I don't think that Local is right here.

Local seems like it should be used to make sure that a single value moves along with an executor's tree.  Local proviceds update/set.  None of these are really what I need.  

Here I'm really using ThreadLocal as a way to ensure that no two threads are accessing the same HTable (HTable has buffers that aren't protected from concurrent access).  

I should probably change this to use HTablePool, but that's a lot more code.