Kafka Stream 0.10.2.0 state store getting exception while store the value

Question

I am using the low level processor API with state stores. Up to 0.10.0.1 it was working fine, but I have upgraded Kafka Streams and I am getting the below error. I figured out that this is due to the changelog and it is looking at the record context:

java.lang.IllegalStateException: This should not happen as timestamp() should only be called while a record is processed
! at org.apache.kafka.streams.processor.internals.AbstractProcessorContext.timestamp(AbstractProcessorContext.java:150)
! at org.apache.kafka.streams.state.internals.StoreChangeLogger.logChange(StoreChangeLogger.java:60)
! at org.apache.kafka.streams.state.internals.ChangeLoggingKeyValueBytesStore.put(ChangeLoggingKeyValueBytesStore.java:47)
! at org.apache.kafka.streams.state.internals.ChangeLoggingKeyValueStore.put(ChangeLoggingKeyValueStore.java:66)
! at     org.apache.kafka.streams.state.internals.MeteredKeyValueStore$2.run(MeteredKeyValueStore.java:67)

---

@Override
    public void process(String arg0, List<Data> data {
        data.forEach((x) -> {
            String rawKey = x.getId();
            Data data = kvStore.get(rawKey);
            long bytesize = data == null ? 0 : data.getVolume();
            x.addVolume(bytesize);
            kvStore.put(rawKey, x);
        });
    }
  
public void start() {
        builder = new KStreamBuilder();
        storeSupplier =     Stores.create(getKVStoreName()).withKeys(getProcessorKeySerde()).withValues(getProcessorValueSerde()).persistent().build();
        builder.addStateStore(storeSupplier);
        stream = builder.stream(Serdes.String(), serde(),getTopicName());
        processStream(stream);
        streams = new KafkaStreams(builder, props);
        streams.cleanUp();
        streams.start();
    }

    @Override
    public void init(ProcessorContext context) {
        super.init(context);
        this.context = context;
        this.context.schedule(timeinterval);
        this.kvStore = (KeyValueStore) context.getStateStore(getKVStoreName());
    }

Answer 1

Exceptions like this may come up when using the same instance of the Processor across multiple streams threads or partitions.

Ensure that you are returning a new instance to the ProcessorSupplier:

new ProcesorSupplier(() -> new Processor(...

The same applies to Transformer and TransformerSupplier as well.

To broadly quote the documentation:

Creating a single Processor/Transformer object and returning the same object reference in ProcesorSupplier/TransformerSupplier#get() would be a violation of the supplier pattern and leads to runtime exceptions.