Kafka Stream aggregation with custom object data type












0















I have a processor that takes json string from a topic, with type GenericRecord.
Now i split the stream in 2 branch.
I take the first branch and i map the (key, value) in 2 string containing a specific field of json and a value of that field and i group by key.
And so far so good.
Now i have to aggregate the stream with a new Type user defined and i receive an exception.



Here the code:



The new type:



private class Tuple {

public int occ;
public int sum;


public Tuple (int occ, int sum) {
this.occ = occ;
this.sum = sum;
}

public void sum (int toAdd) {
this.sum += toAdd;
this.occ ++;
}

public int getAverage () {
return this.sum / this.occ;
}

public String toString() {
return occ + "-> " + sum + ": " + getAverage();
}


The good stream:



  StreamsBuilder builder = new StreamsBuilder();
KStream<GenericRecord, GenericRecord> source =
builder.stream(topic);

KStream<GenericRecord, GenericRecord> branches = source.branch(
(key,value) -> partition(value.toString()),
(key, value) -> true
);

KGroupedStream <String, String> groupedStream = branches[0]
.mapValues(value -> createJson(value.toString()))
.map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
.peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
.groupByKey();


The problem:



   KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
() -> new Tuple (0,0), // initializer
(aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)));



KafkaStreams streams = new KafkaStreams(builder.build(), props);
streams.start();


This is the exception:



   Exception in thread "streamtest-6173d6a2-4a3a-4d76-b793-774719f8b1f5-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Exception caught in process. taskId=1_0, processor=KSTREAM-SOURCE-0000000011, topic=streamtest-KSTREAM-AGGREGATE-STATE-STORE-0000000007-repartition, partition=0, offset=0
at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:318)
at org.apache.kafka.streams.processor.internals.AssignedStreamsTasks.process(AssignedStreamsTasks.java:94)
at org.apache.kafka.streams.processor.internals.TaskManager.process(TaskManager.java:409)
at org.apache.kafka.streams.processor.internals.StreamThread.processAndMaybeCommit(StreamThread.java:964)
at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:832)
at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
Caused by: org.apache.kafka.streams.errors.StreamsException: A serializer (value: io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer) is not compatible to the actual value type (value type: com.mycompany.maventest.Streamer$Tuple). Change the default Serdes in StreamConfig or provide correct Serdes via method parameters.
at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:195)
at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:66)
at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:57)
at org.apache.kafka.streams.state.internals.InnerMeteredKeyValueStore.put(InnerMeteredKeyValueStore.java:206)
at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore.put(MeteredKeyValueBytesStore.java:117)
at org.apache.kafka.streams.kstream.internals.KStreamAggregate$KStreamAggregateProcessor.process(KStreamAggregate.java:94)
at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:50)
at org.apache.kafka.streams.processor.internals.ProcessorNode.runAndMeasureLatency(ProcessorNode.java:244)
at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:133)
at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:143)
at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:126)
at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:90)
at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:87)
at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:302)
... 6 more
Caused by: java.lang.ClassCastException: com.mycompany.maventest.Streamer$Tuple cannot be cast to org.apache.avro.generic.GenericRecord
at io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer.serialize(GenericAvroSerializer.java:39)
at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:191)
... 19 more


How i can resolve this?



----- UPDATE ------



The producer produce with Avro so i have this configuration prperties:



 props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, GenericAvroSerde.class);


If i specific the custom serde this is the result:



 KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
() -> new Tuple(0, 0), // initializer
(aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)),
Materialized.with(Serdes.String(), new MySerde()));


The Exception:



   Exception in thread "streamtest-17deb5c8-ed07-4fcf-bd59-37b75e44b83f-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Deserialization exception handler is set to fail upon a deserialization error. If you would rather have the streaming pipeline continue after a deserialization error, please set the default.deserialization.exception.handler appropriately.
at org.apache.kafka.streams.processor.internals.RecordDeserializer.deserialize(RecordDeserializer.java:80)
at org.apache.kafka.streams.processor.internals.RecordQueue.addRawRecords(RecordQueue.java:97)
at org.apache.kafka.streams.processor.internals.PartitionGroup.addRawRecords(PartitionGroup.java:117)
at org.apache.kafka.streams.processor.internals.StreamTask.addRecords(StreamTask.java:677)
at org.apache.kafka.streams.processor.internals.StreamThread.addRecordsToTasks(StreamThread.java:943)
at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:831)
at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
Caused by: org.apache.kafka.common.errors.SerializationException: Unknown magic byte!


