In case that Kafka server is (temporarily) down, my Spring Boot application ReactiveKafkaConsumerTemplate keeps trying to connect unsuccessfully, thus causing unnecessary traffic and messing the log files:
2021-11-10 14:45:30.265 WARN 24984 --- [onsumer-group-1] org.apache.kafka.clients.NetworkClient : [Consumer clientId=consumer-group-1, groupId=consumer-group] Connection to node -1 (localhost/127.0.0.1:29092) could not be established. Broker may not be available.
2021-11-10 14:45:32.792 WARN 24984 --- [onsumer-group-1] org.apache.kafka.clients.NetworkClient : [Consumer clientId=consumer-group-1, groupId=consumer-group] Bootstrap broker localhost:29092 (id: -1 rack: null) disconnected
2021-11-10 14:45:34.845 WARN 24984 --- [onsumer-group-1] org.apache.kafka.clients.NetworkClient : [Consumer clientId=consumer-group-1, groupId=consumer-group] Connection to node -1 (localhost/127.0.0.1:29092) could not be established. Broker may not be available.
2021-11-10 14:45:34.845 WARN 24984 --- [onsumer-group-1] org.apache.kafka.clients.NetworkClient : [Consumer clientId=consumer-group-1, groupId=consumer-group] Bootstrap broker localhost:29092 (id: -1 rack: null) disconnected
Is it possible to use something like a circuit breaker (an inspiration here or here), so the Spring Boot Kafka client in case of a failure (or even better a few consecutive failures) slows down the pace of its connection attempts, and returns to the normal pace only after the server is up again?
Is there already a ready-made config parameter, or any other solution?
I am aware of the parameter reconnect.backoff.ms, this is how I create the ReactiveKafkaConsumerTemplate bean:
@Bean
public ReactiveKafkaConsumerTemplate<String, MyEvent> kafkaConsumer(KafkaProperties properties) {
final Map<String, Object> map = new HashMap<>(properties.buildConsumerProperties());
map.put(ConsumerConfig.GROUP_ID_CONFIG, "MyGroup");
map.put(ConsumerConfig.RECONNECT_BACKOFF_MS_CONFIG, 10_000L);
final JsonDeserializer<DisplayCurrencyEvent> jsonDeserializer = new JsonDeserializer<>();
jsonDeserializer.addTrustedPackages("com.example.myapplication");
return new ReactiveKafkaConsumerTemplate<>(
ReceiverOptions
.<String, MyEvent>create(map)
.withKeyDeserializer(new ErrorHandlingDeserializer<>(new StringDeserializer()))
.withValueDeserializer(new ErrorHandlingDeserializer<>(jsonDeserializer))
.subscription(List.of("MyTopic")));
}
And still the consumer is trying to connect every 3 seconds.