docs/manual/new_features_2_0.xml - httpd - Git at Google

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 <manualpage metafile="new_features_2_0.xml.meta">

 <title>Overview of new features in Apache HTTP Server 2.0</title>

 <summary>
   <p>This document describes some of the major changes between the
      1.3 and 2.0 versions of the Apache HTTP Server.</p>
 </summary>

 <seealso><a href="upgrading.html">Upgrading to 2.0 from 1.3</a></seealso>

   <section id="core">
     <title>Core Enhancements</title>

     <dl>
       <dt>Unix Threading</dt>

       <dd>On Unix systems with POSIX threads support, Apache httpd can
       now run in a hybrid multiprocess, multithreaded mode. This
       improves scalability for many, but not all configurations.</dd>

       <dt>New Build System</dt>

       <dd>The build system has been rewritten from scratch to be
       based on <code>autoconf</code> and <code>libtool</code>.
       This makes Apache httpd's configuration system more similar to
       that of other packages.</dd>

       <dt>Multiprotocol Support</dt>

       <dd>Apache HTTP Server now has some of the infrastructure in place to
       support serving multiple protocols. <module>mod_echo</module> has
       been written as an example.</dd>

       <dt>Better support for non-Unix
       platforms</dt>

       <dd>Apache HTTP Server 2.0 is faster and more stable on non-Unix
       platforms such as BeOS, OS/2, and Windows. With the
       introduction of platform-specific <a
       href="mpm.html">multi-processing modules</a> (MPMs) and the
       Apache Portable Runtime (APR), these platforms are now
       implemented in their native API, avoiding the often buggy and
       poorly performing POSIX-emulation layers.</dd>

       <dt>New Apache httpd API</dt>

       <dd>The API for modules has changed significantly for 2.0.
       Many of the module-ordering/-priority problems from 1.3 should
       be gone. 2.0 does much of this automatically, and module ordering
       is now done per-hook to allow more flexibility. Also, new calls
       have been added that provide additional module capabilities
       without patching the core Apache HTTP Server.</dd>

       <dt>IPv6 Support</dt>

       <dd>On systems where IPv6 is supported by the underlying
       Apache Portable Runtime library, Apache httpd gets IPv6 listening
       sockets by default. Additionally, the <directive
       module="mpm_common">Listen</directive>, <directive module="core"
       >NameVirtualHost</directive>, and <directive module="core"
       >VirtualHost</directive> directives support
       IPv6 numeric address strings (e.g., "<code>Listen
       [2001:db8::1]:8080</code>").</dd>

       <dt>Filtering</dt>

       <dd>Apache httpd modules may now be written as filters which act on
       the stream of content as it is delivered to or from the
       server. This allows, for example, the output of CGI scripts to
       be parsed for Server Side Include directives using the
       <code>INCLUDES</code> filter in <module>mod_include</module>. The
       module <module>mod_ext_filter</module> allows external programs to
       act as filters in much the same way that CGI programs can act as
       handlers.</dd>

       <dt>Multilanguage Error Responses</dt>

       <dd>Error response messages to the browser are now provided in
       several languages, using SSI documents. They may be customized
       by the administrator to achieve a consistent look and feel.</dd>

       <dt>Simplified configuration</dt>

       <dd>Many confusing directives have been simplified. The often
       confusing <code>Port</code> and <code>BindAddress</code> directives
       are gone; only the <directive module="mpm_common">Listen</directive>
       directive is used for IP address binding; the <directive
       module="core">ServerName</directive> directive specifies the
       server name and port number only for redirection and vhost
       recognition.</dd>

       <dt>Native Windows NT Unicode Support</dt>

       <dd>Apache httpd 2.0 on Windows NT now uses utf-8 for all filename
       encodings. These directly translate to the underlying Unicode
       file system, providing multilanguage support for all Windows
       NT-based installations, including Windows 2000 and Windows XP.
       <em>This support does not extend to Windows 95, 98 or ME, which
       continue to use the machine's local codepage for filesystem
       access.</em></dd>

