I am running a cluster JBoss servers.
Both server has 4 CPUs, dual cores. i.e. 8 logical CPUs.
I want to tune the JVM setting and I found that I can use the following parameters:
+UseParallelOldGC -XX:ParallelGCThreads
I did some load test with different number of ParallelGCThreads.
However, I was surprised from the load test result that, the Full GC time for the UseParallelOldGC is much longer than I didn't use it. E.g.
A) Parallel Old GC = 7
4.1747870 secs
B) Parallel Old GC = 3
4.2135090 secs
C) No Parallel Old GC
2.7176180 secs
Does anyone know any reason why the Parallel GC can perform poor?
Please do not post the same question in multiple forums.
http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4238719