java - 将 ByteBuffer 字段写入 Cassandra 时出现异常

Question

我们有一个 apache beam 数据流作业，它从 Big Query 读取数据并将其转换为 POJO，然后使用 Datastax 驱动程序写入 Cassandra。我最近向表中添加了一个新的 blob 列，并向 POJO 添加了一个 ByteBuffer 字段。

我如何创建 ByteBuffer

String str = objectMapper.writeValueAsString(installSkuAttributes);
byte[] bytes = str.getBytes( StandardCharsets.UTF_8 );
pojo.setInstallAttributes(ByteBuffer.wrap(bytes));

这是管道片段 公共(public)无效executePipeline()抛出异常{

Pipeline pipeline = 
Pipeline.create(jobMetaDataBean.getDataflowPipelineOptions());

.... writeDataToCassandra(installSkuData);

pipeline.run();

在 DAO 编写器中进行必要的更改后，当我运行作业时，出现以下异常。我正在使用 Datastax 驱动程序

Exception in thread "main" org.apache.beam.sdk.Pipeline$PipelineExecutionException: java.lang.IllegalArgumentException: Forbidden IOException when writing to OutputStream
    at org.apache.beam.runners.direct.DirectRunner$DirectPipelineResult.waitUntilFinish(DirectRunner.java:349)
    at org.apache.beam.runners.direct.DirectRunner$DirectPipelineResult.waitUntilFinish(DirectRunner.java:319)
    at org.apache.beam.runners.direct.DirectRunner.run(DirectRunner.java:210)
    at org.apache.beam.runners.direct.DirectRunner.run(DirectRunner.java:66)
    at org.apache.beam.sdk.Pipeline.run(Pipeline.java:311)
    at org.apache.beam.sdk.Pipeline.run(Pipeline.java:297)
    at com.homedepot.productassortment.fullfeed.dataflow.InstallSkusFullFeed.executePipeline(InstallSkusFullFeed.java:216)
    at com.homedepot.productassortment.fullfeed.dataflow.InstallSkusFullFeed.main(InstallSkusFullFeed.java:221)
Caused by: java.lang.IllegalArgumentException: Forbidden IOException when writing to OutputStream
    at org.apache.beam.sdk.util.CoderUtils.encodeToSafeStream(CoderUtils.java:88)
    at org.apache.beam.sdk.util.CoderUtils.encodeToByteArray(CoderUtils.java:69)
    at org.apache.beam.sdk.util.CoderUtils.encodeToByteArray(CoderUtils.java:54)
    at org.apache.beam.sdk.util.CoderUtils.clone(CoderUtils.java:148)
    at org.apache.beam.sdk.util.MutationDetectors$CodedValueMutationDetector.<init>(MutationDetectors.java:117)
    at org.apache.beam.sdk.util.MutationDetectors.forValueWithCoder(MutationDetectors.java:46)
    at org.apache.beam.runners.direct.ImmutabilityCheckingBundleFactory$ImmutabilityEnforcingBundle.add(ImmutabilityCheckingBundleFactory.java:112)
    at org.apache.beam.runners.direct.ParDoEvaluator$BundleOutputManager.output(ParDoEvaluator.java:242)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner.outputWindowedValue(SimpleDoFnRunner.java:219)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner.access$700(SimpleDoFnRunner.java:69)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner$DoFnProcessContext.output(SimpleDoFnRunner.java:517)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner$DoFnProcessContext.output(SimpleDoFnRunner.java:505)
    at com.homedepot.productassortment.fullfeed.dataflow.InstallSkusFullFeed$PrepareDataForCassandraWrite.processElement(InstallSkusFullFeed.java:160)
Caused by: java.io.NotSerializableException: java.nio.HeapByteBuffer
    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.writeObject(ObjectOutputStream.java:348)
    at org.apache.beam.sdk.coders.SerializableCoder.encode(SerializableCoder.java:166)
    at org.apache.beam.sdk.coders.SerializableCoder.encode(SerializableCoder.java:52)
    at org.apache.beam.sdk.coders.IterableLikeCoder.encode(IterableLikeCoder.java:99)
    at org.apache.beam.sdk.coders.IterableLikeCoder.encode(IterableLikeCoder.java:60)
    at org.apache.beam.sdk.coders.Coder.encode(Coder.java:143)
    at org.apache.beam.sdk.util.CoderUtils.encodeToSafeStream(CoderUtils.java:85)
    at org.apache.beam.sdk.util.CoderUtils.encodeToByteArray(CoderUtils.java:69)
    at org.apache.beam.sdk.util.CoderUtils.encodeToByteArray(CoderUtils.java:54)
    at org.apache.beam.sdk.util.CoderUtils.clone(CoderUtils.java:148)
    at org.apache.beam.sdk.util.MutationDetectors$CodedValueMutationDetector.<init>(MutationDetectors.java:117)
    at org.apache.beam.sdk.util.MutationDetectors.forValueWithCoder(MutationDetectors.java:46)
    at org.apache.beam.runners.direct.ImmutabilityCheckingBundleFactory$ImmutabilityEnforcingBundle.add(ImmutabilityCheckingBundleFactory.java:112)
    at org.apache.beam.runners.direct.ParDoEvaluator$BundleOutputManager.output(ParDoEvaluator.java:242)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner.outputWindowedValue(SimpleDoFnRunner.java:219)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner.access$700(SimpleDoFnRunner.java:69)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner$DoFnProcessContext.output(SimpleDoFnRunner.java:517)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner$DoFnProcessContext.output(SimpleDoFnRunner.java:505)
    at com.homedepot.productassortment.fullfeed.dataflow.InstallSkusFullFeed$PrepareDataForCassandraWrite.processElement(InstallSkusFullFeed.java:160)
    at com.homedepot.productassortment.fullfeed.dataflow.InstallSkusFullFeed$PrepareDataForCassandraWrite$DoFnInvoker.invokeProcessElement(Unknown Source)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner.invokeProcessElement(SimpleDoFnRunner.java:185)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimpleDoFnRunner.processElement(SimpleDoFnRunner.java:149)
    at org.apache.beam.repackaged.beam_runners_direct_java.runners.core.SimplePushbackSideInputDoFnRunner.processElementInReadyWindows(SimplePushbackSideInputDoFnRunner.java:78)
    at org.apache.beam.runners.direct.ParDoEvaluator.processElement(ParDoEvaluator.java:189)
    at org.apache.beam.runners.direct.DoFnLifecycleManagerRemovingTransformEvaluator.processElement(DoFnLifecycleManagerRemovingTransformEvaluator.java:55)
    at org.apache.beam.runners.direct.DirectTransformExecutor.processElements(DirectTransformExecutor.java:161)
    at org.apache.beam.runners.direct.DirectTransformExecutor.run(DirectTransformExecutor.java:125)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

Answer 1

真正的问题在这里:

java.io.NotSerializableException: java.nio.HeapByteBuffer

这是由于 ByteBuffer 不可序列化造成的，因此它无法用于分布式工作。您可以通过直接使用 byte[] 作为属性来避免这种情况，或者在可序列化的 ByteBuffer 周围实现一个包装器。