Sizing of the Java memory regions :
Heap Sizing :
The maximum heap size of a Java application is limited by three factors:
1) Process data model (32-bit or 64-bit) and the associated operating system limitations
2) Amount of virtual memory available on the system and
3) Amount of physical memory available on the system.
The size of the Java heap for a particular application can never exceed or even reach the maximum virtual address space of the process data model.
In most cases, using heap sizes greater than 2gig is not recommended for web based applications unless you use a lot of large objects. Using a larger heap size will affect performance due to the garbage collection process taking too long for larger heap sizes. It is very important to test your application if you choose to use a heap size over 2gig when it is available. The test should include a large load so that full garbage collection is performed and data can be collected for the affect this will have on the performance.
Garbage Collection Policies:
The -XX:+UseParallelGC parallel (throughput) garbage collector, or
The -XX:+UseConcMarkSweepGC concurrent (low pause time) garbage collector (also known as CMS)
The -XX:+UseSerialGC serial garbage collector (for smaller applications and systems)
UR's Key Run ;-)
Heap Sizing :
The maximum heap size of a Java application is limited by three factors:
1) Process data model (32-bit or 64-bit) and the associated operating system limitations
2) Amount of virtual memory available on the system and
3) Amount of physical memory available on the system.
The size of the Java heap for a particular application can never exceed or even reach the maximum virtual address space of the process data model.
In most cases, using heap sizes greater than 2gig is not recommended for web based applications unless you use a lot of large objects. Using a larger heap size will affect performance due to the garbage collection process taking too long for larger heap sizes. It is very important to test your application if you choose to use a heap size over 2gig when it is available. The test should include a large load so that full garbage collection is performed and data can be collected for the affect this will have on the performance.
Garbage Collection Policies:
The -XX:+UseParallelGC parallel (throughput) garbage collector, or
The -XX:+UseConcMarkSweepGC concurrent (low pause time) garbage collector (also known as CMS)
The -XX:+UseSerialGC serial garbage collector (for smaller applications and systems)
UR's Key Run ;-)
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