Accessing JVM Diagnostics

JVM Diagnostics (JVMD) is a diagnostic tool that allows you to view the details of an executing Java Virtual Machine (JVM) process. You can see stack frames for executing threads, thread state information, aggregate information about the frequency and cost of method execution, information regarding the holding of Java and DB locks, and details about the objects in the Java heap. JVMD also stores historical data for each JVM it monitors so you can view data relating to things that have happened in the past and get a sense for historical trends.

Using JVMD to access additional information can be useful in situations like the following:

  • You are viewing summary information for a transaction and see that a particular operation is unusually slow or faulty. You want to get more information about the execution of that step, and you initiate a drill through to JVMD from this point.

  • You are viewing the details of a logged transaction instance and you notice that one of the steps in the transaction did not behave as expected. You would like more details about the execution of this step from JVMD, and you initiate a drill through to JVMD from this point.

  • You are viewing a collection of logged messages in the message log search tool and you notice a message that appears abnormal or unusual. You would like to get more details of the handling of that message using JVMD, and you initiate a drill through to JVMD from this point.

This section explains how you configure Business Transaction Management to connect to the Enterprise Manager (EM) Console, and how you access the information described above.

Configuring the Connection to the EM Console

The following procedure specifies the information Business Transaction Management needs to be able to invoke the JVMD UI.

  1. Select System Services from the Navigator.

  2. Find and select the AP_Sphere_Service entry.

  3. Select Admin > Edit Setup Data for AP_Sphere_Service.

  4. Click the Edit XML button.

  5. Scroll to the bottom of the XML document and find the emgcURL element.

  6. Edit this XML element so that it contains the base URL for the EM console. For example, if you have an EM console running at https://adc2101158:4473/em, you would enter https://adc2101158:4473, and the edited entry would look like this:

    <pfx6:emgcURL>https://adc2101158:4473</pfx6:emgcURL>.

    Note that the namespace prefix might be other than pfx6; use whatever value appears in the XML text.

  7. Click the Apply button to save changes.

You will have to supply login information for the JVMD console when you access it. Single sign on is not supported.

Initiating Access to the JVMD Console

You can access the JVMD console from the following entry points:

  • Transaction summary graph Right click on an operation and select Drilldown to JVMD from the drop-list. Supply the service ID and the currently chosen time interval.

  • Transaction instance graph Right click on an operation and select Drilldown to JVMD from the drop-list. Supply the service ID and the instance time (start time and end time). When a step is executed repetitively, the first endpoint on which it was executed is selected.

  • Message search log tool Right click on a message row and select Drilldown to JVMD from the drop-list. Supply the endpoint ID and the time of the message (start time and end time).

In each of these cases, a new window is displayed showing the JVMD screen. In the multi-VM case, JVMD shows a VM group target and aggregate information for that group.