1. A computer implemented method in a data processing system for identifying a memory leak in a heap, wherein the heap comprises a plurality of objects, the computer implemented method comprising: responsive to a processor completing a mark-sweep-compact operation in the heap, clearing an indicator associated with each object in the plurality of objects, wherein the indicator is located in a bit in a header of the each object; initiating a marking operation at a beginning of a user-defined observation period; responsive to an allocation of memory to a new object during the user-defined observation period, marking, by the marking operation, the indicator associated with the new object when the new object is allocated; adding the new object to the heap; responsive to an expiration of the user-defined observation period, identifying objects in the heap having a marked indicator, wherein the identified objects are sources of memory leaks; displaying a graphical representation of the identified objects; and removing the identified objects from the heap.