Reputation: 68985
Following are the snapshots I took after executing perform GC from jvisualvm.
and
First image is Heap stats and 2nd one is perm gen stats. I am not able to understand when I did GC utilized heap size decreased(as expected) but the allocated size of permanent generation increased (though the utilized permgen size remained the same).What could be the possible explanation of such behavior?
JVM arguments used
-Xbootclasspath/p:../xyz.jar
-Xbootclasspath/a:../abc.jar
-Djava.endorsed.dirs=../resolver
-Djava.library.path=../framework
-Djavax.management.builder.initial=JBeanServerBuilder
-Djavax.net.ssl.trustStore=../certs
-Dorg.mortbay.log.class=JettyLogger
-Xms128m
-Xmx256m
-Xdebug
-Xnoagent
-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=2000
Note : I have changed the name(ex xyz.jar) for propriety reasons.
JVm Info:
JVM: Java HotSpot(TM) 64-Bit Server VM (23.6-b04, mixed mode)
Java: version 1.7.0_11, vendor Oracle Corporation
Java Home: /home/aniket/jdk1.7.0_11/jre
JVM Flags: <none>
Upvotes: 7
Views: 1288
Reputation: 1561
Below link will be really useful:
http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html
Upvotes: 3
Reputation: 82008
since nobody offers an answer, I make my comment an answer, although it is a little vague:
I'd guess that the GC reevaluates the various sizes it has to control as part of the collection run. So it might decide that it is a little tight on the perm gen side of things an increase it.
Upvotes: 1