Cache-Key Rewrite

This capability requires Rules Engine - Advanced Rules which must be purchased separately. Contact your CDN account manager to activate it.

Category: Caching

Purpose: Rewrites the cache-keyA relative path that uniquely identifies an asset for the purpose of caching. Our edge servers use this relative path when checking for cached content and when caching content. By default, a cache-key will not contain query string parameters. associated with a request.

A cache-key is the relative path that identifies an asset for the purposes of caching. In other words, our servers will check for a cached version of an asset according to the path defined in its cache-key.

Configure this feature by defining both of the following options:

Option Description

Source

Identify requests whose cache-key will be rewritten via a relative path. This relative path, which starts directly after the hostname in the CDN URL, is shown in blue font below.

http://can.0001.transactcdn.com/800001/myorigin/path/file.ext

Verify that the specified pattern does not conflict with the parent match conditions defined for this feature.

Valid syntax varies according to the number of customer origins that you would like to match.

You may only define a customer origin using a literal value (e.g., marketing) or one of the regular expressions patterns defined above. All other regular expression syntax is disallowed when defining a customer origin. This limitation does not apply to the relative path defined after the content access point.

Destination

Identify the new cache-key via a relative path. This relative path, which starts directly after the hostname in the CDN URL, is shown in blue font in the following sample CDN URL.

http://can.0001.transactcdn.com/800001/CustomerOrigin/Path/file.ext

Use HTTP variables to dynamically construct this relative path. However, you may not use response metadata (e.g., %{resp_ResponseHeader}) when defining a cache-key.

Valid syntax varies according to number of origins being matched in the Source option.

Default Behavior: A request's cache-key is determined by the request URI.