记一次RabbitMQ解决分布式事务问题

案例说明：

经典案例，以目前流行点外卖的案例，用户下单后，调用订单服务，让后订单服务调用派单系统通知送外卖人员送单，这时候订单系统与派单系统采用MQ异步通讯，保证订单表和派单表必须一致！

用传统的HTTP协议不能解决高并发：

RabbitMQ解决分布式事务原理方案

1. 确保生产者一定要将数据投递到MQ服务器中
   • 生产者采用confirm，确认应答机制
   • 如果失败，生产者进行重试。
2. MQ消费者消息能够正常消费消息。
   • 采用手动ACK模式，使用补偿机制，注意幂等性问题。
3. 采用补单机制。
   • 在创建一个补单消费者进行监听，如果订单创建后，又回滚了(数据不一致)，此时需要将订单进行补偿。
   • 交换机采用路由键模式，补单队列和派但队列都绑定同一个路由键。

代码

派件表：

create TABLE platoon(
  id INT PRIMARY KEY AUTO_INCREMENT,
  orderId VARCHAR(255),
  takeout_userId int
 
)

订单表：

create TABLE order_info(
  id INT PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(30),  
  order_money INT,
  orderId VARCHAR(255)
  
);

生产者   

 1.实现接口 implements RabbitTemplate.ConfirmCallback

 2. 重写回调方法 ，成功、失败的调用  

@Override
public void confirm(CorrelationData correlationData, boolean ack, String cause) {

send方法里面调用回调函数：

this.rabbitTemplate.setMandatory(true);
this.rabbitTemplate.setConfirmCallback(this);

yml需要配置回调机制：

###开启消息确认机制 confirms
publisher-confirms: true
publisher-returns: true

 注意：重试也是有一定次数限制的 如果超过一定次数 就需要进行人工补偿了

 下单：

pom:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mayikt</groupId>
    <artifactId>rabbitmq_order</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.1.RELEASE</version>
</parent>
    <dependencies>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!-- mysql 依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- 阿里巴巴数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.14</version>
        </dependency>
        <!-- SpringBoot整合Web组件 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- springboot- 整个 lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!-- 添加springboot对amqp的支持 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>
        <!--fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.49</version>
        </dependency>
    </dependencies>
</project>

基础包：

public interface ApiConstants {
    // 响应请求成功
    String HTTP_RES_CODE_200_VALUE = "success";
    // 系统错误
    String HTTP_RES_CODE_500_VALUE = "fial";
    // 响应请求成功code
    Integer HTTP_RES_CODE_200 = 200;
    // 系统错误
    Integer HTTP_RES_CODE_500 = 500;
    // 未关联QQ账号
    Integer HTTP_RES_CODE_201 = 201;

}

import org.springframework.stereotype.Component;

@Component
public class BaseApiService {

    public ResponseBase setResultError(Integer code, String msg) {
        return setResult(code, msg, null);
    }

    // 返回错误，可以传msg
    public ResponseBase setResultError(String msg) {
        return setResult(ApiConstants.HTTP_RES_CODE_500, msg, null);
    }

    // 返回成功，可以传data值
    public ResponseBase setResultSuccess(Object data) {
        return setResult(ApiConstants.HTTP_RES_CODE_200, ApiConstants.HTTP_RES_CODE_200_VALUE, data);
    }

    // 返回成功，沒有data值
    public ResponseBase setResultSuccess() {
        return setResult(ApiConstants.HTTP_RES_CODE_200, ApiConstants.HTTP_RES_CODE_200_VALUE, null);
    }

    // 返回成功，沒有data值
    public ResponseBase setResultSuccess(String msg) {
        return setResult(ApiConstants.HTTP_RES_CODE_200, msg, null);
    }

    // 通用封装
    public ResponseBase setResult(Integer code, String msg, Object data) {
        return new ResponseBase(code, msg, data);
    }

}

import lombok.Data;

