Java HotSpot Virtual Machine

Hi,

These are the options specified to the VM. The box has 16gigs of memory on it.

XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+PrintGCDetails -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution -XX:MaxPermSize=500m -XX:PermSize=500m -XX:MaxNewSize=4120m -XX:NewSize=4120m -Dcom.sun.xml.namespace.QName.useCompatibleSerialVersionUID=1.0 -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8688 -Dcom.sun.management.jmxremote.authenticate=false
-server -verbosegc -Dsun.net.inetaddr.ttl=600 -Dsun.net.inetaddr.negative.ttl=1


our application is loads a lot of data into the server cache from a DB ( ~ 6.5 Gigs). I am seeing a lot of Full GC's happening even though none of the spaces are shown as full in the GC output. Below is the sample output that I have from the GC, and its outputted virtually all over the logs, including right after I start the server.

Can anyone recommend tweaking any settings that can help me avoid this?

Much appreciated.

[Full GC {Heap before gc invocations=786:
par new generation total 4214784K, used 749836K [0x0000002a9c6f0000, 0x0000002b9def0000, 0x0000002b9def0000)
eden space 4210688K, 17% used [0x0000002a9c6f0000, 0x0000002aca333278, 0x0000002b9d6f0000)
from space 4096K, 0% used [0x0000002b9d6f0000, 0x0000002b9d6f0000, 0x0000002b9daf0000)
to space 4096K, 0% used [0x0000002b9daf0000, 0x0000002b9daf0000, 0x0000002b9def0000)
concurrent mark-sweep generation total 8167424K, used 116027K [0x0000002b9def0000, 0x0000002d906f0000, 0x0000002d906f0000)
concurrent-mark-sweep perm gen total 512000K, used 80871K [0x0000002d906f0000, 0x0000002dafaf0000, 0x0000002dafaf0000)
[CMS: 116027K->127094K(8167424K), 1.0926490 secs] 865864K->127094K(12382208K), [CMS Perm : 80871K->80871K(512000K)]Heap after gc invocations=787:
par new generation total 4214784K, used 0K [0x0000002a9c6f0000, 0x0000002b9def0000, 0x0000002b9def0000)
eden space 4210688K, 0% used [0x0000002a9c6f0000, 0x0000002a9c6f0000, 0x0000002b9d6f0000)
from space 4096K, 0% used [0x0000002b9d6f0000, 0x0000002b9d6f0000, 0x0000002b9daf0000)
to space 4096K, 0% used [0x0000002b9daf0000, 0x0000002b9daf0000, 0x0000002b9def0000)
concurrent mark-sweep generation total 8167424K, used 127094K [0x0000002b9def0000, 0x0000002d906f0000, 0x0000002d906f0000)
concurrent-mark-sweep perm gen total 512000K, used 80871K [0x0000002d906f0000, 0x0000002dafaf0000, 0x0000002dafaf0000)
}
, 1.0928710 secs]
[Full GC {Heap before gc invocations=787:
par new generation total 4214784K, used 46964K [0x0000002a9c6f0000, 0x0000002b9def0000, 0x0000002b9def0000)
eden space 4210688K, 1% used [0x0000002a9c6f0000, 0x0000002a9f4cd2a0, 0x0000002b9d6f0000)
from space 4096K, 0% used [0x0000002b9d6f0000, 0x0000002b9d6f0000, 0x0000002b9daf0000)
to space 4096K, 0% used [0x0000002b9daf0000, 0x0000002b9daf0000, 0x0000002b9def0000)
concurrent mark-sweep generation total 8167424K, used 127094K [0x0000002b9def0000, 0x0000002d906f0000, 0x0000002d906f0000)
concurrent-mark-sweep perm gen total 512000K, used 80871K [0x0000002d906f0000, 0x0000002dafaf0000, 0x0000002dafaf0000)
[CMS: 127094K->127093K(8167424K), 0.8199480 secs] 174059K->127093K(12382208K), [CMS Perm : 80871K->80871K(512000K)]Heap after gc invocations=788:
par new generation total 4214784K, used 0K [0x0000002a9c6f0000, 0x0000002b9def0000, 0x0000002b9def0000)
eden space 4210688K, 0% used [0x0000002a9c6f0000, 0x0000002a9c6f0000, 0x0000002b9d6f0000)
from space 4096K, 0% used [0x0000002b9d6f0000, 0x0000002b9d6f0000, 0x0000002b9daf0000)
to space 4096K, 0% used [0x0000002b9daf0000, 0x0000002b9daf0000, 0x0000002b9def0000)
concurrent mark-sweep generation total 8167424K, used 127093K [0x0000002b9def0000, 0x0000002d906f0000, 0x0000002d906f0000)
concurrent-mark-sweep perm gen total 512000K, used 80871K [0x0000002d906f0000, 0x0000002dafaf0000, 0x0000002dafaf0000)
}