Hello,
I am deploying a module into the Solaris Common Agent container (JMX/JDMK).
I carefully monitored my module classes to make sure all objects we GC'd
after the undeploy.
Next I added classloading of the embedded derby driver, did a shutdown
of the database and unregistered the
driver. Using jmap/jhat (jdk 1.6) I see that all my objects are being
kept alive and that there are a lot
of derby static refs around to java.util.logging.Logger. This leak will
force me to bounce the container during
redeploy since PermGen will eventually exhaust and cause an out of
memory condition.
Is this a known problem? Does derby/javaDB have a bug against static
references to log objects?
Any guidance is very much appreciated.
Sincerely,
Bob Harryman
The jhat reported static refs:
Rootset references to class java.util.logging.Logger (excludes weak refs)
References to class java.util.logging.Logger (84 bytes)
Java Static References
.....
Static reference from
org.apache.derby.impl.services.monitor.BaseMonitor.class$org$apache$derby$iapi$services$monitor$PersistentService
(from class org.apache.derby.impl.services.monitor.BaseMonitor) :
--> class org.apache.derby.iapi.services.monitor.PersistentService (84
bytes) (??:)
--> [EMAIL PROTECTED] (79 bytes) (??:)
--> class com.sun.cacao.impl.ModuleClassLoader (84 bytes) (static field
logger:)
--> [EMAIL PROTECTED] (58 bytes) (??:)
--> class java.util.logging.Logger (84 bytes)
Static reference from
org.apache.derby.impl.services.monitor.BaseMonitor.class$org$apache$derby$io$StorageFactory
(from class org.apache.derby.impl.services.monitor.BaseMonitor) :
--> class org.apache.derby.io.StorageFactory (84 bytes) (??:)
--> [EMAIL PROTECTED] (79 bytes) (??:)
--> class com.sun.cacao.impl.ModuleClassLoader (84 bytes) (static field
logger:)
--> [EMAIL PROTECTED] (58 bytes) (??:)
--> class java.util.logging.Logger (84 bytes)
Here is how I'm doing the analysis:
$ /usr/java/bin/jps -v | grep ontainer
10604 ContainerPrivate -Xms16M -Xmx128M -Dcom.sun.management.jmxremote
-Dfile.encoding=utf-8 -Xdebug -Xnoagent -Djava.compiler=NONE
-Xrunjdwp:transport=dt_socket,server=y,address=9091,suspend=n
-Djavax.management.builder.initial=com.sun.jdmk.JdmkMBeanServerBuilder
-Dcacao.config.dir=/home/bharryma/tools/cacao/2.1_b19/cacao_2.1/etc/cacao/instances/default
$ rm leak
$ /usr/java/bin/jmap -dump:format=b,file=leak 10604
Dumping heap to /home/bharryma/projects/isns/dumps/leak ...
Heap dump file created
$ /usr/java/bin/jhat -J-Xmx512m leak
Reading from leak...
Dump file created Tue May 22 09:14:36 MDT 2007
Snapshot read, resolving...
Resolving 70073 objects...
Chasing references, expect 14 dots..............
Eliminating duplicate references..............
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.
