[ PECO - 1768 ] PySQL: adjust HTTP retry logic to align with Go and Nodejs drivers

src/databricks/sql/auth/retry.py

@@ -285,25 +285,27 @@ def sleep_for_retry(self, response: BaseHTTPResponse) -> bool:
         """
         retry_after = self.get_retry_after(response)
         if retry_after:
-            backoff = self.get_backoff_time()
-            proposed_wait = max(backoff, retry_after)
-            self.check_proposed_wait(proposed_wait)
-            time.sleep(proposed_wait)
-            return True
+            proposed_wait = retry_after
+        else:
+            proposed_wait = self.get_exponential_backoff()
 
-        return False
+        proposed_wait = min(proposed_wait, self.delay_max)
+        self.check_proposed_wait(proposed_wait)
+        time.sleep(proposed_wait)
+        return True
 
-    def get_backoff_time(self) -> float:
-        """Calls urllib3's built-in get_backoff_time.
+    def get_exponential_backoff(self) -> float:
+        """
+        This method implements the exponential backoff algorithm to calculate the delay between retries.
 
         Never returns a value larger than self.delay_max
         A MaxRetryDurationError will be raised if the calculated backoff would exceed self.max_attempts_duration
 
-        Note: within urllib3, a backoff is only calculated in cases where a Retry-After header is not present
-            in the previous unsuccessful request and `self.respect_retry_after_header` is True (which is always true)
+        :return:
         """
 
-        proposed_backoff = super().get_backoff_time()
+        current_attempt = self.stop_after_attempts_count - self.total
+        proposed_backoff = (2**current_attempt) * self.delay_min
         proposed_backoff = min(proposed_backoff, self.delay_max)
         self.check_proposed_wait(proposed_backoff)
 

src/databricks/sql/thrift_backend.py

@@ -64,8 +64,8 @@
 # - 900s attempts-duration lines up w ODBC/JDBC drivers (for cluster startup > 10 mins)
 _retry_policy = {  # (type, default, min, max)
     "_retry_delay_min": (float, 1, 0.1, 60),
-    "_retry_delay_max": (float, 60, 5, 3600),
-    "_retry_stop_after_attempts_count": (int, 30, 1, 60),
+    "_retry_delay_max": (float, 30, 5, 3600),
+    "_retry_stop_after_attempts_count": (int, 5, 1, 60),
     "_retry_stop_after_attempts_duration": (float, 900, 1, 86400),
     "_retry_delay_default": (float, 5, 1, 60),
 }