docs/manual/new_features_2_4.html.en - httpd - Git at Google

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 <p class="menu"><a href="./mod/">Modules</a> | <a href="./mod/directives.html">Directives</a> | <a href="./faq/">FAQ</a> | <a href="./glossary.html">Glossary</a> | <a href="./sitemap.html">Sitemap</a></p>
 <p class="apache">Apache HTTP Server Version 2.3</p>
 <img alt="" src="./images/feather.gif" /></div>
 <div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="./images/left.gif" /></a></div>
 <div id="path">
 <a href="http://www.apache.org/">Apache</a> &gt; <a href="http://httpd.apache.org/">HTTP Server</a> &gt; <a href="http://httpd.apache.org/docs/">Documentation</a> &gt; <a href="./">Version 2.3</a></div><div id="page-content"><div id="preamble"><h1>Overview of new features in Apache HTTP Server 2.4</h1>
 <div class="toplang">
 <p><span>Available Languages: </span><a href="./en/new_features_2_4.html" title="English">&nbsp;en&nbsp;</a> |
 <a href="./fr/new_features_2_4.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
 </div>

   <p>This document describes some of the major changes between the
      2.2 and 2.4 versions of the Apache HTTP Server. For new features since
      version 2.0, see the <a href="new_features_2_2.html">2.2 new features</a>
      document.</p>
 </div>
 <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#core">Core Enhancements</a></li>
 <li><img alt="" src="./images/down.gif" /> <a href="#newmods">New Modules</a></li>
 <li><img alt="" src="./images/down.gif" /> <a href="#module">Module Enhancements</a></li>
 <li><img alt="" src="./images/down.gif" /> <a href="#programs">Program Enhancements</a></li>
 <li><img alt="" src="./images/down.gif" /> <a href="#developer">Module Developer Changes</a></li>
 </ul></div>
 <div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
 <div class="section">
 <h2><a name="core" id="core">Core Enhancements</a></h2>

     <dl>
       <dt>KeepAliveTimeout in milliseconds</dt>

       <dd>It is now possible to specify <code class="directive"><a href="./mod/core.html#keepalivetimeout">KeepAliveTimeout</a></code> in milliseconds.
       </dd>

       <dt>Loadable MPMs</dt>
       <dd>Multiple MPMs can now be built as loadable modules at compile time.
       The MPM of choice can be configured at run time.</dd>

       <dt>Per-module and per-directory LogLevel configuration</dt>
       <dd>The <code class="directive"><a href="./mod/core.html#loglevel">LogLevel</a></code> can now be
       configured per module and per directory.  New levels <code>trace1</code>
       to <code>trace8</code> have been added above the <code>debug</code> log
       level.</dd>

       <dt>Event MPM</dt>
       <dd>The Event MPM is no longer experimental but is rather fully supported.</dd>

       <dt>Asynchronous support</dt>
       <dd>Better support for asynchronous read/write for supporting MPMs and
       platforms.</dd>

       <dt>Per-request configuration sections</dt>
       <dd>&lt;<code class="directive"><a href="./mod/core.html#if">If</a></code>&gt; sections can be used to
       set the configuration based on per-request criteria</dd>

     </dl>
   </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
 <div class="section">
 <h2><a name="newmods" id="newmods">New Modules</a></h2>

     <dl>
       <dt><code class="module"><a href="./mod/mod_allowmethods.html">mod_allowmethods</a></code></dt>
       <dd>New module to restrict certain HTTP methods without interfering with
       authentication or authorization.</dd>

       <dt><code class="module"><a href="./mod/mod_buffer.html">mod_buffer</a></code></dt>
       <dd>Provides for buffering the input and output filter stacks</dd>

       <dt><code class="module"><a href="./mod/mod_data.html">mod_data</a></code></dt>
       <dd>Convert response body into an RFC2397 data URL</dd>

       <dt><code class="module"><a href="./mod/mod_lua.html">mod_lua</a></code></dt>
       <dd>Embeds the <a href="http://www.lua.org/">Lua</a> language into httpd,
       for configuration and small business logic functions.</dd>

       <dt><code class="module"><a href="./mod/mod_proxy_fcgi.html">mod_proxy_fcgi</a></code></dt>
       <dd>FastCGI Protocol backend for <code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code></dd>