       <dt>Regular Expression Library Updated</dt>

       <dd>Apache httpd 2.0 includes the <a href="http://www.pcre.org/">Perl
       Compatible Regular Expression Library</a> (PCRE).  All regular
       expression evaluation now uses the more powerful Perl 5
       syntax.</dd>

     </dl>
   </section>

   <section id="module">
     <title>Module Enhancements</title>

     <dl>
       <dt><module>mod_ssl</module></dt>

       <dd>New module in Apache httpd 2.0. This module is an interface
       to the SSL/TLS encryption protocols provided by
       OpenSSL.</dd>

       <dt><module>mod_dav</module></dt>

       <dd>New module in Apache httpd 2.0. This module implements the HTTP
       Distributed Authoring and Versioning (DAV) specification for
       posting and maintaining web content.</dd>

       <dt><module>mod_deflate</module></dt>

       <dd>New module in Apache httpd 2.0.  This module allows supporting
       browsers to request that content be compressed before delivery,
       saving network bandwidth.</dd>

       <dt><module outdated="true">mod_auth_ldap</module></dt>

       <dd>New module in Apache httpd 2.0.41.  This module allows an LDAP
       database to be used to store credentials for HTTP Basic
       Authentication.  A companion module, <module>mod_ldap</module>
       provides connection pooling and results caching.</dd>

       <dt><module>mod_auth_digest</module></dt>

       <dd>Includes additional support for session caching across
       processes using shared memory.</dd>

       <dt><module>mod_charset_lite</module></dt>

       <dd>New module in Apache httpd 2.0. This experimental module allows
       for character set translation or recoding.</dd>

       <dt><module>mod_file_cache</module></dt>

       <dd>New module in Apache httpd 2.0. This module includes the
       functionality of <code>mod_mmap_static</code> in Apache HTTP
       Server version 1.3, plus adds further caching abilities.</dd>

       <dt><module>mod_headers</module></dt>

       <dd>This module is much more flexible in Apache httpd 2.0. It can now
       modify request headers used by <module>mod_proxy</module>, and
       it can conditionally set response headers.</dd>

       <dt><module>mod_proxy</module></dt>

       <dd>The proxy module has been completely rewritten to take
       advantage of the new filter infrastructure and to implement a
       more reliable, HTTP/1.1 compliant proxy. In addition, new
       <directive module="mod_proxy" type="section">Proxy</directive>
       configuration sections provide more readable (and internally
       faster) control of proxied sites; overloaded <code>&lt;Directory
       "proxy:..."&gt;</code> configuration are not supported. The module
       is now divided into specific protocol support modules including
       <code>proxy_connect</code>, <code>proxy_ftp</code> and
       <code>proxy_http</code>.</dd>

       <dt><module>mod_negotiation</module></dt>

       <dd>A new <directive module="mod_negotiation"
       >ForceLanguagePriority</directive> directive can be used to assure that
       the client receives a single document in all cases, rather than
       NOT ACCEPTABLE or MULTIPLE CHOICES responses. In addition, the
       negotiation and MultiViews algorithms have been cleaned up to
       provide more consistent results and a new form of type map that
       can include document content is provided.</dd>

       <dt><module>mod_autoindex</module></dt>

       <dd>Autoindex'ed directory listings can now be configured to
       use HTML tables for cleaner formatting, and allow finer-grained
       control of sorting, including version-sorting, and wildcard
       filtering of the directory listing.</dd>

       <dt><module>mod_include</module></dt>

       <dd>New directives allow the default start and end tags for SSI elements
       to be changed and allow for error and time format configuration
       to take place in the main configuration file rather than in the
       SSI document. Results from regular expression parsing and grouping
       (now based on Perl's regular expression syntax) can be retrieved
       using <module>mod_include</module>'s variables <code>$0</code>
       .. <code>$9</code>.</dd>

       <dt><module outdated="true">mod_auth_dbm</module></dt>

       <dd>Now supports multiple types of DBM-like databases using the
       <directive>AuthDBMType</directive> directive.</dd>

     </dl>
   </section>
 </manualpage>
	<?xml version='1.0' encoding='UTF-8' ?>
	<!DOCTYPE manualpage SYSTEM "./style/manualpage.dtd">
	<?xml-stylesheet type="text/xsl" href="./style/manual.en.xsl"?>
	<!-- $LastChangedRevision$ -->

