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<manualpage metafile="new_features_2_2.xml.meta">
-<title>Overview of new features in Apache 2.2</title>
+<title>Overview of new features in Apache HTTP Server 2.2</title>
<summary>
<p>This document describes some of the major changes between the
<dl>
<dt>Authn/Authz</dt>
- <dd>...</dd>
+ <dd>The bundled authentication and authorization modules have
+ been refactored. The new mod_authn_alias(already removed from 2.3/2.4)
+ module can greatly simplify certain authentication configurations.
+ See <a href="#module">module name changes</a>, and
+ <a href="#developer">the developer changes</a> for more
+ information about how these changes affects users and module
+ writers.</dd>
<dt>Caching</dt>
- <dd>...</dd>
+ <dd><module>mod_cache</module>, <module>mod_cache_disk</module>, and
+ mod_mem_cache(already removed from 2.3/2.4) have undergone a lot of changes, and
+ are now considered production-quality. <program>htcacheclean</program>
+ has been introduced to clean up <module>mod_cache_disk</module>
+ setups.</dd>
+
+ <dt>Configuration</dt>
+ <dd>The default configuration layout has been simplified and
+ modularised. Configuration snippets which can be used to
+ enable commonly-used features are now bundled with Apache, and
+ can be easily added to the main server config.</dd>
+
+ <dt>Graceful stop</dt>
+ <dd>The <module>prefork</module>, <module>worker</module> and
+ <module>event</module> MPMs now allow <program>httpd</program>
+ to be shutdown gracefully via the
+ <a href="stopping.html#gracefulstop"><code>graceful-stop</code></a>
+ signal. The <directive
+ module="mpm_common">GracefulShutdownTimeout</directive> directive
+ has been added to specify an optional timeout, after which
+ <program>httpd</program> will terminate regardless of the status
+ of any requests being served.</dd>
<dt>Proxying</dt>
- <dd>The new <module>mod_proxy_balancer</module> module provides
+ <dd>The new <module>mod_proxy_balancer</module> module provides
load balancing services for <module>mod_proxy</module>.
The new <module>mod_proxy_ajp</module> module adds support for the
- <code>Apache JServ Protocol version 1.3</code> used by
- <a href="http://jakarta.apache.org/tomcat/">Apache Tomcat</a>.</dd>
+ <code>Apache JServ Protocol version 1.3</code> used by
+ <a href="http://tomcat.apache.org/">Apache Tomcat</a>.</dd>
+
+ <dt>Regular Expression Library Updated</dt>
+ <dd>Version 5.0 of the
+ <a href="http://www.pcre.org/">Perl Compatible Regular Expression
+ Library</a> (PCRE) is now included. <program>httpd</program> can be
+ configured to use a system installation of PCRE by passing the
+ <code>--with-pcre</code> flag to configure.</dd>
<dt>Smart Filtering</dt>
<dd><module>mod_filter</module> introduces dynamic configuration
variable, and dispenses with the more problematic dependencies and
ordering problems in the 2.0 architecture.</dd>
+ <dt>Large File Support</dt>
+ <dd><program>httpd</program> is now built with support for files larger
+ than 2GB on modern 32-bit Unix systems. Support for handling
+ >2GB request bodies has also been added.</dd>
+
+ <dt>Event MPM</dt>
+ <dd>The <module>event</module> MPM uses a separate thread to handle
+ Keep Alive requests and accepting connections. Keep Alive requests
+ have traditionally required httpd to dedicate a worker to handle it.
+ This dedicated worker could not be used again until the Keep Alive
+ timeout was reached.</dd>
+
+ <dt>SQL Database Support</dt>
+ <dd><module>mod_dbd</module>, together with the <code>apr_dbd</code>
+ framework, brings direct SQL support to modules that need it.
+ Supports connection pooling in threaded MPMs.</dd>
+
</dl>
</section>
<section id="module">
<title>Module Enhancements</title>
<dl>
+ <dt>Authn/Authz</dt>
+ <dd>Modules in the aaa directory have been renamed and offer
+ better support for digest authentication. For example,
+ <code>mod_auth</code> is now split into
+ <module>mod_auth_basic</module> and
+ <module>mod_authn_file</module>; <code>mod_auth_dbm</code> is now
+ called <module>mod_authn_dbm</module>; <code>mod_access</code> has
+ been renamed <module>mod_authz_host</module>. There is also a new
+ mod_authn_alias(already removed from 2.3/2.4) module for simplifying
+ certain authentication configurations.