       <dt><code class="module"><a href="./mod/mod_proxy_scgi.html">mod_proxy_scgi</a></code></dt>
       <dd>SCGI Protocol backend for <code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code></dd>

       <dt><code class="module"><a href="./mod/mod_ratelimit.html">mod_ratelimit</a></code></dt>
       <dd>Provides Bandwidth Rate Limiting for Clients</dd>

       <dt><code class="module"><a href="./mod/mod_reflector.html">mod_reflector</a></code></dt>
       <dd>Provides Reflection of a request body as a response via the output filter stack.</dd>

       <dt><code class="module"><a href="./mod/mod_remoteip.html">mod_remoteip</a></code></dt>
       <dd>Replaces the apparent client remote IP address and hostname for the request
       with the IP address list presented by a proxies or a load balancer via
       the request headers.</dd>

       <dt><code class="module"><a href="./mod/mod_reqtimeout.html">mod_reqtimeout</a></code></dt>
       <dd>Set timeout and minimum data rate for receiving requests</dd>

       <dt><code class="module"><a href="./mod/mod_request.html">mod_request</a></code></dt>
       <dd>Provides Filters to handle and make available HTTP request bodies</dd>

       <dt><code class="module"><a href="./mod/mod_slotmem_shm.html">mod_slotmem_shm</a></code></dt>
       <dd>Provides a Slot-based shared memory provider (ala the scoreboard).</dd>

       <dt><code class="module"><a href="./mod/mod_log_debug.html">mod_log_debug</a></code></dt>
       <dd>Allows to add customizable debug logging at different phases of the
       request processing.</dd>

     </dl>
   </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
 <div class="section">
 <h2><a name="module" id="module">Module Enhancements</a></h2>

     <dl>
       <dt><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code></dt>

       <dd><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> can now be configured to use an
       OCSP server to check the validation status of a client
       certificate.  The default responder is configurable, along with
       the decision on whether to prefer the responder designated in
       the client certificate itself.</dd>

       <dd><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> now also supports OCSP stapling, where the
       server pro-actively obtains an OCSP verification of its certificate and
       transmits that to the client during the handshake. </dd>

       <dd><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> can now be configured to share SSL Session
       data between servers through memcached</dd>

       <dt><code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code></dt>

       <dd>The <code class="directive"><a href="./mod/mod_proxy.html#proxypass">ProxyPass</a></code> directive
       is now most optimally configured within a
       <code class="directive"><a href="./mod/core.html#location">Location</a></code> or
       <code class="directive"><a href="./mod/core.html#locationmatch">LocationMatch</a></code>
       block, and offers a significant performance advantage over the traditional
       two-parameter syntax when present in large numbers.</dd>

       <dt><code class="module"><a href="./mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code></dt>

       <dd>More runtime configuration changes for BalancerMembers via balancer-manager</dd>

       <dd>Additional BalancerMembers can be added at runtime via balancer-manager</dd>

       <dd>Runtime configuration of a subset of Balancer parameters</dd>

       <dt><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code></dt>

       <dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> can now cache HEAD requests.</dd>

       <dd>Where possible, <code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> directives can now be set
       per directory, instead of per server.</dd>

       <dd>The base URL of cached URLs can be customised, so that a cluster of
       caches can share the same endpoint URL prefix.</dd>

       <dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> is now capable of serving stale cached
       data when a backend is unavailable (error 5xx).</dd>

       <dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> can now insert HIT/MISS/REVALIDATE into
       an X-Cache header.</dd>

       <dt><code class="module"><a href="./mod/mod_include.html">mod_include</a></code></dt>
       <dd>Support for the 'onerror' attribute within an 'include' element,
       allowing an error document to be served on error instead of the default
       error string.</dd>

       <dt><code class="module"><a href="./mod/mod_cgi.html">mod_cgi</a></code>, <code class="module"><a href="./mod/mod_include.html">mod_include</a></code>,
           <code class="module"><a href="./mod/mod_isapi.html">mod_isapi</a></code>, ...</dt>
       <dd>Translation of headers to environment variables is more strict than
       before to mitigate some possible cross-site-scripting attacks via header
       injection. Headers containing invalid characters (including underscores)
       are now silently dropped. <a href="env.html">Environment Variables
       in Apache</a> has some pointers on how to work around broken legacy
       clients which require such headers. (This affects all modules which
       use these environment variables.)</dd>