@Data
public class ResponseBase {

    private Integer rtnCode;
    private String msg;
    private Object data;

    public ResponseBase() {

    }

    public ResponseBase(Integer rtnCode, String msg, Object data) {
        super();
        this.rtnCode = rtnCode;
        this.msg = msg;
        this.data = data;
    }

    @Override
    public String toString() {
        return "ResponseBase [rtnCode=" + rtnCode + ", msg=" + msg + ", data=" + data + "]";
    }

}

补偿队列：

import lombok.Data;

@Data
public class ResponseBase {

    private Integer rtnCode;
    private String msg;
    private Object data;

    public ResponseBase() {

    }

    public ResponseBase(Integer rtnCode, String msg, Object data) {
        super();
        this.rtnCode = rtnCode;
        this.msg = msg;
        this.data = data;
    }

    @Override
    public String toString() {
        return "ResponseBase [rtnCode=" + rtnCode + ", msg=" + msg + ", data=" + data + "]";
    }

}

entity：

import lombok.Data;

@Data
public class OrderEntity {

    private Long id;
    // 订单名称
    private String name;
    // 下单金额
    private Double orderMoney;
    // 订单id
    private String orderId;
}

mapper：

import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

import com.mayikt.entity.OrderEntity;

public interface OrderMapper {

    @Insert(value = "INSERT INTO `order_info` VALUES (#{id}, #{name}, #{orderMoney},#{orderId})")
    @Options(useGeneratedKeys = true, keyProperty = "id", keyColumn = "id")
    public int addOrder(OrderEntity orderEntity);

    @Select("SELECT id as id ,name as name , order_money as orderMoney,orderId as orderId from order_info where orderId=#{orderId};")
    public OrderEntity findOrderId(@Param("orderId") String orderId);

}

MQ的配置：

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

@Component
public class RabbitmqConfig {

    // 下单并且派单存队列
    public static final String ORDER_DIC_QUEUE = "order_dic_queue";
    // 补单队列，判断订单是否已经被创建
    public static final String ORDER_CREATE_QUEUE = "order_create_queue";
    // 下单并且派单交换机
    private static final String ORDER_EXCHANGE_NAME = "order_exchange_name";

    // 1.定义订单队列
    @Bean
    public Queue directOrderDicQueue() {
        return new Queue(ORDER_DIC_QUEUE);
    }

    // 2.定义补订单队列
    @Bean
    public Queue directCreateOrderQueue() {
        return new Queue(ORDER_CREATE_QUEUE);
    }

    // 2.定义交换机
    @Bean
    DirectExchange directOrderExchange() {
        return new DirectExchange(ORDER_EXCHANGE_NAME);
    }

    // 3.订单队列与交换机绑定
    @Bean
    Binding bindingExchangeOrderDicQueue() {
        return BindingBuilder.bind(directOrderDicQueue()).to(directOrderExchange()).with("orderRoutingKey");
    }

    // 3.补单队列与交换机绑定
    @Bean
    Binding bindingExchangeCreateOrder() {
        return BindingBuilder.bind(directCreateOrderQueue()).to(directOrderExchange()).with("orderRoutingKey");
    }

}

service：

import java.util.UUID;

import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageBuilder;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.support.CorrelationData;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.alibaba.fastjson.JSONObject;
import com.mayikt.base.BaseApiService;
import com.mayikt.base.ResponseBase;
import com.mayikt.entity.OrderEntity;
import com.mayikt.mapper.OrderMapper;

