1. 事务消息
RocketMQ的事务消息,是指发送消息事件和其他事件需要同时成功或同时失败。比如银行转账, A银行的某账户要转一万元到B银行的某账户。A银行发送“B银行账户增加一万元”这个消息,要和“从A银 行账户扣除一万元”这个操作同时成功或者同时失败。RocketMQ采用两阶段提交的方式实现事务消息。
1.1 RocketMQ事务消息的原理
半事务消息发送:生产者将半事务消息发送至RocketMQ服务端。
消息持久化及返回Ack确认:RocketMQ服务端接收到半事务消息并持久化成功后,向生产者返回Ack确认消息已经发送成功。此时消息状态为半事务消息。
执行本地事务逻辑:根据发送结果执行本地事务,如果写入失败,此时half消息对业务不可见,本地事务逻辑不执行。
提交二次确认结果:根据本地事务状态执行Commit或者Rollback。RocketMQ 的事务消息分为3种状态,分别是提交状态、回滚状态、未知状态。
TransactionStatus.CommitTransaction: 提交事务,它允许消费者消费此消息。
TransactionStatus.RollbackTransaction: 回滚事务,它代表该消息将被删除,不允许被消费。
TransactionStatus.Unknown: 未知状态,它代表需要检查消息队列来确定状态。
消息回查:(1) 对没有Commit/Rollback的事务消息,从服务端发起一次回查 (2) Producer收到回查消息,检查回查消息对应的本地事务的状态 (3) 根据本地事务状态,重新Commit或者Rollback。第一次回查后仍未获取到事务状态,则之后每隔30s会再次回查,最多重试15次,超过了就会默认丢弃此消息。
1.2 RocketMQ订单支付功能设计
数据库设计
/* SQLyog Community v13.2.0 (64 bit) MySQL - 8.0.33 : Database - shop ********************************************************************* */ /*!40101 SET NAMES utf8 */; /*!40101 SET SQL_MODE=''*/; /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */; /*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */; /*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */; /*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */; CREATE DATABASE /*!32312 IF NOT EXISTS*/`shop` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */; USE `shop`; /*Table structure for table `shop_order` */ DROP TABLE IF EXISTS `shop_order`; CREATE TABLE `shop_order` ( `id` VARCHAR(50) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin NOT NULL COMMENT '订单id', `total_num` INT DEFAULT NULL COMMENT '数量合计', `moneys` INT DEFAULT NULL COMMENT '金额合计', `pay_type` VARCHAR(1) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL COMMENT '支付类型,1、在线支付、0 货到付款', `create_time` DATETIME DEFAULT NULL COMMENT '订单创建时间', `update_time` DATETIME DEFAULT NULL COMMENT '订单更新时间', `pay_time` DATETIME DEFAULT NULL COMMENT '付款时间', `consign_time` DATETIME DEFAULT NULL COMMENT '发货时间', `end_time` DATETIME DEFAULT NULL COMMENT '交易完成时间', `username` VARCHAR(50) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL COMMENT '用户名称', `recipients` VARCHAR(50) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL COMMENT '收货人', `recipients_mobile` VARCHAR(12) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL COMMENT '收货人手机', `recipients_address` VARCHAR(200) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL COMMENT '收货人地址', `weixin_transaction_id` VARCHAR(30) CHARACTER SET utf8mb3 COLLATE utf8mb3_bin DEFAULT NULL COMMENT '交易流水号', `order_status` INT DEFAULT NULL COMMENT '订单状态,0:未完成,1:已完成,2:已退货', `pay_status` INT DEFAULT NULL COMMENT '支付状态,0:未支付,1:已支付,2:支付失败', `is_delete` INT DEFAULT NULL COMMENT '是否删除', PRIMARY KEY (`id`), KEY `create_time` (`create_time`), KEY `status` (`order_status`), KEY `payment_type` (`pay_type`) ) ENGINE=INNODB DEFAULT CHARSET=utf8mb3 COLLATE=utf8mb3_bin; /*Data for the table `shop_order` */ /*!40101 SET SQL_MODE=@OLD_SQL_MODE */; /*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */; /*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */; /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
添加RocketMQ依赖
<dependency> <groupId>org.apache.rocketmq</groupId> <artifactId>rocketmq-spring-boot-starter</artifactId> </dependency>
bootstrap.yaml配置
