Depending on how long your JRA recording is, the Heap Usage chart can be quite cumbersome to view in full mode; therefore, you can refocus the chart. by dragging the handles on the slide bar to the section of the recording that you want to view. Once you have set the side on the slide bar, you can slide that section to the position of the chart that you are interested in studying.
To change focus on the Heap Usage chart
Click and drag the handles on both sides on the GC Events Overview chart (see Figure 6-2).
Figure 6-2 The GC Events overview zoom function
Drag the GC Events overview chart into the desired position for the Heap Usage chart (see Figure 6-3).