Blue Coat Systems Understanding Blue Coat Proxy Basics: A Guide to Content Policy Language

ProxySG Content Policy Language Guide

cache( )

Controls HTTP and FTP caching behavior. A number of CPL properties affect caching behavior.

•If bypass_cache(yes) is set, then the cache is not accessed and the value of cache( ) is irrelevant.

•If cache(yes) is set, then the force_cache(all) property setting modifies the definition of what is considered a cacheable response.

•The properties cookie_sensitive(yes) and ua_sensitive(yes) have the same effect on caching as cache(no).

Other CPL properties that affect caching behavior are listed in the “See Also” section below. Remember that any conflict between their settings is resolved by CPL’s evaluation logic, which uses the property value that was last set when evaluation ends.

Syntax

cache(yesno)

The default is yes.

where:

•yes—Specifies the default behavior: cache responses from the origin server if they are cacheable.

•no—Do not store the response in the cache, and delete any object that was previously cached for this URL.

Layer and Transaction Notes

•Use only in <Cache> layers.

•Applies to proxy transactions.

Example

;Prevent objects at this URL from being added to the cache. url=http://www.example.com/docs cache(no)

;This example shows use of cache(yes) in an exception to broader no-cache policy. define url.domain condition non_cached_sites

http://example1.com

http://example2.com

end <cache>

condition=non_cached_sites cache(no) <cache>

url.extension=(gif, jpg) cache(yes) ; OK to cache these filetypes regardless.

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