why after about three days , Hotspot frequent running full GC

[renxijuninfo]

why after about three days , Hotspot frequent running full GC, although there are enough old space?

At first the GC is running good about 20 seconds run a young GC and about 15 minute run a full GC. But after about three days the full GC running about every 5 second. 
I use jstat monitor when running full GC the Old Space just used less then 60%.

This is jvm bug or others?

Thanks.


FYI:

# java -version
java version "1.6.0_11"
Java(TM) SE Runtime Environment (build 1.6.0_11-b03)
Java HotSpot(TM) 64-Bit Server VM (build 11.0-b16, mixed mode)

# uname -a
Linux 2.6.18-128.7.1.el5 #1 SMP Wed Aug 19 04:00:49 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux

jps -lmv:

26938 com.caucho.server.resin.Resin -socketwait 58977 -server b -stdout /usr/local/resin/log/stdout.log -stderr /usr/local/resin/log/stderr.log 
-Xmx6144m
-Xms6144m 
-Xss512k 
-XX:PermSize=512M 
-XX:MaxPermSize=512m 
-XX:NewSize=3072m 
-XX:MaxNewSize=3072m 
-XX:SurvivorRatio=14
-XX:MaxTenuringThreshold=15 
-XX:GCTimeRatio=19 
-XX:+DisableExplicitGC 
-XX:+UseParNewGC 
-XX:+CMSScavengeBeforeRemark 
-XX:+UseConcMarkSweepGC 
-XX:+UseCMSCompactAtFullCollection 
-XX:+CMSClassUnloadingEnabled 
-XX:CMSInitiatingOccupancyFraction=80 
-XX:SoftRefLRUPolicyMSPerMB=0 
-XX:+PrintClassHistogram 
-XX:+PrintGCDetails 
-XX:+PrintGCTimeStamps 
-XX:+PrintTenuringDistribution 
-Xloggc:log/gc.log 
-Dcom.sun.management.jmxremote -Xss1m -Dresin.home=/usr/local/resin -Dserver.root=/usr/local/resin -Djava.util.logging.manager=com.caucho.log.LogManagerImpl -Djavax.management.builder.initial=com.caucho.jmx.MBeanServerBuilderImpl 







2010-01-07 



renxijuninfo 
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