I am currently using Spring Integration Kafka to make real-time statistics. Though, the group name makes Kafka search all the previous values the listener didn't read.
@Value("${kafka.consumer.group.id}")
private String consumerGroupId;
@Bean
public ConsumerFactory<String, String> consumerFactory() {
return new DefaultKafkaConsumerFactory<>(getDefaultProperties());
}
public Map<String, Object> getDefaultProperties() {
Map<String, Object> properties = new HashMap<>();
properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
properties.put(ConsumerConfig.GROUP_ID_CONFIG, consumerGroupId);
properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, ByteArrayDeserializer.class);
return properties;
}
@Bean
public ConcurrentKafkaListenerContainerFactory<String, String> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
return factory;
}
@Bean
public KafkaMessageListener listener() {
return new KafkaMessageListener();
}
I would like to begin to the latest offset, and not be bothered by old values. Is there a possibility to reset the offset of the group ?
Because I didn't saw any example of this, I'm gonna explain how I did here.
The class of your @KafkaListener must implement a ConsumerSeekAware class, which will permit to the listener to control the offset seeking when partitions are attributed. (source : https://docs.spring.io/spring-kafka/reference/htmlsingle/#seek )
public class KafkaMessageListener implements ConsumerSeekAware {
@KafkaListener(topics = "your.topic")
public void listen(byte[] payload) {
// ...
}
@Override
public void registerSeekCallback(ConsumerSeekCallback callback) {
}
@Override
public void onPartitionsAssigned(Map<TopicPartition, Long> assignments, ConsumerSeekCallback callback) {
assignments.forEach((t, o) -> callback.seekToEnd(t.topic(), t.partition()));
}
@Override
public void onIdleContainer(Map<TopicPartition, Long> assignments, ConsumerSeekCallback callback) {
}
}
Here, on a rebalance, we use the given callback to seek the last offset for all the given topics. Thanks to Artem Bilan ( https://stackoverflow.com/users/2756547/artem-bilan ) for guiding me to the answer.