How to identify/determine the maximum JVM Heap Size for OC4j components in R12 / 10gAS
Below command will help you to identify the maximum memory heap size than can be allocated to a JVM
process.
java -mx[value]m -version
Start with a higher value like 4G or higher and slowly cut down to the maximum allowed value.
Sample
$ java -mx4096m -version
Invalid maximum heap size: -Xmx4096m
The specified size exceeds the maximum representable size.
Could not create the Java virtual machine.
As you can see my system cant support 4Gig for a JVM.
Now lets reduce to a lesser value, viz., 3Gig
$ java -mx3072m -version
java version “1.5.0.04″
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0.04-_27_jul_2006_10_52)
Java HotSpot(TM) Server VM (build 1.5.0.04 jinteg:07.27.06-16:18 IA64, mixed mode)
Now its clear that the maximum allowed value is 3gig.
cheers,
OraclePitStop.
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How to change Java heap size in R12 to avoid java.lang.OutOfMemoryError: Java heap space error? « OraclePitStop - Lets share some knowledge
September 11, 2008
Thnax for ur way to find out max JVM heap size.
Ajay
March 17, 2009
It’s a good start, but you can fine tune better if you want; for example, your next run should be java -mx3584m -version to see if you can run 3.5 gb. There comes a point where it is academic, but I think another .5gb might be useful if it’s available.
Billy Bennett
May 7, 2009