RabbitMQ的延时重试队列

Posted 2021-12-15 小黄鸡1992

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1.背景

通过上文学习知道了死信队列，如果只是网络抖动，出现异常那么直接进入死信队列，那么是不合理的。这就可以使用延时重试队列，本文将介绍如何实现延时重试队列。

2.原理

图是俺在网上找的，请原作者谅解。

1. 发送到业务队里 如果正常收到 正常运行
2. 如果处理失败 重试 并投入延时队列 如果超过延时时间 重新投入业务队列
3. 如果重试次数大于3 那么进入死信队列

3.代码实现

1.业务队列

这里声明业务队列与绑定关系。

@Configuration
public class BusinessConfig 

    /**
     * yewu1模块direct交换机的名字
     */
    public static final String YEWU1_EXCHANGE = "yewu1_direct_exchange";

    /**
     * demo业务的队列名称
     */
    public static final String YEWU1_DEMO_QUEUE = "yewu1_demo_queue";

    /**
     * demo业务的routekey
     */
    public static final String YEWU1_DEMO_ROUTINGKEY = "yewu1_demo_key";

    /**
     * 业务交换机交换机(一个项目一个业务交换机即可)
     * 1.定义direct exchange，绑定queueTest
     * 2.durable="true" rabbitmq重启的时候不需要创建新的交换机
     * 3.direct交换器相对来说比较简单，匹配规则为：如果路由键匹配，消息就被投送到相关的队列
     * fanout交换器中没有路由键的概念，他会把消息发送到所有绑定在此交换器上面的队列中。
     * topic交换器你采用模糊匹配路由键的原则进行转发消息到队列中
     */
    @Bean
    public DirectExchange yewu1Exchange() 
        DirectExchange directExchange = new DirectExchange(YEWU1_EXCHANGE, true, false);
        return directExchange;
    

    /**
     * 新建队列(一个业务需要一个队列一个routekey 命名格式 项目名-业务名)
     * 1.队列名称
     * 2.durable="true" 持久化 rabbitmq重启的时候不需要创建新的队列
     * 3.exclusive 表示该消息队列是否只在当前connection生效,默认是false
     * 4.auto-delete 表示消息队列没有在使用时将被自动删除 默认是false
     * 5.对nack或者发送超时的 发送给死信队列 args是绑定死信队列
     *
     */
    @Bean
    public Queue yewu1DemoQueue() 
        return new Queue(YEWU1_DEMO_QUEUE, true, false, false);
    

    /**
     * 交换机与routekey绑定
     * 
     * @return
     */
    @Bean
    public Binding yewu1DemoBinding() 
        return BindingBuilder.bind(yewu1DemoQueue()).to(yewu1Exchange())
            .with(YEWU1_DEMO_ROUTINGKEY);
    

2.延时队列

声明延时队列与绑定关系。

@Configuration
public class RetryConfig 

    /**
     * 延时队列 交换机配置标识符(固定)
     */
    public static final String RETRY_LETTER_QUEUE_KEY = "x-dead-letter-exchange";

    /**
     * 延时队列交换机绑定配置键标识符(固定)
     */
    public static final String RETRY_LETTER_ROUTING_KEY = "x-dead-letter-routing-key";

    /**
     * 延时队列消息的配置超时时间枚举(固定)
     */
    public static final String RETRY_MESSAGE_TTL = "x-message-ttl";

    /**
     * yewu1模块延时队列交换机
     */
    public final static String YEWU1_RETRY_EXCHANGE_NAME = "yewu1_retry_exchange";

    /**
     * yewu1模块DEMO业务延时队列
     */
    public final static String YEWU1_DEMO_RETRY_QUEUE_NAME = "yewu1_demo_retry_queue";

    /**
     * yewu1模块DEMO延时队列routekey
     */
    public final static String YEWU1_DEMO_RETRY_ROUTING_KEY = "yewu1_demo_retry_key";

    /**
     * 延时队列交换机
     *
     * @return
     */
    @Bean
    public DirectExchange yewu1RetryExchange() 
        DirectExchange directExchange = new DirectExchange(YEWU1_RETRY_EXCHANGE_NAME, true, false);
        return directExchange;
    

    /**
     * 新建延时队列 一个业务队列需要一个延时队列
     * 
     * @return
     */
    @Bean
    public Queue yewu1DemoRetryQueue() 
        Map<String, Object> args = new ConcurrentHashMap<>(3);
        // 将消息重新投递到业务交换机Exchange中
        args.put(RETRY_LETTER_QUEUE_KEY, BusinessConfig.YEWU1_EXCHANGE);
        args.put(RETRY_LETTER_ROUTING_KEY, BusinessConfig.YEWU1_DEMO_ROUTINGKEY);
        // 消息在队列中延迟3s后超时，消息会重新投递到x-dead-letter-exchage对应的队列中，routingkey为自己指定
        args.put(RETRY_MESSAGE_TTL, 3 * 1000);
        return new Queue(YEWU1_DEMO_RETRY_QUEUE_NAME, true, false, false, args);
    