--- SOLVED ----
I have added also the new serde for the type change in groupBy



 KGroupedStream <String, String> groupedStream = branches[0]
.mapValues(value -> createJson(value.toString()))
.map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
.peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
.groupByKey( Serialized.with(
Serdes.String(), /* key (note: type was modified) */
Serdes.String())); /* value */









share|improve this question





























    0















    I have a processor that takes json string from a topic, with type GenericRecord.
    Now i split the stream in 2 branch.
    I take the first branch and i map the (key, value) in 2 string containing a specific field of json and a value of that field and i group by key.
    And so far so good.
    Now i have to aggregate the stream with a new Type user defined and i receive an exception.



    Here the code:



    The new type:



    private class Tuple {

    public int occ;
    public int sum;


    public Tuple (int occ, int sum) {
    this.occ = occ;
    this.sum = sum;
    }

    public void sum (int toAdd) {
    this.sum += toAdd;
    this.occ ++;
    }

    public int getAverage () {
    return this.sum / this.occ;
    }

    public String toString() {
    return occ + "-> " + sum + ": " + getAverage();
    }


    The good stream:



      StreamsBuilder builder = new StreamsBuilder();
    KStream<GenericRecord, GenericRecord> source =
    builder.stream(topic);

    KStream<GenericRecord, GenericRecord> branches = source.branch(
    (key,value) -> partition(value.toString()),
    (key, value) -> true
    );

    KGroupedStream <String, String> groupedStream = branches[0]
    .mapValues(value -> createJson(value.toString()))
    .map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
    .peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
    .groupByKey();


    The problem:



       KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
    () -> new Tuple (0,0), // initializer
    (aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)));



    KafkaStreams streams = new KafkaStreams(builder.build(), props);
    streams.start();


    This is the exception:



       Exception in thread "streamtest-6173d6a2-4a3a-4d76-b793-774719f8b1f5-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Exception caught in process. taskId=1_0, processor=KSTREAM-SOURCE-0000000011, topic=streamtest-KSTREAM-AGGREGATE-STATE-STORE-0000000007-repartition, partition=0, offset=0
    at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:318)
    at org.apache.kafka.streams.processor.internals.AssignedStreamsTasks.process(AssignedStreamsTasks.java:94)
    at org.apache.kafka.streams.processor.internals.TaskManager.process(TaskManager.java:409)
    at org.apache.kafka.streams.processor.internals.StreamThread.processAndMaybeCommit(StreamThread.java:964)
    at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:832)
    at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
    at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
    Caused by: org.apache.kafka.streams.errors.StreamsException: A serializer (value: io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer) is not compatible to the actual value type (value type: com.mycompany.maventest.Streamer$Tuple). Change the default Serdes in StreamConfig or provide correct Serdes via method parameters.
    at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:195)
    at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:66)
    at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:57)
    at org.apache.kafka.streams.state.internals.InnerMeteredKeyValueStore.put(InnerMeteredKeyValueStore.java:206)
    at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore.put(MeteredKeyValueBytesStore.java:117)
    at org.apache.kafka.streams.kstream.internals.KStreamAggregate$KStreamAggregateProcessor.process(KStreamAggregate.java:94)
    at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:50)
    at org.apache.kafka.streams.processor.internals.ProcessorNode.runAndMeasureLatency(ProcessorNode.java:244)
    at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:133)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:143)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:126)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:90)
    at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:87)
    at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:302)
    ... 6 more
    Caused by: java.lang.ClassCastException: com.mycompany.maventest.Streamer$Tuple cannot be cast to org.apache.avro.generic.GenericRecord
    at io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer.serialize(GenericAvroSerializer.java:39)
    at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:191)
    ... 19 more


    How i can resolve this?



