RabbitMQ 消息顺序性保证

方式一：Consumer设置exclusive

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注意条件

作用于basic.consume
不支持quorum queue

当同时有A、B两个消费者调用basic.consume方法消费，并将exclusive设置为true时，第二个消费者会抛出异常：

com.rabbitmq.client.AlreadyClosedException: channel is already closed due to channel error; protocol method: #method<channel.close>(reply-code=403, reply-text=ACCESS_REFUSED - queue 'test' in vhost '/' in exclusive use, class-id=60, method-id=20)
	at com.rabbitmq.client.impl.AMQChannel.ensureIsOpen(AMQChannel.java:190)
	at com.rabbitmq.client.impl.AMQChannel.rpc(AMQChannel.java:223)
	at com.rabbitmq.client.impl.ChannelN.basicConsume(ChannelN.java:981)
	at com.dms.rabbitmq.TopicSender.lambda$main$2(TopicSender.java:63)
	at java.base/java.lang.Thread.run(Thread.java:840)

Spring AMQP 如何通过exclusive实现顺序消费：

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核心逻辑：

while (!DirectMessageListenerContainer.this.started && isRunning()) {
   this.cancellationLock.reset();
   try {
      for (String queue : queueNames) {
         consumeFromQueue(queue);
      }
   }
   catch (AmqpConnectException | AmqpIOException e) {
      long nextBackOff = backOffExecution.nextBackOff();
      if (nextBackOff < 0 || e.getCause() instanceof AmqpApplicationContextClosedException) {
         DirectMessageListenerContainer.this.aborted = true;
         shutdown();
         this.logger.error("Failed to start container - fatal error or backOffs exhausted",
               e);
         this.taskScheduler.schedule(this::stop, Instant.now());
         break;
      }
      this.logger.error("Error creating consumer; retrying in " + nextBackOff, e);
      doShutdown();
      try {
         Thread.sleep(nextBackOff); // NOSONAR
      }
      catch (InterruptedException e1) {
         Thread.currentThread().interrupt();
      }
      continue; // initialization failed; try again having rested for backOff-interval
   }
   DirectMessageListenerContainer.this.started = true;
   DirectMessageListenerContainer.this.startedLatch.countDown();
}

抛出异常后，会重试
重试间隔、次数受recoveryInterval（默认无限）、recoveryBackOff控制

方式二：single active consumer

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原理：

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代码示例：

Channel ch = ...;
Map<String, Object> arguments = newHashMap<String, Object>();
arguments.put("x-single-active-consumer", true);
ch.queueDeclare("my-queue", false, false, false, arguments);

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参考资料：https://www.rabbitmq.com/blog/2022/07/05/rabbitmq-3-11-feature-preview-single-active-consumer-for-streams