namenode 启动

hdfs\server\namenode\NameNode.java

 public static void main(String argv[]) throws Exception {
    try {
      StringUtils.startupShutdownMessage(NameNode.class, argv, LOG);
      NameNode namenode = createNameNode(argv, null);
      if (namenode != null)
        namenode.join();
    } catch (Throwable e) {
      LOG.error(StringUtils.stringifyException(e));
      System.exit(-1);
    }
  }