java - Java spark kafka 流中的对象不可序列化(org.apache.kafka.clients.consumer.ConsumerRecord)

Question

我很确定我只推送数据字符串并反序列化为字符串。我推送的记录也显示错误。

但是为什么突然出现这种类型的错误，是不是我遗漏了什么？

下面是代码，

    import java.util.HashMap;
    import java.util.HashSet;
    import java.util.Arrays;
    import java.util.Collection;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Set;
    import java.util.concurrent.atomic.AtomicReference;
    import java.util.regex.Pattern;

    import scala.Tuple2;

    import kafka.serializer.StringDecoder;

    import org.apache.spark.SparkConf;
    import org.apache.spark.api.java.JavaPairRDD;
    import org.apache.spark.api.java.JavaRDD;
    import org.apache.spark.api.java.function.*;
    import org.apache.spark.streaming.api.java.*;
    import org.apache.spark.streaming.kafka.HasOffsetRanges;
    import org.apache.spark.streaming.kafka10.*;
    import org.apache.spark.streaming.kafka.OffsetRange;
    import org.apache.spark.streaming.Duration;
    import org.apache.spark.streaming.Durations;

public final class KafkaConsumerDirectStream {
    public static void main(String[] args) throws Exception { 
       try {
                    SparkConf sparkConf = new SparkConf().setAppName("JavaKafkaWordCount11").setMaster("local[*]");
                    sparkConf.set("spark.streaming.concurrentJobs", "3");

                    // Create the context with 2 seconds batch size
                    JavaStreamingContext jssc = new JavaStreamingContext(sparkConf, new Duration(2000));

                    Map<String, Object> kafkaParams = new HashMap<>();
                    // kafkaParams.put("metadata.broker.list", "x.xx.xxx.xxx:9091,
                    // x.xx.xxx.xxx:9092, x.xx.xxx.xxx:9093");

                    kafkaParams.put("bootstrap.servers", "x.xx.xxx.xxx:9091");
                    kafkaParams.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
                    kafkaParams.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
                    kafkaParams.put("group.id", "11_ubiq_12dj");
                    kafkaParams.put("enable.auto.commit", "true");
                    kafkaParams.put("auto.commit.interval.ms", "1000");
                    kafkaParams.put("session.timeout.ms", "30000");
                    kafkaParams.put("auto.offset.reset", "earliest");
                    kafkaParams.put("enable.auto.commit", true);

                    Collection<String> topics = Arrays.asList("TopicQueue");

                    JavaInputDStream<ConsumerRecord<String, String>> stream = KafkaUtils.createDirectStream(jssc,
                            LocationStrategies.PreferBrokers(),
                            ConsumerStrategies.<String, String>Subscribe(topics, kafkaParams));

                    //stream.print();


                    stream.foreachRDD(new VoidFunction<JavaRDD<ConsumerRecord<String, String>>>() {
                        @Override
                        public void call(JavaRDD<ConsumerRecord<String, String>> rdd) {
                            final OffsetRange[] offsetRanges = ((HasOffsetRanges) rdd.rdd()).offsetRanges();
                            rdd.foreachPartition(new VoidFunction<Iterator<ConsumerRecord<String, String>>>() {
                                @Override
                                public void call(Iterator<ConsumerRecord<String, String>> consumerRecords) {
                                    OffsetRange o = offsetRanges[TaskContext.get().partitionId()];

                                    // stream.asInstanceOf[CanCommitOffsets].commitAsync(offsetRanges);
                                    System.out.println(
                                            o.topic() + " " + o.partition() + " " + o.fromOffset() + " " + o.untilOffset());

                                }
                            });
                        }
                    });

                    jssc.start();
                    jssc.awaitTermination();
                } catch (Exception e) {
                    e.printStackTrace();
                }    
    }
}

在引发错误的下方，

 16/11/24 00:19:14 ERROR JobScheduler: Error running job streaming job 1479964754000 ms.0
org.apache.spark.SparkException: Job aborted due to stage failure: Task 0.0 in stage 30.0 (TID 1500) had a not serializable result: org.apache.kafka.clients.consumer.ConsumerRecord
Serialization stack:
    - object not serializable (class: org.apache.kafka.clients.consumer.ConsumerRecord, value: ConsumerRecord(topic = PartWithTopic02Queue, partition = 36, offset = 555, CreateTime = 1479964753779, checksum = 2582644462, serialized key size = -1, serialized value size = 6, key = null, value = Hello0))
    - element of array (index: 0)
    - array (class [Lorg.apache.kafka.clients.consumer.ConsumerRecord;, size 1)
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1450)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1438)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1437)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1437)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:811)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:811)
    at scala.Option.foreach(Option.scala:236)
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:811)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1659)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1618)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1607)
    at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
    at java.lang.Thread.getStackTrace(Thread.java:1117)
    at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:632)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1871)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1884)
    at org.apache.spark.streaming.kafka010.KafkaRDD.take(KafkaRDD.scala:122)
    at org.apache.spark.streaming.kafka010.KafkaRDD.take(KafkaRDD.scala:50)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$print$2$$anonfun$foreachFunc$3$1.apply(DStream.scala:734)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$print$2$$anonfun$foreachFunc$3$1.apply(DStream.scala:733)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(ForEachDStream.scala:51)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(ForEachDStream.scala:51)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(ForEachDStream.scala:51)
    at org.apache.spark.streaming.dstream.DStream.createRDDWithLocalProperties(DStream.scala:415)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply$mcV$sp(ForEachDStream.scala:50)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply(ForEachDStream.scala:50)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply(ForEachDStream.scala:50)
    at scala.util.Try$.apply(Try.scala:161)
    at org.apache.spark.streaming.scheduler.Job.run(Job.scala:39)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply$mcV$sp(JobScheduler.scala:245)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply(JobScheduler.scala:245)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply(JobScheduler.scala:245)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler.run(JobScheduler.scala:244)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1153)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.lang.Thread.run(Thread.java:785)

Answer 1

apache.kafka.clients.consumer.ConsumerRecord 类不可序列化，不能用于 RMI 等。