id="toc">
<li><img alt="" src="../images/down.gif" /> <a href="#proxyexpressdbmfile">ProxyExpressDBMFile</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyexpressdbmtype">ProxyExpressDBMType</a></li>
<li><img alt="" src="../images/down.gif" /> <a href="#proxyexpressenable">ProxyExpressEnable</a></li>
</ul>
<h3>Bugfix checklist</h3><ul class="seealso"><li><a href="https://www.apache.org/dist/httpd/CHANGES_2.4">httpd changelog</a></li><li><a href="https://bz.apache.org/bugzilla/buglist.cgi?bug_status=__open__&amp;list_id=144532&amp;product=Apache%20httpd-2&amp;query_format=specific&amp;order=changeddate%20DESC%2Cpriority%2Cbug_severity&amp;component=mod_proxy_express">Known issues</a></li><li><a href="https://bz.apache.org/bugzilla/enter_bug.cgi?product=Apache%20httpd-2&amp;component=mod_proxy_express">Report a bug</a></li></ul><h3>See also</h3>
<ul class="seealso">
<li><code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code></li>
<li><code class="directive"><a href="../mod/mod_proxy.html#balancermember">BalancerMember</a></code></li>
<li><code class="directive"><a href="../mod/mod_proxy.html#balancergrowth">BalancerGrowth</a></code></li>
<li><code class="directive"><a href="../mod/mod_proxy.html#balancerpersist">BalancerPersist</a></code></li>
<li><code class="directive"><a href="../mod/mod_proxy.html#balancerinherit">BalancerInherit</a></code></li>
<li><a href="#comments_section">Comments</a></li></ul></div>

<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyExpressDBMFile" id="ProxyExpressDBMFile">ProxyExpressDBMFile</a> <a name="proxyexpressdbmfile" id="proxyexpressdbmfile">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Pathname to DBM file.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyExpressDBMFile <var>pathname</var></code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy_express</td></tr>
</table>
  <p>The <code class="directive">ProxyExpressDBMFile</code> directive
    points to the location of the Express map DBM file. This
    file serves to map the incoming server name, obtained from
    the <code>Host:</code> header, to a backend URL.</p>

    <div class="note"><h3>Note</h3>
      <p>The file is constructed from a plain text file format using
        the <code><a href="../programs/httxt2dbm.html">httxt2dbm</a></code>
        utility.</p>

      <div class="example"><h3>ProxyExpress map file</h3><p><code>
        ##<br />
        ##express-map.txt:<br />
        ##<br />
        <br />
        www1.example.com   http://192.168.211.2:8080<br />
        www2.example.com   http://192.168.211.12:8088<br />
        www3.example.com   http://192.168.212.10<br />
      </code></p></div>

      <div class="example"><h3>Create DBM file</h3><p><code>
        httxt2dbm -i express-map.txt -o emap<br />
      </code></p></div>

      <div class="example"><h3>Configuration</h3><pre class="prettyprint lang-config">ProxyExpressEnable on
ProxyExpressDBMFile emap</pre>
</div>
    </div>

</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyExpressDBMType" id="ProxyExpressDBMType">ProxyExpressDBMType</a> <a name="proxyexpressdbmtype" id="proxyexpressdbmtype">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>DBM type of file.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyExpressDBMType <var>type</var></code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyExpressDBMType default</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy_express</td></tr>
</table>
  <p>The <code class="directive">ProxyExpressDBMType</code> directive
    controls the DBM type expected by the module. The default
    is the default DBM type created with <code>
    <a href="../programs/httxt2dbm.html">httxt2dbm</a></code>.</p>
    <p>Possible values are (not all may be available at run time):</p>
<table class="bordered"><tr class="header"><th>Value</th><th>Description</th></tr>
<tr><td><code>db</code></td><td> Berkeley DB files</td></tr>
<tr class="odd"><td><code>gdbm</code></td><td> GDBM files</td></tr>
<tr><td><code>ndbm</code></td><td> NDBM files</td></tr>
<tr class="odd"><td><code>sdbm</code></td><td> SDBM files (always available)</td></tr>
<tr><td><code>default</code></td><td> default DBM type</td></tr>
</table>


</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="directive-section"><h2><a name="ProxyExpressEnable" id="ProxyExpressEnable">ProxyExpressEnable</a> <a name="proxyexpressenable" id="proxyexpressenable">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enable the module functionality.</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyExpressEnable on|off</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyExpressEnable off</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy_express</td></tr>
</table>
  <p>The <code class="directive">ProxyExpressEnable</code> directive
    controls whether the module will be active.</p>

</div>
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