       <dt><code class="module"><a href="./mod/mod_authz_core.html">mod_authz_core</a></code> Authorization Logic Containers</dt>

       <dd>Advanced authorization logic may now be specified using the
           <code class="directive"><a href="./mod/mod_authz_core.html#require">Require</a></code> directive
           and the related container directives, such as
           <code class="directive"><a href="./mod/mod_authz_core.html#requireall">&lt;RequireAll&gt;</a></code>.</dd>

       <dt><code class="module"><a href="./mod/mod_info.html">mod_info</a></code></dt>
       <dd><code class="module"><a href="./mod/mod_info.html">mod_info</a></code> can now dump the pre-parsed configuration
           to stdout during server startup.</dd>

       <dt><code class="module"><a href="./mod/mod_rewrite.html">mod_rewrite</a></code></dt>
       <dd><code class="module"><a href="./mod/mod_rewrite.html">mod_rewrite</a></code> adds the <code>[QSD]</code>
       (Query String Discard) and <code>[END]</code> flags for
       <code class="directive"><a href="./mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> to
       simplify common rewriting scenarios.</dd>
     </dl>
   </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
 <div class="section">
 <h2><a name="programs" id="programs">Program Enhancements</a></h2>

     <dl>
         <dt>fcgistarter</dt>
         <dd>FastCGI deamon starter utility</dd>
         <dt>htcacheclean</dt>
         <dd>Current cached URLs can now be listed, with optional metadata
         included.</dd>
         <dd>Allow explicit deletion of individual cached URLs from the
         cache.</dd>
         <dd>File sizes can now be rounded up to the given block size, making
         the size limits map more closely to the real size on disk.</dd>
         <dd>Cache size can now be limited by the number of inodes, instead
         of or in addition to being limited by the size of the files on
         disk.</dd>
     </dl>
   </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
 <div class="section">
 <h2><a name="developer" id="developer">Module Developer Changes</a></h2>

     <dl>
       <dt>Check Configuration Hook Added</dt>

       <dd>A new hook, <code>check_config</code>, has been added which runs
           between the <code>pre_config</code> and <code>open_logs</code>
           hooks.  It also runs before the <code>test_config</code> hook
           when the <code>-t</code> option is passed to
           <code class="program"><a href="./programs/httpd.html">httpd</a></code>.  The <code>check_config</code> hook
           allows modules to review interdependent configuration directive
           values and adjust them while messages can still be logged to the
           console.  The user can thus be alerted to misconfiguration problems
           before the core <code>open_logs</code> hook function redirects
           console output to the error log.</dd>

       <dt>Expression Parser Added</dt>

       <dd>We now have a general-purpose expression parser, whose API is
           exposed in <var>ap_expr.h</var>.  This is adapted from the
           expression parser previously implemented in
           <code class="module"><a href="./mod/mod_include.html">mod_include</a></code>.</dd>

       <dt>Authorization Logic Containers</dt>

       <dd>Authorization modules now register as a provider, via
       ap_register_auth_provider(), to support advanced authorization logic,
       such as <code class="directive"><a href="./mod/mod_authz_core.html#requireall">&lt;RequireAll&gt;</a></code>.</dd>

       <dt>Small-Object Caching Interface</dt>

       <dd>The <var>ap_socache.h</var> header exposes a provider-based
       interface for caching small data objects, based on the previous
       implementation of the <code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> session cache.
       Providers using a shared-memory cyclic buffer, disk-based dbm
       files, and a memcache distributed cache are currently
       supported.</dd>

       <dt>Cache Status Hook Added</dt>

       <dd>The <code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> module now includes a new
       <code>cache_status</code> hook, which is called when the caching
       decision becomes known. A default implementation is provided
       which adds an optional <code>X-Cache</code> and
       <code>X-Cache-Detail</code> header to the response.</dd>
     </dl>

