Memory Statistics view

The Memory Statistics views displays statistics about the application heap. It provides detailed information such as the number of classes loaded, the number of instances that are alive, and the memory size allocated by every class. Memory statistics are available at the package, class, and instance level.

Display

This view is made of a table where the first column presents the list of items. There are three display modes are available based on the three object types:

Statistics displayed for each object type

The data displayed depends what object type is selected. The statistics available for each object are summarized in the table below.

Column heading Package statistics 
Icon for package
Class statistics
Icon for class
Instance statistics
Icon for instance
Total Instances
The total number of instances that had been created of the selected package, class, or method.
Accumulated by package Accumulated by class Count
Live Instances
The number of instances of the selected package, class, or method, where no garbage collection has taken place.
Accumulated by package Accumulated by class Count
Collected
The number of instances of the selected package, class, or method, that were removed during garbage collection.
Accumulated by package Accumulated by class Count
Total Size
The total size (in bytes) of the selected package, class, or method, of all instances that were created for it, including whatever has been removed through garbage collection.
Accumulated by package Accumulated by class Size
Active Size
The summed size of all live instances. 
Accumulated by package Accumulated by class Size

Note: The totals shown in this view represent only the data that has been collected since you started monitoring your process. If you start monitoring your process half way through the execution, you will only see the totals from the point that you started monitoring. As well, in the package mode, only the totals of the collected classes for that package are shown. Classes that you have filtered out will not be included in the totals.

Note: In order for instance level data to be shown for the active size and collected columns in the Memory Statistics view, instance level data must be collected for the Time Analysis profiling type. To collect instance level data, you must perform the following actions on the Profiling Types page for your profiling set:

  1. In the left hand pane, select the check boxes for Memory Analysis > Basic Memory Analysis and Time Analysis > Execution Time Analysis.
  2. Under Execution Time Analysis, select the Show execution flow graphical details radio button, then click the Advanced >> button and choose Collect instance level information.

For information on how to access the Profiling Types page for a profiling set, see the following tutorial: Analyzing the profiling data from a Java process.

Display symbols

Controls

Toolbar controls

Icon Definition
Icon for package Display the package statistics
Icon for class Display the class statistics
Icon for instance Display the instance statistics
Open source icon Open the source of a selected item.
% icon Shows the percentage of memory allocated.
delta Shows the change in each numeric column since the last refresh.
A button with stylized iconFilter objects based on time, size, total instances, or other criteria.
Export HTML icon Export the data to a file in HTML format.
A button with stylized iconA button with stylized icon Select the columns to be displayed, or sort iconSort by column.

Pop-up menu controls

Icon Definition
Refresh Views icon Refresh the view.
Choose column icon Choose the columns to display.
Show object references Show object references.
Open source icon Open the source of a selected item.

Filtering

The statistics views provide filtering based on name.  Use the Filter field to specify a string pattern. 

Column controls

Click the title of a column to sort it. Click the title of the column again to sort it in reverse order. The title of the column is prefixed with > if the column is sorted in ascending order or with < if it is sorted in descending order.

Columns can be hidden or shown. 

 


Related concepts
Overview of the Profiling Tool
Profiling resources

Related tasks
Applying profiling filters
Profiling an application
Identifying memory-intensive classes


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