消息100%的投递

 

消息如何保障100%的投递成功?

什么是生产端的可靠性投递?

  保障消息的成功发出

  保障MQ节点的成功接收

  发送端收到MQ节点(Broker)确认应答

  完善的消息进行补偿机制

 

BAT/TMD互联网大厂的解决方案:

  消息落库,对消息状态进行打标

  消息的延迟投递,做二次确认,回调检查

 

 

 

 

 

 

幂等性概念

幂等性是什么?

  我们可以借鉴数据库的乐观锁机制

  比如我们执行一条更新库存的SQL语句

  Update t_repository set count = count -1,version = version + 1 where version = 1

  Elasticsearch也是严格遵循幂等性概念,每次数据更新,version+1(博主博客前面有提到)

 

消费端-幂等性保障

在海量订单产生的业务高峰期,如何避免消息的重复消费问题?

 

消费实现幂等性,就意味着,我们的消息永远不会消费多次,即使我们收到了多条一样的消息

 

业界主流的幂等性操作

唯一ID+指纹码机制,利用数据库主键去重

利用Redis的原子性去实现

 

唯一ID+指纹码 机制

唯一ID+指纹码机制,利用数据库主键去重

Select count(1) from T_order where ID=唯一ID+指纹码

好处:实现简单

坏处:高并发下有数据库写入的性能瓶颈

解决方案:根据ID进行分库分表进行算法路由

 

利用Redis的原子性去实现

使用Redis进行幂等,需要考虑的问题

第一:我们是否要进行数据落库,如果落库的话,关键解决的问题是数据库和缓存如何做到原子性?

第二:如果不进行落库,那么都存储到缓存中,如何设置定时同步策略?

 

Confirm确认消息

理解Confirm消息确认机制

消息的确认,是指生产者投递消息后,如果Broker收到消息,则会给我们生产者         一个应答。

生产者进行接收应答,用来确定这条消息是否正常的发送到Broker,这种方式也是消息的可靠性投递的核心保障

 

 

 

如何实现Confirm确认消息?

第一步:在Channel上开启确认模式:channel.confirmSelect()

第二步:在channel上添加监听:addConfirmListener,监听成功和失败的返回结果,根据具体的结果对消息进行重新发送、或记录日志等后续处理!

消费端代码

package com.liuwenwu.rabbitmqaqi.confirm;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;


public class Consumer {
    public static void main(String[] args) throws Exception {
        //1 创建ConnectionFactory
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.241.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        //2 获取C    onnection
        Connection connection = connectionFactory.newConnection();

        //3 通过Connection创建一个新的Channel
        Channel channel = connection.createChannel();

        String exchangeName = "test_confirm_exchange";
        String routingKey = "confirm.#";
        String queueName = "test_confirm_queue";

        //4 声明交换机和队列 然后进行绑定设置, 最后制定路由Key
        channel.exchangeDeclare(exchangeName, "topic", true);
        channel.queueDeclare(queueName, true, false, false, null);
        channel.queueBind(queueName, exchangeName, routingKey);

        //5 创建消费者
        QueueingConsumer queueingConsumer = new QueueingConsumer(channel);
        channel.basicConsume(queueName, true, queueingConsumer);

        while(true){
            QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery();
            String msg = new String(delivery.getBody());

            System.err.println("消费端: " + msg);
        }


    }
}

服务提供方代码

package com.liuwenwu.rabbitmqaqi.confirm;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.ConfirmListener;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

import java.io.IOException;


public class Producer {
    public static void main(String[] args) throws Exception {
        //1 创建ConnectionFactory
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.241.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        //2 获取C    onnection
        Connection connection = connectionFactory.newConnection();

        //3 通过Connection创建一个新的Channel
        Channel channel = connection.createChannel();


        //4 指定我们的消息投递模式: 消息的确认模式
        channel.confirmSelect();

        String exchangeName = "test_confirm_exchange";
        String routingKey = "confirm.save";

        //5 发送一条消息
        String msg = "Hello RabbitMQ Send confirm message!";
        channel.basicPublish(exchangeName, routingKey, null, msg.getBytes());

        //6 添加一个确认监听
        channel.addConfirmListener(new ConfirmListener() {
            @Override
            public void handleNack(long deliveryTag, boolean multiple) throws IOException {
                System.err.println("-------no ack!-----------");
            }

            @Override
            public void handleAck(long deliveryTag, boolean multiple) throws IOException {
                System.err.println("-------ack!-----------");
            }
        });
    }
}

Return返回消息

Return Listener用于处理一些不可路由的消息!