server: port: 8085 spring: application: name: mall-order datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/shop?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC username: root password: 123456 cloud: nacos: config: file-extension: yaml server-addr: localhost:8848 discovery: #Nacos的注册地址 server-addr: localhost:8848 rocketmq: name-server: localhost:9876 producer: group: test-group-producer
Service层
public interface OrderService extends IService<Order> { //添加订单 void add(Order order); //修改订单支付状态 void pay(String id); } @Service public class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements OrderService{ @Autowired OrderMapper orderMapper; @Transactional(rollbackFor = Exception.class) @Override public void add(Order order) { order.setCreateTime(new Date()); orderMapper.insert(order); //这里仅仅生成订单,还有扣减库存等等一系列操作省略 } @Transactional(rollbackFor = Exception.class) @Override public void pay(String id) { //模拟支付完成,修改订单的支付状态 Order order = orderMapper.selectById(id); order.setPayStatus(1); order.setPayTime(new Date()); orderMapper.updateById(order); } }
创建生产者
@RestController @Slf4j public class TestController { @Autowired OrderMapper orderMapper; @Autowired RocketMQTemplate rocketMQTemplate; @RequestMapping("/send") public String send(){ String id = UUID.randomUUID().toString(); String msg = "订单"+id+"支付成功"; Order order=new Order(); order.setId(id); order.setCreateTime(new Date()); order.setMoneys(100); order.setUsername("张三"); Message<String> message = MessageBuilder.withPayload(msg).setHeader("key",id).build(); TransactionSendResult result = rocketMQTemplate.sendMessageInTransaction("order", message, order); String transactionId = result.getTransactionId(); String status = result.getSendStatus().name(); log.info("发送消息成功 transactionId={} status={} ",transactionId,status); return "success"; } }
创建消费者
@Component @Slf4j @RocketMQMessageListener(consumerGroup = "test-consumer",topic = "order",messageModel = MessageModel.CLUSTERING) public class RocketMQListen implements RocketMQListener<MessageExt> { @Override public void onMessage(MessageExt messageExt) { String body = new String(messageExt.getBody(), StandardCharsets.UTF_8); System.out.println(body); } }
生产者消息监听器
@Component @RocketMQTransactionListener public class TransactionMsgListener implements RocketMQLocalTransactionListener { @Autowired OrderService orderService; @Override public RocketMQLocalTransactionState executeLocalTransaction(Message message, Object o) { Order order = (Order) o; try { //生成订单 orderService.add(order); return RocketMQLocalTransactionState.UNKNOWN; }catch (Throwable throwable){ throwable.printStackTrace(); return RocketMQLocalTransactionState.ROLLBACK; } } @Override public RocketMQLocalTransactionState checkLocalTransaction(Message message) { String key = message.getHeaders().get("key").toString(); System.out.println("回查订单id "+key+" 回查时间"+new Date()); Order order = orderService.getById(key); if(order!=null) { long l = new Date().getTime() - order.getCreateTime().getTime(); long time = l / (1000 * 60); //超时1分钟后,就会把未支付的订单进行删除 if (time > 1) { orderService.removeById(key); System.out.println("订单" + key + "删除"); //订单,库存等一系列操作 return RocketMQLocalTransactionState.ROLLBACK; } Integer payStatus = order.getPayStatus(); if (payStatus == 1) { return RocketMQLocalTransactionState.COMMIT; } return RocketMQLocalTransactionState.UNKNOWN; } else return RocketMQLocalTransactionState.ROLLBACK; } }
测试
这里通过生产者发送五个事务消息,生成五个订单,然后两个订单在一分钟内修改支付状态为已支付,超时一分钟未支付就会删除订单回退。运行截图如下: