Figure 8-10 Monitoring Metric: Current Live Heap ObjectsTable 8-1 Data Shown in Current Live Heap Objects Visualizer

Column Heading

Description

Class

Name of class to which object belongs

% Heap Used

Percent of allocated heap used

Bytes

Cumulative size occupied by the object (in bytes)

+/- First Bytes

The total change in the amount of bytes held for this class since the first snapshot

 

was taken.

+/- Last Bytes

The change in the amount of bytes held for this class since the last snapshot was

 

taken (most recent increment).

Count

Number of current live instances of the object class

+/- First Count

The total change in the number of objects held for this class since the first snapshot

 

was taken.

+/- Last Count

The change in the number of objects held for this class since the last snapshot was

 

taken (most recent increment).

 

 

Details

When the heap is large with many objects, refreshing the snapshot will affect system performance more than refreshing from a smaller heap with fewer objects.

Sort by any of the data types by clicking the column heading in the Current Live Heap Objects table. Continue clicking on the same column heading to toggle the sort between ascending and descending order for numerical columns and by alphabetical order for columns containing text.

You can copy all or part of the data displayed into a temporary buffer, then paste or append it into a spreadsheet or other similar software using a keyboard shortcut.

To select a portion of the data, click and drag the cursor across the desired rows and columns of data. The selected rows change color. Then click Copy Selection to Buffer in the tool bar to capture the data.

130 Using Visualizer Functions