@Override
  public List<ReplicationPeerDescription> listReplicationPeers(String regex)
    throws ReplicationException, IOException {
    if (cpHost != null) {
      cpHost.preListReplicationPeers(regex);
    }
    LOG.debug("{} list replication peers, regex={}", getClientIdAuditPrefix(), regex);
    Pattern pattern = regex == null ? null : Pattern.compile(regex);
    List<ReplicationPeerDescription> peers = this.replicationPeerManager.listPeers(pattern);
    if (cpHost != null) {
      cpHost.postListReplicationPeers(regex);
    }
    return peers;
  }
Fetch the configured {@link LoadBalancer} class name. If none is set, a default is returned.
<p/>
Notice that, the base load balancer will always be {@link RSGroupBasedLoadBalancer} now, so
this method will return the balancer used inside each rs group.
@return The name of the {@link LoadBalancer} in use.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java