Reschedule rate limited telegram task instead of retry

engine/apps/alerts/tasks/notify_user.py

@@ -445,10 +445,12 @@ def perform_notification(log_record_pk, use_default_notification_policy_fallback
         try:
             TelegramToUserConnector.notify_user(user, alert_group, notification_policy)
         except RetryAfter as e:
+            task_logger.exception(f"Telegram API rate limit exceeded. Retry after {e.retry_after} seconds.")
             countdown = getattr(e, "retry_after", 3)
-            raise perform_notification.retry(
-                (log_record_pk, use_default_notification_policy_fallback), countdown=countdown, exc=e
+            perform_notification.apply_async(
+                (log_record_pk, use_default_notification_policy_fallback), countdown=countdown
             )
+            return
 
     elif notification_channel == UserNotificationPolicy.NotificationChannel.SLACK:
         # TODO: refactor checking the possibility of sending a notification in slack

engine/apps/alerts/tests/test_notify_user.py

@@ -360,10 +360,12 @@ def test_perform_notification_telegram_retryafter_error(
     countdown = 15
     exc = RetryAfter(countdown)
     with patch.object(TelegramToUserConnector, "notify_user", side_effect=exc) as mock_notify_user:
-        with pytest.raises(RetryAfter):
+        with patch.object(perform_notification, "apply_async") as mock_apply_async:
             perform_notification(log_record.pk, False)
 
     mock_notify_user.assert_called_once_with(user, alert_group, user_notification_policy)
+    # task is rescheduled using the countdown value from the exception
+    mock_apply_async.assert_called_once_with((log_record.pk, False), countdown=countdown)
     assert alert_group.personal_log_records.last() == log_record