NonStop Server for Java Programmer's Reference (NSJ 4.2+)

Garbage Collection (GC)
This topic discusses implementation-specific information about garbage collection for NonStop Server for Java 4.
The topics are:
General Information on Garbage Collection●
Heap Layout●
Managing Generation Size●
Implementation of Garbage Collector Types●
General Information on Garbage Collection
In general, garbage collectors, the various GC algorithms, and modeling in the NonStop Server for Java 4 are the
same as those implemented by Sun Microsystems in their JVM. Accordingly, you should refer to the Sun
Microsystems web site for details about garbage collection. But keep in mind that some of the information is not
applicable to NonStop Server for Java 4. Links to pertinent information (but not all the information) on the Sun
Microsystems web site are:
Tuning Garbage Collection with 1.4.2 Java Virtual Machine (http://java.sun.com/docs/hotspot/gc1.4.2/)●
Turbo-charging the Java HotSpot Virtual Machine, v1.4.x to Improve the Performance and Scalability of
Application Servers by Alka Gupta and Michael Doyle
(http://developer.java.sun.com/developer/technicalArticles/Programming/turbo/)
●
Improving Java Application Performance and Scalability by Reducing Garbage Collection Times and Sizing
Memory Using JDK 1.4.1 by Nagendra Nagarajayya and J. Steven Mayer
(http://developers.sun.com/techtopics/mobility/midp/articles/garbagecollection2/)
●
Heap Layout
In NonStop Server for Java 4, the memory is managed in generations (or memory pools) based on objects at
different ages for Java objects. Layout for generations is illustrated and described below.
Layout for Generations