Once a memory thrash problem is identified in a particular collection, start the diagnostic session by drilling down into the suspected problematic class.

Select the class name to monitor and click Drill Down at the top of the Object Instance Tracking dashboard or right-click the class name and select the Drill Down option.

After the drill down action is triggered, data collection for object instances is performed every minute. This data collection is considered to be a diagnostic session and the Object Instance Tracking dashboard for that class is updated with this icon , to indicate that a diagnostic session is in progress.

The Object Instance Tracking dashboard indicates possible cases of memory thrash. Prime indicators of memory thrash problems indicated on the Object Instance Tracking dashboard are:

• Current Instance Count: A high number indicates the possible allocation of a large number of temporary objects.
• Shallow Size: Is the approximate memory used by all instances in a class. A large number for shallow size signals potential memory thrash.
• Instance Count Trend: A saw wave is an instant indication of memory thrash.

If you suspect you have a memory thrash problem at this point, then you should verify that this is the case. See To verify memory thrash.