Seata分布式事务实战前言Seata是阿里巴巴开源的分布式事务解决方案支持AT、TCC、Saga等多种事务模式。本文将详细介绍Seata的安装配置和AT模式的使用。一、Seata核心概念1.1 架构图┌─────────────────────────────────────────────────────┐ │ Seata Architecture │ │ │ │ ┌──────────────────────────────────────────────┐ │ │ │ TC (Transaction Coordinator) │ │ │ │ Global Session Branch Session Manager │ │ │ └──────────────────────────────────────────────┘ │ │ ▲ ▲ │ │ │ TM │ TM │ │ ┌──────┴──────┐ ┌──────┴──────┐ │ │ │ TM (Transaction Manager) │ │ │ │ │ ┌──────────────────┐ │ │ │ │ │ │ Business Logic │ │ │ │ │ │ └──────────────────┘ │ │ │ │ └────────────────────────┘ │ │ │ │ │ │ ┌──────────────────────────────────────────────┐ │ │ │ RM (Resource Manager) │ │ │ │ ┌──────────┐ ┌──────────┐ ┌──────────┐ │ │ │ │ │ Order DB │ │ Stock DB │ │ Pay DB │ │ │ │ │ └──────────┘ └──────────┘ └──────────┘ │ │ │ └──────────────────────────────────────────────┘ │ └─────────────────────────────────────────────────────┘二、Seata Server配置2.1 Docker部署# docker-compose.yml version: 3.8 services: seata: image: seataio/seata-server:1.7.0 container_name: seata-server ports: - 8091:8091 - 7091:7091 environment: - STORE_MODEdb - SEATA_CONFIG_NAMEfile:/root/seata-config/registry - SEATA_IP127.0.0.1 volumes: - ./config:/root/seata-config - seata_data:/root/seata-server/resources depends_on: - mysql mysql: image: mysql:8.0 environment: MYSQL_ROOT_PASSWORD: root_password MYSQL_DATABASE: seata三、AT模式配置3.1 依赖引入dependency groupIdcom.alibaba.cloud/groupId artifactIdspring-cloud-starter-alibaba-seata/artifactId /dependency dependency groupIdio.seata/groupId artifactIdseata-spring-boot-starter/artifactId /dependency3.2 应用配置seata: enabled: true application-id: ${spring.application.name} tx-service-group: my-test-tx-group enable-auto-data-source-proxy: true config: type: nacos nacos: server-addr: ${spring.cloud.nacos.server-addr} namespace: ${spring.cloud.nacos.config.namespace:} group: SEATA_GROUP >Service Slf4j public class OrderServiceImpl implements OrderService { GlobalTransactional(name create-order, rollbackFor Exception.class) Override public OrderDTO createOrder(CreateOrderRequest request) { log.info(Creating order: {}, request); // 1. 创建订单 Order order createLocalOrder(request); // 2. 扣减库存远程调用 boolean stockReduced inventoryClient.reduceStock( request.getProductId(), request.getQuantity() ); if (!stockReduced) { throw new BusinessException(Stock reduction failed); } // 3. 扣减余额远程调用 boolean balanceDeducted accountClient.deductBalance( request.getUserId(), request.getAmount() ); if (!balanceDeducted) { throw new BusinessException(Balance deduction failed); } return orderMapper.toDTO(order); } Transactional public Order createLocalOrder(CreateOrderRequest request) { Order order new Order(); order.setOrderNumber(generateOrderNumber()); order.setUserId(request.getUserId()); order.setProductId(request.getProductId()); order.setQuantity(request.getQuantity()); order.setAmount(request.getAmount()); order.setStatus(OrderStatus.PENDING); return orderRepository.save(order); } }4.2 事务传播Service public class OrderServiceImpl { GlobalTransactional(name outer-transaction) public void outerTransaction() { // 外层事务 createOrder(); // 嵌套事务自动加入外层事务 nestedTransaction(); } Transactional(propagation Propagation.REQUIRES_NEW) public void nestedTransaction() { // 独立事务 doSomething(); } }五、TCC模式配置5.1 TCC接口定义LocalTCC public interface InventoryTccService { TwoPhaseBusinessAction( name prepareInventory, commitMethod commit, rollbackMethod rollback ) boolean prepare( BusinessActionContext actionContext, BusinessActionContextParameter(paramName productId) Long productId, BusinessActionContextParameter(paramName quantity) Integer quantity ); boolean commit(BusinessActionContext actionContext); boolean rollback(BusinessActionContext actionContext); } Service Slf4j public class InventoryTccServiceImpl implements InventoryTccService { Override Transactional public boolean prepare(BusinessActionContext actionContext, Long productId, Integer quantity) { log.info(TCC Prepare: productId{}, quantity{}, productId, quantity); // 预扣减库存 return inventoryRepository.reserveStock(productId, quantity); } Override Transactional public boolean commit(BusinessActionContext actionContext) { log.info(TCC Commit); // 确认扣减 Long productId (Long) actionContext.getActionContext(productId); Integer quantity (Integer) actionContext.getActionContext(quantity); inventoryRepository.confirmStock(productId, quantity); return true; } Override Transactional public boolean rollback(BusinessActionContext actionContext) { log.info(TCC Rollback); // 释放库存 Long productId (Long) actionContext.getActionContext(productId); Integer quantity (Integer) actionContext.getActionContext(quantity); inventoryRepository.releaseStock(productId, quantity); return true; } }5.2 TCC调用Service public class OrderService { Autowired private InventoryTccService inventoryTccService; GlobalTransactional(name create-order-tcc) public void createOrderWithTcc(CreateOrderRequest request) { // 订单创建逻辑... // TCC调用 boolean reserved inventoryTccService.prepare( new BusinessActionContext(), request.getProductId(), request.getQuantity() ); if (!reserved) { throw new BusinessException(Stock reservation failed); } } }六、总结Seata提供了完善的分布式事务解决方案AT模式对业务代码零侵入适合大多数场景TCC模式性能更高适合对性能有较高要求的场景。
