SDX VPX Instances Test

NetScaler SDX supports multiple NetScaler instances on a single hardware appliance. An administrator can effectively partition the physical box into as many as 16 virtual instances. This helps enterprises running specific virtual versions of the SDX with different settings, configurations and software versions tuned to work with specific services within an enterprise.

If any of these virtual NetScaler instances is rendered unavailable, then users may be denied access to the critical services associated with that instance. Moreover, if an instance is poorly sized with CPU, memory, and network resources, or is utilizing resources excessively, the performance of that instance and the other instances supported by that SDX will naturally deteriorate for want of adequate resources. This is why, the availability, resource configuration, and resource usage of each virtual NetScaler instance should be monitored and administrators proactively notified of any inaccessibility or resource contention on any instance. This is what the SDX VPX instances test does! 

This test auto-discovers the VPX instances that the target NetScaler SDX appliance supports and reports the availability of each instance. If the test alerts to an instance unavailability, you can use this test to once again verify why that instance is inaccessible - is it because the instance is down or the VM hosting that instance is halted? The test also monitors the resource configuration of each instance and the percent resource consumption of every instance; in the process, the test points you to resource-hungry instances, and thus The uptime of each instance is also reported, so that administrators can promptly detect unscheduled instance reboots and unplanned instance downtime.

Target of the test : A NetScaler SDX

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each VPX instance 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.

Report Manager Time

By default, this flag is set to Yes, indicating that, by default, the detailed diagnosis of this test, if enabled, will report the shutdown and reboot times of the VPX instances in the manager’s time zone. If this flag is set to No, then the shutdown and reboot times are shown in the time zone of the system where the remote agent is running.

DD Frequency

Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD Frequency.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise 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

Virtual machine state

Indicates the current state of the VM hosting this VPX instance.

 

The values that this measure can report and their corresponding numeric values have been listed in the table below:

Numeric Value Measure Value
100 Running
0 Halted

Note:

By default, this measure reports the above-mentioned Measure Values to indicate the current state of a VM. However, in the graph of this measure, the Measure Values will be represented using their corresponding numeric equivalents only.

Instance state

Indicates the current state of this VPX instance.

 

The values that this measure can report and their corresponding numeric values have been listed in the table below:

Numeric Value Measure Value
100 Up
0 Down

When a user complains that a NetScaler VPX instance is inaccessible, then check the value of this measure for that instance to determine whether/not that instance is up and running. If it is, then check the value of the Virtual machine state measure for the same instance to determine whether the Virtual machine is running or halted.

Note:

By default, this measure reports the above-mentioned Measure Values to indicate the current state of a VPX instance. However, in the graph of this measure, the Measure Values will be represented using their corresponding numeric equivalents only.

CPU usage

Indicates the percentage of allocated CPU used by this VPX instance.

Percent

A value close to 100% is indicative of excessive CPU usage by the VPX instance.

Compare the value of this measure across instances to know which instance is over-utilizing CPU. You may want to consider increasing the CPU allocation to that instance.

Total memory

Indicates the total memory of this VPX instance.

MB

 

Memory usage

Indicates the percentage of memory used by this instance.

MB

A value close to 100% is indicative of excessive memory usage by the VPX instance.

Compare the value of this measure across instances to know which instance is over-utilizing memory. You may want to consider increasing the memory allocation to that instance.

Input throughput

Indicates the bandwidth consumed by incoming traffic to this VPX instance.

Mbps

 

Output throughput

Indicates the bandwidth consumed by outgoing traffic from this VPX instance.

Mbps

 

Total throughput

Indicates the total bandwidth consumption of this instance.

Mbps

Total throughput is the sum of the Input throughput and Output throughput measures of the VPX instance. If this value increases consistently, it is indicative of excessive bandwidth consumption by the instance.

You may want to periodically compare the value of Total throughput (i.e., actual throughput) with the value of the Assign throughtput (i.e., allocated throughput measure of an instance. This will reveal if bandwidth sizing for that instance has been done on the basis of its real-time bandwidth consumption. Based on these observations, you can choose to reconfigure the bandwidth allocation to the instance. For example, you may have set the throughput allocation mode as fixed for an instance, and may have hard-allocated throughput resources to that instance. Later however, by tracking changes to the value of the Total throughput measure, you may discover that the hard limit is often violated, causing the SDX appliance to drop traffic. In such a case, you may want to consider changing the allocation mode to burstable. When using the burstable option, options are available to allow over commitment of throughput above the set throughput value that is required.

