Citrix Systems 9.2 manual Chapter

Chapter 3 Configuring Advanced Expressions: Getting Started 61

5.Configure the expression as described in “To configure an advanced policy expression by using the configuration utility,” on page 58.

Configuring Advanced Expressions Outside the Context of a Policy

A number of functions, including the following, can require an advanced expression that is not part of a policy:

•Integrated Caching selectors. You define multiple non-compound expressions (selectlets) in the definition of the selector. Each selectlet is in an implicit logical AND relationship with the others.

•Load Balancing. You configure an expression for the TOKEN method of load balancing for a load balancing virtual server.

•Rewrite actions. Expressions define the location of the rewrite action and the type of rewriting to be performed, depending on the type of rewrite action that you are configuring. For example, a DELETE action only uses a target expression. A REPLACE action uses a target expression and an expression to configure the replacement text.

•Rate-based policies: You use advanced expressions to configure Limit Selectors. You can use these selectors when configuring policies to throttle the rate of traffic to various servers. You define up to five non-compound expressions (selectlets) in the definition of the selector. Each selectlet is in an implicit logical AND with the others.

To configure an advanced expression outside a policy by using the

NetScaler command line (cache selector example)

From the NetScaler command line, enter the command for configuring the object that requires an advanced expression. Following is an example of configuring a cache selector. Note that line breaks in the following example are for readability. Do not insert line breaks in the command:

add cache selector mainpage_selector "http.req.cookie.value(\"ABC_def\")" "http.req.url.query.value(\"_ghi\")" http.req.url.path "http.req.body(150).typecast_nvlist_t(\'=\',\'&\').value(\"por tlet_C{actionForm.endDate}\")" "http.req.body(150).typecast_nvlist_t(\'=\',\'&\').value(\"por tlet_C{actionForm.startDate}\")"

Following is an equivalent command that uses the more readable q delimiter, as described in “Configuring Advanced Expressions in a Policy,” on page 57:

add cache selector mainpage_selector q~http.req.cookie.value("ABC_def")~