implement basic watermarking

Author: iasoon

ray_beam_runner/portability/context_management.py

@@ -163,15 +163,18 @@ def setup(self):
                         pcoll_id,
                         self.execution_context.safe_coders.get(coder_id, coder_id),
                     )
+
                 elif transform.spec.urn == bundle_processor.DATA_OUTPUT_URN:
                     data_output[transform.unique_name] = pcoll_id
                     coder_id = self.execution_context.data_channel_coders[
                         translations.only_element(transform.inputs.values())
                     ]
                 else:
                     raise NotImplementedError
-                data_spec = beam_fn_api_pb2.RemoteGrpcPort(coder_id=coder_id)
-                transform.spec.payload = data_spec.SerializeToString()
+                if pcoll_id != translations.IMPULSE_BUFFER:
+                    data_spec = beam_fn_api_pb2.RemoteGrpcPort(coder_id=coder_id)
+                    transform.spec.payload = data_spec.SerializeToString()
+
             elif transform.spec.urn in translations.PAR_DO_URNS:
                 payload = proto_utils.parse_Bytes(
                     transform.spec.payload, beam_runner_api_pb2.ParDoPayload

ray_beam_runner/portability/execution.py

@@ -345,20 +345,9 @@ def get(self, pcoll) -> List[ray.ObjectRef]:
 
 @ray.remote
 class RayWatermarkManager(watermark_manager.WatermarkManager):
-    def __init__(self):
-        # the original WatermarkManager performs a lot of computation
-        # in its __init__ method. Because Ray calls __init__ whenever
-        # it deserializes an object, we'll move its setup elsewhere.
-        self._initialized = False
-        self._pcollections_by_name = {}
-        self._stages_by_name = {}
-
-    def setup(self, stages):
-        if self._initialized:
-            return
-        logging.debug("initialized the RayWatermarkManager")
-        self._initialized = True
-        watermark_manager.WatermarkManager.setup(self, stages)
+    def set_pcoll_produced_watermark(self, name, watermark):
+        element = self._pcollections_by_name[name]
+        element.set_produced_watermark(watermark)
 
 
 class RayRunnerExecutionContext(object):
@@ -371,6 +360,7 @@ def __init__(
         state_servicer: Optional[RayStateManager] = None,
         worker_manager: Optional[RayWorkerHandlerManager] = None,
         pcollection_buffers: PcollectionBufferManager = None,
+        watermark_manager: Optional[RayWatermarkManager] = None,
     ) -> None:
         ray.util.register_serializer(
             beam_runner_api_pb2.Components,
@@ -405,7 +395,9 @@ def __init__(
             for t in s.transforms
             if t.spec.urn == bundle_processor.DATA_INPUT_URN
         }
-        self._watermark_manager = RayWatermarkManager.remote()
+        self.watermark_manager = watermark_manager or RayWatermarkManager.remote(
+            self.stages
+        )
         self.pipeline_context = pipeline_context.PipelineContext(pipeline_components)
         self.safe_windowing_strategies = {
             # TODO: Enable safe_windowing_strategy after
@@ -419,14 +411,6 @@ def __init__(
         self.worker_manager = worker_manager or RayWorkerHandlerManager()
         self.timer_coder_ids = self._build_timer_coders_id_map()
 
-    @property
-    def watermark_manager(self):
-        # We don't need to wait for this line to execute with ray.get,
-        # because any further calls to the watermark manager actor will
-        # have to wait for it.
-        self._watermark_manager.setup.remote(self.stages)
-        return self._watermark_manager
-
     @staticmethod
     def next_uid():
         # TODO(pabloem): Use stats actor for UIDs.
@@ -464,6 +448,7 @@ def __reduce__(self):
             self.state_servicer,
             self.worker_manager,
             self.pcollection_buffers,
+            self.watermark_manager,
         )
 
         def deserializer(*args):
@@ -475,6 +460,7 @@ def deserializer(*args):
                 args[4],
                 args[5],
                 args[6],
+                args[7],
             )
 
         return (deserializer, data)

