Exemplo n.º 1
0
 public int compare(Object o1, Object o2) {
   TaskTrackerStatus p1 = (TaskTrackerStatus) o1;
   TaskTrackerStatus p2 = (TaskTrackerStatus) o2;
   if (p1.getLastSeen() < p2.getLastSeen()) {
     return -1;
   } else if (p1.getLastSeen() > p2.getLastSeen()) {
     return 1;
   } else {
     return (p1.getTrackerName().compareTo(p2.getTrackerName()));
   }
 }
Exemplo n.º 2
0
    /**
     * The run method lives for the life of the JobTracker, and removes TaskTrackers that have not
     * checked in for some time.
     */
    public void run() {
      while (shouldRun) {
        //
        // Thread runs periodically to check whether trackers should be expired.
        // The sleep interval must be no more than half the maximum expiry time
        // for a task tracker.
        //
        try {
          Thread.sleep(TASKTRACKER_EXPIRY_INTERVAL / 3);
        } catch (InterruptedException ie) {
        }

        //
        // Loop through all expired items in the queue
        //
        synchronized (taskTrackers) {
          synchronized (trackerExpiryQueue) {
            long now = System.currentTimeMillis();
            TaskTrackerStatus leastRecent = null;
            while ((trackerExpiryQueue.size() > 0)
                && ((leastRecent = (TaskTrackerStatus) trackerExpiryQueue.first()) != null)
                && (now - leastRecent.getLastSeen() > TASKTRACKER_EXPIRY_INTERVAL)) {

              // Remove profile from head of queue
              trackerExpiryQueue.remove(leastRecent);
              String trackerName = leastRecent.getTrackerName();

              // Figure out if last-seen time should be updated, or if tracker is dead
              TaskTrackerStatus newProfile =
                  (TaskTrackerStatus) taskTrackers.get(leastRecent.getTrackerName());
              // Items might leave the taskTracker set through other means; the
              // status stored in 'taskTrackers' might be null, which means the
              // tracker has already been destroyed.
              if (newProfile != null) {
                if (now - newProfile.getLastSeen() > TASKTRACKER_EXPIRY_INTERVAL) {
                  // Remove completely
                  updateTaskTrackerStatus(trackerName, null);
                  lostTaskTracker(leastRecent.getTrackerName());
                } else {
                  // Update time by inserting latest profile
                  trackerExpiryQueue.add(newProfile);
                }
              }
            }
          }
        }
      }
    }