一、背景
我们作为Kafka在使用Kafka是,必然考虑消息消费失败的重试次数,重试后仍然失败如何处理,要么阻塞,要么丢弃,或者保存
二、设置消费失败重试次数
1 默认重试次数在哪里看
Kafka3.0 版本默认失败重试次数为10次,准确讲应该是1次正常调用+9次重试,这个在这个类可以看到 org.springframework.kafka.listener.SeekUtils
2 如何修改重试次数
据我的实验,spring-kafka3.0版本通过application.yml 配置是行不通的,也没有找到任何一项配置可以改重试次数的(网上很多说的通过配置spring.kafka.consumer.retries 可以配置,我尝试过了,至少3.0版本是不行的,如果有人成功试过可以通过application.yml 配置消费者的消费的重试次数可以留言通知我,谢谢)
经过我不懈努力和尝试,只能通过Java代码配置的方式才可以,并且这种方式相对于application.yml配置更加灵活细致,上代码
public CommonErrorHandler commonErrorHandler() {
BackOff backOff = new FixedBackOff(5000L, 3L);
return new DefaultErrorHandler(backOff);
}
然后把这个handler 添加到ConcurrentKafkaListenerContainerFactory中就行了
三、设置消费失败处理方式
1 保存到数据库重试
我们需要在创建DefaultErrorHandler类时加入一个ConsumerAwareRecordRecoverer参数就可以了,这样在重试3次后仍然失败就会保存到数据库中,注意这里save to db成功之后,我认为没有必要执行consumer.commitSync方法,首先这个consumer.commitSync这个方法默认是提交当前批次的最大的offset(可能会导致丢失消息),其次不提交Kafka的消费者仍然回去消费后面的消息,只要后面的消息,消费成功了,那么依然会提交offset,覆盖了这个offset
public CommonErrorHandler commonErrorHandler() {
// 创建 FixedBackOff 对象
BackOff backOff = new FixedBackOff(5000L, 3L);
DefaultErrorHandler defaultErrorHandler = new DefaultErrorHandler((ConsumerAwareRecordRecoverer) (record, consumer, exception) -> {
log.info("save to db " + record.value().toString());
}, backOff);
return defaultErrorHandler;
}
如果你硬要提交也可以试试下面这种,指定提交当前的offset
public CommonErrorHandler commonErrorHandler() {
// 创建 FixedBackOff 对象
BackOff backOff = new FixedBackOff(5000L, 3L);
DefaultErrorHandler defaultErrorHandler = new DefaultErrorHandler((ConsumerAwareRecordRecoverer) (record, consumer, exception) -> {
log.info("save to db " + record.value().toString());
Map<TopicPartition, OffsetAndMetadata> offsets = new HashMap<>();
offsets.put(new TopicPartition(record.topic(),record.partition()),new OffsetAndMetadata(record.offset()));
consumer.commitSync(offsets);
}, backOff);
return defaultErrorHandler;
}
2 发送到Kafka死信队列
仍然在创建DefaultErrorHandler类时加入一个DeadLetterPublishingRecoverer 类就行了,默认会把消息发到kafkaTemplate 配置的topic名字为your_topic+.DLT
@Autowired
private KafkaTemplate<String, String> kafkaTemplate;
public CommonErrorHandler commonErrorHandler() {
// 创建 FixedBackOff 对象
BackOff backOff = new FixedBackOff(5000L, 3L);
DefaultErrorHandler defaultErrorHandler = new DefaultErrorHandler(new DeadLetterPublishingRecoverer(kafkaTemplate), backOff);
return defaultErrorHandler;
}
ConsumerRecordRecoverer 接口总共就这2种实现方式
四、整体消费者代码粘贴
1 application.yml
kafka-consumer:
bootstrapServers: 192.168.31.114:9092
groupId: goods-center
#后台的心跳线程必须在30秒之内提交心跳,否则会reBalance
sessionTimeOut: 30000
autoOffsetReset: latest
#取消自动提交,即便如此 spring会帮助我们自动提交
enableAutoCommit: false
#自动提交间隔
autoCommitInterval: 1000
#拉取的最小字节
fetchMinSize: 1
#拉去最小字节的最大等待时间
fetchMaxWait: 500
maxPollRecords: 50
#300秒的提交间隔,如果程序大于300秒提交,会报错
maxPollInterval: 300000
#心跳间隔
heartbeatInterval: 10000
keyDeserializer: org.apache.kafka.common.serialization.LongDeserializer
valueDeserializer: org.springframework.kafka.support.serializer.JsonDeserializer
2 KafkaListenerProperties
package com.ychen.goodscenter.fafka;
import lombok.Getter;
import lombok.Setter;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;
@Configuration
//指定配置文件的前缀
@ConfigurationProperties(prefix = "kafka-consumer")
@Getter
@Setter
public class KafkaListenerProperties {
private String groupId;
private String sessionTimeOut;
private String bootstrapServers;
private String autoOffsetReset;
private boolean enableAutoCommit;
private String autoCommitInterval;
private String fetchMinSize;
private String fetchMaxWait;
private String maxPollRecords;
private String maxPollInterval;
private String heartbeatInterval;
private String keyDeserializer;
private String valueDeserializer;
}
3 KafkaConsumerConfig
package com.ychen.goodscenter.fafka;
import com.alibaba.fastjson2.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
import org.springframework.kafka.config.KafkaListenerContainerFactory;
import org.springframework.kafka.core.ConsumerFactory;
import org.springframework.kafka.core.DefaultKafkaConsumerFactory;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.listener.*;
import org.springframework.util.backoff.BackOff;
import org.springframework.util.backoff.FixedBackOff;
import java.util.HashMap;
import java.util.Map;
@Configuration
@EnableConfigurationProperties(KafkaListenerProperties.class)
@Slf4j
