Although I did see a drop in initial memory usage, things went south again as the run continued past the 2-4 hour mark.  I have poured over my source several times and am starting to loose faith that Drools can provide anything other than a single threaded rules engine.  Although the engine itself is fast, it seems it cannot scale from a memory perspective.  I understand I am not providing much detail or a use case, but perhaps there are some official best practices documented somewhere on how to scale Drools?  I cannot get valuable heap dumps because the heaps are enormous.  I have continuously been told that Drools doesn't perform by colleagues and was hoping they were wrong.  Any pointers or help is greatly appreciated.