new_features_2_4.html.en revision 4624ec7c743a08f22e90521b97d612c9499ae7ef
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
<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" />
<link href="/style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
<link href="/images/favicon.ico" rel="shortcut icon" /></head>
<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="&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="Fran�ais">&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="#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>
</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_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.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_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_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_allowmethods.html">mod_allowmethods</a></code></dt>
<dd>New module to restrict certain HTTP methods without interfering with
authentication or authorization.</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>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>, all
provided by the <code class="module"><a href="/mod/mod_authz_core.html">mod_authz_core</a></code> module.</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="Fran�ais">&nbsp;fr&nbsp;</a></p>
</div><div id="footer">
<p class="apache">Copyright 2010 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>
</body></html>