XM JVM Threads Test

This test reports the status of threads running in the XenMobile JVM. Using this test, you can figure out the resource hungry threads and also the threads that are sparsely utilized.

Target of the test : A Citrix XenMobile

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the target XenMobile server that is being monitored

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.

Port

The port at which the specified host listens. By default, this is 4443.

Username and Password

Specify the credentials of a XenMobile user with Administrator privileges.

Confirm Password

Confirm the password by retyping it here.

SSL

Indicate whether/not the XenMobile server is SSL-enabled. By default, this flag is set to Yes.

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

Is Contention monitoring enabled?

Indicates whether/not contention monitoring is enabled.

 

Some Java virtual machines may support thread contention monitoring. When thread contention monitoring is enabled, the accumulated elapsed time that the thread has blocked for synchronization or waited for notification will be collected and returned in the ThreadInfo object.

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

Measure Value Numeric Value
Yes 1
No 0

Note:

By default, this measure reports the Measure Values discussed in the table above. However, the graph of this measure is indicated using the numeric equivalents only.

Is CPU time enabled?

Indicates whether/not the CPU time measuring is enabled.

 

A Java virtual machine implementation may support measuring the CPU time for the current thread, for any thread, or for no threads.

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

Measure Value Numeric Value
Yes 1
No 0

Note:

By default, this measure reports the Measure Values discussed in the table above. However, the graph of this measure is indicated using the numeric equivalents only.

Peak threads

Indicates the highest number of live threads since XenMobile JVM started.

Number

 

Total started threads

Indicates the total number of threads started (including daemon, non-daemon, and terminated) during the last measurement period.

Number

 

Threads

Indicates the total number of threads (including daemon and non-daemon threads).

Number

 

Daemon threads

Indicates the current number of live daemon threads.

Number

 

Waiting threads

Indicates the number of threads that are currently in a waiting state.

Number

A thread is said to be in a Waiting state if the thread enters a synchronized block, tries to take a lock that is already held by another thread, and hence, waits till the other thread notifies that it has released the lock.

Ideally, the value of this measure should be low. A very high value could be indicative of excessive waiting activity on the JVM. You can use the detailed diagnosis of this measure, if enabled, to figure out which threads are currently in the waiting state.

While waiting, the Java application program does no productive work and its ability to complete the task-at-hand is degraded. A certain amount of waiting may be acceptable for Java application programs. However, when the amount of time spent waiting becomes excessive or if the number of times that waits occur exceeds a reasonable amount, the Java application program may not be programmed correctly to take advantage of the available resources. When this happens, the delay caused by the waiting Java application programs elongates the response time experienced by an end user. An enterprise may use Java application programs to perform various functions. Delays based on abnormal degradation consume employee time and may be costly to corporations.

Runnable threads

Indicates the current number of threads in a runnable state.

Number

The detailed diagnosis of this measure, if enabled, provides the name of the threads, the CPU usage by the threads, the time for which the thread was in a blocked state, waiting state, etc.

Blocked threads

Indicates the number of threads that are currently in a blocked state.

Number

If a thread is trying to take a lock (to enter a synchronized block), but the lock is already held by another thread, then such a thread is called a blocked thread.

The detailed diagnosis of this measure, if enabled, provides in-depth information related to the blocked threads.

Timed waiting threads

Indicates the number of threads in a TIMED_WAITING state.

Number

When a thread is in the TIMED_WAITING state, it implies that the thread is waiting for another thread to do something, but will give up after a specified time out period.

To view the details of threads in the TIMED_WAITING state, use the detailed diagnosis of this measure, if enabled.