本文介绍如何在springboot项目中集成kafka收发message。
pom依赖
springboot相关的依赖我们就不提了,和kafka相关的只依赖一个spring-kafka集成包
<dependency>
<groupId>org.springframework.kafka</groupId>
<artifactId>spring-kafka</artifactId>
</dependency>
Kafka相关的yaml配置
spring:
kafka:
bootstrap-servers: 30.46.35.29:9092
producer:
retries: 3
acks: -1
batch-size: 16384
buffer-memory: 33554432
key-serializer: org.apache.kafka.common.serialization.StringSerializer
value-serializer: org.apache.kafka.common.serialization.StringSerializer
compression-type: lz4
properties:
linger.ms: 1
'interceptor.classes': com.tencent.qidian.ma.commontools.trace.kafka.TracingProducerInterceptor
consumer:
heartbeat-interval: 3000
max-poll-records: 100
enable-auto-commit: false
key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
properties:
session.timeout.ms: 30000
listener:
concurrency: 3
type: batch
ack-mode: manual_immediate
生产者配置
1)通过@Configuration、@EnableKafka,声明Config并且打开KafkaTemplate能力。
2)生成bean,@Bean
常见配置参考:
package com.somnus.config.kafka;
@Configuration
@EnableKafka
public class KafkaProducerConfig {
@Resource
private KafkaProperties kafkaProperties;
public Map<String, Object> producerConfigs() {
Map<String, Object> props = new HashMap<>();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaProperties.getBootstrapServers());
props.put(ProducerConfig.RETRIES_CONFIG, kafkaProperties.getProducer().getRetries());
props.put(ProducerConfig.BATCH_SIZE_CONFIG, kafkaProperties.getProducer().getBatchSize());
props.put(ProducerConfig.LINGER_MS_CONFIG, kafkaProperties.getProducer().getProperties().get("linger.ms"));
props.put(ProducerConfig.BUFFER_MEMORY_CONFIG, kafkaProperties.getProducer().getBufferMemory());
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, kafkaProperties.getProducer().getKeySerializer());
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, kafkaProperties.getProducer().getValueSerializer());
return props;
}
public ProducerFactory<String, String> producerFactory() {
return new DefaultKafkaProducerFactory<>(producerConfigs());
}
@Bean
public KafkaTemplate<String, String> kafkaTemplate() {
return new KafkaTemplate<>(producerFactory());
}
}
消费端配置
1)通过@Configuration、@EnableKafka,声明Config并且打开KafkaTemplate能力。
2)生成bean,@Bean
常见配置参考:
package com.tencent.qidian.ma.maaction.web.config.kafka;
import jakarta.annotation.Resource;
import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
import org.springframework.boot.autoconfigure.kafka.KafkaProperties.Listener.Type;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.annotation.EnableKafka;
import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
import org.springframework.kafka.config.KafkaListenerContainerFactory;
import org.springframework.kafka.core.ConsumerFactory;
import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
import org.springframework.kafka.listener.ContainerProperties.AckMode;
/**
* KafkaBeanConfiguration
*/
@Configuration
@EnableKafka
public class KafkaBeanConfiguration {
@Resource
private ConsumerFactory consumerFactory;
@Resource
private KafkaProperties kafkaProperties;
@Bean(name = "kafkaListenerContainerFactory")
public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<String, String>>
kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, String> factory =
new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
factory.getContainerProperties().setAckMode(kafkaProperties.getListener().getAckMode());
factory.setConcurrency(kafkaProperties.getListener().getConcurrency());
if (kafkaProperties.getListener().getType().equals(Type.BATCH)) {
factory.setBatchListener(true);
}
return factory;
}
// 此bean为了后续演示使用,参考消费演示中的containerFactory属性配置
@Bean(name = "tenThreadsKafkaListenerContainerFactory1")
public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<String, String>>
tenThreadsKafkaListenerContainerFactory1() {
ConcurrentKafkaListenerContainerFactory<String, String> factory =
new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory);
factory.getContainerProperties().setAckMode(kafkaProperties.getListener().getAckMode());
factory.setConcurrency(10);
if (kafkaProperties.getListener().getType().equals(Type.BATCH)) {
factory.setBatchListener(true);
}
return factory;
}
public ConsumerFactory<String, String> consumerFactory() {
return new DefaultKafkaConsumerFactory<>(consumerConfigs());
}
public Map<String, Object> consumerConfigs() {
Map<String, Object> propsMap = new HashMap<>();
propsMap.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaProperties.getBootstrapServers());
propsMap.put(ConsumerConfig.MAX_POLL_RECORDS_CONFIG,kafkaProperties.getConsumer().getMaxPollRecords());
propsMap.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, kafkaProperties.getConsumer().getEnableAutoCommit());
propsMap.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, kafkaProperties.getConsumer().getProperties().get("session.timeout.ms"));
propsMap.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, kafkaProperties.getConsumer().getKeyDeserializer());
propsMap.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, kafkaProperties.getConsumer().getValueDeserializer());
return propsMap;
}
}
SpringBoot 集成 KafkaTemplate 发送Kafka消息
@Resource
private ObjectMapper mapper;
@Resource
private KafkaTemplate<String, String> kafkaTemplate;
try {
Order order = new Order();
String message = mapper.writeValueAsString(order);
CompletableFuture<SendResult<String, String>> future = kafkaTemplate.send("order", message);
future.thenAccept(result -> {
if (result.getRecordMetadata() != null) {
log.debug("send message:{} with offset:{}", message, result.getRecordMetadata().offset());
}
}).exceptionally(exception -> {
log.error("KafkaProducer send message failure,topic={},data={}", topic, message, exception);
return null;
});
} catch (Exception e) {
log.error("KafkaProducer send message exception,topic={},message={}", topic, message, e);
}
SpringBoot 集成 @KafkaListener 消费Kafka消息
max.poll.interval.ms
默认为5分钟
如果两次poll操作间隔超过了这个时间,broker就会认为这个consumer处理能力太弱,会将其踢出消费组,将分区分配给别的consumer消费,触发rebalance 。
如果你的消费者节点总是在重启完不久就不消费了,可以考虑检查改配置项或者优化你的消费者的消费速度等等。
max.poll.records
max-poll-records是Kafka consumer的一个配置参数,表示consumer一次从Kafka broker中拉取的最大消息数目,默认值为500条。在Kafka中,一个消费者组可以有多个consumer实例,每个consumer实例负责消费一个或多个partition的消息,每个consumer实例一次从broker中可以拉取一个或多个消息。
max-poll-records参数的作用就是控制每次拉取消息的最大数目,以实现消费弱化和控制内存资源的需求。
参考Kafka中的max-poll-records和listener.concurrency配置
@Resource
private ObjectMapper mapper;
@KafkaListener(
id = "order_consumer",
topics = "order",
groupId = "g_order_consumer_group",
//可配置containerFactory参数,使用指定的containerFactory,不配置默认使用名称是kafkaListenerContainerFactory的bean
//containerFactory = "kafkaListenerContainerFactory1",
properties = {"max.poll.interval.ms:300000", "max.poll.records:1"}
)
// 可以只有ConsumerRecords<String, String> records参数。ack参数非必需,ack.acknowledge()是为了防消息丢失
public void consume(ConsumerRecords<String, String> records, Acknowledgment ack) {
for (ConsumerRecord<String, String> record : records) {
String msg = record.value();
log.info("Consume msg:{}", msg);
try {
Order order = mapper.readValue(val, Order.class);
// 处理业务逻辑
} catch (Exception e) {
log.error("Consume failed, msg:{}", val, e);
}
}
ack.acknowledge();
}