/** Process incoming heartbeat messages from the task trackers. */ public synchronized int emitHeartbeat(TaskTrackerStatus trackerStatus, boolean initialContact) { String trackerName = trackerStatus.getTrackerName(); trackerStatus.setLastSeen(System.currentTimeMillis()); synchronized (taskTrackers) { synchronized (trackerExpiryQueue) { boolean seenBefore = updateTaskTrackerStatus(trackerName, trackerStatus); if (initialContact) { // If it's first contact, then clear out any state hanging around if (seenBefore) { lostTaskTracker(trackerName); } } else { // If not first contact, there should be some record of the tracker if (!seenBefore) { return InterTrackerProtocol.UNKNOWN_TASKTRACKER; } } if (initialContact) { trackerExpiryQueue.add(trackerStatus); } } } updateTaskStatuses(trackerStatus); // LOG.info("Got heartbeat from "+trackerName); return InterTrackerProtocol.TRACKERS_OK; }
//////////////////////////////////////////////////// // InterTrackerProtocol //////////////////////////////////////////////////// public void initialize(String taskTrackerName) { synchronized (taskTrackers) { boolean seenBefore = updateTaskTrackerStatus(taskTrackerName, null); if (seenBefore) { lostTaskTracker(taskTrackerName); } } }