On 11/15/2012 06:45 PM, lars hofhansl wrote:
Yes. If there are failures in the source cluster the replicated data might be delivered out of order.
ok.
Note that you will never see partial rows applied; replication will enforce HBase's ACID guarantee here,
ok.
but rows might be delivered out of order, which means the ordering of deletes and puts might change, and hence lead to *temporary* visibility of deleted data. Eventually the state will be correct, though.
I understand that there are situations in which the reordering results in temporary visibility of deleted data. But additionally I also think that there are (unlikely) situations which can lead to permanent visibility of deleted data on the replica.
The situation I think of is: - put followed by delete on source cluster - reordering resulting in delete followed by put on replica - delete gets executed on replica - a major compaction happens on the replica (thus "really" deleting) - put gets executed on the replica (thus permanently staying there) Is there an error in my reasoning? thanks, Jan
