RabbitMQ实现消息的消费确认,死信队列、延迟重试队列

消息的消费确认实现原理:

当消费者的消息消费异常时,消息进入延迟重试队列,待超时后从新发送到重试队列指定的死信队列,死信队列从新消费信息,若是又出现死信状况,继续进入延时重试队列,依次循环,当重试超过3次后,消息进入失败队列等待相应的消费者特殊处理或人工处理。java

死信队列

死信队列中(dead letter)死信的消息来源:git

  1. 消息被拒绝(basic.reject或basic.nack)而且requeue=false
  2. 消息TTL过时(x-message-ttl参数值即为超时时间)
  3. 队列达到最大长度(队列满了,没法再添加数据到mq中)

普通队列指定死信队列的相关参数:github

  • x-dead-letter-exchange: 用来设置死信后发送的交换机
  • x-dead-letter-routing-key:用来设置死信的routingKey
  • x-message-ttl: 单位毫秒,消息、队列的生命周期。超时后消息会变成dead message

延迟队列

延迟队列存储的对象为对应的延时消息,等待指定时间后,消费者才拿到这个消息进行消费。RabbitMQ自己没有直接支持的延迟队列功能,咱们能够设置 x-message-ttl,来控制消息的生存时间,若是超时,则消息成为dead letter(死信),进入死信队列,将死信队列指定为普通的消费队列便可实现延迟消费。web


声明交换器
  • 邮件交换器 emailExchange
@Bean
   public TopicExchange emailExchange() {
       return (TopicExchange)ExchangeBuilder.topicExchange("emailExchange").durable(true).build();
   }
  • 重试交换器 retryExchange
@Bean
   public TopicExchange retryExchange() {
       return (TopicExchange)ExchangeBuilder.topicExchange("retryExchange").durable(true).build();
   }
  • 失败交换器 faildExchange
@Bean
   public TopicExchange faildExchange() {
       return (TopicExchange)ExchangeBuilder.topicExchange("faildExchange").durable(true).build();
   }

声明队列
/** * 死信队列 交换机标识符 */
    private static final String X_DEAD_LETTER_EXCHANGE = "x-dead-letter-exchange";
    /** * 死信队列交换机routing-key标识符 */
    private static final String X_DEAD_LETTER_ROUTING_KEY = "x-dead-letter-routing-key";
    /** * 死信队列消息的超时时间枚举 */
    private static final String X_MESSAGE_TTL = "x-message-ttl";
  • 邮件队列 emailQueue
@Bean
   public Queue emailQueue() {
       return new Queue("emailQueue");
   }
  • 重试队列 retryQueue(此处我指定了其死信队列为emailQueue队列)
@Bean
   public Queue retryQueue() {
       Map<String, Object> args = new ConcurrentHashMap<>(3);
       // 将消息从新投递到emailExchange中
       args.put(DEAD_LETTER_QUEUE_KEY, "emailExchange");
       args.put(DEAD_LETTER_ROUTING_KEY, "email.topic.retry");
       //消息在队列中延迟30s后超时,消息会从新投递到x-dead-letter-exchage对应的队列中,routingkey为本身指定
       args.put(X_MESSAGE_TTL, 30 * 1000);
       return QueueBuilder.durable("retryQueue").withArguments(args).build();
   }
  • 失败队列 faildQueue
@Bean
   public Queue faildQueue() {
       return QueueBuilder.durable("faildQueue").build();
   }

绑定响应的交换器与队列
@Bean
    public Binding topicQueueBinding(@Qualifier("emailQueue") Queue queue,
                                      @Qualifier("emailExchange") TopicExchange exchange) {
        return BindingBuilder.bind(queue).to(exchange).with("email.topic.*");
    }
    @Bean
    public Binding retryDirectBinding(@Qualifier("retryQueue") Queue queue,
                                      @Qualifier("retryExchange") TopicExchange exchange) {
        return BindingBuilder.bind(queue).to(exchange).with("email.retry.*");
    }
    @Bean
    public Binding failDirectBinding(@Qualifier("faildQueue") Queue queue,
                                     @Qualifier("faildExchange") TopicExchange exchange) {
        return BindingBuilder.bind(queue).to(exchange).with("email.faild.*");
    }

配置生产者消息确认回调(具体处理逻辑需按业务状况,此处只输出了信息)
@Bean
    public AmqpTemplate amqpTemplate(){
		// 在消息没有被路由到合适的队列状况下,Broker会将消息返回给生产者,
		// 为true时若是Exchange根据类型和消息Routing Key没法路由到一个合适的Queue存储消息,
		// Broker会调用Basic.Return回调给handleReturn(),再回调给ReturnCallback,将消息返回给生产者。
		// 为false时,丢弃该消息
        rabbitTemplate.setMandatory(true);

        // 消息确认,须要配置 spring.rabbitmq.publisher-confirms = true
        rabbitTemplate.setConfirmCallback((correlationData, ack, cause) -> {
        
        	//根据返回的状态,生产者能够处理失败与成功的相应信息,好比发送失败,可重发,转发或者存入日志等
        	//if(ack){
        	// correlationData.getId()为message惟一标识,须要生产者发送message时传入自定义的correlationData才能获取到,不然为null
        	// //do something
        	//}else{
        	// correlationData.getId()
			// //do something 
			//}
        	
        	//此处只作打印,不对生产者发送失败的信息处理
            System.out.println("------------------------------------------------");
            System.out.println("ConfirmCallBackListener:correlationData=" + correlationData + ",ack=" + ack + ",cause=" + cause);
            System.out.println("------------------------------------------------");
            
        });
        
        // 消息发送失败返回到队列中,须要配置spring.rabbitmq.publisher-returns = true
        rabbitTemplate.setReturnCallback((message, replyCode, replyText, exchange, routingKey) -> {
        
            System.out.println("------------------------------------------------");
            System.out.println("ReturnCallBackListener:message=" + new String(message.getBody()) + ",replyCode=" + replyCode + ",replyText=" + replyText + ",exchange=" + exchange + ",routingKey=" + routingKey);
            System.out.println("------------------------------------------------");
            
        });

        return rabbitTemplate;
    }

生产者发送消息
package com.bhy702.website;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

/** * @author: Hongyuan Bai * @create: 2019-06-27 13:45:43 * @description: */
@RunWith(SpringRunner.class)
@SpringBootTest
public class RabbitMQTest {

    @Autowired
    private AmqpTemplate rabbitTemplate;

    public static final String EXCHANGE = "emailExchange";
    public static final String ROUTING_KEY = "email.topic.queue";

    @Test
    public void test() {

        for (int i = 100; i < 105; i++){
            rabbitTemplate.convertAndSend(EXCHANGE,ROUTING_KEY,"message:"+(i+1));
        }
    }

}

消费者消费消息
package com.bhy702.website.common.rabbitmq;

import com.rabbitmq.client.Channel;
import lombok.extern.slf4j.Slf4j;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.stereotype.Component;
import java.io.IOException;


/** * @author: Hongyuan Bai * @create: 2019-06-27 13:38:46 * @description: */
@Slf4j
@Component
public class RabbitConsumer2 {

    @Autowired
    private JavaMailSender javaMailSender;

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @RabbitListener(queues = "emailQueue")
    public void sendMail(Message message, Channel channel) throws IOException {
    
        try {
            /** 手动抛出异常,测试消息重试 */
            int i = 1 / 0;

