SDX CPU Summary Test

Typically, when creating VPX instances on a Citrix ADC SDX appliance, you can allocate CPU cores to each instance depending on their processing requirements. While a single core is usually set aside for the use of the Management Service on the SDX appliance, the rest are available for allocation to the VPX instances.

If one/more instances engage in CPU-intensive operations, it can result in a severe contention for CPU resources on the appliance. This in turn can degrade the performance of the VPX instances and the SDX appliance as a whole. To avoid this, SDX administrators should continuously track the overall CPU usage of the SDX appliance and capture a potential CPU contention before it aggravates and adversely impacts performance. The SDX CPU Summary test helps administrators with this!

This test reports the number of CPU cores the SDX appliance supports and the average CPU usage of the appliance across all the cores. In the process, the test warns administrators of a probable CPU contention on the appliance and prompts speedy action, so that performance does not suffer.

Target of the test : Citrix ADC SDX

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the target ADC SDX.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.


The host for which the test is to be configured.

SDX Username and SDX Password

To monitor a ADC SDX device, the eG agent should be configured with the credentials of a user with read-only privileges to the target device. Specify the credentials of such a user in the SDX Username and SDX Password text boxes.

Confirm Password

Confirm the password by retyping it here.


The eG agent collects performance metrics by invoking NITRO (ADC Interface Through Restful interfaces and Objects) APIs on the target ADC SDX 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 SDX 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

CPU utilization

Indicates the percent CPU usage of the SDX appliance.


A value close to 100% is a cause of concern, as it could indicate excessive CPU usage by one/more VPX instances on the target SDX appliance. If this condition is left unchecked, it can cause the overall performance of the SDX to significantly deteriorate and badly impact user-experience with the appliance.

Under such circumstances, it might be good practice to compare the value of the CPU usage measure of the SDX VPX Instances test across all VPX instances operating on the target appliance. This will point you to the VPX instances that are CPU-hungry and are contributing to the CPU contention. To prevent the contention, you can decide to either allocate more cores to the CPU-starved instances or change the CPU allocation mode of the instance - i.e., from shared to dedicated or vice-versa.

CPU cores

Indicates the total number of CPU cores the SDX appliance supports.