public class KafkaConsumerConfig {
@Autowired
private KafkaListenerProperties kafkaListenerProperties;
@Autowired
private KafkaTemplate<String, String> kafkaTemplate;
@Bean
public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<String, String>> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, String> factory = new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
// 并发数 多个微服务实例会均分
factory.setConcurrency(2);
// factory.setBatchListener(true);
factory.setCommonErrorHandler(commonErrorHandler());
ContainerProperties containerProperties = factory.getContainerProperties();
// 是否设置手动提交
containerProperties.setAckMode(ContainerProperties.AckMode.MANUAL_IMMEDIATE);
return factory;
}
private ConsumerFactory<String, String> consumerFactory() {
Map<String, Object> consumerConfigs = consumerConfigs();
log.info("消费者的配置信息:{}", JSONObject.toJSONString(consumerConfigs));
return new DefaultKafkaConsumerFactory<>(consumerConfigs);
}
public CommonErrorHandler commonErrorHandler() {
// 创建 FixedBackOff 对象
BackOff backOff = new FixedBackOff(5000L, 3L);
DefaultErrorHandler defaultErrorHandler = new DefaultErrorHandler(new DeadLetterPublishingRecoverer(kafkaTemplate), backOff);
// DefaultErrorHandler defaultErrorHandler = new DefaultErrorHandler((ConsumerAwareRecordRecoverer) (record, consumer, exception) -> {
// log.info("save to db " + record.value().toString());
// Map<TopicPartition, OffsetAndMetadata> offsets = new HashMap<>();
// offsets.put(new TopicPartition(record.topic(),record.partition()),new OffsetAndMetadata(record.offset()));
// consumer.commitSync(offsets);
// }, backOff);
return defaultErrorHandler;
}
public Map<String, Object> consumerConfigs() {
Map<String, Object> propsMap = new HashMap<>();
// 服务器地址
propsMap.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, kafkaListenerProperties.getBootstrapServers());
// 是否自动提交
propsMap.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, kafkaListenerProperties.isEnableAutoCommit());
// 自动提交间隔
propsMap.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, kafkaListenerProperties.getAutoCommitInterval());
//会话时间
propsMap.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, kafkaListenerProperties.getSessionTimeOut());
//key序列化
propsMap.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, kafkaListenerProperties.getKeyDeserializer());
//value序列化
propsMap.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, kafkaListenerProperties.getValueDeserializer());
// 心跳时间
propsMap.put(ConsumerConfig.HEARTBEAT_INTERVAL_MS_CONFIG, kafkaListenerProperties.getHeartbeatInterval());
// 分组id
propsMap.put(ConsumerConfig.GROUP_ID_CONFIG, kafkaListenerProperties.getGroupId());
//消费策略
propsMap.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, kafkaListenerProperties.getAutoOffsetReset());
// poll记录数
propsMap.put(ConsumerConfig.MAX_POLL_RECORDS_CONFIG, kafkaListenerProperties.getMaxPollRecords());
//poll时间
propsMap.put(ConsumerConfig.MAX_POLL_INTERVAL_MS_CONFIG, kafkaListenerProperties.getMaxPollInterval());
propsMap.put("spring.json.trusted.packages", "com.ychen.**");
return propsMap;
}
}
4 MessageListener
package com.ychen.goodscenter.fafka;
import com.ychen.goodscenter.service.OrderService;
import com.ychen.goodscenter.vo.req.SubmitOrderReq;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DuplicateKeyException;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.kafka.support.Acknowledgment;
import org.springframework.stereotype.Component;
@Component
@Slf4j
public class MessageListener {
@Autowired
private OrderService orderService;
@KafkaListener(topics = "order-message-topic", containerFactory = "kafkaListenerContainerFactory")
public void processMessage(ConsumerRecord<Long, SubmitOrderReq> record, Acknowledgment acknowledgment) {
log.info("order-message-topic message Listener, Thread ID: " + Thread.currentThread().getId());
try {
log.info("order-message-topic message received, orderId: {}", record.value().getOrderId());
orderService.submitOrder(record.value());
// 同步提交
acknowledgment.acknowledge();
log.info("order-message-topic message acked: orderId: {}", record.value().getOrderId());
} catch (DuplicateKeyException dupe) {
// 处理异常情况
log.error("order-message-topic message error DuplicateKeyException", dupe);
// 重复数据,忽略掉,同步提交
acknowledgment.acknowledge();
}
}
}