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<modulesynopsis metafile="mod_proxy_http.xml.meta">

<name>mod_proxy_http</name>

<description>HTTP support module for

<module>mod_proxy</module></description>

<status>Extension</status>

<sourcefile>mod_proxy_http.c</sourcefile>

<identifier>proxy_http_module</identifier>

<summary>

<p>This module <em>requires</em> the service of <module

>mod_proxy</module>. It provides the features used for

proxying HTTP requests. <module>mod_proxy_http</module>

supports HTTP/0.9, HTTP/1.0 and HTTP/1.1. It does <em>not</em>

provide any caching abilities. If you want to set up a caching

proxy, you might want to use the additional service of the

<module>mod_cache</module> module.</p>

<p>Thus, in order to get the ability of handling HTTP proxy requests,

<module>mod_proxy</module> and <module>mod_proxy_http</module>

have to be present in the server.</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><module>mod_proxy</module></seealso>

<seealso><module>mod_proxy_connect</module></seealso>

<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 HTTP protocol

provider:</p>

<dl>

<dt>proxy-sendextracrlf</dt>

<dd>Causes proxy to send an extra CR-LF newline on the end of a

request. This is a workaround for a bug in some browsers.</dd>

<dt>force-proxy-request-1.0</dt>

<dd>Forces the proxy to send requests to the backend as HTTP/1.0

and disables HTTP/1.1 features.</dd>

<dt>proxy-nokeepalive</dt>

<dd>Forces the proxy to close the backend connection after

each request.</dd>

<dt>proxy-chain-auth</dt>

<dd>If the proxy requires authentication, it will read and

consume the proxy authentication credentials sent by the client.

With <var>proxy-chain-auth</var> it will <em>also</em> forward

the credentials to the next proxy in the chain. This may

be necessary if you have a chain of proxies that share

authentication information. <strong>Security Warning:</strong>

Do not set this unless you know you need it, as it forwards

sensitive information!</dd>

<dt>proxy-sendcl</dt>

<dd>HTTP/1.0 required all HTTP requests that include a body

(e.g. POST requests) to include a <var>Content-Length</var>

header. This environment variable forces the Apache proxy to

send this header to the backend server, regardless of what the

Client sent to the proxy. It ensures compatibility when

proxying for an HTTP/1.0 or unknown backend. However, it

may require the entire request to be buffered by the proxy,

so it becomes very inefficient for large requests.</dd>

<dt>proxy-sendchunks or proxy-sendchunked</dt>

<dd>This is the opposite of <var>proxy-sendcl</var>. It allows

request bodies to be sent to the backend using chunked transfer

encoding. This allows the request to be efficiently streamed,

but requires that the backend server supports HTTP/1.1.</dd>

<dt>proxy-interim-response</dt>

<dd>This variable takes values <code>RFC</code> or

<code>Suppress</code>. Earlier httpd versions would suppress

HTTP interim (1xx) responses sent from the backend. This is

technically a violation of the HTTP protocol. In practice,

if a backend sends an interim response, it may itself be

extending the protocol in a manner we know nothing about,

or just broken. So this is now configurable: set

<code>proxy-interim-response RFC</code> to be fully protocol

compliant, or <code>proxy-interim-response Suppress</code>

to suppress interim responses.</dd>

<dt>proxy-initial-not-pooled</dt>

<dd>If this variable is set no pooled connection will be reused

if the client connection is an initial connection. This avoids

the "proxy: error reading status line from remote server" error message

caused by the race condition that the backend server closed the

pooled connection after the connection check by the proxy and

before data send by the proxy reached the backend. It has to be

kept in mind that setting this variable downgrades performance,

especially with HTTP/1.0 clients.

</dd>

</dl>

</section>

</modulesynopsis>