From the review of
HBASE-7206, there are two opposing concerns having to do with references to procedures being held.
1) One approach says to use weak references so that they can be GC'ed.
2) The counterargument is that potentially leaves all references weak and causes some procedures to be prematurely gc'ed.
We need to determine which is the case and fix it so that the procedures/subprocedures are not prematurely collected and not leaked.