Traffic Ops - Migrating from 2.0 to 2.2

Apache Traffic Server 7.x (Cachekey Plugin)

In Traffic Ops 2.2 we have added support for Apache Traffic Server 7.x. With 7.x comes support for the new cachekey plugin which replaces the cacheurl plugin which is now deprecated. While not needed immediately it is recommended to start replacing cacheurl usages with cachekey as soon as possible because ATS 6.x already supports the new cachekey plugin.

It is also recommended to thoroughly vet your cachekey replacement by comparing with an existing key value. There are inconsistencies in the 6.x version of cachekey which have been fixed in 7.x (or require this patch(cachekeypatch) on 6.x to match 7.x). So to ensure you have a matching key value you should use the xdebug plugin before fully implementing your cachekey replacement.

First if you are currently using a regex for your delivery service you will have to remove that existing value. Then you will need to make a new DS profile and assign parameters in it to the cachekey.config file.

Some common parameters are

static-prefix      - This is used for a simple domain replacement
separator          - Used by cachekey and in general is always a single space
remove-path        - Removes path information from the URL
remove-all-params  - Removes parameters from the URL
capture-prefix-uri - This is usually used in combination with remove-path and remove-all-params.
                     Capture-prefix-uri will let you use your own full regex value for non simple cases

Examples of Cacheurl to Cachekey Replacements

Original regex value:

http://test.net/(.*) http://test-cdn.net/$1

Cachekey parameters:

Parameter	File	Value
static-prefix	cachekey.config	http://test-cdn.net/
separator	cachekey.config	(empty space)

Original regex value:

http://([^?]+)(?:?|$) http://test-cdn.net/$1

Cachekey parameters:

Parameter	File	Value
remove-path	cachekey.config	true
remove-all-params	cachekey.config	true
separator	cachekey.config	(empty space)
capture-prefix-uri	cachekey.config	/https?:\/\/([^?]*)/http:\/\/test-cdn.net\/$1/

Also note the s? used here so that both http and https requests will end up with the same key value

Original regex value:

http://test.net/([^?]+)(?:\?|$) http://test-cdn.net/$1

Cachekey parameters:

Parameter	File	Value
static-prefix	cachekey.config	http://test-cdn.net/
separator	cachekey.config	(empty space)
remove-all-params	cachekey.config	true

Further documentation on the cachekey plugin can be found at ApacheTrafficServerDocs