Citrix Systems 9.2 How Features Use Actions After Policy Evaluation, Binding a Policy Globally

22Citrix NetScaler Policy Configuration and Reference Guide

•A policy evaluates to TRUE and its Goto statement value is END. No further policies or policy banks in this feature are evaluated.

•An external policy bank is invoked, its evaluation returns an END, and the Goto statement uses a value of USE_INVOCATION_RESULT or END.

Evaluation continues with the next policy bank for this feature. For example, if the current bank is the request-time override bank, the NetScaler next evaluates request-time policy banks for the virtual servers.

•The NetScaler has walked through all the policy banks in this feature, but has not encountered an END.

If this is the last entry to be evaluated in this policy bank, the NetScaler proceeds to the next feature.

How Features Use Actions After Policy Evaluation

After evaluating all relevant policies for a particular data point (for example, an HTTP request), the NetScaler stores all the actions that are associated with any policy that matched the data.

For most features, all the actions from matching policies are applied to a traffic packet as it leaves the NetScaler. The Integrated Caching feature only applies one action: CACHE or NOCACHE. This action is associated with the policy with the lowest priority value in the “highest priority” policy bank (for example, request-time override policies are applied before virtual server-specific policies).

Binding a Policy Globally

The following binding procedures are typical. However, refer to the documentation for the feature of interest to you for complete instructions.

To bind an Integrated Caching advanced policy globally by using the

NetScaler command line

At the NetScaler command prompt, type:

bind cache global <policyName> -priority <positiveInteger> [-type

REQ_OVERRIDE REQ_DEFAULT RES_OVERRIDE RES_DEFAULT]

Example

bind cache global myCachePolicy -priority 100 -type req_default

The type argument is optional to maintain backward compatibility. If you omit the type, the policy is bound to REQ_DEFAULT or RES_DEFAULT, depending on whether the policy rule is a response-time or a request-time expression.