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jvm tuning

Mario Almeida

Joined: Sep 13, 2010
Posts: 11
Hi All,

OS Centos 5.5 64Bit
2 Xeon Quad core 2.66Ghz, 8GB ram
JBOSS 4.2.3.GA
JDK 1.6u21

Can someone help me in tuning JVM


Please download gc00.log file from

SumitPal Pal

Joined: Aug 31, 2010
Posts: 22
I think you should ask this question - why do you need to do Heap Tuning - are you seeing excessive GC happening - then identify - what GC is happening excessive - Minor one / Major ones.

Is there an issue with the Application - too much object creation etc

Have you tried to answer those questions

Sometimes some 3rd party libraries - call GC explicitly in the code - try to see if you can add this flag
-DisableExplicitGC in the JVM_OPT and see if it reduces the number of GCs
kri shan
Ranch Hand

Joined: Apr 08, 2004
Posts: 1432
-XX:PermSize=180m -XX:MaxPermSize=180m
Your PermSize and MaxPermSize are size. Can you increase your MaxPermSize ?
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