Apache HTTP Server Version 2.2

This document refers to the 2.2 version of Apache httpd, which is no longer maintained. The active release is documented here. If you have not already upgraded, please follow this link for more information.
You may follow this link to go to the current version of this document.
In order to assist folks upgrading, we maintain a document
describing information critical to existing Apache users. These
are intended to be brief notes, and you should be able to find
more information in either the New Features document, or in
the src/CHANGES file.
This document describes only the changes from 2.0 to 2.2. If you are upgrading from version 1.3, you should also consult the 1.3 to 2.0 upgrading document.
The compilation process is very similar to the one used in
version 2.0. Your old configure command line (as
found in build/config.nice in the installed server
directory) can be used in some cases. The most significant change
required will be to account for changes in module names, in
particular for the authentication and authorization modules.
Some details of changes:
mod_imagemapmod_auth_basic,
mod_authn_file, mod_authz_user, and
mod_authz_groupfilemod_authz_hostmod_authnz_ldapYour existing version 2.0 config files and startup scripts can
usually be used unchanged in version 2.2. Some small
adjustments may be necessary for particular configurations as
discussed below. In addition, if you dynamically load the
standard modules using the LoadModule directive, then you will
need to account for the module name changes mentioned above.
If you choose to use the new default
configuration file for version 2.2, you will find that it has
been greatly simplified by removing all but the most essential
configuration settings. A set of example configuration settings
for more advanced features is present in the
conf/extra/ directory of the installed server. Default
configuration files are installed in the conf/original
directory.
Some runtime configuration changes that you may notice:
apachectl option
startssl is no longer available. To enable SSL
support, you should edit httpd.conf to include the
relevant mod_ssl directives and then use
apachectl start to start the server. An example
configuration to activate mod_ssl has been
included in conf/extra/httpd-ssl.conf.UseCanonicalName is now
Off. If you did not have this directive in your
config file, you can add UseCanonicalName On to
retain the old behavior.mod_userdir will no longer act
on requests unless a UserDir directive specifying a
directory name is present in the config file. To restore the
old default behavior, place the directive UserDir
public_html in your config file.AuthDigestFile
from mod_auth_digest has been merged with
AuthUserFile
and is now part of mod_authn_file.RewriteRule directives
are evaluated before ProxyPass ones.mod_cache, which was
experimental in Apache 2.0, is now a standard module.mod_disk_cache, which was
experimental in Apache 2.0, is now a standard module.mod_mem_cache, which was
experimental in Apache 2.0, is now a standard module.mod_charset_lite, which was
experimental in Apache 2.0, is now a standard module.mod_dumpio, which was
experimental in Apache 2.0, is now a standard module.Many third-party modules designed for version 2.0 will work unchanged with the Apache HTTP Server version 2.2. But all modules must be recompiled before being loaded.