Add backoff jitter

mlflow/environment_variables.py

@@ -101,6 +101,12 @@ def get(self):
     "MLFLOW_HTTP_REQUEST_BACKOFF_FACTOR", int, 2
 )
 
+#: Specifies the backoff jitter between MLflow HTTP request failures
+#: (default: ``1.0``)
+MLFLOW_HTTP_REQUEST_BACKOFF_JITTER = _EnvironmentVariable(
+    "MLFLOW_HTTP_REQUEST_BACKOFF_JITTER", float, 1.0
+)
+
 #: Specifies the timeout in seconds for MLflow HTTP requests
 #: (default: ``120``)
 MLFLOW_HTTP_REQUEST_TIMEOUT = _EnvironmentVariable("MLFLOW_HTTP_REQUEST_TIMEOUT", int, 120)

mlflow/utils/request_utils.py

@@ -71,6 +71,7 @@ def download_chunk(*, range_start, range_end, headers, download_path, http_uri):
 def _cached_get_request_session(
     max_retries,
     backoff_factor,
+    backoff_jitter,
     retry_codes,
     raise_on_status,
     # To create a new Session object for each process, we use the process id as the cache key.
@@ -92,6 +93,7 @@ def _cached_get_request_session(
         "status": max_retries,
         "status_forcelist": retry_codes,
         "backoff_factor": backoff_factor,
+        "backoff_jitter": backoff_jitter,
         "raise_on_status": raise_on_status,
     }
     if Version(urllib3.__version__) >= Version("1.26.0"):
@@ -106,14 +108,15 @@ def _cached_get_request_session(
     return session
 
 
-def _get_request_session(max_retries, backoff_factor, retry_codes, raise_on_status):
+def _get_request_session(max_retries, backoff_factor, backoff_jitter, retry_codes, raise_on_status):
     """
     Returns a `Requests.Session` object for making an HTTP request.
 
     :param max_retries: Maximum total number of retries.
     :param backoff_factor: a time factor for exponential backoff. e.g. value 5 means the HTTP
       request will be retried with interval 5, 10, 20... seconds. A value of 0 turns off the
       exponential backoff.
+    :param backoff_jitter: A random jitter to add to the backoff interval.
     :param retry_codes: a list of HTTP response error codes that qualifies for retry.
     :param raise_on_status: whether to raise an exception, or return a response, if status falls
       in retry_codes range and retries have been exhausted.
@@ -122,14 +125,22 @@ def _get_request_session(max_retries, backoff_factor, retry_codes, raise_on_stat
     return _cached_get_request_session(
         max_retries,
         backoff_factor,
+        backoff_jitter,
         retry_codes,
         raise_on_status,
         _pid=os.getpid(),
     )
 
 
 def _get_http_response_with_retries(
-    method, url, max_retries, backoff_factor, retry_codes, raise_on_status=True, **kwargs
+    method,
+    url,
+    max_retries,
+    backoff_factor,
+    backoff_jitter,
+    retry_codes,
+    raise_on_status=True,
+    **kwargs,
 ):
     """
     Performs an HTTP request using Python's `requests` module with an automatic retry policy.
@@ -140,14 +151,17 @@ def _get_http_response_with_retries(
     :param backoff_factor: a time factor for exponential backoff. e.g. value 5 means the HTTP
       request will be retried with interval 5, 10, 20... seconds. A value of 0 turns off the
       exponential backoff.
+    :param backoff_jitter: A random jitter to add to the backoff interval.
     :param retry_codes: a list of HTTP response error codes that qualifies for retry.
     :param raise_on_status: whether to raise an exception, or return a response, if status falls
       in retry_codes range and retries have been exhausted.
     :param kwargs: Additional keyword arguments to pass to `requests.Session.request()`
 
     :return: requests.Response object.
     """
-    session = _get_request_session(max_retries, backoff_factor, retry_codes, raise_on_status)
+    session = _get_request_session(
+        max_retries, backoff_factor, backoff_jitter, retry_codes, raise_on_status
+    )
     return session.request(method, url, **kwargs)
 
 

mlflow/utils/rest_utils.py

@@ -5,6 +5,7 @@
 
 from mlflow.environment_variables import (
     MLFLOW_HTTP_REQUEST_BACKOFF_FACTOR,
+    MLFLOW_HTTP_REQUEST_BACKOFF_JITTER,
     MLFLOW_HTTP_REQUEST_MAX_RETRIES,
     MLFLOW_HTTP_REQUEST_TIMEOUT,
 )
@@ -30,6 +31,7 @@ def http_request(
     method,
     max_retries=None,
     backoff_factor=None,
+    backoff_jitter=None,
     extra_headers=None,
     retry_codes=_TRANSIENT_FAILURE_RESPONSE_CODES,
     timeout=None,
@@ -60,9 +62,14 @@ def http_request(
 
     :return: requests.Response object.
     """
-    max_retries = max_retries or MLFLOW_HTTP_REQUEST_MAX_RETRIES.get()
-    backoff_factor = backoff_factor or MLFLOW_HTTP_REQUEST_BACKOFF_FACTOR.get()
-    timeout = timeout or MLFLOW_HTTP_REQUEST_TIMEOUT.get()
+    max_retries = MLFLOW_HTTP_REQUEST_MAX_RETRIES.get() if max_retries is None else max_retries
+    backoff_factor = (
+        MLFLOW_HTTP_REQUEST_BACKOFF_FACTOR.get() if backoff_factor is None else backoff_factor
+    )
+    backoff_jitter = (
+        MLFLOW_HTTP_REQUEST_BACKOFF_JITTER.get() if backoff_jitter is None else backoff_jitter
+    )
+    timeout = MLFLOW_HTTP_REQUEST_TIMEOUT.get() if timeout is None else timeout
     hostname = host_creds.host
     auth_str = None
     if host_creds.username and host_creds.password:
@@ -101,6 +108,7 @@ def http_request(
             url,
             max_retries,
             backoff_factor,
+            backoff_jitter,
             retry_codes,
             raise_on_status,
             headers=headers,