Assign throughput

Indicates the throughput assigned/allocated to this instance.

Mbps

HTTP request

Indicates the rate at which this instance receives HTTP requests.

Requests/Sec

 

HA master state

Indicates whether this instance is the primary or secondary instance in an HA setup.

 

The values that this measure can report and their corresponding numeric values are listed in the table below:

Numeric Value Measure Value
100 Primary
0 Secondary

Note:

By default, this measure reports the above-mentioned Measure Values to indicate the master state of the instance. However, in the graph of this measure, the Measure Values will be represented using their corresponding numeric equivalents only.

Is HA synchronization enabled?

Indicates whether/not HA synchronization is enabled on this instance.

 

The values that this measure can report and their corresponding numeric values are listed in the table below:

Numeric Value Measure Value
1 Yes
0 No

Note:

By default, this measure reports the above-mentioned Measure Values to indicate the HA sync status of an instance. However, in the graph of this measure, the Measure Values will be represented using their corresponding numeric equivalents only.

Is L2 mode enabled?

Indicates whether/not L2 mode is allowed on this instance.

 

In Layer 2 (L2) mode, a NetScaler instance acts as a learning bridge and forwards all packets for which it is not the destination. Some features, such as Cloud Bridge, require that L2 mode be enabled on the NetScaler instance. With L2 mode enabled, the instance can receive and forward packets for MAC addresses other than its own MAC address. However, if a user wants to enable L2 mode on a NetScaler instance running on an SDX appliance, the administrator must first allow L2 mode on that instance.

If the L2 mode is allowed on an instance, then this measure will report the value Yes. If the L2 mode is not allowed, then this measure will report the value No for that instance.

The numeric values that correspond to the measure values are as follows:

Numeric Value Measure Value
1 Yes
0 No

Note:

By default, this measure reports the above-mentioned Measure Values to indicate the L2 mode status. However, in the graph of this measure, the Measure Values will be represented using their corresponding numeric equivalents only.

Assigned packets

Indicates the rate at which this instance can receive packets.

Packets/Sec

 

Number of SSL cores up

Indicates the number of SSL cores that are currently up and running.

Number

The term ‘SSL Core’ is used to represent an assignment in hardware of a number of Cavium cores. The SDX appliance uses these Cavium cores to accelerate SSL traffic in hardware.

Number of SSL cores

Indicates the total number of SSL cores assigned to this instance.

Number

Instances cannot share SSL cores. Any SSL cores that are allocated at the time of provisioning an instance are dedicated to that instance.

Memory and SSL Cores are interlinked, so when assigning each SSL core it will be necessary to assign 1Gb of memory per core.

Has the VPX instance device been rebooted?

Indicates whether/not this instance was rebooted during the last measurement period.

 

The values that this measure can report and their corresponding numeric values are listed in the table below:

Numeric Value Measure Value
1 Yes
0 No

Note:

By default, this measure reports the above-mentioned Measure Values to indicate the reboot status of an instance. However, in the graph of this measure, the Measure Values will be represented using their corresponding numeric equivalents only.

Uptime of the VPX instance during the last measure period

Indicates the time period for which this instance was up since the last time this test ran.

Secs

If the instance has not been rebooted during the last measurement period and the agent has been running continuously, this value will be equal to the measurement period. If the instance was rebooted during the last measurement period, this value will be less than the measurement period of the test. For example, if the measurement period is 300 secs, and if the instance was rebooted 120 secs back, this metric will report a value of 120 seconds.  The accuracy of this metric is dependent on the measurement period - the smaller the measurement period, greater the accuracy.

Total uptime of the VPX instance

Indicates the total time for which this instance was up since its last reboot.

 

This measure displays the number of years, months, days, hours, minutes and seconds since the last reboot. Administrators may wish to be alerted if an instance has been running without a reboot for a very long period. Setting a threshold for this metric allows administrators to determine such conditions.