Chapter 14. Apache HTTP Server

203

#

Deny from all

#

Allow from .your_domain.com

# /Location

Again, you must fill in

.your_domain.com

.

14.5.66.

ProxyRequests

If you uncomment the

IfModule

tags surrounding the

ProxyRequests

directives, your Apache

HTTP Server will also function as a proxy server. You will also need to load the

mod_proxy

module.

For instructions on how to load in modules, see Section 14.7.

14.5.67.

ProxyVia

The

ProxyVia

command controls whether or not an HTTP Via: header line is sent along with requests

or replies which go through the Apache proxy server. The Via: header will show the hostname if

ProxyVia

is set to

On

, the hostname and the Apache HTTP Server version for

Full

, any Via: lines

will be passed along unchanged for

Off

, and Via: lines will be removed for

Block

.

14.5.68. Cache Directives

A number of cache directives are commented out in the proxy

IfModule

tags mentioned above. If

you are using the proxy server functionality and you want to also enable the proxy cache, you should

uncomment the cache directives as described. The default settings for your cache directives should be

appropriate for most configurations.

CacheRoot

sets the name of the directory which will contain cached files. The default

CacheRoot

is

/var/cache/httpd

.

CacheSize

sets how much space the cache can use, in KB. The default

CacheSize

is

5

KB.

CacheGcInterval

sets a number of hours. After that number of hours, files in the cache will be

deleted if the cache is using more space than allowed by

CacheSize

. The default for

CacheGcIn 

terval

is four hours.

Cached HTML documents will be retained (without a reload from the originating Web server) in the

cache for a maximum number of hours set by

CacheMaxExpire

. The default is

24

hours.

The

CacheLastModifiedFactor

affects the creation of an expiry (expiration) date for a document

which did not come from its originating server with its own expiry set. The default

CacheLastMod 

ifiedFactor

is set to

0.1

, meaning that the expiry date for such documents equals one tenth of the

amount of time since the document was last modified.

CacheDefaultExpire

is the expiry time in hours for a document that was received using a protocol

that does not support expiry times. The default is set to one hour.

Any document that is retrieved from a host or domain that matches one set in

NoCache

will not be

cached. If you know of hosts or domains from which you do not want to cache documents, uncomment

NoCache

and set their domains or hostnames here.

14.5.69.

NameVirtualHost

You will need to use the

NameVirtualHost

directive for the IP address and port number, if necessary,

of any name based virtual hosts you are setting up. The name based virtual hosts configuration is used

when you want to set up different virtual hosts for different domains, but you do not have or do not

want to use different IP addresses for all of the different domain names for which your Web server

serves documents.