Major Description
When I worked on HBASE-2195 I added a mechanism for an edit to identify its source cluster, so that replication would not bounce it back to the source.
See: this.clusterId = zkHelper.getUUIDForCluster(zkHelper.getZookeeperWatcher()); in ReplicationSource, and put.setClusterId(entry.getKey().getClusterId()); in ReplicationSink.
In master-master replication scenarios, it would very useful if CopyTable would identify the source cluster (by tagging each Put/Delete with the source clusterId before applying it).