     <p>The developer documentation contains a
     <a href="developer/new_api_2_4.html">detailed list of API changes</a>.</p>
   </div></div>
 <div class="bottomlang">
 <p><span>Available Languages: </span><a href="./en/new_features_2_4.html" title="English">&nbsp;en&nbsp;</a> |
 <a href="./fr/new_features_2_4.html" hreflang="fr" rel="alternate" title="Français">&nbsp;fr&nbsp;</a></p>
 </div><div id="footer">
 <p class="apache">Copyright 2011 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
 <p class="menu"><a href="./mod/">Modules</a> | <a href="./mod/directives.html">Directives</a> | <a href="./faq/">FAQ</a> | <a href="./glossary.html">Glossary</a> | <a href="./sitemap.html">Sitemap</a></p></div>
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	<title>Overview of new features in Apache HTTP Server 2.4 - Apache HTTP Server</title>
	<link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
	<link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
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	<body id="manual-page"><div id="page-header">
	<p class="menu"><a href="./mod/">Modules</a> \| <a href="./mod/directives.html">Directives</a> \| <a href="./faq/">FAQ</a> \| <a href="./glossary.html">Glossary</a> \| <a href="./sitemap.html">Sitemap</a></p>
	<p class="apache">Apache HTTP Server Version 2.3</p>
	<img alt="" src="./images/feather.gif" /></div>
	<div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
	<div id="path">
	<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="./">Version 2.3</a></div><div id="page-content"><div id="preamble"><h1>Overview of new features in Apache HTTP Server 2.4</h1>
	<div class="toplang">
	<p><span>Available Languages: </span><a href="./en/new_features_2_4.html" title="English"> en </a> \|
	<a href="./fr/new_features_2_4.html" hreflang="fr" rel="alternate" title="Français"> fr </a></p>
	</div>

	<p>This document describes some of the major changes between the
	2.2 and 2.4 versions of the Apache HTTP Server. For new features since
	version 2.0, see the <a href="new_features_2_2.html">2.2 new features</a>
	document.</p>
	</div>
	<div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#core">Core Enhancements</a></li>
	<li><img alt="" src="./images/down.gif" /> <a href="#newmods">New Modules</a></li>
	<li><img alt="" src="./images/down.gif" /> <a href="#module">Module Enhancements</a></li>
	<li><img alt="" src="./images/down.gif" /> <a href="#programs">Program Enhancements</a></li>
	<li><img alt="" src="./images/down.gif" /> <a href="#developer">Module Developer Changes</a></li>
	</ul></div>
	<div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
	<div class="section">
	<h2><a name="core" id="core">Core Enhancements</a></h2>

	<dl>
	<dt>KeepAliveTimeout in milliseconds</dt>

	<dd>It is now possible to specify <code class="directive"><a href="./mod/core.html#keepalivetimeout">KeepAliveTimeout</a></code> in milliseconds.
	</dd>

	<dt>Loadable MPMs</dt>
	<dd>Multiple MPMs can now be built as loadable modules at compile time.
	The MPM of choice can be configured at run time.</dd>

	<dt>Per-module and per-directory LogLevel configuration</dt>
	<dd>The <code class="directive"><a href="./mod/core.html#loglevel">LogLevel</a></code> can now be
	configured per module and per directory. New levels <code>trace1</code>
	to <code>trace8</code> have been added above the <code>debug</code> log
	level.</dd>

	<dt>Event MPM</dt>
	<dd>The Event MPM is no longer experimental but is rather fully supported.</dd>

	<dt>Asynchronous support</dt>
	<dd>Better support for asynchronous read/write for supporting MPMs and
	platforms.</dd>

	<dt>Per-request configuration sections</dt>
	<dd><<code class="directive"><a href="./mod/core.html#if">If</a></code>> sections can be used to
	set the configuration based on per-request criteria</dd>

	</dl>
	</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
	<div class="section">
	<h2><a name="newmods" id="newmods">New Modules</a></h2>

	<dl>
	<dt><code class="module"><a href="./mod/mod_allowmethods.html">mod_allowmethods</a></code></dt>
	<dd>New module to restrict certain HTTP methods without interfering with
	authentication or authorization.</dd>

	<dt><code class="module"><a href="./mod/mod_buffer.html">mod_buffer</a></code></dt>
	<dd>Provides for buffering the input and output filter stacks</dd>

	<dt><code class="module"><a href="./mod/mod_data.html">mod_data</a></code></dt>
	<dd>Convert response body into an RFC2397 data URL</dd>

	<dt><code class="module"><a href="./mod/mod_lua.html">mod_lua</a></code></dt>
	<dd>Embeds the <a href="http://www.lua.org/">Lua</a> language into httpd,
	for configuration and small business logic functions.</dd>

