private long executePeerProcedure(AbstractPeerProcedure<?> procedure) throws IOException {
    if (!isReplicationPeerModificationEnabled()) {
      throw new IOException("Replication peer modification disabled");
    }
    long procId = procedureExecutor.submitProcedure(procedure);
    procedure.getLatch().await();
    return procId;
  }
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