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8 <title>Overview of new features in Apache HTTP Server 2.2 - Apache HTTP Server</title>
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14 <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>
15 <p class="apache">Apache HTTP Server Version 2.3</p>
16 <img alt="" src="./images/feather.gif" /></div>
17 <div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
19 <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 2.2</h1>
21 <p><span>Available Languages: </span><a href="./en/new_features_2_2.html" title="English"> en </a> |
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28 <p>This document describes some of the major changes between the
29 2.0 and 2.2 versions of the Apache HTTP Server. For new features since
30 version 1.3, see the <a href="new_features_2_0.html">2.0 new features</a>
33 <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#core">Core Enhancements</a></li>
34 <li><img alt="" src="./images/down.gif" /> <a href="#module">Module Enhancements</a></li>
35 <li><img alt="" src="./images/down.gif" /> <a href="#programs">Program Enhancements</a></li>
36 <li><img alt="" src="./images/down.gif" /> <a href="#developer">Module Developer Changes</a></li>
38 <div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
40 <h2><a name="core" id="core">Core Enhancements</a></h2>
45 <dd>The bundled authentication and authorization modules have
46 been refactored. The new mod_authn_alias(already removed from 2.3/2.4)
47 module can greatly simplify certain authentication configurations.
48 See <a href="#module">module name changes</a>, and
49 <a href="#developer">the developer changes</a> for more
50 information about how these changes affects users and module
54 <dd><code class="module"><a href="./mod/mod_cache.html">mod_cache</a></code>, <code class="module"><a href="./mod/mod_cache_disk.html">mod_cache_disk</a></code>, and
55 mod_mem_cache(already removed from 2.3/2.4) have undergone a lot of changes, and
56 are now considered production-quality. <code class="program"><a href="./programs/htcacheclean.html">htcacheclean</a></code>
57 has been introduced to clean up <code class="module"><a href="./mod/mod_cache_disk.html">mod_cache_disk</a></code>
60 <dt>Configuration</dt>
61 <dd>The default configuration layout has been simplified and
62 modularised. Configuration snippets which can be used to
63 enable commonly-used features are now bundled with Apache, and
64 can be easily added to the main server config.</dd>
66 <dt>Graceful stop</dt>
67 <dd>The <code class="module"><a href="./mod/prefork.html">prefork</a></code>, <code class="module"><a href="./mod/worker.html">worker</a></code> and
68 <code class="module"><a href="./mod/event.html">event</a></code> MPMs now allow <code class="program"><a href="./programs/httpd.html">httpd</a></code>
69 to be shutdown gracefully via the
70 <a href="stopping.html#gracefulstop"><code>graceful-stop</code></a>
71 signal. The <code class="directive"><a href="./mod/mpm_common.html#gracefulshutdowntimeout">GracefulShutdownTimeout</a></code> directive
72 has been added to specify an optional timeout, after which
73 <code class="program"><a href="./programs/httpd.html">httpd</a></code> will terminate regardless of the status
74 of any requests being served.</dd>
77 <dd>The new <code class="module"><a href="./mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code> module provides
78 load balancing services for <code class="module"><a href="./mod/mod_proxy.html">mod_proxy</a></code>.
79 The new <code class="module"><a href="./mod/mod_proxy_ajp.html">mod_proxy_ajp</a></code> module adds support for the
80 <code>Apache JServ Protocol version 1.3</code> used by
81 <a href="http://jakarta.apache.org/tomcat/">Apache Tomcat</a>.</dd>
83 <dt>Regular Expression Library Updated</dt>
84 <dd>Version 5.0 of the
85 <a href="http://www.pcre.org/">Perl Compatible Regular Expression
86 Library</a> (PCRE) is now included. <code class="program"><a href="./programs/httpd.html">httpd</a></code> can be
87 configured to use a system installation of PCRE by passing the
88 <code>--with-pcre</code> flag to configure.</dd>
90 <dt>Smart Filtering</dt>
91 <dd><code class="module"><a href="./mod/mod_filter.html">mod_filter</a></code> introduces dynamic configuration
92 to the output filter chain. It enables filters to be conditionally
93 inserted, based on any Request or Response header or environment
94 variable, and dispenses with the more problematic dependencies and
95 ordering problems in the 2.0 architecture.</dd>
97 <dt>Large File Support</dt>
98 <dd><code class="program"><a href="./programs/httpd.html">httpd</a></code> is now built with support for files larger
99 than 2GB on modern 32-bit Unix systems. Support for handling
100 >2GB request bodies has also been added.</dd>
103 <dd>The <code class="module"><a href="./mod/event.html">event</a></code> MPM uses a separate thread to handle
104 Keep Alive requests and accepting connections. Keep Alive requests
105 have traditionally required httpd to dedicate a worker to handle it.
