Merge pull request #77 from Koed00/dev

Adds stale db connection check before every transaction

django_q/cluster.py

@@ -117,8 +117,8 @@ def __init__(self, stop_event, start_event, broker=None, timeout=Conf.TIMEOUT, s
         self.task_queue = Queue(maxsize=Conf.QUEUE_LIMIT) if Conf.QUEUE_LIMIT else Queue()
         self.result_queue = Queue()
         self.event_out = Event()
-        self.monitor = Process()
-        self.pusher = Process()
+        self.monitor = None
+        self.pusher = None
         if start:
             self.start()
 
@@ -163,7 +163,7 @@ def spawn_monitor(self):
     def reincarnate(self, process):
         """
         :param process: the process to reincarnate
-        :type process: Process
+        :type process: Process or None
         """
         if process == self.monitor:
             self.monitor = self.spawn_monitor()
@@ -276,7 +276,7 @@ def stop(self):
 
 def pusher(task_queue, event, broker=None):
     """
-    Pulls tasks of the Redis List and puts them in the task queue
+    Pulls tasks of the broker and puts them in the task queue
     :type task_queue: multiprocessing.Queue
     :type event: multiprocessing.Event
     """
@@ -318,11 +318,12 @@ def monitor(result_queue, broker=None):
         broker = get_broker()
     name = current_process().name
     logger.info(_("{} monitoring at {}").format(name, current_process().pid))
-    db.close_old_connections()
     for task in iter(result_queue.get, 'STOP'):
+        # acknowledge
         ack_id = task.pop('ack_id', False)
         if ack_id:
             broker.acknowledge(ack_id)
+        # save the result
         save_task(task)
         if task['success']:
             logger.info(_("Processed [{}]").format(task['name']))
@@ -340,7 +341,6 @@ def worker(task_queue, result_queue, timer, timeout=Conf.TIMEOUT):
     """
     name = current_process().name
     logger.info(_('{} ready for work at {}').format(name, current_process().pid))
-    db.close_old_connections()
     task_count = 0
     # Start reading the task queue
     for task in iter(task_queue.get, 'STOP'):
@@ -360,6 +360,7 @@ def worker(task_queue, result_queue, timer, timeout=Conf.TIMEOUT):
                 result = (e, False)
         # We're still going
         if not result:
+            db.close_old_connections()
             # execute the payload
             timer.value = task['kwargs'].pop('timeout', timeout or 0)  # Busy
             try:
@@ -388,6 +389,7 @@ def save_task(task):
     if not task.get('save', Conf.SAVE_LIMIT > 0) and task['success']:
         return
     # SAVE LIMIT > 0: Prune database, SAVE_LIMIT 0: No pruning
+    db.close_old_connections()
     try:
         if task['success'] and 0 < Conf.SAVE_LIMIT <= Success.objects.count():
             Success.objects.last().delete()
@@ -412,6 +414,7 @@ def scheduler(broker=None):
     """
     if not broker:
         broker = get_broker()
+    db.close_old_connections()
     try:
         for s in Schedule.objects.exclude(repeats=0).filter(next_run__lt=timezone.now()):
             args = ()