Rabbitmq 高级特性 - 消费端限流

Rabbitmq 高级特性 - 消费端限流

• 消费端步骤(在原有RabbitMQ 高级特性 Consumer Ack的基础)

  1. 新建信监听类

     package com.yang.listener;
     
     import com.rabbitmq.client.Channel;
     import org.springframework.amqp.core.Message;
     import org.springframework.amqp.rabbit.listener.api.ChannelAwareMessageListener;
     import org.springframework.stereotype.Component;
     
     /**
      * consumer限流机制
      */
     @Component
     public class QosListener implements ChannelAwareMessageListener {
         @Override
         public void onMessage(Message message, Channel channel) throws Exception {
     
         }
     }
     
     

  2. 限流的步骤

     1. 确保ack机制为手动签收(配置文件监听容器哪里acknowledge="manual")

         
            <rabbitmq:listener-container connection-factory="connectionFactory" acknowledge="manual">
                <rabbit:listener ref="qosListener" queue-names="test_queue_confirm"/>
            rabbitmq:listener-container>
        

     2. Listener-container配置属性(刚刚定义监听器容器哪里配prefetch="1")

        	<rabbitmq:listener-container connection-factory="connectionFactory" acknowledge="manual" prefetch="1">
                <rabbit:listener ref="qosListener" queue-names="test_queue_confirm"/>
            rabbitmq:listener-container>
        

        

  3. 完整代码

     package com.yang.listener;
     
     import com.rabbitmq.client.Channel;
     import org.springframework.amqp.core.Message;
     import org.springframework.amqp.rabbit.listener.api.ChannelAwareMessageListener;
     import org.springframework.stereotype.Component;
     
     /**
      * consumer限流机制
      *      1. 确保ack机制为手动签收
      *      2. Listener-container配置属性
      *          perfetch = 1, 表示消费端每次从mq来消费,知道手动确认完毕后,才会继续拉取下一条消息
      */
     @Component
     public class QosListener implements ChannelAwareMessageListener {
         @Override
         public void onMessage(Message message, Channel channel) throws Exception {
             //1. 获取消息
             System.out.println(new String(message.getBody()));
             //2. 处理业务逻辑
             System.out.println("处理业务逻辑");
             //3. 签收
             channel.basicAck(message.getMessageProperties().getDeliveryTag(),true);
         }
     }
     
     

  4. 在以前写过的代码生成者里面,发送请求(RabbitMQ 高级特性 - 消息的可靠性投递)

     	@Test
         public void testSend() {
             for (int i = 0; i < 10; i++) {
                 //1. 发送消息
                 rabbitTemplate.convertAndSend("test_exchange_confirm","confirm","message confirm ...");
             }
     
         }
     

     

  5. 为了看到效果把签收消息注释调,这样它只会拉取一条,来消费因为它认为我们还没有完成.

     @Component
     public class QosListener implements ChannelAwareMessageListener {
         @Override
         public void onMessage(Message message, Channel channel) throws Exception {
             //1. 获取消息
             System.out.println(new String(message.getBody()));
             //2. 处理业务逻辑
             System.out.println("处理业务逻辑");
             //3. 签收
     //        channel.basicAck(message.getMessageProperties().getDeliveryTag(),true);
         }
     }
     

  6. 运行结果
     

  7. 使用接受的签收的(为了看到效果,每次停止1秒)

     @Component
     public class QosListener implements ChannelAwareMessageListener {
         @Override
         public void onMessage(Message message, Channel channel) throws Exception {
             //1. 获取消息
             System.out.println(new String(message.getBody()));
             //2. 处理业务逻辑
             System.out.println("处理业务逻辑");
             //3. 签收
             channel.basicAck(message.getMessageProperties().getDeliveryTag(),true);
             
             Thread.sleep(1000);
         }
     }
     
     

  8. 运行结果(可以看到间隔一秒一条,图片看不出)
     

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• 消费端限流小结
  1. 在rabbit:listener-container 中配置 prefetch属性设置消费端一次拉取多少消息
  2. 消费端的确认模式一定为手动确认。acknowledge=“manual”
  • 一定要手动确认!
  • 一定要手动确认!
  • 一定要手动确认!