+ </dd>
+
<dt><module>mod_authnz_ldap</module></dt>
- <dd>This module is a port of the 2.0
- <code>mod_auth_ldap</code> module to the 2.2 <code>Authn/Authz</code>
- framework. New features include using LDAP attribute values and
- complicated search filters in the
- <directive module="core">Require</directive> directive.</dd>
+ <dd>This module is a port of the 2.0
+ <code>mod_auth_ldap</code> module to the 2.2 <code>Authn/Authz</code>
+ framework. New features include using LDAP attribute values and
+ complicated search filters in the
+ <directive module="mod_authz_core">Require</directive> directive.</dd>
+
+ <dt><module>mod_authz_owner</module></dt>
+ <dd>A new module that authorizes access to files based
+ on the owner of the file on the file system</dd>
+
+ <dt><module>mod_version</module></dt>
+ <dd>A new module that allows configuration blocks to be enabled based on the
+ version number of the running server.</dd>
<dt><module>mod_info</module></dt>
<dd>Added a new <code>?config</code> argument which will show
the configuration directives as parsed by Apache, including
- their file name and line number. The module also
+ their file name and line number. The module also
shows the order of all request hooks and additional
build information, similar to <code>httpd -V</code>.</dd>
+
+ <dt><module>mod_ssl</module></dt>
+ <!-- Need Info on SSLEngine Support? -->
+ <dd>Added a support for
+ <a href="http://www.ietf.org/rfc/rfc2817.txt">RFC 2817</a>, which
+ allows connections to upgrade from clear text to TLS encryption.</dd>
+
+ <dt><module>mod_imagemap</module></dt>
+ <dd><code>mod_imap</code> has been renamed to
+ <module>mod_imagemap</module> to avoid user confusion.</dd>
+ </dl>
+
+ </section>
+
+ <section id="programs">
+ <title>Program Enhancements</title>
+ <dl>
+ <dt><program>httpd</program></dt>
+ <dd>A new command line option <code>-M</code> has been added that
+ lists all modules that are loaded based on the current
+ configuration. Unlike the <code>-l</code> option, this list
+ includes DSOs loaded via <module>mod_so</module>.</dd>
+
+ <dt><program>httxt2dbm</program></dt>
+ <dd>A new program used to generate dbm files from text input,
+ for use in <directive module="mod_rewrite">RewriteMap</directive>
+ with the <code>dbm</code> map type.</dd>
</dl>
</section>
<section id="developer">
<title>Module Developer Changes</title>
<dl>
- <dt>APR 1.0 API</dt>
+ <dt><glossary>APR</glossary> 1.0 API</dt>
- <dd>Apache 2.2 uses the APR 1.0 API. All depreciated functions and
- symbols have been removed from <code>APR</code> and
- <code>APR-Util</code>. For details, see the
+ <dd>Apache 2.2 uses the APR 1.0 API. All deprecated functions and
+ symbols have been removed from <code>APR</code> and
+ <code>APR-Util</code>. For details, see the
<a href="http://apr.apache.org/">APR Website</a>.</dd>
+ <dt>Authn/Authz</dt>
+ <dd>The bundled authentication and authorization modules have
+ been renamed along the following lines:
+ <ul>
+ <li><code>mod_auth_*</code> -> Modules that implement an HTTP
+ authentication mechanism</li>
+ <li><code>mod_authn_*</code> -> Modules that provide a backend
+ authentication provider</li>
+ <li><code>mod_authz_*</code> -> Modules that implement
+ authorization (or access)</li>
+ <li><code>mod_authnz_*</code> -> Module that implements both
+ authentication & authorization</li>
+ </ul>
+ There is a new authentication backend provider
+ scheme which greatly eases the construction of new authentication
+ backends.</dd>
+
<dt>Connection Error Logging</dt>
<dd>A new function, <code>ap_log_cerror</code> has been added to log
- errors that occure with the client's connection. When logged,
+ errors that occur with the client's connection. When logged,
the message includes the client IP address.</dd>
<dt>Test Configuration Hook Added</dt>
<dd>A new hook, <code>test_config</code> has been added to aid
modules that want to execute special code only when the user passes
- <code>-t</code> to httpd.</dd>
+ <code>-t</code> to <program>httpd</program>.</dd>
<dt>Set Threaded MPM's Stacksize</dt>
- <dd>A new directive, <code>ThreadStackSize</code> has been added to
+ <dd>A new directive, <directive module="mpm_common"
+ >ThreadStackSize</directive> has been added to
set the stack size on all threaded MPMs. This is required
for some third-party modules on platforms with small default
thread stack size.</dd>
<dt>Protocol handling for output filters</dt>
- <dd>In the past, every filter has been responsible for ensuring
+ <dd>In the past, every filter has been responsible for ensuring
that it generates the correct response headers where it affects
them. Filters can now delegate common protocol management to
<module>mod_filter</module>, using the
<code>ap_register_output_filter_protocol</code> or
<code>ap_filter_protocol</code> calls.</dd>
+
+ <dt>Monitor hook added</dt>
+ <dd>Monitor hook enables modules to run regular/scheduled jobs
+ in the parent (root) process.</dd>
+
+ <dt>Regular expression API changes</dt>
+
+ <dd>The <code>pcreposix.h</code> header is no longer available;
+ it is replaced by the new <code>ap_regex.h</code> header. The
+ POSIX.2 <code>regex.h</code> implementation exposed by the old
+ header is now available under the <code>ap_</code> namespace
+ from <code>ap_regex.h</code>. Calls to <code>regcomp</code>,
+ <code>regexec</code> and so on can be replaced by calls to
+ <code>ap_regcomp</code>, <code>ap_regexec</code>.</dd>
+
+ <dt>DBD Framework (SQL Database API)</dt>
+
+ <dd><p>With Apache 1.x and 2.0, modules requiring an SQL backend
+ had to take responsibility for managing it themselves. Apart
+ from reinventing the wheel, this can be very inefficient, for
+ example when several modules each maintain their own connections.</p>
+
+ <p>Apache 2.1 and later provides the <code>ap_dbd</code> API for
+ managing database connections (including optimised strategies
+ for threaded and unthreaded MPMs), while APR 1.2 and later provides
+ the <code>apr_dbd</code> API for interacting with the database.</p>
+
+ <p>New modules SHOULD now use these APIs for all SQL database
+ operations. Existing applications SHOULD be upgraded to use it
+ where feasible, either transparently or as a recommended option
+ to their users.</p></dd>
</dl>
</section>
</manualpage>