        } catch (Exception e) {
        
            long retryCount = getRetryCount(message.getMessageProperties());

            if (retryCount >= 3) {

                /** 重试次数超过3次,则将消息发送到失败队列等待特定消费者处理或者人工处理 */
                try {
                    rabbitTemplate.convertAndSend("faildExchange","email.faild.myfaild", message);
                    log.info("消费者消费消息在重试3次后依然失败,将消息发送到faild队列,发送消息:" + new String(message.getBody()));
                } catch (Exception e1) {
                    log.error("消息在发送到faild队列的时候报错:" + e1.getMessage() + ",原始消息:"+ new String(message.getBody()));
                }

            } else {

                try {
                    /** 重试次数不超过3次,则将消息发送到重试队列等待从新被消费(重试队列延迟超时后信息被发送到相应死信队列从新消费,即延迟消费)*/
                    rabbitTemplate.convertAndSend("retryExchange", "email.retry.myRetry", message);
                    log.info("消费者消费失败,消息发送到重试队列;" + "原始消息:" + new String(message.getBody()) + ";第" + (retryCount+1) + "次重试");
                } catch (Exception e1) {
                    log.error("消息发送到重试队列的时候,异常了:" + e1.getMessage() + ",从新发送消息");
                }
            }
        } finally {
            /** * 不管消费成功仍是消费失败,都要手动进行ack,由于即便消费失败了,也已经将消息从新投递到重试队列或者失败队列 * 若是不进行ack,生产者在超时后会进行消息重发,若是消费者依然不能处理,则会存在死循环 */
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
        }
    }
    
 	/** * 获取消息被重试的次数 */
	public long getRetryCount(MessageProperties messageProperties) {
        Long retryCount = 0L;
        if (null != messageProperties) {
            List<Map<String, ?>> deaths = messageProperties.getXDeathHeader();
            if(deaths != null && deaths.size()>0){
                Map<String, Object> death = (Map<String, Object>)deaths.get(0);
                retryCount = (Long) death.get("count");
            }

        }
        return retryCount;
    }

}

properties配置文件中RabbitMQ相关配置
spring.application.name=rabbitMQ-test
spring.rabbitmq.host=RabbitMQ服务器的IP地址
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
spring.rabbitmq.virtual-host=/

# 开启发布者发送确认
spring.rabbitmq.publisher-confirms=true
# 开启发布者发送失败退回
spring.rabbitmq.publisher-returns=true

# 开启ACK手动确认
spring.rabbitmq.listener.simple.acknowledge-mode=manual
spring.rabbitmq.listener.direct.acknowledge-mode=manual

# 参数设为 true 时,交换器没法根据自身的类型和路由键找到一个符合条件的队列,
# 那么 RabbitMQ 会调用 Basic.Return 命令将消息返回给生产者
 spring.rabbitmq.template.mandatory=true

# 开启rabbitmq的生产端重试机制,默认是false,默认重试3次
spring.rabbitmq.template.retry.enabled=true

# 开启rabbitmq的消费端重试机制,默认是false,默认重试3次
# spring.rabbitmq.listener.simple.retry.enabled=true
# 设置重试的次数
# spring.rabbitmq.listener.simple.retry.max-attempts=5

测试效果展现:

消息进入emailQueue邮件队列后,出现消费异常会进入retryQueue重试队列等待延迟重试

在这里插入图片描述

消费异常的消息所有进入重试队列等待延迟重试,30秒后消息超时会转发到指定的死信队列,也就是回到emailQueue邮件队列

在这里插入图片描述

通过3次重试后,消息仍然未被消费,消息进入faildQueue失败队列等待相应的消费者特殊处理或人工处理

在这里插入图片描述

查看faildQueue失败队列中消息的相关信息以下

在这里插入图片描述


当前只解决了消息的可靠性消费,要保证消息所有投递成功,就涉及到RabbitMQ的可靠性投递。
RabbitMQ消息的可靠性投递与消费的完整解决方案- -可参考另外一篇博客 点这里

欢迎访问本文的我的博客连接: https://br-bai.github.io/2019/06/29/RabbitMQ实现消息的消费确认,死信队列、延迟重试队列/spring