[FSSDK-12149] [Python] Add Event Retries

optimizely/event_dispatcher.py

@@ -49,7 +49,7 @@ def dispatch_event(event: event_builder.Event) -> None:
             session = requests.Session()
 
             retries = Retry(total=EventDispatchConfig.RETRIES,
-                            backoff_factor=0.1,
+                            backoff_factor=0.2,
                             status_forcelist=[500, 502, 503, 504])
             adapter = HTTPAdapter(max_retries=retries)
 

optimizely/odp/odp_event_manager.py

@@ -163,6 +163,8 @@ def _flush_batch(self) -> None:
 
         self.logger.debug(f'ODP event queue: flushing batch size {batch_len}.')
         should_retry = False
+        initial_retry_interval = 0.2  # 200ms
+        max_retry_interval = 1.0  # 1 second
 
         for i in range(1 + self.retry_count):
             try:
@@ -176,7 +178,12 @@ def _flush_batch(self) -> None:
             if not should_retry:
                 break
             if i < self.retry_count:
-                self.logger.debug('Error dispatching ODP events, scheduled to retry.')
+                # Exponential backoff: 200ms, 400ms, 800ms, ... capped at 1s
+                delay = initial_retry_interval * (2 ** i)
+                if delay > max_retry_interval:
+                    delay = max_retry_interval
+                self.logger.debug(f'Error dispatching ODP events, retrying after {delay}s.')
+                time.sleep(delay)
 
         if should_retry:
             self.logger.error(Errors.ODP_EVENT_FAILED.format(f'Failed after {i} retries: {self._current_batch}'))

tests/test_odp_event_manager.py

@@ -265,7 +265,7 @@ def test_odp_event_manager_retry_failure(self, *args):
 
         with mock.patch.object(
             event_manager.api_manager, 'send_odp_events', new_callable=CopyingMock, return_value=True
-        ) as mock_send:
+        ) as mock_send, mock.patch('time.sleep') as mock_sleep:
             event_manager.send_event(**self.events[0])
             event_manager.send_event(**self.events[1])
             event_manager.flush()
@@ -275,7 +275,9 @@ def test_odp_event_manager_retry_failure(self, *args):
             [mock.call(self.api_key, self.api_host, self.processed_events)] * number_of_tries
         )
         self.assertEqual(len(event_manager._current_batch), 0)
-        mock_logger.debug.assert_any_call('Error dispatching ODP events, scheduled to retry.')
+        # Verify exponential backoff delays: 0.2s, 0.4s, 0.8s
+        mock_sleep.assert_has_calls([mock.call(0.2), mock.call(0.4), mock.call(0.8)])
+        mock_logger.debug.assert_any_call('Error dispatching ODP events, retrying after 0.2s.')
         mock_logger.error.assert_called_once_with(
             f'ODP event send failed (Failed after 3 retries: {self.processed_events}).'
         )
@@ -288,15 +290,17 @@ def test_odp_event_manager_retry_success(self, *args):
 
         with mock.patch.object(
             event_manager.api_manager, 'send_odp_events', new_callable=CopyingMock, side_effect=[True, True, False]
-        ) as mock_send:
+        ) as mock_send, mock.patch('time.sleep') as mock_sleep:
             event_manager.send_event(**self.events[0])
             event_manager.send_event(**self.events[1])
             event_manager.flush()
             event_manager.event_queue.join()
 
         mock_send.assert_has_calls([mock.call(self.api_key, self.api_host, self.processed_events)] * 3)
         self.assertEqual(len(event_manager._current_batch), 0)
-        mock_logger.debug.assert_any_call('Error dispatching ODP events, scheduled to retry.')
+        # Verify exponential backoff delays: 0.2s, 0.4s (only 2 delays for 3 attempts)
+        mock_sleep.assert_has_calls([mock.call(0.2), mock.call(0.4)])
+        mock_logger.debug.assert_any_call('Error dispatching ODP events, retrying after 0.2s.')
         mock_logger.error.assert_not_called()
         self.assertStrictTrue(event_manager.is_running)
         event_manager.stop()