@Override
  protected Class<?> getRpcSchedulerFactoryClass(Configuration conf) {
    return conf.getClass(MASTER_RPC_SCHEDULER_FACTORY_CLASS, SimpleRpcSchedulerFactory.class);
  }
@return Subset of configuration to pass initializing regionservers: e.g. the filesystem to use
        and root directory to use.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java