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")~