标签:mysql 阿里 bit new throws 技术 nec pool 依赖
案例:
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。
RabbitMQ解决分布式事务原理: 采用最终一致性原理。
需要保证以下三要素
1、确认生产者一定要将数据投递到MQ服务器中(采用MQ消息确认机制)
2、MQ消费者消息能够正确消费消息,采用手动ACK模式,使用不补偿机制(注意重试幂等性问题)
3、如何保证第一个事务先执行,采用补偿机制(补单机制),在创建一个补单消费者进行监听,如果订单没有创建成功,进行补单。
用传统的HTTP协议不能解决高并发:
MQ解决分布式事务一致性
案例中 订单表 和 派单表必须一致!
用MQ 可以做流量削峰值
MQ解决分布式事务最终一致性思想
1. 确保生产者消息 一定要投递到MQ服务器端成功
如果生产者投递消息到MQ服务器成功
场景1 如果消费者消费消息失败了
生产者是不需要回滚事务。 消费者采用手动ack应答方式 进行补偿机制,补偿的过程中注意 幂等性 问题。
分布式事务中遵循base理论 遵循cpa理论
如何确保生产者发送消息一定发送到MQ消息服务器端成功? confirm机制 确认应答机制
场景2 如果生产者发送消息到MQ服务器端失败
使用生产者重试机制进行发消息
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
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
上面已经实现了确保消息发送给 消费者 此时的数据不一致问题 就是:
场景3. 如何保证第一个事务先执行,生产者投递消息到MQ服务器成功,消费者消费消息成功了,但是订单事务回滚了。 (生产者投递消息给消费者消费成功 然后 生产者回滚了)
MQ解决分布式原理通过最终一致性解决总体框架图: 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
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>
标签:mysql 阿里 bit new throws 技术 nec pool 依赖
原文地址:https://www.cnblogs.com/toov5/p/10289999.html