Hi Lukasz,
Thanks for promptly fixing this [1]. I saw that the current element was
not set correctly when timers are processed, but wanted to make sure any
changes would be aligned with the harness processing model.
I think I favor the currentElementOrTimer approach because it makes
things more explicit, but the solution is fine for now.
Thanks,
Max
[1] https://github.com/apache/beam/pull/6902
On 31.10.18 19:09, Lukasz Cwik wrote:
I filed https://issues.apache.org/jira/browse/BEAM-5930.
On Wed, Oct 31, 2018 at 10:22 AM Lukasz Cwik <lc...@google.com
<mailto:lc...@google.com>> wrote:
That looks like a bug in the FnApiDoFnRunner.java
The FnApiStateAccessor is given a callback to get the current
element and it is not handling the case where the current element is
a timer.
callback:
https://github.com/apache/beam/blob/29c443162a2fe4c89d26336b30aa6e3a3bfbade8/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnApiDoFnRunner.java#L212
where the current "element" gets set:
https://github.com/apache/beam/blob/29c443162a2fe4c89d26336b30aa6e3a3bfbade8/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnApiDoFnRunner.java#L220
where the current "timer" gets set:
https://github.com/apache/beam/blob/29c443162a2fe4c89d26336b30aa6e3a3bfbade8/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnApiDoFnRunner.java#L237
The easiest fix would be to have the callback return the first non
null from currentElement/currentTimer but longer term I think we'll
want a different solution. Alternatively, we could collapse
currentElement and currentTimer to be currentElementOrTimer which
would solve the accessor issue.
On Wed, Oct 31, 2018 at 9:50 AM Maximilian Michels <m...@apache.org
<mailto:m...@apache.org>> wrote:
Hi,
I have a question regarding user state during timer callback in
the FnApiDoFnRunner (Java SDK Harness).
I've started implementing Timers for the portable Flink Runner.
I can register a timer via the timer output collection and fire
the timer via the timer input of the SDK Harness. But when I try
to access state in the Timer callback, I get the exception below.
Is this a bug or if not, how is the timer's key supposed to be
set? I assume that it should be set from the timer element which
contains the key.
Thanks,
Max
Caused by: java.util.concurrent.ExecutionException:
java.lang.RuntimeException: Error received from SDK harness for
instruction 72: java.util.concurrent.ExecutionException:
java.lang.NullPointerException
at
java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357)
at
java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895)
at
org.apache.beam.sdk.fn.data.CompletableFutureInboundDataClient.awaitCompletion(CompletableFutureInboundDataClient.java:49)
at
org.apache.beam.sdk.fn.data.BeamFnDataInboundObserver.awaitCompletion(BeamFnDataInboundObserver.java:90)
at
org.apache.beam.fn.harness.BeamFnDataReadRunner.blockTillReadFinishes(BeamFnDataReadRunner.java:185)
at
org.apache.beam.fn.harness.control.ProcessBundleHandler.processBundle(ProcessBundleHandler.java:292)
at
org.apache.beam.fn.harness.control.BeamFnControlClient.delegateOnInstructionRequestType(BeamFnControlClient.java:161)
at
org.apache.beam.fn.harness.control.BeamFnControlClient.lambda$processInstructionRequests$0(BeamFnControlClient.java:145)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at
org.apache.beam.model.fnexecution.v1.BeamFnApi$StateKey$BagUserState$Builder.setKey(BeamFnApi.java:49694)
at
org.apache.beam.fn.harness.state.FnApiStateAccessor.createBagUserStateKey(FnApiStateAccessor.java:451)
at
org.apache.beam.fn.harness.state.FnApiStateAccessor.bindBag(FnApiStateAccessor.java:244)
at
org.apache.beam.sdk.state.StateSpecs$BagStateSpec.bind(StateSpecs.java:487)
at
org.apache.beam.sdk.state.StateSpecs$BagStateSpec.bind(StateSpecs.java:477)
at
org.apache.beam.fn.harness.FnApiDoFnRunner$OnTimerContext.state(FnApiDoFnRunner.java:671)
at
StateTest$5$OnTimerInvoker$expiry$ZXhwaXJ5.invokeOnTimer(Unknown
Source)
at
org.apache.beam.sdk.transforms.reflect.ByteBuddyDoFnInvokerFactory$DoFnInvokerBase.invokeOnTimer(ByteBuddyDoFnInvokerFactory.java:187)
at
org.apache.beam.fn.harness.FnApiDoFnRunner.processTimer(FnApiDoFnRunner.java:244)
at
org.apache.beam.fn.harness.DoFnPTransformRunnerFactory.lambda$createRunnerForPTransform$0(DoFnPTransformRunnerFactory.java:134)
at
org.apache.beam.sdk.fn.data.BeamFnDataInboundObserver.accept(BeamFnDataInboundObserver.java:81)
at
org.apache.beam.sdk.fn.data.BeamFnDataInboundObserver.accept(BeamFnDataInboundObserver.java:32)
at
org.apache.beam.sdk.fn.data.BeamFnDataGrpcMultiplexer$InboundObserver.onNext(BeamFnDataGrpcMultiplexer.java:139)
at
org.apache.beam.sdk.fn.data.BeamFnDataGrpcMultiplexer$InboundObserver.onNext(BeamFnDataGrpcMultiplexer.java:125)
at
org.apache.beam.sdk.fn.stream.ForwardingClientResponseObserver.onNext(ForwardingClientResponseObserver.java:50)
at
org.apache.beam.vendor.grpc.v1.io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onMessage(ClientCalls.java:407)
at
org.apache.beam.vendor.grpc.v1.io.grpc.ForwardingClientCallListener.onMessage(ForwardingClientCallListener.java:33)
at
org.apache.beam.vendor.grpc.v1.io.grpc.ForwardingClientCallListener.onMessage(ForwardingClientCallListener.java:33)
at
org.apache.beam.vendor.grpc.v1.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1MessagesAvailable.runInContext(ClientCallImpl.java:519)
at
org.apache.beam.vendor.grpc.v1.io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
at
org.apache.beam.vendor.grpc.v1.io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