ray_beam_runner/portability/ray_fn_runner.py

@@ -42,7 +42,7 @@
 from apache_beam.runners.portability.fn_api_runner import translations
 from apache_beam.runners.portability.fn_api_runner.execution import ListBuffer
 from apache_beam.transforms import environments
-from apache_beam.utils import proto_utils
+from apache_beam.utils import proto_utils, timestamp
 
 import ray
 from ray_beam_runner.portability.context_management import RayBundleContextManager
@@ -227,7 +227,9 @@ def _run_stage(
           bundle_context_manager (execution.BundleContextManager): A description of
             the stage to execute, and its context.
         """
+
         bundle_context_manager.setup()
+
         runner_execution_context.worker_manager.register_process_bundle_descriptor(
             bundle_context_manager.process_bundle_descriptor
         )
@@ -246,6 +248,8 @@ def _run_stage(
             for k in bundle_context_manager.transform_to_buffer_coder
         }
 
+        watermark_manager = runner_execution_context.watermark_manager
+
         final_result = None  # type: Optional[beam_fn_api_pb2.InstructionResponse]
 
         while True:
@@ -262,19 +266,26 @@ def _run_stage(
 
             final_result = merge_stage_results(final_result, last_result)
             if not delayed_applications and not fired_timers:
+                # Processing has completed; marking all outputs as completed
+                for output_pc in bundle_outputs:
+                    _, update_output_pc = translations.split_buffer_id(output_pc)
+                    watermark_manager.set_pcoll_produced_watermark.remote(
+                        update_output_pc, timestamp.MAX_TIMESTAMP
+                    )
                 break
             else:
-                # TODO: Enable following assertion after watermarking is implemented
-                # assert (ray.get(
-                # runner_execution_context.watermark_manager
-                # .get_stage_node.remote(
-                #     bundle_context_manager.stage.name)).output_watermark()
-                #         < timestamp.MAX_TIMESTAMP), (
-                #     'wrong timestamp for %s. '
-                #     % ray.get(
-                #     runner_execution_context.watermark_manager
-                #     .get_stage_node.remote(
-                #     bundle_context_manager.stage.name)))
+                assert (
+                    ray.get(
+                        watermark_manager.get_stage_node.remote(
+                            bundle_context_manager.stage.name
+                        )
+                    ).output_watermark()
+                    < timestamp.MAX_TIMESTAMP
+                ), "wrong timestamp for %s. " % ray.get(
+                    watermark_manager.get_stage_node.remote(
+                        bundle_context_manager.stage.name
+                    )
+                )
                 input_data = delayed_applications
                 input_timers = fired_timers
 
@@ -288,6 +299,20 @@ def _run_stage(
         # TODO(pabloem): Make sure that side inputs are being stored somewhere.
         # runner_execution_context.commit_side_inputs_to_state(data_side_input)
 
+        # assert that the output watermark was correctly set for this stage
+        stage_node = ray.get(
+            runner_execution_context.watermark_manager.get_stage_node.remote(
+                bundle_context_manager.stage.name
+            )
+        )
+        assert (
+            stage_node.output_watermark() == timestamp.MAX_TIMESTAMP
+        ), "wrong output watermark for %s. Expected %s, but got %s." % (
+            stage_node,
+            timestamp.MAX_TIMESTAMP,
+            stage_node.output_watermark(),
+        )
+
         return final_result
 
     def _run_bundle(
@@ -346,6 +371,21 @@ def _run_bundle(
         #           coder_impl=bundle_context_manager.get_input_coder_impl(
         #               other_input))
 
+        # TODO: replace placeholder sets when timers are implemented
+        watermark_updates = fn_runner.FnApiRunner._build_watermark_updates(
+            runner_execution_context,
+            transform_to_buffer_coder.keys(),
+            set(),  # expected_timers
+            set(),  # pcolls_with_da
+            delayed_applications.keys(),
+            set(),  # watermarks_by_transform_and_timer_family
+        )
+
+        for pc_name, watermark in watermark_updates.items():
+            runner_execution_context.watermark_manager.set_pcoll_watermark.remote(
+                pc_name, watermark
+            )
+
         newly_set_timers = {}
         return result, newly_set_timers, delayed_applications, output