1ms start, 1.25 rate, 500ms max

Author: sleepyStick

pymongo/asynchronous/client_session.py

@@ -472,8 +472,8 @@ def _max_time_expired_error(exc: PyMongoError) -> bool:
 # This limit is non-configurable and was chosen to be twice the 60 second
 # default value of MongoDB's `transactionLifetimeLimitSeconds` parameter.
 _WITH_TRANSACTION_RETRY_TIME_LIMIT = 120
-_BACKOFF_MAX = 1
-_BACKOFF_INITIAL = 0.050  # 50ms initial backoff
+_BACKOFF_MAX = 0.500  # 500ms max backoff
+_BACKOFF_INITIAL = 0.001  # 1ms initial backoff
 
 
 def _within_time_limit(start_time: float) -> bool:
@@ -711,7 +711,7 @@ async def callback(session, custom_arg, custom_kwarg=None):
         while True:
             if retry:  # Implement exponential backoff on retry.
                 jitter = random.random()  # noqa: S311
-                backoff = jitter * min(_BACKOFF_INITIAL * (2**retry), _BACKOFF_MAX)
+                backoff = jitter * min(_BACKOFF_INITIAL * (1.25**retry), _BACKOFF_MAX)
                 await asyncio.sleep(backoff)
             retry += 1
             await self.start_transaction(

pymongo/synchronous/client_session.py

@@ -470,8 +470,8 @@ def _max_time_expired_error(exc: PyMongoError) -> bool:
 # This limit is non-configurable and was chosen to be twice the 60 second
 # default value of MongoDB's `transactionLifetimeLimitSeconds` parameter.
 _WITH_TRANSACTION_RETRY_TIME_LIMIT = 120
-_BACKOFF_MAX = 1
-_BACKOFF_INITIAL = 0.050  # 50ms initial backoff
+_BACKOFF_MAX = 0.500  # 500ms max backoff
+_BACKOFF_INITIAL = 0.001  # 1ms initial backoff
 
 
 def _within_time_limit(start_time: float) -> bool:
@@ -709,7 +709,7 @@ def callback(session, custom_arg, custom_kwarg=None):
         while True:
             if retry:  # Implement exponential backoff on retry.
                 jitter = random.random()  # noqa: S311
-                backoff = jitter * min(_BACKOFF_INITIAL * (2**retry), _BACKOFF_MAX)
+                backoff = jitter * min(_BACKOFF_INITIAL * (1.25**retry), _BACKOFF_MAX)
                 time.sleep(backoff)
             retry += 1
             self.start_transaction(read_concern, write_concern, read_preference, max_commit_time_ms)