code: public void generateSummaryTable(JspWriter out,
                                     JobTracker tracker) throws IOException {
      ClusterStatus status = tracker.getClusterStatus();
      int maxMapTasks = status.getMaxMapTasks();
      int maxReduceTasks = status.getMaxReduceTasks();
      int numTaskTrackers = status.getTaskTrackers();
      String tasksPerNodeStr;
      if (numTaskTrackers > 0) {
        double tasksPerNodePct = (double) (maxMapTasks + maxReduceTasks) / (double) numTaskTrackers;
        tasksPerNodeStr = percentFormat.format(tasksPerNodePct);
      } else {
        tasksPerNodeStr = "-";
      }
      out.print("<maps>" + status.getMapTasks() + "</maps>\n" +
              "<reduces>" + status.getReduceTasks() + "</reduces>\n" +
              "<total_submissions>" + tracker.getTotalSubmissions() + "</total_submissions>\n" +
              "<nodes>" + status.getTaskTrackers() + "</nodes>\n" +
              "<map_task_capacity>" + status.getMaxMapTasks() + "</map_task_capacity>\n" +
              "<reduce_task_capacity>" + status.getMaxReduceTasks() + "</reduce_task_capacity>\n" +
              "<avg_tasks_per_node>" + tasksPerNodeStr + "</avg_tasks_per_node>\n");
    }
docs: Generates an XML-formatted block that summarizes the state of the JobTracker.