[BEAM-10143] ClassCastException in GROUP BY with non-global window

• Type: Bug
• Status: Resolved
• Priority: P2
• Resolution: Unresolved
• Fix Version/s: 2.23.0
• Component/s: dsl-sql, sdk-py-core
• Assignee: Brian Hulette
• Reporter: Maximilian Michels
• Created: 28/May/20 18:00
• Updated: 22/Jul/20 17:52

Description

I'm using the SqlTransform as an external transform from within a Python
pipeline. I apply windowing before a GROUP BY query as mentioned as the first option in https://beam.apache.org/documentation/dsls/sql/extensions/windowing-and-triggering/:

  input
      | "Window" >> beam.WindowInto(window.FixedWindows(30))
      | "Aggregate" >>
      SqlTransform("""Select field, count(field) from PCOLLECTION
                      WHERE ...
		      GROUP BY field
                   """)

This results in an exception:

Caused by: java.lang.ClassCastException: org.apache.beam.sdk.transforms.windowing.IntervalWindow cannot be cast to org.apache.beam.sdk.transforms.windowing.GlobalWindow
	at org.apache.beam.sdk.transforms.windowing.GlobalWindow$Coder.encode(GlobalWindow.java:59)
	at org.apache.beam.sdk.coders.IterableLikeCoder.encode(IterableLikeCoder.java:98)
	at org.apache.beam.sdk.coders.IterableLikeCoder.encode(IterableLikeCoder.java:60)
	at org.apache.beam.sdk.util.WindowedValue$FullWindowedValueCoder.encode(WindowedValue.java:588)
	at org.apache.beam.sdk.util.WindowedValue$FullWindowedValueCoder.encode(WindowedValue.java:581)
	at org.apache.beam.sdk.util.WindowedValue$FullWindowedValueCoder.encode(WindowedValue.java:541)
	at org.apache.beam.sdk.fn.data.BeamFnDataSizeBasedBufferingOutboundObserver.accept(BeamFnDataSizeBasedBufferingOutboundObserver.java:109)
	at org.apache.beam.fn.harness.BeamFnDataWriteRunner.consume(BeamFnDataWriteRunner.java:154)
	at org.apache.beam.fn.harness.data.PCollectionConsumerRegistry$MetricTrackingFnDataReceiver.accept(PCollectionConsumerRegistry.java:216)
	at org.apache.beam.fn.harness.data.PCollectionConsumerRegistry$MetricTrackingFnDataReceiver.accept(PCollectionConsumerRegistry.java:179)

	at org.apache.beam.runners.fnexecution.control.FnApiControlClient$ResponseStreamObserver.onNext(FnApiControlClient.java:178)
	at org.apache.beam.runners.fnexecution.control.FnApiControlClient$ResponseStreamObserver.onNext(FnApiControlClient.java:158)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.stub.ServerCalls$StreamingServerCallHandler$StreamingServerCallListener.onMessage(ServerCalls.java:251)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.ForwardingServerCallListener.onMessage(ForwardingServerCallListener.java:33)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.Contexts$ContextualizedServerCallListener.onMessage(Contexts.java:76)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ServerCallImpl$ServerStreamListenerImpl.messagesAvailableInternal(ServerCallImpl.java:309)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ServerCallImpl$ServerStreamListenerImpl.messagesAvailable(ServerCallImpl.java:292)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ServerImpl$JumpToApplicationThreadServerStreamListener$1MessagesAvailable.runInContext(ServerImpl.java:782)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
	at org.apache.beam.vendor.grpc.v1p26p0.io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	... 1 more

Issue Links

• is caused by: BEAM-10308 Component id assignement is not consistent across PipelineContext instances
• relates to: BEAM-9621 Python SqlTransform follow-ups
• links to: GitHub Pull Request #12076