Spring Cloud Stream + Kafka Stream - KStream not consuming message from the topic - apache-kafka-streams

Question

Trying our a sample project using Spring Cloud Stream + Kafka Stream but the Messages published to the input topic/queue are not consumed by the Processor method (KStream as argument).
Binding Definition
public interface WordCountChannelBindings {
// Channel to PUBLISH and FETCH 'words'
String _wordsOutput = "words_output_channel";
String _wordsInput = "words_input_channel";
// Channel to PUBLISH and FETCH 'words-count' details
String _countOutput = "counts_output_channel";
String _countInput = "counts_input_channel";
// Source
#Output(_wordsOutput)
MessageChannel _wordsOutput();
// Sink
#Input(_wordsInput)
KStream<String, PageViewEvent> _wordsInput();
// Source
#Output(_countOutput)
KStream<String, Long> _countOutput();
// Sink
#Input(_countInput)
KTable<String, Long> _countInput();
}
Producer
#Scheduled(fixedDelay = 1000)
public void wordsProducer() {
List<String> names = Arrays.asList("mfisher", "dyser", "schacko", "abilan", "ozhurakousky", "grussell");
List<String> pages = Arrays.asList("blog", "sitemap", "initializr", "news", "colophon", "about");
String rPage = pages.get(new Random().nextInt(pages.size()));
String rName = pages.get(new Random().nextInt(names.size()));
PageViewEvent pageViewEvent = new PageViewEvent(rName, rPage, Math.random() > .5 ? 10 : 1000);
// Publish the words into the OUTPUT Topic
this.wordCountChannelBindings._wordsOutput().send(
MessageBuilder.withPayload(pageViewEvent)
.build());
log.info("Words published - {}", pageViewEvent);
}
Processor
#Component
public class WordsStreamProcessor {
#StreamListener
#SendTo(WordCountChannelBindings._countOutput)
public KStream<String, Long> process(#Input(WordCountChannelBindings._wordsInput) KStream<String, PageViewEvent> input) {
log.info("Process data - {}", input);
return input.filter((key, value) -> value.getDuration() > 10)
.map((key, value) -> new KeyValue<>(value.getPage(), "0"))
.groupByKey()
.count(Materialized.as("wordscount"))
.toStream();
}
}
Consumer
#StreamListener
public void wordsCountConsumer(#Input(WordCountChannelBindings._countInput) KTable<String, Long> wordsCountDetails) {
log.info("Consumed Result - {}", wordsCountDetails);
}
SB Main class
#EnableScheduling
#EnableBinding(WordCountChannelBindings.class)
#SpringBootApplication
public class SpringCloudStreamKafkaApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudStreamKafkaApplication.class, args);
}
}
application.yml
spring.cloud.stream.kafka.binder:
brokers:
- localhost:9092
spring.cloud.stream.kafka.streams.binder:
applicationId: word-count-sample
configuration:
commit.interval.ms: 100
default.key.serde: org.apache.kafka.common.serialization.Serdes$StringSerde
default.value.serde: org.apache.kafka.common.serialization.Serdes$StringSerde
spring.cloud.stream.bindings.words_output_channel:
destination: words_topic
producer:
headerMode: none
spring.cloud.stream.bindings.words_input_channel:
destination: words_topic
consumer:
headerMode: none
spring.cloud.stream.bindings.counts_output_channel:
destination: counts_topic
producer:
useNativeEncoding: true
spring.cloud.stream.bindings.counts_input_channel:
destination: counts_topic
consumer:
useNativeDecoding: true
headerMode: none
group: wordscount
contentType: application/json
spring.cloud.stream.kafka.streams.bindings.counts_output_channel:
producer:
keySerde: org.apache.kafka.common.serialization.Serdes$StringSerde
valueSerde: org.apache.kafka.common.serialization.Serdes$LongSerde
spring.cloud.stream.kafka.streams.bindings.counts_input_channel:
consumer:
keySerde: org.apache.kafka.common.serialization.Serdes$StringSerde
valueSerde: org.apache.kafka.common.serialization.Serdes$LongSerde
Logs
2020-07-17 12:31:45.893 INFO 17236 --- [ask-scheduler-4] l.k.s.s.c.stream.producer.WordsProducer : Words published - PageViewEvent(userId=about, page=colophon, duration=1000)
2020-07-17 12:31:46.895 INFO 17236 --- [ask-scheduler-8] l.k.s.s.c.stream.producer.WordsProducer : Words published - PageViewEvent(userId=initializr, page=blog, duration=10)
2020-07-17 12:31:47.899 INFO 17236 --- [ask-scheduler-3] l.k.s.s.c.stream.producer.WordsProducer : Words published - PageViewEvent(userId=blog, page=news, duration=1000)
2020-07-17 12:31:48.900 INFO 17236 --- [ask-scheduler-9] l.k.s.s.c.stream.producer.WordsProducer : Words published - PageViewEvent(userId=sitemap, page=about, duration=10)
As shown in the above logs the PageViewEvent is published to the topic every second but the Processor method which supposed to transform the event is not consuming the messages. No error seen in the log.
Kindly help to get this working.
Initially tried with
<spring-cloud.version>Hoxton</spring-cloud.version>
<version>2.3.1.RELEASE</version>
and also with
<spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
<version>2.0.1.RELEASE</version>
But facing the same issue.