7. Suppression of Full GC by Using the Explicit Memory Management Functionality
With Application Server, you can use a memory space other than the Java heap as the Java object placement destination when executing a Java application. The function is called the Explicit Memory Management functionality. You can suppress occurrence of Full GC by using this functionality efficiently.
This chapter describes how you can use the Explicit Memory Management functionality to suppress occurrence of Full GC.
Note that this functionality cannot be used if G1 GC is used. If the -XX:+HitachiUseExplicitMemory option is specified when G1 GC is used, the following message is sent to the standard output and the Java VM terminates:
Using -XX:+UseG1GC and -XX:+HitachiUseExplicitMemory at the same time is not supported.
Also note that on the application server, the Explicit Memory Management functionality is enabled by default. Therefore, if you use G1 GC, specify the -XX:-HitachiUseExplicitMemory option.
- Organization of this chapter
-
-
7.2 Overview of the Explicit Memory Management functionality
-
7.3 Overview of memory space used in the Explicit Memory Management functionality
-
7.5 Objects that you can optionally place in the Explicit heap in the application
-
7.6 Life cycle of Explicit memory block and executed processes
-
7.7 Releasing Explicit memory blocks when the automatic release functionality is enabled
-
7.8 Releasing Explicit memory blocks when the automatic release functionality is disabled
-
7.9 Releasing Explicit memory blocks by using the javagc command
-
7.10 Reducing time required for automatic release processing of Explicit memory blocks
-
7.11 Reducing memory usage of the Explicit heap that is used in an HTTP session
-
7.12 Implementing the Java program that uses the Explicit Memory Management functionality API
-
7.14 Precautions for using the Explicit Memory Management functionality