@Override
  public ReplicationPeerConfig getReplicationPeerConfig(String peerId)
    throws ReplicationException, IOException {
    if (cpHost != null) {
      cpHost.preGetReplicationPeerConfig(peerId);
    }
    LOG.info(getClientIdAuditPrefix() + " get replication peer config, id=" + peerId);
    ReplicationPeerConfig peerConfig = this.replicationPeerManager.getPeerConfig(peerId)
      .orElseThrow(() -> new ReplicationPeerNotFoundException(peerId));
    if (cpHost != null) {
      cpHost.postGetReplicationPeerConfig(peerId);
    }
    return peerConfig;
  }
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