Shows the maximum heap size and the amount of used and free space in it. This view can be displayed as a line graph or area graph.
When you profile a Java 1.5+ JVM, the drop down list at the top offers all available memory pools. Please see the article on tuning garbage collection for more information on heap memory pools. In addition, there are several memory pools for non-heap data structures. The drop down list shows all available memory pools in a tree-like structure, so you can display the sum of all heap pools (the default selection) or the sum of all non-heap pools in the graph.
When a view is shown as an area graph, the line which shows the total value is given by the upper bound of the filled area while the single contributions are shown as stacked area segments.
In this mode, the time scale on the time axis does not change with time and the time axis can be scrolled with the scrollbar on the bottom which appears if the total time span does not fit into the current view size. If the current time is visible, the view is in auto-follow mode where the time axis is scrolled automatically when new data arrives to always show the current time. If you are not in auto-follow mode, because you scrolled back in time, just move the scrollbar to the right end of the time scale to re-enable auto-following.
You can adjust the scale of the time axis by zooming in or out.
Zooming in increases
the level of detail while
zooming out decreases
it. You change the zoom level by
The time scale on the time axis is adjusted continuously in order to show the total time span in the current size of the view. Zooming is not possible in this mode.