Start from 5.9, Activemq comes with another HA option called ReplicatedLevelDB. I would recommend start from 5.9.1 at least, and I found a lot bugs in the 5.9.
basic idea, Zookeeper as the central coordination point, every broker talked to the Zk , ZK wills tell the member information like who is the master. slave talks to master node to fetch the incremental change when it come online.
for the configuration, each member in a cluster share the same broker name, zookeepeer address, and zkPass.
and transportconnector is transparent to the underlining persistence layer.