Communicator e3000 MPE/iX Release 7.0 Express 1 (Software Release C.70.01) (30216-90328)

54 Chapter3

New Networking

Apache 1.3.14 for MPE/iX

DSOs created without -DEAPI may work but may generate an error message in the

error_log ﬁle.

Additional Modules

The Apache 1.3.14 for MPE/iX contains the same static modules that are part of Apache

1.3.9 for MPE/iX. To view the complete set of modules, execute the Apache binary with the

"-l" option:

shell/iX>/APACHE/PUB/HTTPD -l

The following modules were introduced in Apache 1.3.9 and are also included in Apache

1.3.14:

• mod_proxy, for using the HP e3000 as a proxy server

• mod_rewrite, for large-scale translation of URLs to a new address

• mod_digest, a new browser authentication scheme (future browser feature)

• mod_vhost_alias, for easy management of large numbers of virtual servers with similar

conﬁgurations

• mod_so, makes DSOs loadable

mod_proxy - With this module, Apache can act as a proxy server, or intermediary, when

clients make web server requests. Instead of a client making a direct request to a web

server, the client makes a request to the proxy server. The proxy server then makes the

actual request to the web server. The web server responds to the proxy server who then

forwards the response back to the original client.

The proxy server can also cache documents and resources that pass through the proxy

interface. If the proxy server has a copy of a requested document, it can return the copy

immediately without contacting the web server.

mod_rewrite - Mod_rewrite is a very powerful module for translating requested URLs to

new addresses on the ﬂy. The URL manipulations can depend on various tests, such as

server variables, environment variables, HTTP headers and time stamps. New translation

rules can be added to existing ones. Because of this module's functionality and ﬂexibility,

it is complex to use. Extensive documentation on mod_rewrite is available from the

Apache Software Foundation web site, http://www.apache.org.

mod_digest - This module provides a method of authentication, called Digest

Authentication. Although Digest Authentication is not currently used by web browsers on

the market, it is available to use whenever web browsers adopt this type of authentication.

Web browsers currently use Basic Authentication, a less secure authentication scheme.

mod_vhost_alias - Mod_vhost_alias simpliﬁes the use of large numbers of virtual hosts by

replacing static virtual host conﬁgurations (<VirtualHost>) with dynamic conﬁguration.

With this feature, adding more virtual hosts does not require reconﬁguring or restarting

Apache. Apache startup is also faster and uses less memory because the httpd.conf ﬁle is

smaller.

mod_so - This module implements the Dynamic Shared Object (DSO) mechanism for

loading executable code and modules into Apache at Apache start-up time.