Timeline Java Heap Report
The Timeline Java Heap Report provides a snapshot of heap memory used by Java objects when the application is running in the Java Virtual Machine (JVM). This information will help you to understand if the application is running in optimal condition and take any necessary actions.
The information in the report is displayed in two sections:
- A line graph displaying the Used Heap denoted by the blue line and Heap Size denoted by the green line.
- A data table with detailed information about each Used Heap.
To access the report
- In the myStrobe window, select a Performance Profile. For more information, see Creating performance profile.
- Click
and select Java >JVM Name-PID from the menu.
- From the list of available Strobe for Java report, select the Timeline Java Heap Report.
The report is generated in the form of a line graph. - Select the Timeline Java Heap Report. This will generate the report in the form of a line graph.
In the line graph:
- Used heap is the actual memory engaged by the object.
- Size in Mb is the memory size in megabyte occupied by an individual threads in a jvm.
- Profile Name is the Performance Profile that you selected while generating this report to measure the application run time.
- Job Name is the name of the job in which the java program is running and for which you requested the measurement session.
- Initiated On is the time stamp when you started the measurement request.
- The y (vertical) Heap size axis represents the maximum heap memory (in megabytes).
- The x (horizontal) axis displays time stamps based on the specified time interval.
- The blue Used heap line represents the highs and lows of the heap memory used by an object in the specified time interval.
- The straight green Heap size line represents the maximum heap memory that the object uses.
You can perform the following actions on the line graph:
- To view the exact heap value at a point, hover over that point.
- To zoom in, click and drag the line at a data point.
- To zoom out, double-click the line.
- To create and save notes on the observations you make in the report, click
.
Data table
When you select a data point of a specific Used Heap on the graph, the corresponding information gets displayed in the data table.
To view or hide details about a specific thread, click 
and 
.
The data table consists of the following fields:
Field | Description |
|---|---|
Used Heap | Indicates the heap memory in use |
Timestamp | Displays the date and time |
Pool Name | Indicates the name of the memory pool |
Current Used Memory | Indicates the memory size used in the current jvm environment |
Current Free Memory | Indicates the memory size that is free in the current jvm environment |
Current Percentage Used | Indicates the used memory size in percentage |
Pre GC Used Memory | Displays the memory size in use before the garbage collection is run |
Post GC Used Memory | Displays the memory size in use after the garbage collection empties the memory space |