@Service
public class OrderService extends BaseApiService implements RabbitTemplate.ConfirmCallback {
    @Autowired
    private OrderMapper orderMapper;
    @Autowired
    private RabbitTemplate rabbitTemplate;

    public ResponseBase addOrderAndDispatch() {
        //先下单 订单表插入数据
        OrderEntity orderEntity = new OrderEntity();
        orderEntity.setName("黄焖鸡米饭");
        // 价格是300元
        orderEntity.setOrderMoney(300d);
        // 商品id
        String orderId = UUID.randomUUID().toString();
        orderEntity.setOrderId(orderId);
        // 1.先下单，创建订单 (往订单数据库中插入一条数据)
        int orderResult = orderMapper.addOrder(orderEntity);
        System.out.println("orderResult:" + orderResult);
        if (orderResult <= 0) {
            return setResultError("下单失败!");
        }
        // 2.订单表插插入完数据后 订单表发送 外卖小哥
        send(orderId);
    //    int i = 1/0;   //发生异常
        return setResultSuccess();
    }

    private void send(String orderId) {
        JSONObject jsonObect = new JSONObject();
        jsonObect.put("orderId", orderId);
        String msg = jsonObect.toJSONString();
        System.out.println("msg:" + msg);
        // 封装消息
        Message message = MessageBuilder.withBody(msg.getBytes()).setContentType(MessageProperties.CONTENT_TYPE_JSON)
                .setContentEncoding("utf-8").setMessageId(orderId).build();
        // 构建回调返回的数据
        CorrelationData correlationData = new CorrelationData(orderId);
        // 发送消息
        this.rabbitTemplate.setMandatory(true);
        this.rabbitTemplate.setConfirmCallback(this);
        rabbitTemplate.convertAndSend("order_exchange_name", "orderRoutingKey", message, correlationData);

    }

    // 生产消息确认机制 生产者往服务器端发送消息的时候 采用应答机制
    @Override
    public void confirm(CorrelationData correlationData, boolean ack, String cause) {
        String orderId = correlationData.getId(); //id 都是相同的哦  全局ID
        System.out.println("消息id:" + correlationData.getId()); 
        if (ack) { //消息发送成功
            System.out.println("消息发送确认成功");
        } else {
            //重试机制
            send(orderId); 
            System.out.println("消息发送确认失败:" + cause);
        }

    }

}

controller：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.mayikt.base.BaseApiService;
import com.mayikt.base.ResponseBase;
import com.mayikt.service.OrderService;

@RestController
public class OrderController extends BaseApiService {
    @Autowired
    private OrderService orderService;

    @RequestMapping("/addOrder")
    public ResponseBase addOrder() {
        return orderService.addOrderAndDispatch();
    }

}

yml：

spring:
  rabbitmq:
  ####连接地址
    host: 192.168.91.6
   ####端口号   
    port: 5672
   ####账号 
    username: admin
   ####密码  
    password: admin
   ### 地址
    virtual-host: /admin_toov5
    ###开启消息确认机制 confirms
    publisher-confirms: true
    publisher-returns: true 
  #数据库连接信息
  datasource: 
        name: test
        url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedStatements=TRUE
        username: root
        password: root
        # 使用druid数据源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver

启动类：

package com.mayikt;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.mayikt.mapper")
@SpringBootApplication
public class AppOrder {

    public static void main(String[] args) {
        SpringApplication.run(AppOrder.class, args);
    }

}

派单：

 

Entity:

package com.mayikt.entity;

import lombok.Data;

@Data
public class DispatchEntity {

    private Long id;
    // 订单号
    private String orderId;
    // 外卖员id
    private Long takeoutUserId;
    
}

Mapper:

package com.mayikt.mapper;

import org.apache.ibatis.annotations.Insert;

import com.mayikt.entity.DispatchEntity;

public interface DispatchMapper {

    /**
     * 新增派单任务
     */
    @Insert("INSERT into platoon values (null,#{orderId},#{takeoutUserId});")
    public int insertDistribute(DispatchEntity distributeEntity);

}

consumer:

 做一些路由器 队列 路由键的绑定 声明工作

package com.mayikt.rabbitmq.consumer;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

@Component
public class RabbitmqConfig {

    // 下单并且派单存队列
    public static final String ORDER_DIC_QUEUE = "order_dic_queue";
    // 补单队列，判断订单是否已经被创建
    public static final String ORDER_CREATE_QUEUE = "order_create_queue";
    // 下单并且派单交换机
    private static final String ORDER_EXCHANGE_NAME = "order_exchange_name";

