Rewrite Policy Test

Rewrite refers to the rewriting of some information in the requests or responses handled by the Citrix ADC appliance. Rewriting can help in providing access to the requested content without exposing unnecessary details about the Web site’s actual configuration.

To rewrite the HTTP or TCP requests or responses, you need to enable the rewrite feature on the Citrix ADC appliance.

After enabling the rewrite feature, you need to configure one or more actions unless a built-in rewrite action is sufficient.

After you create any needed rewrite action(s), you must create at least one rewrite policy to select the requests that you want the Citrix ADC appliance to rewrite. A rewrite policy consists of a rule, which itself consists of one or more expressions, and an associated action that is performed if a request or response matches the rule.

When a request or response matches a policy, administrators need to be notified. This way, they can figure out how effective or not a policy is. Most importantly, administrators will want to know if a policy evaluation results in an undefined event. This is a cue to the administrators to scrutinize the policy configuration for errors. Using the Rewrite Policy test, administrators can achieve both!

This test auto-discovers rewrite policies and notifies administrators if there are requests/responses matching any of these policies. Likewise, the test also reports if the evaluation of any policy results in UNDEF events. This way, the test turns the spotlight on improperly configured policies, thus enabling administrators to amend such policies for optimum results.

Target of the test : A Citrix ADC VPX/MPX

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each rewrite policy configured on the Citrix ADC VPX/MPX appliance being monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.


The IP address of the host for which the test is being configured.

NetScaler Username, NetScaler Password, and Confirm Password

To monitor a ADC device, the eG agent should be configured with the credentials of a user with read-only privileges to the target ADC device. Specify the credentials of such a user in the NetScaler Username and NetScaler Password text boxes. Then, confirm the password by retyping it in the Confirm Password text box.


The eG agent collects performance metrics by invoking NITRO (ADC Interface Through Restful interfaces and Objects) APIs on the target ADC device. Typically, the NITRO APIs can be invoked through the HTTP or the HTTPS mode. By default, the eG agent invokes the NITRO APIs using the HTTPS mode. This is why, the SSL flag is set to Yes by default. If the target ADC device is not SSL-enabled, then the NITRO APIs can be accessed through the HTTP mode only. In this case, set the SSL flag to No.

Measurements made by the test
Measurement Description Measurement Unit Interpretation


Indicates the number of requests/responses that matched this policy during the last measurement period.


Compare the value of this measure across polices to know which policy is invoked the most and which is not. Scrutinizing the least-used policies may throw some light on inconsistencies (if any) in their configuration.

Undefined policy hits

Indicates the number of times this policy's evaluation resulted in an UNDEF event, during the last measurement period.


An UNDEF event indicates an internal error condition. This is why, the value 0 is typically desired for this measure.