CODEWITHSUNDEEP
google-cloud-dataflowgoogle-cloud-pubsubapache-beam
jimmy
jimmy

Reputation: 4881

Apache Beam PubSub Reader Exceptions

I'm running a Pipeline with a PubSub Source and I'm experiencing some strange exceptions from crashing my Pipeline. I can process a few elements (3-10) just fine and then all of a sudden one of the following two error messages gets thrown. Both don't give me a clue what I might be doing wrong so I removed all of my Transforms and only left the Source in and the problem still exists. I'm posting just some test strings to the PubSub. Any help is appreciated.

Exception 1:

[WARNING]
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:293)
        at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.NullPointerException
        at org.apache.beam.sdk.io.PubsubUnboundedSource$PubsubReader.ackBatch(PubsubUnboundedSource.java:640)
        at org.apache.beam.sdk.io.PubsubUnboundedSource$PubsubCheckpoint.finalizeCheckpoint(PubsubUnboundedSource.java:313)
        at org.apache.beam.runners.direct.UnboundedReadEvaluatorFactory$UnboundedReadEvaluator.getReader(UnboundedReadEvaluatorFactory.java:174)
        at org.apache.beam.runners.direct.UnboundedReadEvaluatorFactory$UnboundedReadEvaluator.processElement(UnboundedReadEvaluatorFactory.java:127)
        at org.apache.beam.runners.direct.TransformExecutor.processElements(TransformExecutor.java:139)
        at org.apache.beam.runners.direct.TransformExecutor.run(TransformExecutor.java:107)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

Exception 2:

[WARNING]
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:293)
        at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.IllegalStateException: Cannot finalize a restored checkpoint
        at org.apache.beam.sdk.repackaged.com.google.common.base.Preconditions.checkState(Preconditions.java:444)
        at org.apache.beam.sdk.io.PubsubUnboundedSource$PubsubCheckpoint.finalizeCheckpoint(PubsubUnboundedSource.java:293)
        at org.apache.beam.runners.direct.UnboundedReadEvaluatorFactory$UnboundedReadEvaluator.finishRead(UnboundedReadEvaluatorFactory.java:205)
        at org.apache.beam.runners.direct.UnboundedReadEvaluatorFactory$UnboundedReadEvaluator.processElement(UnboundedReadEvaluatorFactory.java:142)
        at org.apache.beam.runners.direct.TransformExecutor.processElements(TransformExecutor.java:139)
        at org.apache.beam.runners.direct.TransformExecutor.run(TransformExecutor.java:107)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

Basic Code:

PipelineOptions options = PipelineOptionsFactory.create(); 
PubsubOptions dataflowOptions = options.as(PubsubOptions.class);
dataflowOptions.setStreaming(true);

Pipeline p = Pipeline.create(options);

p.apply(PubsubIO.<String>read().subscription("my-subscription")
    .withCoder(StringUtf8Coder.of())));

Execution:

mvn compile exec:java -Dexec.mainClass=my.package.SalesTransactions -Dexec.args="--runner BlockingDataflowRunner --project=my-project --tempLocation=gs://my-project/tmp"

Upvotes: 3

Views: 620

Answers (1)

Flavio Fiszman
Flavio Fiszman

Reputation: 76

This problem exists because of a Bug (BEAM-1656) in the DirectRunner and a precondition within PubsubCheckpoint.

The answer Apache Beam: PubsubReader fails with NPE contains more information about the bug and how to solve it. Thanks!

Upvotes: 2

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