apache derby default CacheManager

[Monti Gable]

Hello,

I am not sure if it is the right place to ask about apache derby; but if it is I had heap out of memory where 1 of the objects occupying ~20% of the heap was org.apache.derby.impl.services.cache.ConcurrentCache. I run multiple instances of embedded derby databases within my java application where I restart from time to time the databases to reclaim the heap but eventually it gets me.
I looked up that I can shutdown and clean ConcurrentCache or org.apache.derby.iapi.services.cache.CacheManager, but I could not find what syntax will get me the handles (it seems there no static methods too).
I would greatly appreciate any help at this point.