106 This dedicated worker could not be used again until the Keep Alive
107 timeout was reached.</dd>
109 <dt>SQL Database Support</dt>
110 <dd><code class="module"><a href="./mod/mod_dbd.html">mod_dbd</a></code>, together with the <code>apr_dbd</code>
111 framework, brings direct SQL support to modules that need it.
112 Supports connection pooling in threaded MPMs.</dd>
115 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
116 <div class="section">
117 <h2><a name="module" id="module">Module Enhancements</a></h2>
121 <dd>Modules in the aaa directory have been renamed and offer
122 better support for digest authentication. For example,
123 <code>mod_auth</code> is now split into
124 <code class="module"><a href="./mod/mod_auth_basic.html">mod_auth_basic</a></code> and
125 <code class="module"><a href="./mod/mod_authn_file.html">mod_authn_file</a></code>; <code>mod_auth_dbm</code> is now
126 called <code class="module"><a href="./mod/mod_authn_dbm.html">mod_authn_dbm</a></code>; <code>mod_access</code> has
127 been renamed <code class="module"><a href="./mod/mod_authz_host.html">mod_authz_host</a></code>. There is also a new
128 mod_authn_alias(already removed from 2.3/2.4) module for simplifying
129 certain authentication configurations.
132 <dt><code class="module"><a href="./mod/mod_authnz_ldap.html">mod_authnz_ldap</a></code></dt>
133 <dd>This module is a port of the 2.0
134 <code>mod_auth_ldap</code> module to the 2.2 <code>Authn/Authz</code>
135 framework. New features include using LDAP attribute values and
136 complicated search filters in the
137 <code class="directive"><a href="./mod/mod_authz_core.html#require">Require</a></code> directive.</dd>
139 <dt><code class="module"><a href="./mod/mod_authz_owner.html">mod_authz_owner</a></code></dt>
140 <dd>A new module that authorizes access to files based
141 on the owner of the file on the file system</dd>
143 <dt><code class="module"><a href="./mod/mod_version.html">mod_version</a></code></dt>
144 <dd>A new module that allows configuration blocks to be enabled based on the
145 version number of the running server.</dd>
147 <dt><code class="module"><a href="./mod/mod_info.html">mod_info</a></code></dt>
148 <dd>Added a new <code>?config</code> argument which will show
149 the configuration directives as parsed by Apache, including
150 their file name and line number. The module also
151 shows the order of all request hooks and additional
152 build information, similar to <code>httpd -V</code>.</dd>
154 <dt><code class="module"><a href="./mod/mod_ssl.html">mod_ssl</a></code></dt>
156 <dd>Added a support for
157 <a href="http://www.ietf.org/rfc/rfc2817.txt">RFC 2817</a>, which
158 allows connections to upgrade from clear text to TLS encryption.</dd>
160 <dt><code class="module"><a href="./mod/mod_imagemap.html">mod_imagemap</a></code></dt>
161 <dd><code>mod_imap</code> has been renamed to
162 <code class="module"><a href="./mod/mod_imagemap.html">mod_imagemap</a></code> to avoid user confusion.</dd>
165 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
166 <div class="section">
167 <h2><a name="programs" id="programs">Program Enhancements</a></h2>
170 <dt><code class="program"><a href="./programs/httpd.html">httpd</a></code></dt>
171 <dd>A new command line option <code>-M</code> has been added that
172 lists all modules that are loaded based on the current
173 configuration. Unlike the <code>-l</code> option, this list
174 includes DSOs loaded via <code class="module"><a href="./mod/mod_so.html">mod_so</a></code>.</dd>
176 <dt><code class="program"><a href="./programs/httxt2dbm.html">httxt2dbm</a></code></dt>
177 <dd>A new program used to generate dbm files from text input,
178 for use in <code class="directive"><a href="./mod/mod_rewrite.html#rewritemap">RewriteMap</a></code>
179 with the <code>dbm</code> map type.</dd>
181 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
182 <div class="section">
183 <h2><a name="developer" id="developer">Module Developer Changes</a></h2>
