CODEWITHSUNDEEP
apache-kafkaspring-kafka
alexandruRobert
alexandruRobert

Reputation: 99

Kafka automatically transforms the server ip into localhost

I am trying to get to know Kafka but I am having some problems. I installed Kafka on a Centos8 VPS, and everything works when I am connected to the VPS.

For the record, I opened the 9092 port for remote access.

The problem is that when I try to create a Message using Spring Boot, the Producer tries to connect to localhost instead of using the server ip address.

This is the configuration Bean :

    @Bean
    public ProducerFactory<String, String> producerStringFactory() {
        Map<String, Object> config = new HashMap<>();

        // the server name
        config.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "152.225.215.185:9092");
        // the key type
        config.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
        // the value type
        config.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);

        return new DefaultKafkaProducerFactory<String, String>(config);

    }

I use a simple method for producing Messages, with a hard coded topic name:

// code
    private static final String TOPIC = "testTopic1";
//code

    @GetMapping("/publish/{message}")
    public String postString(@PathVariable String message) {

        kafkaStringTemplate.send(TOPIC, "This is a message sent to the " + TOPIC + " topic");
        return "Published:  " + message;

    }

When I launch a request I get the ip adress declared in the configuration bean :

2021-04-17 12:20:01.986  INFO 2520 --- [nio-8080-exec-1] o.a.k.clients.producer.ProducerConfig    : ProducerConfig values: 
    acks = 1
    batch.size = 16384
    bootstrap.servers = [152.255.215.185:9092]

But then Spring tries to connect to localhost, I suppose because Kafka is set to automatically use localhost

2021-04-17 12:20:06.591  WARN 2520 --- [ad | producer-1] org.apache.kafka.clients.NetworkClient   : [Producer clientId=producer-1] Connection to node 0 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.

I suppose the answer is somewhere the Kafka configuration files.

Thank you for your answers. For the record, I started learning Apache Kafka yesterday, so please excuse me for misusing technical terms.

Upvotes: 1

Views: 3383

Answers (1)

alexandruRobert
alexandruRobert

Reputation: 99

I found the solution thanks to a video published by SelfTuts on Youtube:

https://www.youtube.com/watch?v=jY5fzVCkABg

I had to modify the server.properties file :

 nano /usr/local/kafka/config/server.properties

Inside the file I added the server hosting Kafka Ip's address for the advertised.listeners and to the zookeeper.connect properties.

advertised.listeners=PLAINTEXT://152.255.215.185:9092
zookeeper.connect=152.255.215.185:2181

Upvotes: 3

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