Kafka没有连接到下面的问题

Question

2021-09-09 21:42:40.039  WARN 14636 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-mygroup-1, groupId=mygroup] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2021-09-09 21:42:40.039  WARN 14636 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-mygroup-1, groupId=mygroup] Bootstrap broker localhost:9092 (id: -1 rack: null) disconnected
2021-09-09 21:42:41.778  WARN 14636 --- [ad | producer-1] org.apache.kafka.clients.NetworkClient   : [Producer clientId=producer-1] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2021-09-09 21:42:41.779  WARN 14636 --- [ad | producer-1] org.apache.kafka.clients.NetworkClient   : [Producer clientId=producer-1] Bootstrap broker localhost:9092 (id: -1 rack: null) disconnected
2021-09-09 21:42:43.001  WARN 14636 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-mygroup-1, groupId=mygroup] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2021-09-09 21:42:43.002  WARN 14636 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-mygroup-1, groupId=mygroup] Bootstrap broker localhost:9092 (id: -1 rack: null) disconnected
2021-09-09 21:42:44.634  WARN 14636 --- [ad | producer-1] org.apache.kafka.clients.NetworkClient   : [Producer clientId=producer-1] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2021-09-09 21:42:44.634  WARN 14636 --- [ad | producer-1] org.apache.kafka.clients.NetworkClient   : [Producer clientId=producer-1] Bootstrap broker localhost:9092 (id: -1 rack: null) disconnected
2021-09-09 21:42:45.908  WARN 14636 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-mygroup-1, groupId=mygroup] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2021-09-09 21:42:45.908  WARN 14636 --- [ntainer#0-0-C-1] org.apache.kafka.clients.NetworkClient   : [Consumer clientId=consumer-mygroup-1, groupId=mygroup]

代码

@Service
public class KafKaConsumerService {
private final Logger logger = 
LoggerFactory.getLogger(KafKaConsumerService.class);

@KafkaListener(topics="mytopic", groupId="mygroup")
public void consumeFromTopic(String message) {
System.out.println("Consummed message "+message);
}
}
public class KafKaProducerService {
private static final Logger logger = 
LoggerFactory.getLogger(KafKaProducerService.class);

public static final String topic = "mytopic";

@Autowired 
private KafkaTemplate<String, String> kafkaTemp;

public void publishToTopic(String message) {
System.out.println("Publishing to topic "+topic);
this.kafkaTemp.send(topic, message);
}
}

属性

spring.kafka.consumer.bootstrap-servers=localhost:9092
spring.kafka.consumer.group-id=mygroup
spring.kafka.consumer.auto-offset-reset=earliest
spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.producer.bootstrap-servers=localhost:9092
spring.kafka.producer.key-deserializer = org.apache.kafka.common.serialization.StringDeserializer
spring.kafka.producer.value-deserializer = org.apache.kafka.common.serialization.StringDeserializer

Answer 1

你得到这个警告是因为以下Apache-Kafka配置

KAFKA_AUTO_CREATE_TOPICS_ENABLE: 'false'

这意味着在Spring Boot启动时，消费者尝试从mytopic收听/消费消息但它实际上并不存在。

请先创建主题或将上述配置更改为

KAFKA_AUTO_CREATE_TOPICS_ENABLE: 'true'