It's 5pm Friday, so I'm not going into a lot of detail, but we've also seen problems with 0.20.4. Specifically:
1. possible deadlock HBASE-2545 2. Regions not getting flushed with message that it exceeds max number of store files putting it back on the flush queue. 3. More regions assigned to RS than present in META (possibly assigned to multiple RS) We've rolled back to 0.20.3, preferring to bear those ills we have than fly to others we know not of. YMMV, our cluster was messed up when we started.
