code: protected void initGlobalSetting(Configuration conf,
        AbstractList<File> dataDirs) throws IOException {
      this.dataDirs = dataDirs;
      this.conf = conf;
      storage = new DataStorage(this);
      
      // global DN settings
      initConfig(conf);
      registerMXBean();
      initDataXceiver(conf);
      startInfoServer(conf);
      initIpcServer(conf);
  
      myMetrics = new DataNodeMetrics(conf, storage.getStorageID());
      setCountingLoggers(myMetrics);
      threadLivenessReporter = new DatanodeThreadLivenessReporter(conf.getLong(
          "dfs.datanode.thread.liveness.threshold", 240 * 1000),
          myMetrics.threadActiveness);
    }
docs: Initialize global settings for DN