    // 1.定义派单队列
    @Bean
    public Queue OrderDicQueue() {
        return new Queue(ORDER_DIC_QUEUE);
    }
/*
    // 2.定义补订单队列
    @Bean
    public Queue directCreateOrderQueue() {
        return new Queue(ORDER_CREATE_QUEUE);
    }*/

    // 2.定义交换机
    @Bean
    DirectExchange directOrderExchange() {
        return new DirectExchange(ORDER_EXCHANGE_NAME);
    }

    // 3.订单队列与交换机绑定
    @Bean
    Binding bindingExchangeOrderDicQueue() {
        return BindingBuilder.bind(OrderDicQueue()).to(directOrderExchange()).with("orderRoutingKey");
    }

    /*// 3.补单队列与交换机绑定
    @Bean
    Binding bindingExchangeCreateOrder() {
        return BindingBuilder.bind(OrderDicQueue()).to(directOrderExchange()).with("orderRoutingKey");
    }*/

}

派件消费：

package com.mayikt.rabbitmq.consumer;

import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.handler.annotation.Headers;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson.JSONObject;
import com.mayikt.entity.DispatchEntity;
import com.mayikt.mapper.DispatchMapper;
import com.rabbitmq.client.Channel;

/**
 * 派单服务
 */
@Component
public class DispatchConsumer {
    @Autowired
    private DispatchMapper dispatchMapper;

    @RabbitListener(queues = "order_dic_queue")
    public void process(Message message, @Headers Map<String, Object> headers, Channel channel) throws Exception {
        String messageId = message.getMessageProperties().getMessageId();
        String msg = new String(message.getBody(), "UTF-8");
        System.out.println("派单服务平台" + msg + ",消息id:" + messageId);
        JSONObject jsonObject = JSONObject.parseObject(msg);
        String orderId = jsonObject.getString("orderId");
        if (StringUtils.isEmpty(orderId)) {
            // 日志记录
            return;
        }
        DispatchEntity dispatchEntity = new DispatchEntity();
        // 订单id
        dispatchEntity.setOrderId(orderId);
        // 外卖员id
        dispatchEntity.setTakeoutUserId(12l);
        
        try {
            int insertDistribute = dispatchMapper.insertDistribute(dispatchEntity);
            if (insertDistribute > 0) {
                // 手动签收消息,通知mq服务器端删除该消息
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
            }
        } catch (Exception e) {
            e.printStackTrace();
            // // 丢弃该消息
            channel.basicNack(message.getMessageProperties().getDeliveryTag(), false, false);
        }
    }

}

启动类：

package com.mayikt;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.mayikt.mapper")
@SpringBootApplication
public class AppDispatch {

    public static void main(String[] args) {
        SpringApplication.run(AppDispatch.class, args);
    }

}

yml：

spring:
  rabbitmq:
  ####连接地址
    host: 192.168.91.6
   ####端口号   
    port: 5672
   ####账号 
    username: admin
   ####密码  
    password: admin
   ### 地址
    virtual-host: /admin_toov5
    listener:
      simple:
        retry:
        ####开启消费者（程序出现异常的情况下会）进行重试
          enabled: true
         ####最大重试次数
          max-attempts: 5
        ####重试间隔次数
          initial-interval: 3000
        ####开启手动ack  
        acknowledge-mode: manual
         
  #数据库连接信息
  datasource: 
        name: test
        url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedStatements=TRUE
        username: root
        password: root
        # 使用druid数据源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
server:
  port: 8081

pom：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.itmayiedu</groupId>
    <artifactId>rabbitmq_stock</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>
    <dependencies>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!-- mysql 依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- 阿里巴巴数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.14</version>
        </dependency>
        <!-- SpringBoot整合Web组件 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- springboot- 整个 lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!-- 添加springboot对amqp的支持 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>
        <!--fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.49</version>
        </dependency>
    </dependencies>
</project>