Monday, October 25, 2010

Modifying the JVM heap size Formula

The total value of all server JVM heap sizes within the dynamic cluster for a specific node must be less than half of the total RAM of that computer. To determine the maximum heap size setting for a single server instance, use the following equation:
total_RAM / 2 / number_of_servers = maximum_heap_size
For example, to support three servers on a machine with 1.5 GB of RAM:
1.5 GB / 2 = 750 MB
750 MB / 3 = 250 MB
The maximum heap size is 250 MB for each server instance.