fix + lint

sdks/python/apache_beam/ml/transforms/embeddings/vertex_ai.py

@@ -19,10 +19,10 @@
 # Follow https://cloud.google.com/vertex-ai/docs/python-sdk/use-vertex-ai-python-sdk # pylint: disable=line-too-long
 # to install Vertex AI Python SDK.
 
-from collections.abc import Iterable
-from collections.abc import Sequence
 import logging
 import time
+from collections.abc import Iterable
+from collections.abc import Sequence
 from typing import Any
 from typing import Optional
 
@@ -101,6 +101,15 @@ def __init__(
     self.task_type = task_type
     self.title = title
 
+    # Configure AdaptiveThrottler and throttling metrics for client-side
+    # throttling behavior.
+    # See https://docs.google.com/document/d/1ePorJGZnLbNCmLD9mR7iFYOdPsyDA1rDnTpYnbdrzSU/edit?usp=sharing
+    # for more details.
+    self.throttled_secs = Metrics.counter(
+        VertexAIImageEmbeddings, "cumulativeThrottlingSeconds")
+    self.throttler = AdaptiveThrottler(
+        window_ms=1, bucket_ms=1, overload_ratio=2)
+
   @retry.with_exponential_backoff(
       num_retries=5, retry_filter=_retry_on_appropriate_gcp_error)
   def get_request(