work工作消息队列Round-robin与Fair dispatch

一：介绍

1.模型

　　有两种情形，分别是轮训分发与公平分发。

　　

2.出现的场景

　　考虑到simple queue中的缺点。

　　因为生产者发送消息后，消费者消费要花费时间，这个会造成消息的堆积。

二：Round robin--轮循

1.发送程序

　　这个与简单程序类似，只是发送多条数据而已。

 package com.mq.work.round;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.Connection;

 public class RoundWorkSend {
     private static final String QUENE_NAME="test_work_queue";
     public static void main(String[] args) throws Exception {
         //获取一个连接
         Connection connection= ConnectionUtil.getConnection();
         //从连接中获取一个通道
         Channel channel=connection.createChannel();
         //创建队列声明
         channel.queueDeclare(QUENE_NAME,false,false,false,null);

         //消息与发送放入for循环
         for (int i=0;i<50;i++){
             String msg="hello "+i;
             System.out.println("[send msg]:"+msg);
             channel.basicPublish("",QUENE_NAME,null,msg.getBytes());
             Thread.sleep(i*1);
         }

         //关闭连接
         channel.close();
         connection.close();
     }
 }

2.消费者一

 package com.mq.work.round;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.*;

 import java.io.IOException;

 public class RoundWorkReceive1 {
     private static final String QUENE_NAME="test_work_queue";
     public static void main(String[] args)throws Exception{
         //获取一个连接
         Connection connection = ConnectionUtil.getConnection();
         //创建通道
         Channel channel = connection.createChannel();
         //创建队列声明
         channel.queueDeclare(QUENE_NAME,false,false,false,null);
         //创建消费者
         DefaultConsumer consumer=new DefaultConsumer(channel){
             @Override
             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                 String msg=new String(body,"utf-8");
                 System.out.println("[1]receive msg:"+msg);
                 try {
                     Thread.sleep(200);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }finally {
                     System.out.println("done");
                 }
             }
         };
         //监听队列
         boolean autoAck=true;
         channel.basicConsume(QUENE_NAME,autoAck,consumer);
     }
 }

3.消费者二

 package com.mq.work.round;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.*;

 import java.io.IOException;

 public class RoundWorkReceive2 {
     private static final String QUENE_NAME="test_work_queue";
     public static void main(String[] args)throws Exception{
         //获取一个连接
         Connection connection = ConnectionUtil.getConnection();
         //创建通道
         Channel channel = connection.createChannel();
         //创建队列声明
         channel.queueDeclare(QUENE_NAME,false,false,false,null);
         //创建消费者
         DefaultConsumer consumer=new DefaultConsumer(channel){
             @Override
             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                 String msg=new String(body,"utf-8");
                 System.out.println("[2]receive msg:"+msg);
                 try {
                     Thread.sleep(300);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }finally {
                     System.out.println("done");
                 }
             }
         };
         //监听队列
         boolean autoAck=true;
         channel.basicConsume(QUENE_NAME,autoAck,consumer);
     }
 }

4.现象

　　send

　　

　　receive1：

　　

　　receive2：

　　

三：fair dispatcher

1.介绍

　　使用公平分发需要关闭自动应答，改成手动。

　　有一种通俗的说法是：能者多劳。　

2.生产者

　　需要改动的地方是：每个消费者在得到确认消息之前，消息队列不得发送一个消息给消费者，一次只能处理一个消息。

 package com.mq.work.fair;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.Connection;

 public class FairWorkSend {
     private static final String QUENE_NAME="test_work_queue";
     public static void main(String[] args) throws Exception {
         //获取一个连接
         Connection connection= ConnectionUtil.getConnection();
         //从连接中获取一个通道
         Channel channel=connection.createChannel();
         //创建队列声明
         channel.queueDeclare(QUENE_NAME,false,false,false,null);

         //限制发送给一个消费者不得超过1条
         int prefetchCount=1;
         channel.basicQos(prefetchCount);

         //消息与发送放入for循环
         for (int i=0;i<50;i++){
             String msg="hello "+i;
             System.out.println("[send msg]:"+msg);
             channel.basicPublish("",QUENE_NAME,null,msg.getBytes());
             Thread.sleep(i*1);
         }

         //关闭连接
         channel.close();
         connection.close();
     }
 }

3.消费者一

　　需要改动的行数,14，18，33,38

 package com.mq.work.fair;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.*;

 import java.io.IOException;

 public class FairWorkReceive1 {
     private static final String QUENE_NAME="test_work_queue";
     public static void main(String[] args)throws Exception{
         //获取一个连接
         Connection connection = ConnectionUtil.getConnection();
         //创建通道
         final Channel channel = connection.createChannel();
         //创建队列声明
         channel.queueDeclare(QUENE_NAME,false,false,false,null);

         //一次只能发送一个消息
         channel.basicQos(1);

         //创建消费者
         DefaultConsumer consumer=new DefaultConsumer(channel){
             @Override
             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                 String msg=new String(body,"utf-8");
                 System.out.println("[1]receive msg:"+msg);
                 try {
                     Thread.sleep(200);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }finally {
                     System.out.println("done");
                     //手动应答
                     channel.basicAck(envelope.getDeliveryTag(),false);
                 }
             }
         };
         //监听队列,不是自动应答
         boolean autoAck=false;
         channel.basicConsume(QUENE_NAME,autoAck,consumer);
     }
 }

3.消费者二

　　与消费者一不同点在于消费每个消息的时间不同。

 package com.mq.work.fair;

 import com.mq.utils.ConnectionUtil;
 import com.rabbitmq.client.*;

 import java.io.IOException;

 public class FairWorkReceive2 {
     private static final String QUENE_NAME="test_work_queue";
     public static void main(String[] args)throws Exception{
         //获取一个连接
         Connection connection = ConnectionUtil.getConnection();
         //创建通道
         final Channel channel = connection.createChannel();
         //创建队列声明
         channel.queueDeclare(QUENE_NAME,false,false,false,null);

         //一次只能发送一个消息
         channel.basicQos(1);

         //创建消费者
         DefaultConsumer consumer=new DefaultConsumer(channel){
             @Override
             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                 String msg=new String(body,"utf-8");
                 System.out.println("[1]receive msg:"+msg);
                 try {
                     Thread.sleep(500);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }finally {
                     System.out.println("done");
                     //手动应答
                     channel.basicAck(envelope.getDeliveryTag(),false);
                 }
             }
         };
         //监听队列,不是自动应答
         boolean autoAck=false;
         channel.basicConsume(QUENE_NAME,autoAck,consumer);
     }
 }

4.现象

　　消费者一：

　　

　　消费者二：