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[英]Message produced to kafka but consumers does not receive “some” of the messages
[英]Spring Boot Kafka Consumers does not consume in the order the messages are produced
我做了两个 Spring Boot 项目。 一个是卡夫卡制作人,另一个是听众。 然后我有一个这样的 dockerfile:我为 Zookeeper 和 Kafka 创建了一个容器,还有一个生产者容器和两个消费者容器。
version: '3'
services:
zookeeper:
image: wurstmeister/zookeeper
container_name: zookeeper
restart: always
ports:
- 2181:2181
kafka:
image: wurstmeister/kafka
container_name: kafka
restart: always
ports:
- 9092:9092
depends_on:
- zookeeper
links:
- zookeeper:zookeeper
environment:
KAFKA_ADVERTISED_HOST_NAME: kafka
KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
consumer1:
image: consumer:0.0.1-SNAPSHOT
container_name: consumer1
depends_on:
- kafka
restart: always
ports:
- 8081:8081
environment:
SERVER_PORT: 8081
depends_on:
- kafka
links:
- kafka:kafka
consumer2:
image: consumer:0.0.1-SNAPSHOT
container_name: consumer2
depends_on:
- kafka
restart: always
ports:
- 8082:8082
environment:
SERVER_PORT: 8082
depends_on:
- kafka
links:
- kafka:kafka
producer:
image: producer:0.0.1-SNAPSHOT
container_name: producer
depends_on:
- kafka
restart: always
ports:
- 8080:8080
environment:
SERVER_PORT: 8080
depends_on:
- kafka
links:
- kafka:kafka
现在到我的问题。 我希望我的消费者从我已经完成的同一主题中消费。 但是 - 似乎他们并没有按照生产者生产消息的顺序来消费消息。
正如您在下面看到的,“数字:4”在“数字:3”之前被消耗,例如:
producer | i: 0
consumer2 | Number: 0
producer | i: 1
consumer2 | Number: 1
producer | i: 2
consumer1 | Number: 2
producer | i: 3
producer | i: 4
consumer2 | Number: 4
producer | i: 5
consumer1 | Number: 6
producer | i: 6
consumer2 | Number: 3
producer | i: 7
producer | i: 8
producer | i: 9
consumer2 | Number: 5
producer | i: 10
consumer1 | Number: 10
producer | i: 11
我的 KafkaProducer 类:
@Service
public class KafkaProducer {
@Value("${topic.name.producer}")
private String topicName;
@Autowired
private KafkaTemplate<String, String> kafkaStringTemplate;
public void sendList(String word) {
kafkaStringTemplate.send(topicName, word);
}
}
我有一个 for 循环,用
for (int i = 0; i < 100; i++) {
producer.sendList("Number: " + i);
}
在我的生产者项目中,我有一个 TopicConfiguration:
@Configuration
public class TopicConfiguration
{
@Value(value = "${spring.kafka.producer.bootstrap-servers}")
private String bootstrapAddress;
@Value(value = "${topic.name.producer}")
private String topicName;
@Bean
public NewTopic generalTopic() {
return TopicBuilder.name(topicName)
.partitions(3)
.replicas(1)
.build();
}
@Bean
public KafkaAdmin kafkaAdmin()
{
Map<String, Object> configs = new HashMap<>();
configs.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
return new KafkaAdmin(configs);
}
}
Application.Properties 文件:
server.port=${SERVER_PORT}
# Producer properties
spring.kafka.producer.bootstrap-servers=kafka:9092
#spring.kafka.producer.bootstrap-servers=172.21.0.2:9092
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.group-id=group-1
topic.name.producer=test
# Common Kafka Properties
auto.create.topics.enable=true
我的消费者项目:
@Service
public class KafkaConsumer {
@Value("${topic.name.consumer")
private String topicName;
@KafkaListener(topics = "${topic.name.consumer}", groupId = "group-1")
public void consumeLinks(String word) throws InterruptedException {
System.out.println(word);
Thread.sleep(5000);
}
}
应用程序属性文件:
#server.port=8081
server.port=${SERVER_PORT}
# Producer properties
spring.kafka.consumer.bootstrap-servers=kafka:9092
#spring.kafka.consumer.bootstrap-servers=172.21.0.2:9092
#spring.kafka.consumer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
#spring.kafka.consumer.value-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.consumer.max-poll-records=1
spring.kafka.consumer.group-id=group-1
topic.name.consumer=test
spring.kafka.consumer.auto-offset-reset=earliest
# Common Kafka Properties
auto.create.topics.enable=true
我试过谷歌但没有找到任何解决方案,或者我没有问题不知道如何解决。 是否有人可以告诉我缺少什么或有一个指向傻瓜页面的链接如何解决它?
您的主题有 3 个分区。 除非您只使用一个分区,否则不会有订单保证。 更具体地说,数据仅在分区内排序; 每个消费者都在使用在其分配的分区中排序的数据。
要显示这一点,请尝试
@KafkaListener(topics = "${topic.name.consumer}", groupId = "group-1")
public void consumeLinks(
@Payload String word,
@Header(KafkaHeaders.RECEIVED_PARTITION_ID) int partition) {
System.out.println(
"Received Message: " + word
+ " from partition: " + partition);
如果您使用一个分区,这意味着您在该消费者组中只能有一个消费者。
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