7.12.1 Determine whether to use the Explicit Memory Management functionality in the application
Full GC might occur frequently despite tuning the Java heap and following the procedure in 7.11.1 How to estimate the memory size of Explicit heap (Estimating memory size used in J2EE server). In this case, consider using the Explicit Memory Management functionality in the application.
First, identify which object is causing Full GC to occur. If Full GC can be controlled by deploying a specific object in the Explicit heap, then use the Explicit Memory Management 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 Memory Management functionality, use the automatic allocation setup file and Explicit Memory Management functionality API. For details about using the Explicit Memory Management functionality to reduce the frequency of Full GC, see 7. Suppression of Full GC by Using the Explicit Memory Management Functionality in the uCosminexus Application Server Expansion Guide.