Flume HDFS接收器写入错误“无协议:值”

Question

尝试运行水槽作业时，我收到下面给出的错误。我正在云时代设置上运行它。

• Kafka是来源
• Morphline用作拦截器，从中创建avro记录
• 接收器为HDFS

完全相同的文件(morphline，avro schema等。水槽配置)。但是在另一个环境中，它会抛出这个错误。

2019-07-15 14:24:17,669 WARN org.apache.flume.sink.hdfs.BucketWriter: Caught IOException writing to HDFSWriter (no protocol: value). Closing file (hdfs://8.8.8.8:8020/user/hive/warehouse/folder/folder/FlumeData.1563162656585.tmp) and rethrowing exception.
2019-07-15 14:24:17,670 INFO org.apache.flume.sink.hdfs.BucketWriter: Closing hdfs://8.8.8.8:8020/user/hive/warehouse/folder/folder/FlumeData.1563162656585.tmp
2019-07-15 14:24:17,670 ERROR org.apache.flume.sink.hdfs.HDFSEventSink: process failed
java.lang.NullPointerException
        at org.apache.flume.sink.hdfs.AvroEventSerializer.flush(AvroEventSerializer.java:187)
        at org.apache.flume.sink.hdfs.HDFSDataStream.close(HDFSDataStream.java:131)
        at org.apache.flume.sink.hdfs.BucketWriter$3.call(BucketWriter.java:327)
        at org.apache.flume.sink.hdfs.BucketWriter$3.call(BucketWriter.java:323)
        at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:701)
        at org.apache.flume.auth.SimpleAuthenticator.execute(SimpleAuthenticator.java:50)
        at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:698)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
2019-07-15 14:24:17,671 ERROR org.apache.flume.SinkRunner: Unable to deliver event. Exception follows.
org.apache.flume.EventDeliveryException: java.lang.NullPointerException
        at org.apache.flume.sink.hdfs.HDFSEventSink.process(HDFSEventSink.java:451)
        at org.apache.flume.sink.DefaultSinkProcessor.process(DefaultSinkProcessor.java:67)
        at org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:145)
        at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
        at org.apache.flume.sink.hdfs.AvroEventSerializer.flush(AvroEventSerializer.java:187)
        at org.apache.flume.sink.hdfs.HDFSDataStream.close(HDFSDataStream.java:131)
        at org.apache.flume.sink.hdfs.BucketWriter$3.call(BucketWriter.java:327)
        at org.apache.flume.sink.hdfs.BucketWriter$3.call(BucketWriter.java:323)
        at org.apache.flume.sink.hdfs.BucketWriter$9$1.run(BucketWriter.java:701)
        at org.apache.flume.auth.SimpleAuthenticator.execute(SimpleAuthenticator.java:50)
        at org.apache.flume.sink.hdfs.BucketWriter$9.call(BucketWriter.java:698)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        ... 1 more

我能够在水槽上找到相关代码：https://github.com/apache/flume/blob/trunk/flume-ng-sinks/flume-hdfs-sink/src/main/java/org/apache/flume/sink/hdfs/BucketWriter.java（行：602）

// write the event
try {
  sinkCounter.incrementEventDrainAttemptCount();
  callWithTimeout(new CallRunner<Void>() {
    @Override
    public Void call() throws Exception {
      writer.append(event); // could block
      return null;
    }
  });
} catch (IOException e) {
  LOG.warn("Caught IOException writing to HDFSWriter ({}). Closing file (" +
      bucketPath + ") and rethrowing exception.",
      e.getMessage());
  close(true);
  throw e;
}

错误：捕获写入HDFSWriter的IO异常（无协议：值）。关闭文件

我无法弄清楚错误no协议：值是什么意思。

我找不到任何与Flume和HDFS相关的上下文中提到过这个错误。

Answer 1

配置中缺少 Incerceptor 协议 -- 添加了“file：/”在解决了问题的Flume配置文件中。

类似问题参考：https://community.cloudera.com/t5/Data-Ingestion-Integration/Flume-HDFS-sink-error-quot-unknown-protocol-hdfs-quot/td-p/19344