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<title>Upgrading to 2.4 from 2.2</title>

<summary>

<p>In order to assist folks upgrading, we maintain a document

describing information critical to existing Apache HTTP Server users. These

are intended to be brief notes, and you should be able to find

more information in either the <a

href="new_features_2_4.html">New Features</a> document, or in

the <code>src/CHANGES</code> file. Application and module developers

can find a summary of API changes in the <a href="developer/new_api_2_4.html"

>API updates</a> overview.</p>

<p>This document describes changes in server behavior that might

require you to change your configuration or how you use the server

in order to continue using 2.4 as you are currently using 2.2.

To take advantage of new features in 2.4, see the New Features

document.</p>

<p>This document describes only the changes from 2.2 to 2.4. If you

are upgrading from version 2.0, you should also consult the <a

href="http://httpd.apache.org/docs/2.2/upgrading.html">2.0 to 2.2

upgrading document.</a></p>

</summary>

<seealso><a href="new_features_2_4.html">Overview of new features in

Apache HTTP Server 2.4</a></seealso>

<section id="compile-time">

<title>Compile-Time Configuration Changes</title>

<p>The compilation process is very similar to the one used in

version 2.2. Your old <code>configure</code> command line (as

found in <code>build/config.nice</code> in the installed server

directory) can be used in most cases. There are some changes in

the default settings. Some details of changes:</p>

<ul>

<li>These modules have been removed: mod_authn_default,

mod_authz_default, mod_mem_cache. If you were using

mod_mem_cache in 2.2, look at <module>mod_cache_disk</module> in

2.4.</li>

<li>All load balancing implementations have been moved to

individual, self-contained mod_proxy submodules, e.g.

<module>mod_lbmethod_bybusyness</module>. You might need

to build and load any of these that your configuration

uses.</li>

<li>Platform support has been removed for BeOS, TPF, and

even older platforms such as A/UX, Next, and Tandem. These were

believed to be broken anyway.</li>

<li>configure: dynamic modules (DSO) are built by default</li>

<li>configure: the "most" module set gets built by default</li>

</ul>

</section>

<section id="run-time">

<title>Run-Time Configuration Changes</title>

<p>There have been significant changes in authorization configuration,

and other minor configuration changes, that could require changes to your 2.2

configuration files before using them for 2.4.</p>

<section id="authz">

<title>Authorization</title>

<p>Any configuration file that uses authorization will likely

need changes.</p>

<p>You should review the <a href="howto/auth.html">Authentication,

Authorization and Access Control Howto</a>, especially the section

<a href="howto/auth.html#beyond">Beyond just authorization</a>

which explains the new mechanisms for controlling the order in

which the authorization directives are applied.</p>

<section id="access">

<title>Access control</title>

<p>In 2.2, access control based on client hostname, IP address,

and other characteristics of client requests was done using the

directives <directive

module="mod_access_compat">Order</directive>, <directive

module="mod_access_compat">Allow</directive>, <directive

module="mod_access_compat">Deny</directive>, and <directive

module="mod_access_compat">Satisfy</directive>.</p>

<p>In 2.4, such access control is done in the same way as other

authorization checks, using the new module

<module>mod_authz_host</module>. The old access control idioms

should be replaced by the new authentication mechanisms,

although for compatibility with old configurations, the new

module <module>mod_access_compat</module> is provided.</p>

<p>Here are some examples of old and new ways to do the same

access control.</p>

<p>In this example, all requests are denied.</p>

<example>

<title>2.2 configuration:</title>

Order deny,allow<br />

Deny from all

</example>

<example>

<title>2.4 configuration:</title>

Require all denied

</example>

<p>In this example, all requests are allowed.</p>

<example>

<title>2.2 configuration:</title>

Order allow,deny<br />

Allow from all

</example>

<example>

<title>2.4 configuration:</title>

Require all granted

</example>

<p>In the following example, all hosts in the example.org domain

are allowed access; all other hosts are denied access.</p>

<example>

<title>2.2 configuration:</title>

Order Deny,Allow<br />

Deny from all<br />

Allow from example.org

</example>

<example>

<title>2.4 configuration:</title>

Require host example.org

</example>

</section>

</section>

<section id="config">

<title>Other configuration changes</title>

<p>Some other small adjustments may be necessary for particular

configurations as discussed below.</p>

<ul>

<li><directive>MaxRequestsPerChild</directive> has been renamed to

<directive module="mpm_common">MaxConnectionsPerChild</directive>,

which describes more accurately what it does.</li>

<li>The <directive module="core">DefaultType</directive>

directive no longer has any effect, other than to emit a

warning if it's used with any value other than

<code>none</code>. You need to use other configuration

settings to replace it in 2.4.

