finalize过程

之前说过case有两个

 switch (startOpt) {
      case FORMAT:
        boolean aborted = format(conf, true);
        System.exit(aborted ? 1 : 0);
      case FINALIZE:
        aborted = finalize(conf, true);
        System.exit(aborted ? 1 : 0);
      default:
    }

现在看下finalize：

private static boolean finalize(Configuration conf,
                               boolean isConfirmationNeeded
                               ) throws IOException {
    Collection<File> dirsToFormat = FSNamesystem.getNamespaceDirs(conf);
    Collection<File> editDirsToFormat =
                               FSNamesystem.getNamespaceEditsDirs(conf);
    FSNamesystem nsys = new FSNamesystem(new FSImage(dirsToFormat,
                                         editDirsToFormat), conf);
    System.err.print(
        "\"finalize\" will remove the previous state of the files system.\n"
        + "Recent upgrade will become permanent.\n"
        + "Rollback option will not be available anymore.\n");
    if (isConfirmationNeeded) {
      System.err.print("Finalize filesystem state ? (Y or N) ");
      if (!(System.in.read() == 'Y')) {
        System.err.println("Finalize aborted.");
        return true;
      }
      while(System.in.read() != '\n'); // discard the enter-key
    }
    nsys.dir.fsImage.finalizeUpgrade();
    return false;
  }

接下来会牵扯一些rpc相关的.

问题：

<property>
  <name>dfs.namenode.handler.count</name>
  <value>10</value>
  <description>The number of server threads for the namenode.</description>
</property>