mod_proxy_fcgi.xml revision 193b3e56c39bd0833fe0ab3cb44503839d1d9164
<?xml version="1.0"?>
<!-- $LastChangedRevision$ -->
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<modulesynopsis metafile="mod_proxy_fcgi.xml.meta">
<name>mod_proxy_fcgi</name>
<description>FastCGI support module for
<module>mod_proxy</module></description>
<status>Extension</status>
<identifier>proxy_fcgi_module</identifier>
<compatibility>Available in version 2.3 and later</compatibility>
<summary>
<p>This module <em>requires</em> the service of <module
>mod_proxy</module>. It provides support for the
<p>Thus, in order to get the ability of handling the <code>FastCGI</code>
protocol, <module>mod_proxy</module> and
<module>mod_proxy_fcgi</module> have to be present in the server.</p>
<module>mod_proxy_fcgi</module> has no provision for starting the
application process; <program>fcgistarter</program> is provided
(on some platforms) for that purpose. Alternatively, external launching
or process management may be available in the FastCGI application
framework in use.</p>
<note type="warning"><title>Warning</title>
<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>
</note>
</summary>
<seealso><program>fcgistarter</program></seealso>
<seealso><module>mod_proxy</module></seealso>
<section id="examples"><title>Examples</title>
<p>Remember, in order to make the following examples work, you have to
enable <module>mod_proxy</module> and <module>mod_proxy_fcgi</module>.</p>
<example><title>Single application instance</title>
<highlight language="config">
ProxyPass /myapp/ fcgi://localhost:4000/
</highlight>
</example>
<p>This application should be able to handle multiple concurrent
connections. <module>mod_proxy</module> enables connection reuse by
default, so after a request has been completed the connection will be
held open by that httpd child process and won't be reused until that
httpd process routes another request to the application. If the
FastCGI application is unable to handle enough concurrent connections
from httpd, requests can block waiting for the application to close
an existing connection. One way to resolve this is to disable connection
reuse on the <directive>ProxyPass</directive> directive, as shown in
the following example:</p>
<example><title>Single application instance, no connection reuse</title>
<highlight language="config">
ProxyPass /myapp/ fcgi://localhost:4000/ disablereuse=on
</highlight>
</example>
<p> The following example passes the request URI as a filesystem
path for the PHP-FPM daemon to run. The request URL is implicitly added
to the 2nd parameter. The hostname and port following fcgi:// are where
PHP-FPM is listening.</p>
<example><title>PHP-FPM</title>
<highlight language="config">
</highlight>
</example>
<p> The following example passes the request URI as a filesystem
path for the PHP-FPM daemon to run. In this case, PHP-FPM is listening on
a unix domain socket (UDS). Requires 2.4.9 or later. With this syntax,
the hostname and optional port following fci:// are ignored.</p>
<example><title>PHP-FPM with UDS</title>
<highlight language="config">
</highlight>
</example>
<p>The balanced gateway needs <module>mod_proxy_balancer</module> and
at least one load balancer algorithm module, such as
<module>mod_lbmethod_byrequests</module>, in addition to the proxy
modules listed above. <module>mod_lbmethod_byrequests</module> is the
default, and will be used for this example configuration.</p>
<example><title>Balanced gateway to multiple application instances</title>
<highlight language="config">
ProxyPass /myapp/ balancer://myappcluster/
<Proxy balancer://myappcluster/>
BalancerMember fcgi://localhost:4000
BalancerMember fcgi://localhost:4001
</Proxy>
</highlight>
</example>
</section>
<section id="env"><title>Environment Variables</title>
<p>In addition to the configuration directives that control the
behaviour of <module>mod_proxy</module>, there are a number of
<dfn>environment variables</dfn> that control the FCGI protocol
provider:</p>
<dl>
<dt>proxy-fcgi-pathinfo</dt>
<dd>By default <module>mod_proxy_fcgi</module> will neither create
nor export the <var>PATH_INFO</var> environment variable. This allows
the backend FCGI server to correctly determine <var>SCRIPT_NAME</var>
and <var>Script-URI</var> and be compliant with RFC 3875 section 3.3.
If instead you need <module>mod_proxy_fcgi</module> to generate
a "best guess" for <var>PATH_INFO</var>, set this env-var.
This is a workaround for a bug in some FCGI implementations.</dd>
</dl>
</section>
</modulesynopsis>