If a full garbage collection occurs frequently even when the procedures described in Java Heap Tuning and 7.10.1 How to estimate the memory size of Explicit heap (Estimating memory size used in J2EE server) are executed, determine the use of explicit management heap functionality in the application.
Firstly, determine the object that causes the occurrence of a full garbage collection. If full garbage collection can be controlled by deploying a specific object in the Explicit heap, then use the explicit management heap functionality.
However, you must know the life-cycle of the object to be deployed in the Explicit heap. Determine the applicability when the timing to create the object and the timing when the object is no longer required is clear in the Java program.
To apply the explicit management heap functionality, use the automatic allocation setup file and explicit management heap functionality API. For details about avoiding a full garbage collection using the Explicit Memory Management functionality, see 8. Preventing the Occurrence of Full Garbage Collection using the Explicit Memory Management functionality in the uCosminexus Application Server Expansion Guide.