如何在Apache Beam Java中將TestStreams與MultiOutput類一起使用

Question

我正在嘗試編寫一個Beam Streaming管道，該管道僅從PubSub隊列中讀取，分析數據並寫入兩個BigQuery表之一。 因此，代碼利用了側面輸出的優勢，可以從DoFn內部寫入兩個表之一。 我遇到以下錯誤消息：java.lang.IllegalArgumentException：無法序列化DoFnAndMainOutput{doFn=com.pipeline.PubSubToBigQuery$ParsePubSubMessage@50eca7c6，mainOutputTag = Tag}。 我將在下面附加完整的錯誤消息，DoFn和Test類：

DoFn：

public static class PubsubMessageToTableRow
            extends PTransform<PCollection<PubsubMessage>, PCollectionTuple> {

        private TupleTag<TableRow> soundEventReadings;
        private TupleTag<TableRow> doorEventReadings;

        public PubsubMessageToTableRow(TupleTag<TableRow> soundEventReadings, TupleTag<TableRow> doorEventReadings){
            this.soundEventReadings = soundEventReadings;
            this.doorEventReadings = doorEventReadings;
        }

        @Override
        public PCollectionTuple expand(PCollection<PubsubMessage> input) {

            return input.apply("Parse PubSub Message",
                    ParDo.of(new ParsePubSubMessage(soundEventReadings, doorEventReadings))
                    .withOutputTags(soundEventReadings, TupleTagList.of(doorEventReadings)));

        }
    }

    /**
     * Parse the PubSub Json message and create either a Door or Sound Event. Then create a TableRow object from the
     * event objects.
     */
    public static class ParsePubSubMessage extends DoFn<PubsubMessage, TableRow> {

        private final TupleTag<TableRow> soundEventReadings;
        private final TupleTag<TableRow> doorEventReadings;

        public ParsePubSubMessage(TupleTag<TableRow> soundEventReadings,
                                  TupleTag<TableRow> doorEventReadings) {
            this.soundEventReadings = soundEventReadings;
            this.doorEventReadings = doorEventReadings;
        }


        @ProcessElement
        public void processElement(ProcessContext c, MultiOutputReceiver out) throws IOException{
            PubsubMessage message = c.element();
            String jsonString = new String(message.getPayload(), StandardCharsets.UTF_8);
            ObjectMapper mapper = new ObjectMapper();

            // A DoorEvent can either be a door open/close event signified with #door# in the SensorName or can
            // be a motion event from the motion sensor next to the door signified with #motion# in the SensorName
            if (jsonString.contains("#door#") || jsonString.contains("#motion#")){
                DoorEvent doorEvent = mapper.readValue(jsonString, DoorEvent.class);
                out.get(doorEventReadings).output(doorEvent.toTableRow());
            } else if (jsonString.contains("noiseFloor")){
                SoundEvent soundEvent = mapper.readValue(jsonString, SoundEvent.class);
                out.get(soundEventReadings).output(soundEvent.toTableRow());
            }
        }
    }

測試

 @Rule
    public final transient TestPipeline testPipeline = TestPipeline.create();

    @Test
    public void testPubsubMessageToTableRow() throws IOException{
        String jsonDoorEvent = "{\"EventID\":\"12\",\"HomeID\":" +
                "\"22222\",\"SmartThingsSensorName\":" +
                "\"sa#door#1#front_door\",\"State\":\"closed\",\"Label\":false," +
                "\"HasBeenLabelled\":false,\"EventTime\":\"2019-01-09T12:22:22Z\",\"CreateDate\":" +
                "\"2019-01-09T15:17:00Z\",\"ModifyDate\":\"2019-01-09T15:17:00Z\"}";

        TableRow door = doorEvent.toTableRow();

        TableRow outputDoorRow = new TableRow().set("EventID", "12")
                .set("HomeID", "22222")
                .set("SmartThingsSensorName", "sa#door#1#front_door")
                .set("State", "closed")
                .set("Label", false)
                .set("HasBeenLabelled", false)
                .set("EventTime", "2019-01-09T12:22:22Z")
                .set("CreateDate", "2019-01-09T15:17:00Z")
                .set("ModifyDate", "2019-01-09T15:17:00Z");

