No transaction need here. and Avoid catching exceptions inside atomic… (#176)

* No transaction need here. and Avoid catching exceptions inside atomic! refer to: https://docs.djangoproject.com/en/2.1/topics/db/transactions/#controlling-transactions-explicitly

* No transaction need here. and Avoid catching exceptions inside atomic! refer to: https://docs.djangoproject.com/en/2.1/topics/db/transactions/#controlling-transactions-explicitly

* No transaction need here. and Avoid catching exceptions inside atomic! refer to: https://docs.djangoproject.com/en/2.1/topics/db/transactions/#controlling-transactions-explicitly

optimization: only retry for the failed updates

Author: tinylambda

django_celery_beat/schedulers.py

@@ -252,19 +252,20 @@ def reserve(self, entry):
     def sync(self):
         info('Writing entries...')
         _tried = set()
+        _failed = set()
         try:
             close_old_connections()
-            with transaction.atomic():
-                while self._dirty:
-                    try:
-                        name = self._dirty.pop()
-                        _tried.add(name)
-                        self.schedule[name].save()
-                    except (KeyError, ObjectDoesNotExist):
-                        pass
+
+            while self._dirty:
+                name = self._dirty.pop()
+                try:
+                    self.schedule[name].save()
+                    _tried.add(name)
+                except (KeyError, ObjectDoesNotExist) as exc:
+                    _failed.add(name)
         except (DatabaseError, InterfaceError) as exc:
-            # retry later
-            self._dirty |= _tried
+            # retry later, only for the failed ones
+            self._dirty |= _failed
             logger.exception('Database error while sync: %r', exc)
 
     def update_from_dict(self, mapping):