	<dt><code class="module"><a href="./mod/mod_proxy_fcgi.html">mod_proxy_fcgi</a></code></dt>
	<dd>FastCGI Protocol backend for <code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code></dd>

	<dt><code class="module"><a href="./mod/mod_proxy_scgi.html">mod_proxy_scgi</a></code></dt>
	<dd>SCGI Protocol backend for <code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code></dd>

	<dt><code class="module"><a href="./mod/mod_ratelimit.html">mod_ratelimit</a></code></dt>
	<dd>Provides Bandwidth Rate Limiting for Clients</dd>

	<dt><code class="module"><a href="./mod/mod_reflector.html">mod_reflector</a></code></dt>
	<dd>Provides Reflection of a request body as a response via the output filter stack.</dd>

	<dt><code class="module"><a href="./mod/mod_remoteip.html">mod_remoteip</a></code></dt>
	<dd>Replaces the apparent client remote IP address and hostname for the request
	with the IP address list presented by a proxies or a load balancer via
	the request headers.</dd>

	<dt><code class="module"><a href="./mod/mod_reqtimeout.html">mod_reqtimeout</a></code></dt>
	<dd>Set timeout and minimum data rate for receiving requests</dd>

	<dt><code class="module"><a href="./mod/mod_request.html">mod_request</a></code></dt>
	<dd>Provides Filters to handle and make available HTTP request bodies</dd>

	<dt><code class="module"><a href="./mod/mod_slotmem_shm.html">mod_slotmem_shm</a></code></dt>
	<dd>Provides a Slot-based shared memory provider (ala the scoreboard).</dd>

	<dt><code class="module"><a href="./mod/mod_log_debug.html">mod_log_debug</a></code></dt>
	<dd>Allows to add customizable debug logging at different phases of the
	request processing.</dd>

	</dl>
	</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
	<div class="section">
	<h2><a name="module" id="module">Module Enhancements</a></h2>

	<dl>
	<dt><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code></dt>

	<dd><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> can now be configured to use an
	OCSP server to check the validation status of a client
	certificate. The default responder is configurable, along with
	the decision on whether to prefer the responder designated in
	the client certificate itself.</dd>

	<dd><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> now also supports OCSP stapling, where the
	server pro-actively obtains an OCSP verification of its certificate and
	transmits that to the client during the handshake. </dd>

	<dd><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> can now be configured to share SSL Session
	data between servers through memcached</dd>

	<dt><code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code></dt>

	<dd>The <code class="directive"><a href="./mod/mod_proxy.html#proxypass">ProxyPass</a></code> directive
	is now most optimally configured within a
	<code class="directive"><a href="./mod/core.html#location">Location</a></code> or
	<code class="directive"><a href="./mod/core.html#locationmatch">LocationMatch</a></code>
	block, and offers a significant performance advantage over the traditional
	two-parameter syntax when present in large numbers.</dd>

	<dt><code class="module"><a href="./mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code></dt>

	<dd>More runtime configuration changes for BalancerMembers via balancer-manager</dd>

	<dd>Additional BalancerMembers can be added at runtime via balancer-manager</dd>

	<dd>Runtime configuration of a subset of Balancer parameters</dd>

	<dt><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code></dt>

	<dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> can now cache HEAD requests.</dd>

	<dd>Where possible, <code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> directives can now be set
	per directory, instead of per server.</dd>

	<dd>The base URL of cached URLs can be customised, so that a cluster of
	caches can share the same endpoint URL prefix.</dd>

	<dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> is now capable of serving stale cached
	data when a backend is unavailable (error 5xx).</dd>

	<dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> can now insert HIT/MISS/REVALIDATE into
	an X-Cache header.</dd>

	<dt><code class="module"><a href="./mod/mod_include.html">mod_include</a></code></dt>
	<dd>Support for the 'onerror' attribute within an 'include' element,
	allowing an error document to be served on error instead of the default
	error string.</dd>

