The master UI is supposed to give us a cluster key we can copy/paste to add a replication peer in the hbase shell. the shell explains that it should look like this:
However, on my example cluster with ZK quorum with 3 servers, the master ui gives this:
Note that the quorum members are newline separated instead of comma and that the port appears on each member instead of after the set of host names.
Workaround is to manually construct the cluster key from the details in the field.