@Override
  public RpcScheduler create(Configuration conf, PriorityFunction priority, Abortable server) {
    int handlerCount = conf.getInt(HConstants.REGION_SERVER_HANDLER_COUNT,
      HConstants.DEFAULT_REGION_SERVER_HANDLER_COUNT);
    return new FifoRpcScheduler(conf, handlerCount);
  }
Factory to use when you want to use the {@link FifoRpcScheduler}
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/FifoRpcSchedulerFactory.java