Robert Harryman wrote:
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?
As far as I know, Derby does not use the java.util.logging package at all, so
your findings puzzle me. Then again, maybe I am misunderstanding what you are
asking...
(Derby (and Java DB) versions up to and including 10.2 support J2SE 1.3, which
does not include the logging API).
Do you get similar results (references to java.util.logging.Logger) if you run
the following query in jhat's OQL tool?
select referrers(f) from java.util.logging.Logger f
(lists Java objects that hold reference to java.util.logging.Logger)
or for example
select
referees(heap.findClass("org.apache.derby.impl.services.monitor.BaseMonitor"))
(returns an array of Java objects to which the given Java object directly refers
to).
--
John
