SDX CPU Core Usage Test

The SDX CPU Summary test alerts administrators to abnormal CPU usage on an SDX appliance, which can typically be caused by one/more CPU cores being utilized excessively. The question now is, which CPU cores are contributing to the CPU contention. The SDX CPU Core Usage test answers this question by reporting the average CPU usage of each CPU core of an SDX appliance.

Target of the test : A NetScaler SDX

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each CPU core of the target NetScaler SDX.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The host for which the test is to be configured.

SDX Username and SDX Password

To monitor a NetScaler 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 passwordby retyping it here.

SSL

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

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Average CPU core usage

Indicates the percent CPU usage of this CPU core.

Percent

A value close to 100% is a cause of concern, as it could indicate excessive usage of a core 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.

Use the detailed diagnosis of this measure to know which instances are utilizing the core. Then, check the value of the CPU usage measure (reported by the SDX VPX Instances test) for each of those instances to know which instance is hogging the CPU resources.

The detailed diagnosis of the Avg CPU core usage measure reveals the core number, the physical CPU resources mapped to each core, and the instances that are utilizing the core. If a core is over-utilized, then this information will point you to the instances that could be contributing to the excessive usage.

Figure 1 : The detailed diagnosis of the Avg CPU core usage measure