186 <dt><a class="glossarylink" href="./glossary.html#apr" title="see glossary">APR</a> 1.0 API</dt>
188 <dd>Apache 2.2 uses the APR 1.0 API. All deprecated functions and
189 symbols have been removed from <code>APR</code> and
190 <code>APR-Util</code>. For details, see the
191 <a href="http://apr.apache.org/">APR Website</a>.</dd>
194 <dd>The bundled authentication and authorization modules have
195 been renamed along the following lines:
197 <li><code>mod_auth_*</code> -> Modules that implement an HTTP
198 authentication mechanism</li>
199 <li><code>mod_authn_*</code> -> Modules that provide a backend
200 authentication provider</li>
201 <li><code>mod_authz_*</code> -> Modules that implement
202 authorization (or access)</li>
203 <li><code>mod_authnz_*</code> -> Module that implements both
204 authentication & authorization</li>
206 There is a new authentication backend provider
207 scheme which greatly eases the construction of new authentication
210 <dt>Connection Error Logging</dt>
212 <dd>A new function, <code>ap_log_cerror</code> has been added to log
213 errors that occur with the client's connection. When logged,
214 the message includes the client IP address.</dd>
216 <dt>Test Configuration Hook Added</dt>
218 <dd>A new hook, <code>test_config</code> has been added to aid
219 modules that want to execute special code only when the user passes
220 <code>-t</code> to <code class="program"><a href="./programs/httpd.html">httpd</a></code>.</dd>
222 <dt>Set Threaded MPM's Stacksize</dt>
224 <dd>A new directive, <code class="directive"><a href="./mod/mpm_common.html#threadstacksize">ThreadStackSize</a></code> has been added to
225 set the stack size on all threaded MPMs. This is required
226 for some third-party modules on platforms with small default
227 thread stack size.</dd>
229 <dt>Protocol handling for output filters</dt>
231 <dd>In the past, every filter has been responsible for ensuring
232 that it generates the correct response headers where it affects
233 them. Filters can now delegate common protocol management to
234 <code class="module"><a href="./mod/mod_filter.html">mod_filter</a></code>, using the
235 <code>ap_register_output_filter_protocol</code> or
236 <code>ap_filter_protocol</code> calls.</dd>
238 <dt>Monitor hook added</dt>
239 <dd>Monitor hook enables modules to run regular/scheduled jobs
240 in the parent (root) process.</dd>
242 <dt>Regular expression API changes</dt>
244 <dd>The <code>pcreposix.h</code> header is no longer available;
245 it is replaced by the new <code>ap_regex.h</code> header. The
246 POSIX.2 <code>regex.h</code> implementation exposed by the old
247 header is now available under the <code>ap_</code> namespace
248 from <code>ap_regex.h</code>. Calls to <code>regcomp</code>,
249 <code>regexec</code> and so on can be replaced by calls to
250 <code>ap_regcomp</code>, <code>ap_regexec</code>.</dd>
252 <dt>DBD Framework (SQL Database API)</dt>
254 <dd><p>With Apache 1.x and 2.0, modules requiring an SQL backend
255 had to take responsibility for managing it themselves. Apart
256 from reinventing the wheel, this can be very inefficient, for
257 example when several modules each maintain their own connections.</p>
259 <p>Apache 2.1 and later provides the <code>ap_dbd</code> API for
260 managing database connections (including optimised strategies
261 for threaded and unthreaded MPMs), while APR 1.2 and later provides
262 the <code>apr_dbd</code> API for interacting with the database.</p>
264 <p>New modules SHOULD now use these APIs for all SQL database
265 operations. Existing applications SHOULD be upgraded to use it
266 where feasible, either transparently or as a recommended option
267 to their users.</p></dd>
270 <div class="bottomlang">
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276 </div><div id="footer">
277 <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>
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