    ----- UPDATE ------



    The producer produce with Avro so i have this configuration prperties:



     props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
    props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, GenericAvroSerde.class);


    If i specific the custom serde this is the result:



     KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
    () -> new Tuple(0, 0), // initializer
    (aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)),
    Materialized.with(Serdes.String(), new MySerde()));


    The Exception:



       Exception in thread "streamtest-17deb5c8-ed07-4fcf-bd59-37b75e44b83f-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Deserialization exception handler is set to fail upon a deserialization error. If you would rather have the streaming pipeline continue after a deserialization error, please set the default.deserialization.exception.handler appropriately.
    at org.apache.kafka.streams.processor.internals.RecordDeserializer.deserialize(RecordDeserializer.java:80)
    at org.apache.kafka.streams.processor.internals.RecordQueue.addRawRecords(RecordQueue.java:97)
    at org.apache.kafka.streams.processor.internals.PartitionGroup.addRawRecords(PartitionGroup.java:117)
    at org.apache.kafka.streams.processor.internals.StreamTask.addRecords(StreamTask.java:677)
    at org.apache.kafka.streams.processor.internals.StreamThread.addRecordsToTasks(StreamThread.java:943)
    at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:831)
    at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
    at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
    Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
    Caused by: org.apache.kafka.common.errors.SerializationException: Unknown magic byte!


    --- SOLVED ----
    I have added also the new serde for the type change in groupBy



     KGroupedStream <String, String> groupedStream = branches[0]
    .mapValues(value -> createJson(value.toString()))
    .map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
    .peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
    .groupByKey( Serialized.with(
    Serdes.String(), /* key (note: type was modified) */
    Serdes.String())); /* value */









    share|improve this question



























      0












      0








      0








      I have a processor that takes json string from a topic, with type GenericRecord.
      Now i split the stream in 2 branch.
      I take the first branch and i map the (key, value) in 2 string containing a specific field of json and a value of that field and i group by key.
      And so far so good.
      Now i have to aggregate the stream with a new Type user defined and i receive an exception.



      Here the code:



      The new type:



      private class Tuple {

      public int occ;
      public int sum;


      public Tuple (int occ, int sum) {
      this.occ = occ;
      this.sum = sum;
      }

      public void sum (int toAdd) {
      this.sum += toAdd;
      this.occ ++;
      }

      public int getAverage () {
      return this.sum / this.occ;
      }

      public String toString() {
      return occ + "-> " + sum + ": " + getAverage();
      }


      The good stream:



        StreamsBuilder builder = new StreamsBuilder();
      KStream<GenericRecord, GenericRecord> source =
      builder.stream(topic);

      KStream<GenericRecord, GenericRecord> branches = source.branch(
      (key,value) -> partition(value.toString()),
      (key, value) -> true
      );

      KGroupedStream <String, String> groupedStream = branches[0]
      .mapValues(value -> createJson(value.toString()))
      .map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
      .peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
      .groupByKey();


      The problem:



         KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
      () -> new Tuple (0,0), // initializer
      (aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)));



      KafkaStreams streams = new KafkaStreams(builder.build(), props);
      streams.start();


      This is the exception:



