Spring Reactive kafka Receiver always overrides bootstrap server to localhost

Question

I am trying to write Spring boot applications for a Reactive Kafka consumer using @EnableKafka and @KafkaListener annotations. i have configured my kafka brokers are on different machine. when i give bootstrap-server to advertised host of kafka brokers, it is always overriding advertised host ip addresses to localhost. below are my code.

pom.xml file:-

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.kafka</groupId>
    <artifactId>spring-kafka</artifactId>
</dependency>
<dependency>
    <groupId>io.projectreactor.kafka</groupId>
    <artifactId>reactor-kafka</artifactId>
    <version>1.0.0.RELEASE</version>
</dependency>

config:-

@Configuration
@EnableKafka
public class AppConfig {

    @Bean
    Map consumerProps() {
        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.12.12.24:9092,192.14.14.28:9092");
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "example-group");
        props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, true);
        props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, "100");
        props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, "15000");
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG,StringDeserializer.class);
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        return props;
    }

    @Bean
    ReceiverOptions receiverOptions() {

        ReceiverOptions receiverOptions = ReceiverOptions.create(consumerProps()).subscription(Arrays.asList("hellochange"));

        return receiverOptions;
    }

    @Bean
    public KafkaReceiver kafkaReceiver() {
        return KafkaReceiver.create(receiverOptions());
    }

}

Consumer:-

@Service
public class ChangeListener {

    @Autowired
    KafkaReceiver kafkaReceiver;

    @KafkaListener(topics="hellochange",groupId="example-group")
    public void receiver() {
        kafkaReceiver.receive().subscribe(System.out::println);
    }

}

Console:-

 auto.commit.interval.ms = 5000
    auto.offset.reset = latest
    bootstrap.servers = [localhost:9092]
    check.crcs = true
    client.id = 
    connections.max.idle.ms = 540000
    enable.auto.commit = true
2018-06-07 19:59:17.640  WARN 23536 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-1, groupId=example-group] Connection to node -1 could not be established. Broker may not be available.

I have validated without spring configurations in a simple consumer and non-reactive Spring kafka, for both, it is working fine. only Reactor kafka with EnableKafka and KafkaListener annotations i am getting this problem.

am i missing something/ doing wrong here ? can we use EnableKafka and KafkaListener annotations with Reactor Kafka in Spring boot?

P.S. i understood, @EnableKafka and @KafkaListener are not reactive, if i remove spring-kafka from pom.xml, both the annotations are not available.

Like @EnableKafka and @KafkaListener for non-reactive kafka, is there any annotations are available to configure reactive kafka consumer with Spring boot application?

Answer 1

You cannot use KafkaListener annotations with Reactor Kafka; @KafkaListener is not reactive.