        Map<String, String> attributes = new HashMap<>();
        attributes.put("eventTime", "2019-01-09T12:22:22Z");
        PubsubMessage messageDoor = new PubsubMessage(jsonDoorEvent.getBytes(), attributes);

        final TupleTag<TableRow> doorEventReadings = new TupleTag<TableRow>(){};

        TestStream<PubsubMessage> createEvent =
                TestStream.create(PubsubMessageWithAttributesCoder.of())
                .addElements(messageDoor).advanceWatermarkToInfinity();

        PCollectionTuple tuple = testPipeline
                .apply("Create Stream", createEvent)
                .apply("Parse pipeline",
                        new PubSubToBigQuery.PubsubMessageToTableRow(soundEventReadings, doorEventReadings));

        PCollection<TableRow> doorEventOutput = tuple.get(doorEventReadings);
        PAssert.that(doorEventOutput).containsInAnyOrder(outputDoorRow);

        testPipeline.run().waitUntilFinish();
     }

堆棧跟蹤：

java.lang.IllegalArgumentException: unable to serialize DoFnAndMainOutput{doFn=com.pipeline.PubSubToBigQuery$ParsePubSubMessage@50eca7c6, mainOutputTag=Tag<output>}

    at org.apache.beam.sdk.util.SerializableUtils.serializeToByteArray(SerializableUtils.java:57)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation.translateDoFn(ParDoTranslation.java:462)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation$1.translateDoFn(ParDoTranslation.java:160)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation.payloadForParDoLike(ParDoTranslation.java:695)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation.translateParDo(ParDoTranslation.java:156)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation$ParDoPayloadTranslator.translate(ParDoTranslation.java:111)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.PTransformTranslation.toProto(PTransformTranslation.java:206)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation.getParDoPayload(ParDoTranslation.java:547)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.ParDoTranslation.isSplittable(ParDoTranslation.java:557)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.construction.PTransformMatchers$4.matches(PTransformMatchers.java:194)
    at org.apache.beam.sdk.Pipeline$2.visitPrimitiveTransform(Pipeline.java:278)
    at org.apache.beam.sdk.runners.TransformHierarchy$Node.visit(TransformHierarchy.java:668)
    at org.apache.beam.sdk.runners.TransformHierarchy$Node.visit(TransformHierarchy.java:660)
    at org.apache.beam.sdk.runners.TransformHierarchy$Node.visit(TransformHierarchy.java:660)
    at org.apache.beam.sdk.runners.TransformHierarchy$Node.access$600(TransformHierarchy.java:311)
    at org.apache.beam.sdk.runners.TransformHierarchy.visit(TransformHierarchy.java:245)
    at org.apache.beam.sdk.Pipeline.traverseTopologically(Pipeline.java:458)
    at org.apache.beam.sdk.Pipeline.replace(Pipeline.java:256)
    at org.apache.beam.sdk.Pipeline.replaceAll(Pipeline.java:209)
    at org.apache.beam.runners.direct.DirectRunner.run(DirectRunner.java:170)
    at org.apache.beam.runners.direct.DirectRunner.run(DirectRunner.java:66)
    at org.apache.beam.sdk.Pipeline.run(Pipeline.java:311)
    at org.apache.beam.sdk.testing.TestPipeline.run(TestPipeline.java:348)
    at org.apache.beam.sdk.testing.TestPipeline.run(TestPipeline.java:329)
    at com.ecobee.hm_occupancy_data_pipeline.PubSubToBigQueryTest.testPubsubMessageToTableRow(PubSubToBigQueryTest.java:118)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.apache.beam.sdk.testing.TestPipeline$1.evaluate(TestPipeline.java:317)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.io.NotSerializableException: com.pipeline.PubSubToBigQueryTest
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
    at org.apache.beam.sdk.util.SerializableUtils.serializeToByteArray(SerializableUtils.java:53)
    ... 48 more

Answer 1

問題出在日志中： java.io.NotSerializableException: com.pipeline.PubSubToBigQueryTest 。 使您的測試工具可Serializable ，這應該解決它。 或嘗試將所有DoFns和其他DoFns功能移到單獨的可序列化類中。