public static void main(String argv[]
                          ) throws IOException, InterruptedException {
    StringUtils.startupShutdownMessage(JobTracker.class, argv, LOG);

    try {
      if (argv.length == 0) {
        JobTracker tracker = startTracker(new JobConf());
        tracker.offerService();
        return;
      }
      if ("-instance".equals(argv[0]) && argv.length == 2) {
        int instance = Integer.parseInt(argv[1]);
        if (instance == 0 || instance == 1) {
          JobConf conf = new JobConf();
          JobConf.overrideConfiguration(conf, instance);
          JobTracker tracker = startTracker(conf);
          tracker.offerService();
          return;
        }
      }
      if ("-dumpConfiguration".equals(argv[0]) && argv.length == 1) {
        dumpConfiguration(new PrintWriter(System.out));
        return;
      }
      System.out.println("usage: JobTracker [-dumpConfiguration]");
      System.out.println("       JobTracker [-instance <0|1>]");
      System.exit(-1);

    } catch (Throwable e) {
      LOG.fatal(StringUtils.stringifyException(e));
      System.exit(-1);
    }
  }
public static void main ( String argv [ ] ) throws IOException , InterruptedException { StringUtils . startupShutdownMessage ( JobTracker . class , argv , LOG ) ; try { if ( argv . length == 0 ) { JobTracker tracker = startTracker ( new JobConf ( ) ) ; tracker . offerService ( ) ; return ; } if ( "-instance" . equals ( argv [ 0 ] ) && argv . length == 2 ) { int instance = Integer . parseInt ( argv [ 1 ] ) ; if ( instance == 0 || instance == 1 ) { JobConf conf = new JobConf ( ) ; JobConf . overrideConfiguration ( conf , instance ) ; JobTracker tracker = startTracker ( conf ) ; tracker . offerService ( ) ; return ; } } if ( "-dumpConfiguration" . equals ( argv [ 0 ] ) && argv . length == 1 ) { dumpConfiguration ( new PrintWriter ( System . out ) ) ; return ; } System . out . println ( "usage: JobTracker [-dumpConfiguration]" ) ; System . out . println ( "       JobTracker [-instance <0|1>]" ) ; System . exit ( - 1 ) ; } catch ( Throwable e ) { LOG . fatal ( StringUtils . stringifyException ( e ) ) ; System . exit ( - 1 ) ; } }
Start the JobTracker process.  This is used only for debugging.  As a rule,
JobTracker should be run as part of the DFS Namenode process.