	<dt><code class="module"><a href="./mod/mod_cgi.html">mod_cgi</a></code>, <code class="module"><a href="./mod/mod_include.html">mod_include</a></code>,
	<code class="module"><a href="./mod/mod_isapi.html">mod_isapi</a></code>, ...</dt>
	<dd>Translation of headers to environment variables is more strict than
	before to mitigate some possible cross-site-scripting attacks via header
	injection. Headers containing invalid characters (including underscores)
	are now silently dropped. <a href="env.html">Environment Variables
	in Apache</a> has some pointers on how to work around broken legacy
	clients which require such headers. (This affects all modules which
	use these environment variables.)</dd>

	<dt><code class="module"><a href="./mod/mod_authz_core.html">mod_authz_core</a></code> Authorization Logic Containers</dt>

	<dd>Advanced authorization logic may now be specified using the
	<code class="directive"><a href="./mod/mod_authz_core.html#require">Require</a></code> directive
	and the related container directives, such as
	<code class="directive"><a href="./mod/mod_authz_core.html#requireall"><RequireAll></a></code>.</dd>

	<dt><code class="module"><a href="./mod/mod_info.html">mod_info</a></code></dt>
	<dd><code class="module"><a href="./mod/mod_info.html">mod_info</a></code> can now dump the pre-parsed configuration
	to stdout during server startup.</dd>

	<dt><code class="module"><a href="./mod/mod_rewrite.html">mod_rewrite</a></code></dt>
	<dd><code class="module"><a href="./mod/mod_rewrite.html">mod_rewrite</a></code> adds the <code>[QSD]</code>
	(Query String Discard) and <code>[END]</code> flags for
	<code class="directive"><a href="./mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> to
	simplify common rewriting scenarios.</dd>
	</dl>
	</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
	<div class="section">
	<h2><a name="programs" id="programs">Program Enhancements</a></h2>

	<dl>
	<dt>fcgistarter</dt>
	<dd>FastCGI deamon starter utility</dd>
	<dt>htcacheclean</dt>
	<dd>Current cached URLs can now be listed, with optional metadata
	included.</dd>
	<dd>Allow explicit deletion of individual cached URLs from the
	cache.</dd>
	<dd>File sizes can now be rounded up to the given block size, making
	the size limits map more closely to the real size on disk.</dd>
	<dd>Cache size can now be limited by the number of inodes, instead
	of or in addition to being limited by the size of the files on
	disk.</dd>
	</dl>
	</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
	<div class="section">
	<h2><a name="developer" id="developer">Module Developer Changes</a></h2>

	<dl>
	<dt>Check Configuration Hook Added</dt>

	<dd>A new hook, <code>check_config</code>, has been added which runs
	between the <code>pre_config</code> and <code>open_logs</code>
	hooks. It also runs before the <code>test_config</code> hook
	when the <code>-t</code> option is passed to
	<code class="program"><a href="./programs/httpd.html">httpd</a></code>. The <code>check_config</code> hook
	allows modules to review interdependent configuration directive
	values and adjust them while messages can still be logged to the
	console. The user can thus be alerted to misconfiguration problems
	before the core <code>open_logs</code> hook function redirects
	console output to the error log.</dd>

	<dt>Expression Parser Added</dt>

	<dd>We now have a general-purpose expression parser, whose API is
	exposed in <var>ap_expr.h</var>. This is adapted from the
	expression parser previously implemented in
	<code class="module"><a href="./mod/mod_include.html">mod_include</a></code>.</dd>

	<dt>Authorization Logic Containers</dt>

	<dd>Authorization modules now register as a provider, via
	ap_register_auth_provider(), to support advanced authorization logic,
	such as <code class="directive"><a href="./mod/mod_authz_core.html#requireall"><RequireAll></a></code>.</dd>

	<dt>Small-Object Caching Interface</dt>

	<dd>The <var>ap_socache.h</var> header exposes a provider-based
	interface for caching small data objects, based on the previous
	implementation of the <code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code> session cache.
	Providers using a shared-memory cyclic buffer, disk-based dbm
	files, and a memcache distributed cache are currently
	supported.</dd>

	<dt>Cache Status Hook Added</dt>

	<dd>The <code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code> module now includes a new
	<code>cache_status</code> hook, which is called when the caching
	decision becomes known. A default implementation is provided
	which adds an optional <code>X-Cache</code> and
	<code>X-Cache-Detail</code> header to the response.</dd>
	</dl>

	<p>The developer documentation contains a
	<a href="developer/new_api_2_4.html">detailed list of API changes</a>.</p>
	</div></div>
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