</li>

<li><directive module="core">EnableSendfile</directive> now

defaults to Off.</li>

<li><module>mod_log_config</module>: <a

href="modules/mod_log_config.html#formats">${cookie}C</a>

matches whole cookie names. Previously any substring would

match.</li>

<li><module>mod_dav_fs</module>: The format of the <directive

module="dav_fs">DavLockDB</directive> file has changed for

systems with inodes. The old <directive

module="dav_fs">DavLockDB</directive> file must be deleted on

upgrade.

</li>

<li><directive module="core">KeepAlive</directive> only

accepts values of <code>On</code> or <code>Off</code>.

Previously, any value other than "Off" or "0" was treated as

"On".</li>

<li>Directives AcceptMutex, LockFile, RewriteLock, SSLMutex,

SSLStaplingMutex, and WatchdogMutexPath have been replaced

with a single <directive module="core">Mutex</directive>

directive. You will need to evaluate any use of these removed

directives in your 2.2 configuration to determine if they can

just be deleted or will need to be replaced using <directive

module="core">Mutex</directive>.</li>

<li><module>mod_cache</module>: <directive

module="cache">CacheIgnoreURLSessionIdentifiers</directive>

now does an exact match against the query string instead of a

partial match. If your configuration was using partial

strings, e.g. using <code>sessionid</code> to match

<code>/someapplication/image.gif;jsessionid=123456789</code>,

then you will need to change to the full string

<code>jsessionid</code>.

</li>

<li><module>mod_ldap</module>: <directive

module="ldap">LDAPTrustedClientCert</directive> is now

consistently a per-directory setting only. If you use this

directive, review your configuration to make sure it is

present in all the necessary directory contexts.</li>

<li><module>mod_filter</module>: <directive

module="filter">FilterProvider</directive> syntax has changed and

now uses a boolean expression to determine if a filter is applied.

</li>

</ul>

</section>

</section>

<section id="misc">

<title>Misc Changes</title>

<ul>

<li><module>mod_auto_index</module>: will now extract titles and

display descriptions for .xhtml files, which were previously

ignored.</li>

<li><module>mod_ssl</module>: The default format of the <code>*_DN</code>

variables has changed. The old format can still be used with the new

<code>LegacyDNStringFormat</code> argument to <directive

module="mod_ssl">SSLOptions</directive>.</li>

<li><program>htpasswd</program> now uses MD5 hash by default on

all platforms.</li>

<li>The <directive module="core">NameVirtualHost</directive>

directive no longer has any effect, other than to emit a

warning. Any address/port combination appearing in multiple

virtual hosts is implicitly treated as a name-based virtual host.

</li>

</ul>

</section>

<section id="third-party">

<title>Third Party Modules</title>

<p>All modules must be recompiled for 2.4 before being loaded.</p>

<p>Many third-party modules designed for version 2.2 will

otherwise work unchanged with the Apache HTTP Server version 2.4.

Some will require changes; see the <a href="developer/new_api_2_4.html">API

update</a> overview.</p>

</section>

<section id="commonproblems">

<title>Common problems when upgrading</title>

<ul><li>Startup errors:

<ul>

<li><code>Invalid command 'User', perhaps misspelled or defined by a module not included in the server configuration</code> - load module <module>mod_unixd</module></li>

<li><code>Invalid command 'Require', perhaps misspelled or defined by a module not included in the server configuration</code>, or

<code>Invalid command 'Order', perhaps misspelled or defined by a module not included in the server configuration</code>

- load module <module>mod_access_compat</module>, or update configuration to 2.4 authorization directives.</li>

<li><code>Ignoring deprecated use of DefaultType in line NN of /path/to/httpd.conf</code> - remove <directive module="core">DefaultType</directive>

and replace with other configuration settings.</li>

</ul></li>

<li>Errors serving requests:

<ul>

<li><code>configuration error: couldn't check user: /path</code> -

load module <module>mod_authn_core</module>.</li>

</ul>

</li>

</ul>

</section>

</manualpage>