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
死信队列中(dead letter)死信的消息来源:git
普通队列指定死信队列的相关参数:github
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
@Bean public TopicExchange emailExchange() { return (TopicExchange)ExchangeBuilder.topicExchange("emailExchange").durable(true).build(); }
@Bean public TopicExchange retryExchange() { return (TopicExchange)ExchangeBuilder.topicExchange("retryExchange").durable(true).build(); }
@Bean public TopicExchange faildExchange() { return (TopicExchange)ExchangeBuilder.topicExchange("faildExchange").durable(true).build(); }
/** * 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";
@Bean public Queue emailQueue() { return new Queue("emailQueue"); }
@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(); }
@Bean public Queue faildQueue() { return QueueBuilder.durable("faildQueue").build(); }
@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.*"); }
@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; }
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)); } } }
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; } }
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
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
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
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
查看faildQueue失败队列中消息的相关信息以下
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