	<!--
	Licensed to the Apache Software Foundation (ASF) under one or more
	contributor license agreements. See the NOTICE file distributed with
	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You under the Apache License, Version 2.0
	(the "License"); you may not use this file except in compliance with
	the License. You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	-->

	<manualpage metafile="new_features_2_0.xml.meta">

	<title>Overview of new features in Apache HTTP Server 2.0</title>

	<summary>
	<p>This document describes some of the major changes between the
	1.3 and 2.0 versions of the Apache HTTP Server.</p>
	</summary>

	<seealso><a href="upgrading.html">Upgrading to 2.0 from 1.3</a></seealso>

	<section id="core">
	<title>Core Enhancements</title>

	<dl>
	<dt>Unix Threading</dt>

	<dd>On Unix systems with POSIX threads support, Apache httpd can
	now run in a hybrid multiprocess, multithreaded mode. This
	improves scalability for many, but not all configurations.</dd>

	<dt>New Build System</dt>

	<dd>The build system has been rewritten from scratch to be
	based on <code>autoconf</code> and <code>libtool</code>.
	This makes Apache httpd's configuration system more similar to
	that of other packages.</dd>

	<dt>Multiprotocol Support</dt>

	<dd>Apache HTTP Server now has some of the infrastructure in place to
	support serving multiple protocols. <module>mod_echo</module> has
	been written as an example.</dd>

	<dt>Better support for non-Unix
	platforms</dt>

	<dd>Apache HTTP Server 2.0 is faster and more stable on non-Unix
	platforms such as BeOS, OS/2, and Windows. With the
	introduction of platform-specific <a
	href="mpm.html">multi-processing modules</a> (MPMs) and the
	Apache Portable Runtime (APR), these platforms are now
	implemented in their native API, avoiding the often buggy and
	poorly performing POSIX-emulation layers.</dd>

	<dt>New Apache httpd API</dt>

	<dd>The API for modules has changed significantly for 2.0.
	Many of the module-ordering/-priority problems from 1.3 should
	be gone. 2.0 does much of this automatically, and module ordering
	is now done per-hook to allow more flexibility. Also, new calls
	have been added that provide additional module capabilities
	without patching the core Apache HTTP Server.</dd>

	<dt>IPv6 Support</dt>

	<dd>On systems where IPv6 is supported by the underlying
	Apache Portable Runtime library, Apache httpd gets IPv6 listening
	sockets by default. Additionally, the <directive
	module="mpm_common">Listen</directive>, <directive module="core"
	>NameVirtualHost</directive>, and <directive module="core"
	>VirtualHost</directive> directives support
	IPv6 numeric address strings (e.g., "<code>Listen
	[2001:db8::1]:8080</code>").</dd>

	<dt>Filtering</dt>

	<dd>Apache httpd modules may now be written as filters which act on
	the stream of content as it is delivered to or from the
	server. This allows, for example, the output of CGI scripts to
	be parsed for Server Side Include directives using the
	<code>INCLUDES</code> filter in <module>mod_include</module>. The
	module <module>mod_ext_filter</module> allows external programs to
	act as filters in much the same way that CGI programs can act as
	handlers.</dd>

	<dt>Multilanguage Error Responses</dt>

	<dd>Error response messages to the browser are now provided in
	several languages, using SSI documents. They may be customized
	by the administrator to achieve a consistent look and feel.</dd>

	<dt>Simplified configuration</dt>

	<dd>Many confusing directives have been simplified. The often
	confusing <code>Port</code> and <code>BindAddress</code> directives
	are gone; only the <directive module="mpm_common">Listen</directive>
	directive is used for IP address binding; the <directive
	module="core">ServerName</directive> directive specifies the
	server name and port number only for redirection and vhost
	recognition.</dd>

	<dt>Native Windows NT Unicode Support</dt>

	<dd>Apache httpd 2.0 on Windows NT now uses utf-8 for all filename
	encodings. These directly translate to the underlying Unicode
	file system, providing multilanguage support for all Windows
	NT-based installations, including Windows 2000 and Windows XP.
	<em>This support does not extend to Windows 95, 98 or ME, which
	continue to use the machine's local codepage for filesystem
	access.</em></dd>

