SDX Memory Usage Test

The NetScaler SDX appliance provides memory that can be shared across VPX instances provisioned on the appliance.

Since memory is shared, if one/more instances consume memory excessively, the other instances will be forced to contend for limited memory resources. This, naturally, will degrade the performance of those instances and also that of the SDX appliance. If such a memory contention is to be prevented, administrators should track the memory used by the appliance, proactively detect a potential memory contention, and rapidly initiate pre-emptive measures. This is where the SDX Memory Usage test helps!

This test monitors the memory usage of the SDX appliance and promptly alerts administrators if usage exceeds permissible limits. In the process, the test warns administrators of a probable memory contention and urges them to take immediate action.

Target of the test : A NetScaler SDX

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each interface supported by 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 password by 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.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Total memory

Indicates the total memory capacity of the SDX appliance.

GB

 

Free memory

Indicates the amount of memory that is unused.

GB

A high value is desired for this measure.

Used memory

Indicates the amount of memory that is in use.

GB

If the value of this measure is equal to or close to the value of the Total memory measure, it is a cause for concern.

Memory usage

Indicates the percentage of memory that is used.

Percent

If the value of this measure is close to 100%, it indicates that appliance and the instances on it will soon run out of memory resources. Under such circumstances, it is good practice to use the SDX VPX Instances test to identify the memory-hungry VPX instances that are provisioned on the SDX appliance. By generating time-of-day graphs of the memory usage of those instances, you can figure out if those instances have been consuming a lot of memory consistently or sporadically. If the anomaly is consistent, you may want to consider increasing the memory allocation to such instances and decreasing the memory allocation to those that use less memory.