         Exception in thread "streamtest-6173d6a2-4a3a-4d76-b793-774719f8b1f5-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Exception caught in process. taskId=1_0, processor=KSTREAM-SOURCE-0000000011, topic=streamtest-KSTREAM-AGGREGATE-STATE-STORE-0000000007-repartition, partition=0, offset=0
      at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:318)
      at org.apache.kafka.streams.processor.internals.AssignedStreamsTasks.process(AssignedStreamsTasks.java:94)
      at org.apache.kafka.streams.processor.internals.TaskManager.process(TaskManager.java:409)
      at org.apache.kafka.streams.processor.internals.StreamThread.processAndMaybeCommit(StreamThread.java:964)
      at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:832)
      at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
      at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
      Caused by: org.apache.kafka.streams.errors.StreamsException: A serializer (value: io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer) is not compatible to the actual value type (value type: com.mycompany.maventest.Streamer$Tuple). Change the default Serdes in StreamConfig or provide correct Serdes via method parameters.
      at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:195)
      at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:66)
      at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:57)
      at org.apache.kafka.streams.state.internals.InnerMeteredKeyValueStore.put(InnerMeteredKeyValueStore.java:206)
      at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore.put(MeteredKeyValueBytesStore.java:117)
      at org.apache.kafka.streams.kstream.internals.KStreamAggregate$KStreamAggregateProcessor.process(KStreamAggregate.java:94)
      at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:50)
      at org.apache.kafka.streams.processor.internals.ProcessorNode.runAndMeasureLatency(ProcessorNode.java:244)
      at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:133)
      at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:143)
      at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:126)
      at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:90)
      at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:87)
      at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:302)
      ... 6 more
      Caused by: java.lang.ClassCastException: com.mycompany.maventest.Streamer$Tuple cannot be cast to org.apache.avro.generic.GenericRecord
      at io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer.serialize(GenericAvroSerializer.java:39)
      at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:191)
      ... 19 more


      How i can resolve this?



      ----- UPDATE ------



      The producer produce with Avro so i have this configuration prperties:



       props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
      props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, GenericAvroSerde.class);


      If i specific the custom serde this is the result:



       KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
      () -> new Tuple(0, 0), // initializer
      (aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)),
      Materialized.with(Serdes.String(), new MySerde()));


      The Exception:



         Exception in thread "streamtest-17deb5c8-ed07-4fcf-bd59-37b75e44b83f-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Deserialization exception handler is set to fail upon a deserialization error. If you would rather have the streaming pipeline continue after a deserialization error, please set the default.deserialization.exception.handler appropriately.
      at org.apache.kafka.streams.processor.internals.RecordDeserializer.deserialize(RecordDeserializer.java:80)
      at org.apache.kafka.streams.processor.internals.RecordQueue.addRawRecords(RecordQueue.java:97)
      at org.apache.kafka.streams.processor.internals.PartitionGroup.addRawRecords(PartitionGroup.java:117)
      at org.apache.kafka.streams.processor.internals.StreamTask.addRecords(StreamTask.java:677)
      at org.apache.kafka.streams.processor.internals.StreamThread.addRecordsToTasks(StreamThread.java:943)
      at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:831)
      at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
      at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
      Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
      Caused by: org.apache.kafka.common.errors.SerializationException: Unknown magic byte!


      --- SOLVED ----
      I have added also the new serde for the type change in groupBy



       KGroupedStream <String, String> groupedStream = branches[0]
      .mapValues(value -> createJson(value.toString()))
      .map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
      .peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
      .groupByKey( Serialized.with(
      Serdes.String(), /* key (note: type was modified) */
      Serdes.String())); /* value */









      share|improve this question
















      I have a processor that takes json string from a topic, with type GenericRecord.
      Now i split the stream in 2 branch.
      I take the first branch and i map the (key, value) in 2 string containing a specific field of json and a value of that field and i group by key.
      And so far so good.
      Now i have to aggregate the stream with a new Type user defined and i receive an exception.



      Here the code:



      The new type:



      private class Tuple {

      public int occ;
      public int sum;


      public Tuple (int occ, int sum) {
      this.occ = occ;
      this.sum = sum;
      }

      public void sum (int toAdd) {
      this.sum += toAdd;
      this.occ ++;
      }

      public int getAverage () {
      return this.sum / this.occ;
      }

      public String toString() {
      return occ + "-> " + sum + ": " + getAverage();
      }


      The good stream:



        StreamsBuilder builder = new StreamsBuilder();
      KStream<GenericRecord, GenericRecord> source =
      builder.stream(topic);

      KStream<GenericRecord, GenericRecord> branches = source.branch(
      (key,value) -> partition(value.toString()),
      (key, value) -> true
      );