	<dt>Regular Expression Library Updated</dt>

	<dd>Apache httpd 2.0 includes the <a href="http://www.pcre.org/">Perl
	Compatible Regular Expression Library</a> (PCRE). All regular
	expression evaluation now uses the more powerful Perl 5
	syntax.</dd>

	</dl>
	</section>

	<section id="module">
	<title>Module Enhancements</title>

	<dl>
	<dt><module>mod_ssl</module></dt>

	<dd>New module in Apache httpd 2.0. This module is an interface
	to the SSL/TLS encryption protocols provided by
	OpenSSL.</dd>

	<dt><module>mod_dav</module></dt>

	<dd>New module in Apache httpd 2.0. This module implements the HTTP
	Distributed Authoring and Versioning (DAV) specification for
	posting and maintaining web content.</dd>

	<dt><module>mod_deflate</module></dt>

	<dd>New module in Apache httpd 2.0. This module allows supporting
	browsers to request that content be compressed before delivery,
	saving network bandwidth.</dd>

	<dt><module outdated="true">mod_auth_ldap</module></dt>

	<dd>New module in Apache httpd 2.0.41. This module allows an LDAP
	database to be used to store credentials for HTTP Basic
	Authentication. A companion module, <module>mod_ldap</module>
	provides connection pooling and results caching.</dd>

	<dt><module>mod_auth_digest</module></dt>

	<dd>Includes additional support for session caching across
	processes using shared memory.</dd>

	<dt><module>mod_charset_lite</module></dt>

	<dd>New module in Apache httpd 2.0. This experimental module allows
	for character set translation or recoding.</dd>

	<dt><module>mod_file_cache</module></dt>

	<dd>New module in Apache httpd 2.0. This module includes the
	functionality of <code>mod_mmap_static</code> in Apache HTTP
	Server version 1.3, plus adds further caching abilities.</dd>

	<dt><module>mod_headers</module></dt>

	<dd>This module is much more flexible in Apache httpd 2.0. It can now
	modify request headers used by <module>mod_proxy</module>, and
	it can conditionally set response headers.</dd>

	<dt><module>mod_proxy</module></dt>

	<dd>The proxy module has been completely rewritten to take
	advantage of the new filter infrastructure and to implement a
	more reliable, HTTP/1.1 compliant proxy. In addition, new
	<directive module="mod_proxy" type="section">Proxy</directive>
	configuration sections provide more readable (and internally
	faster) control of proxied sites; overloaded <code><Directory
	"proxy:..."></code> configuration are not supported. The module
	is now divided into specific protocol support modules including
	<code>proxy_connect</code>, <code>proxy_ftp</code> and
	<code>proxy_http</code>.</dd>

	<dt><module>mod_negotiation</module></dt>

	<dd>A new <directive module="mod_negotiation"
	>ForceLanguagePriority</directive> directive can be used to assure that
	the client receives a single document in all cases, rather than
	NOT ACCEPTABLE or MULTIPLE CHOICES responses. In addition, the
	negotiation and MultiViews algorithms have been cleaned up to
	provide more consistent results and a new form of type map that
	can include document content is provided.</dd>

	<dt><module>mod_autoindex</module></dt>

	<dd>Autoindex'ed directory listings can now be configured to
	use HTML tables for cleaner formatting, and allow finer-grained
	control of sorting, including version-sorting, and wildcard
	filtering of the directory listing.</dd>

	<dt><module>mod_include</module></dt>

	<dd>New directives allow the default start and end tags for SSI elements
	to be changed and allow for error and time format configuration
	to take place in the main configuration file rather than in the
	SSI document. Results from regular expression parsing and grouping
	(now based on Perl's regular expression syntax) can be retrieved
	using <module>mod_include</module>'s variables <code>$0</code>
	.. <code>$9</code>.</dd>

	<dt><module outdated="true">mod_auth_dbm</module></dt>

	<dd>Now supports multiple types of DBM-like databases using the
	<directive>AuthDBMType</directive> directive.</dd>

	</dl>
	</section>
	</manualpage>