When the BIG-IP® system caches responses from the origin web server, it uses certain HTTP request parameters to create a Unique Content Identifier (UCI). The BIG-IP system stores the UCI in the form of a compiled response, and uses the UCI to easily match future requests to the correct content in the module's cache.
You can configure variation rules to add or modify the parameters on which the BIG-IP system bases its caching process. If the BIG-IP system receives two requests that are identical except for the value of a query parameter defined in the variation rule, it creates a different UCI for each, and caches each response under its unique UCI.
Consider a site that receives requests from customers and partners, and wants to serve different content to each. For this site, you could create a variation rule in which you specify that when a request contains a version cookie set to a value of 1, the BIG-IP system serves a page specifically for customers, and when the version cookie is set to a value of 2, it serves a page specifically for partners. For this rule, the BIG-IP system caches the following three compiled responses.
This example shows a variation rule for a user-defined acceleration policy. For this example site, you have three top-level nodes on the Policy Tree.
This site also has the following two considerations.
For this example, you create the following two variation rules.