      KGroupedStream <String, String> groupedStream = branches[0]
      .mapValues(value -> createJson(value.toString()))
      .map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
      .peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
      .groupByKey();


      The problem:



         KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
      () -> new Tuple (0,0), // initializer
      (aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)));



      KafkaStreams streams = new KafkaStreams(builder.build(), props);
      streams.start();


      This is the exception:



         Exception in thread "streamtest-6173d6a2-4a3a-4d76-b793-774719f8b1f5-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Exception caught in process. taskId=1_0, processor=KSTREAM-SOURCE-0000000011, topic=streamtest-KSTREAM-AGGREGATE-STATE-STORE-0000000007-repartition, partition=0, offset=0
      at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:318)
      at org.apache.kafka.streams.processor.internals.AssignedStreamsTasks.process(AssignedStreamsTasks.java:94)
      at org.apache.kafka.streams.processor.internals.TaskManager.process(TaskManager.java:409)
      at org.apache.kafka.streams.processor.internals.StreamThread.processAndMaybeCommit(StreamThread.java:964)
      at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:832)
      at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
      at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
      Caused by: org.apache.kafka.streams.errors.StreamsException: A serializer (value: io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer) is not compatible to the actual value type (value type: com.mycompany.maventest.Streamer$Tuple). Change the default Serdes in StreamConfig or provide correct Serdes via method parameters.
      at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:195)
      at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:66)
      at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore$1.innerValue(MeteredKeyValueBytesStore.java:57)
      at org.apache.kafka.streams.state.internals.InnerMeteredKeyValueStore.put(InnerMeteredKeyValueStore.java:206)
      at org.apache.kafka.streams.state.internals.MeteredKeyValueBytesStore.put(MeteredKeyValueBytesStore.java:117)
      at org.apache.kafka.streams.kstream.internals.KStreamAggregate$KStreamAggregateProcessor.process(KStreamAggregate.java:94)
      at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:50)
      at org.apache.kafka.streams.processor.internals.ProcessorNode.runAndMeasureLatency(ProcessorNode.java:244)
      at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:133)
      at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:143)
      at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:126)
      at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:90)
      at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:87)
      at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:302)
      ... 6 more
      Caused by: java.lang.ClassCastException: com.mycompany.maventest.Streamer$Tuple cannot be cast to org.apache.avro.generic.GenericRecord
      at io.confluent.kafka.streams.serdes.avro.GenericAvroSerializer.serialize(GenericAvroSerializer.java:39)
      at org.apache.kafka.streams.state.StateSerdes.rawValue(StateSerdes.java:191)
      ... 19 more


      How i can resolve this?



      ----- UPDATE ------



      The producer produce with Avro so i have this configuration prperties:



       props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
      props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, GenericAvroSerde.class);


      If i specific the custom serde this is the result:



       KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
      () -> new Tuple(0, 0), // initializer
      (aggKey, newValue, aggValue) -> new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue)),
      Materialized.with(Serdes.String(), new MySerde()));


      The Exception:



         Exception in thread "streamtest-17deb5c8-ed07-4fcf-bd59-37b75e44b83f-StreamThread-1" org.apache.kafka.streams.errors.StreamsException: Deserialization exception handler is set to fail upon a deserialization error. If you would rather have the streaming pipeline continue after a deserialization error, please set the default.deserialization.exception.handler appropriately.
      at org.apache.kafka.streams.processor.internals.RecordDeserializer.deserialize(RecordDeserializer.java:80)
      at org.apache.kafka.streams.processor.internals.RecordQueue.addRawRecords(RecordQueue.java:97)
      at org.apache.kafka.streams.processor.internals.PartitionGroup.addRawRecords(PartitionGroup.java:117)
      at org.apache.kafka.streams.processor.internals.StreamTask.addRecords(StreamTask.java:677)
      at org.apache.kafka.streams.processor.internals.StreamThread.addRecordsToTasks(StreamThread.java:943)
      at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:831)
      at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:767)
      at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:736)
      Caused by: org.apache.kafka.common.errors.SerializationException: Error deserializing Avro message for id -1
      Caused by: org.apache.kafka.common.errors.SerializationException: Unknown magic byte!


