A load balancer component is not part of Neo4j nor part of Spring Data Neo4j. For a sample setup using Neo4j as server is documented at http://docs.neo4j.org/chunked/stable/ha-haproxy.html.
Since your application uses SDN in embedded HA mode, you need to expose the status of your local instance (master or slave) yourself to achieve the same like /db/manage/server/ha/master does in server mode. You might use HighlyAvailableGraphDatabase.isMaster()
in your implementation.