Is replication supported in pseudo-distributed mode? What would be a test that could be run to confirm that all mutations are reaching the target HBase instance?
I think it should work in Pseudo Distributed mode. Make sure you setup 2 Pseudo Distributed Mode on two different nodes.
I have used HBase replication in Production and it was reliable. Once thing to notice is that its Asynchronous replication.
I think, HBase should have Replication JUnits around mutations. Still, you would like to test then you can try all the valid combinations