Chatta subito con l'assistenza
Chat con il supporto

Foglight for Java EE Technologies 5.9.7.5 - Application Servers User Guide

Monitoring Application Servers Monitoring Systems Monitoring Servers Monitoring Applications Monitoring Requests Managing Traces Using Object Tracking to Locate a Memory Leak Monitoring Methods Application Servers Monitor Views
JVM view Method Groups view Request Types view Entity EJBs view Message Driven EJBs view Stateful Session EJBs view Stateless Session EJBs view Deployed Applications view JSPs/Servlets components view Resource Adapters components view Web Applications components view Web Services components view .NET views JBoss Services views Oracle Services views Tomcat Services views WebLogic Services views WebSphere Services views JMX Administration dashboard JMX Explorer dashboard
Appendix: Regular Expressions

Calculating the LiveObjectLifespanLimit value

Foglight for Java EE Technologies provides a suggested lifespan value for the agent to track a live object before marking it as expired. Depending on the complexity of your application along with your JVM heap settings and resulting garbage collection rate, the default value of 900 seconds (15 minutes) may not be appropriate.
An appropriate value for the LiveObjectLifespanLimit property can be derived from your observations of the time between the major garbage collections taking place. If the LiveObjectLifespanLimit is shorter than the time between major garbage collections, the agent may be prematurely marking objects as expired.
If you are able to have object tracking use additional memory, you may want to increase the LiveObjectLifespanLimit value to span the interval between major garbage collections. However, keep in mind that increasing this value does require additional memory within the application server heap.

Enabling Object Tracking

Once you have set the necessary agent properties, you can enable object tracking from the Application Servers Monitor dashboard.
To enable Object Tracking:
1
On the navigation panel, under Dashboards, click Application Servers > Monitor.
2
Click the Servers tile and select a server.
3
In the server details view, click JVM (not the status icon).
Figure 33. The server details view.
4
In the Java Virtual Machine (JVM) view, click the Object Tracking tab.
5
Do one of the following:
•
Click Enable Object Tracking.
Select the length of time (duration) to enable object tracking.
or
•
Select one or more classes from the list, then click Track Per Request Type.
Select Enable.

Examining Object Tracking data

The results of any object tracking requests are listed on the Object Tracking tab of the Java Virtual Machine (JVM) view.
Figure 34. The Object Tracking tab view.
Review the Live and Expired values. Classes with a large Expired value should be considered for investigation.
The Object Tracking tab contains a table that shows class group data for the selected JVM. This table contains the following information:
 
Table 21. Information contained in the class group data table for a selected JVM.
Data Item
Description
Class
Name of the class.
Package
The package of the tracked class.
Is Directly Tracked
This column is checked if the class is directly tracked. Classes that are directly tracked are those specified in the ObjectTrackingClasses property in agent property file. Classes that are not directly tracked are allocated by directly tracked classes, but these classes are only tracked when allocated by a directly tracked class.
Tracking Per Request Type
If checked, classes are tracked on a per request type basis when object tracking is enabled. It is recommended that per request type tracking be done only when actively investigating a specific class. Narrowing down your investigation places less overhead on your JVM.
Health
State of the class health. You can click the icon in the Health column to obtain alarm information.
Objects > Tracked > Trend
Trend of live objects displayed in a spark line.
Objects > Tracked > Live
The number of live objects tracked.
Objects > Tracked > Expired
The number of tracked expired objects.
Objects > Allocated
The number of allocated objects.
Estimated Size (bytes) > Tracked > Trend
Trend of live objects displayed in a spark line.
Estimated Size (bytes) > Tracked > Live
An estimated size of the tracked live objects.
Estimated Size (bytes) > Tracked > Expired
An estimated size of the tracked expired objects.
Estimated Size (bytes) > Allocated
An estimated size of the allocated objects.
Tracked Lifespan(s) > Expired and Collected
The estimate value of Expired and Collected life spans.

Reviewing track per request type data

The Object Tracking tab also offers the option to track by request type. This option is useful when you have identified a suspected memory leak source.
To enable tracking per request type:
1
On the Object Tracking tab of the Java Virtual Machine (JVM) view, select a class in the Object Tracking table.
2
Click Track Per Request Type.
3
Click Enable.
4
Wait for the data to collect.
5
Click the name of the class (in the Class column) to review a list of request types that allocate the object of the class.
From the Object Tracking Class view, you can review the metrics to identify a list of request types potentially causing the memory leak. Then you can collect single traces for that request type to find out where the memory has been allocated.
Related Documents

The document was helpful.

Seleziona valutazione

I easily found the information I needed.

Seleziona valutazione