Currently, when moving tables or servers to a group, only groupInfo is checked. And in RSGroup implementation, groupinfo is written to disk before regions movements are done. If there are some problems caused move regions abort, some regions will be on wrong regionservers. What's the worse, retry the move operation will be rejected because of the correct groupinfo.
We think when moving, not only groupInfo should be checked, but also relevant region assignments should be checked and corrected.