正常情况:我们的消息生产者,通过指定一个Exchange和RoutingKey,把消息送达到某一个队列中去,然后我们的消费者监听队列,进行消费处理操作!

异常情况:在某些情况下,如果我们在发送消息的时候,当前的Exchange不存在或者指定的路由key路由不到,这个时候如果我们需要监听这种不可达的消息,就需要使用Return Listener!

 

在基础API中有一个关键的配置项

Mandatory:如果为true,则监听器会接收到路由不可达的消息,然后进行后续处理,如果为false,那么Broker端自动删除该消息!

 

 

 

消费端代码

package com.liuwenwu.rabbitmqaqi.returnlistener;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;


public class Consumer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.241.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();

        String exchangeName = "test_return_exchange";
        String routingKey = "return.#";
        String queueName = "test_return_queue";

        channel.exchangeDeclare(exchangeName, "topic", true, false, null);
        channel.queueDeclare(queueName, true, false, false, null);
        channel.queueBind(queueName, exchangeName, routingKey);

        QueueingConsumer queueingConsumer = new QueueingConsumer(channel);

        channel.basicConsume(queueName, true, queueingConsumer);

        while(true){
            QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery();
            String msg = new String(delivery.getBody());
            System.err.println("消费者: " + msg);
        }

    }
}

生产端代码

package com.liuwenwu.rabbitmqaqi.returnlistener;

import com.rabbitmq.client.*;

import java.io.IOException;


public class Producer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.241.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();

        String exchange = "test_return_exchange";
        String routingKey = "return.save";
        String routingKeyError = "abc.save";

        String msg = "Hello RabbitMQ Return Message";


        channel.addReturnListener(new ReturnListener() {
            @Override
            public void handleReturn(int replyCode, String replyText, String exchange,
                                     String routingKey, AMQP.BasicProperties properties, byte[] body) throws IOException {

                System.err.println("---------handle  return----------");
                System.err.println("replyCode: " + replyCode);
                System.err.println("replyText: " + replyText);
                System.err.println("exchange: " + exchange);
                System.err.println("routingKey: " + routingKey);
                System.err.println("properties: " + properties);
                System.err.println("body: " + new String(body));
            }
        });

        //消息投递成功,会被消费者所消费
//        channel.basicPublish(exchange, routingKey, true, null, msg.getBytes());
        //消息不可达,将触发ReturnListener
         channel.basicPublish(exchange, routingKeyError, true, null, msg.getBytes());
    }
}

自定义消费者

我们一般就是在代码中编写while循环,进行consumer.nextDelivery方法进行获取下一条消息,然后进行消费处理!

但是我们使用自定义的Consumer更加的方便,解耦性更加的强,也是实际工作中最常用的使用方式!

 

自定义消费端代码

package com.liuwenwu.rabbitmqaqi.consumer;

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;

import java.io.IOException;


public class MyConsumer extends DefaultConsumer {


    public MyConsumer(Channel channel) {
        super(channel);
    }

    @Override
    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
        System.err.println("-----------consume message----------");
        System.err.println("consumerTag: " + consumerTag);
        System.err.println("envelope: " + envelope);
        System.err.println("properties: " + properties);
        System.err.println("body: " + new String(body));
    }
}

消费端调用

package com.liuwenwu.rabbitmqaqi.consumer;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;


public class Consumer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.241.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();


        String exchangeName = "test_consumer_exchange";
        String routingKey = "consumer.#";
        String queueName = "test_consumer_queue";

        channel.exchangeDeclare(exchangeName, "topic", true, false, null);
        channel.queueDeclare(queueName, true, false, false, null);
        channel.queueBind(queueName, exchangeName, routingKey);

        channel.basicConsume(queueName, true, new MyConsumer(channel));

    }
}

生产端调用

package com.liuwenwu.rabbitmqaqi.consumer;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;


public class Producer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.241.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");

        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();

        String exchange = "test_consumer_exchange";
        String routingKey = "consumer.save";

        String msg = "Hello RabbitMQ Consumer Message";

        for(int i =0; i<5; i ++){
            channel.basicPublish(exchange, routingKey, true, null, msg.getBytes());
        }

    }
}

 

posted on 2019-12-06 11:33  骑猪南下L  阅读(188)  评论(0编辑  收藏  举报