      --- SOLVED ----
      I have added also the new serde for the type change in groupBy



       KGroupedStream <String, String> groupedStream = branches[0]
      .mapValues(value -> createJson(value.toString()))
      .map((key, value) -> KeyValue.pair(new String("T_DUR_CICLO"), value.getNumberValue("payload", "T_DUR_CICLO")))
      .peek((key, value) -> System.out.println("key=" + key + ", value=" + value))
      .groupByKey( Serialized.with(
      Serdes.String(), /* key (note: type was modified) */
      Serdes.String())); /* value */






      apache-kafka aggregation apache-kafka-streams






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      edited Nov 20 '18 at 22:22









      Nishu Tayal

      12.1k73481




      12.1k73481










      asked Nov 20 '18 at 20:14









      AndreaAndrea

      205




      205
























          1 Answer
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          1














          Kafka streams will use the default Serde unless it is explicitly specified with the operations.



          In the aggregate() method, you are defining valueType as Tuple while the default serde is for GenericRecord hence it throws the exception. You need to specify the serde like below :



           KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
          () -> new Tuple (0,0), // initializer
          (aggKey, newValue, aggValue) ->
          new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue))
          ,Materialized.with(keySerde, tupleSerde));


          It will use the tupleSerde for this operation. You can find the example here:
          https://docs.confluent.io/current/streams/developer-guide/dsl-api.html#aggregating






          share|improve this answer























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            Kafka streams will use the default Serde unless it is explicitly specified with the operations.



            In the aggregate() method, you are defining valueType as Tuple while the default serde is for GenericRecord hence it throws the exception. You need to specify the serde like below :



             KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
            () -> new Tuple (0,0), // initializer
            (aggKey, newValue, aggValue) ->
            new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue))
            ,Materialized.with(keySerde, tupleSerde));


            It will use the tupleSerde for this operation. You can find the example here:
            https://docs.confluent.io/current/streams/developer-guide/dsl-api.html#aggregating






            share|improve this answer




























              1














              Kafka streams will use the default Serde unless it is explicitly specified with the operations.



              In the aggregate() method, you are defining valueType as Tuple while the default serde is for GenericRecord hence it throws the exception. You need to specify the serde like below :



               KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
              () -> new Tuple (0,0), // initializer
              (aggKey, newValue, aggValue) ->
              new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue))
              ,Materialized.with(keySerde, tupleSerde));


              It will use the tupleSerde for this operation. You can find the example here:
              https://docs.confluent.io/current/streams/developer-guide/dsl-api.html#aggregating






              share|improve this answer


























                1












                1








                1







                Kafka streams will use the default Serde unless it is explicitly specified with the operations.



                In the aggregate() method, you are defining valueType as Tuple while the default serde is for GenericRecord hence it throws the exception. You need to specify the serde like below :



                 KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
                () -> new Tuple (0,0), // initializer
                (aggKey, newValue, aggValue) ->
                new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue))
                ,Materialized.with(keySerde, tupleSerde));


                It will use the tupleSerde for this operation. You can find the example here:
                https://docs.confluent.io/current/streams/developer-guide/dsl-api.html#aggregating






                share|improve this answer













                Kafka streams will use the default Serde unless it is explicitly specified with the operations.



                In the aggregate() method, you are defining valueType as Tuple while the default serde is for GenericRecord hence it throws the exception. You need to specify the serde like below :



                 KTable<String, Tuple> aggregatedStream = groupedStream.aggregate(
                () -> new Tuple (0,0), // initializer
                (aggKey, newValue, aggValue) ->
                new Tuple (aggValue.occ + 1, aggValue.sum + Integer.parseInt(newValue))
                ,Materialized.with(keySerde, tupleSerde));


                It will use the tupleSerde for this operation. You can find the example here:
                https://docs.confluent.io/current/streams/developer-guide/dsl-api.html#aggregating







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 20 '18 at 20:47









                Nishu TayalNishu Tayal

                12.1k73481




                12.1k73481






























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