    /**
     * 绑定以上定义关系
     * 
     * @return
     */
    @Bean
    public Binding retryDirectBinding() 
        return BindingBuilder.bind(yewu1DemoRetryQueue()).to(yewu1RetryExchange())
            .with(YEWU1_DEMO_RETRY_ROUTING_KEY);
    

3.死信队列

声明私信队列与绑定关系。

@Configuration
public class DeadConfig 

    /**
     * 死信队列
     */
    public final static String FAIL_QUEUE_NAME = "fail_queue";

    /**
     * 死信交换机
     */
    public final static String FAIL_EXCHANGE_NAME = "fail_exchange";

    /**
     * 死信routing
     */
    public final static String FAIL_ROUTING_KEY = "fail_routing";

    /**
     * 创建配置死信队列
     *
     */
    @Bean
    public Queue deadQueue() 
        return new Queue(FAIL_QUEUE_NAME, true, false, false);
    

    /**
     * 死信交换机
     *
     * @return
     */
    @Bean
    public DirectExchange deadExchange() 
        DirectExchange directExchange = new DirectExchange(FAIL_EXCHANGE_NAME, true, false);
        return directExchange;
    

    /**
     * 绑定关系
     * 
     * @return
     */
    @Bean
    public Binding failBinding() 
        return BindingBuilder.bind(deadQueue()).to(deadExchange()).with(FAIL_ROUTING_KEY);
    

4.生产者

生产者如上文，通用代码。

@RestController
@RequestMapping("/TestRabbit")
public class ProducerDemo 

    @Resource
    private RabbitTemplate rabbitTemplate;

    //@RequestMapping("/sendDirect")
    String sendDirect(@RequestBody String message) throws Exception 
        System.out.println("开始生产");
        CorrelationData data = new CorrelationData(UUID.randomUUID().toString());
        rabbitTemplate.convertAndSend(BusinessConfig.YEWU1_EXCHANGE, BusinessConfig.YEWU1_DEMO_ROUTINGKEY,
            message, data);
        System.out.println("结束生产");
        System.out.println("发送id:" + data);
        return "OK,sendDirect:" + message;
    

5.消费者

大量的逻辑，请参考注释。

public enum RabbitEnum 
 
    /**
     * 处理成功
     */
    ACCEPT,
 
    /**
     * 可以重试的错误
     */
    RETRY,
 
    /**
     * 无需重试的错误
     */
    REJECT
@Component
public class ConsumerDemo 

    private final static Logger logger = LoggerFactory.getLogger(ConsumerDemo.class);

    @Resource
    private RabbitTemplate rabbitTemplate;

    // @RabbitListener(queues = "yewu1_demo_queue")
    protected void consumer(Message message, Channel channel) throws Exception 
        RabbitEnum ackSign = RabbitEnum.RETRY;
        System.out.println(message.getMessageProperties().getCorrelationId());
        try 
            // 可以加入重复消费判断
            int i = 1 / 0;

         catch (Exception e) 
            ackSign = RabbitEnum.RETRY;
            throw e;
         finally 
            // 通过finally块来保证Ack/Nack会且只会执行一次
            if (ackSign == RabbitEnum.ACCEPT) 
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
             else if (ackSign == RabbitEnum.RETRY) 
                String correlationData =
                    (String)message.getMessageProperties().getHeaders().get("spring_returned_message_correlation");
                System.out.println(message.getMessageProperties().getCorrelationId());
                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 
                        channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
                        rabbitTemplate.convertAndSend(DeadConfig.FAIL_EXCHANGE_NAME, DeadConfig.FAIL_ROUTING_KEY,
                            message, new CorrelationData(correlationData));
                        logger.info("连续失败三次，将消息发送到死信队列,发送消息:" + new String(message.getBody()));
                     catch (Exception e1) 
                        channel.basicNack(message.getMessageProperties().getDeliveryTag(), false, false);
                        logger.error("发送死信队列报错:" + e1.getMessage() + ",原始消息:" + new String(message.getBody()));
                    
                 else 
                    try 
                        channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
                        // 重试次数不超过3次,则将消息发送到重试队列等待重新被消费
                        rabbitTemplate.convertAndSend(RetryConfig.YEWU1_RETRY_EXCHANGE_NAME,
                            RetryConfig.YEWU1_DEMO_RETRY_ROUTING_KEY, message,
                            new CorrelationData(correlationData));
                        logger.info("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) 
                        channel.basicNack(message.getMessageProperties().getDeliveryTag(), false, false);
                        logger.error("消息发送到重试队列的时候，异常了:" + e1.getMessage() + ",重新发送消息");
                    
                
            
        
    

  

    /**
     * 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;
    

参考：https://www.cnblogs.com/mfrank/p/11260355.html

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