分布式事务Seata使用

• • Seata Client快速开始

Seata Client快速开始

1.启动Seata Server端，Seata Server使用nacos作为配置中心和注册中心
参考：Seata服务搭建 —— nacos

2.配置微服务整合seata
第一步：添加maven依赖

<!-- seata -->
<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-seata</artifactId>
</dependency>

第二步：各微服务对应数据库中添加undo_log表

CREATE TABLE `undo_log` (
  `branch_id` bigint(20) NOT NULL COMMENT 'branch transaction id',
  `xid` varchar(100) NOT NULL COMMENT 'global transaction id',
  `context` varchar(128) NOT NULL COMMENT 'undo_log context,such as serialization',
  `rollback_info` longblob NOT NULL COMMENT 'rollback info',
  `log_status` int(11) NOT NULL COMMENT '0:normal status,1:defense status',
  `log_created` datetime(6) NOT NULL COMMENT 'create datetime',
  `log_modified` datetime(6) NOT NULL COMMENT 'modify datetime',
  UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='AT transaction mode undo table';

第三步：配置事务分组

server:
  port: 8072
# 数据库
spring:
  datasource:
    username: root
    password: root
    url: jdbc:mysql://106.14.156.185:3306/seata_stock?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource

    # 初始化时运行sql脚本
    # schema:
     # - classpath:sql/schema.sql
    #initialization-mode: never
  application:
    name: alibaba-stock-seata
  cloud:
    nacos:
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos
    alibaba:
      seata:
        tx-service-group: default_tx_group  # 配置事务分组
# 设置mybatis
mybatis:
  mapper-locations: classpath*:mapper/*.xml
  type-aliases-package: com.mry.seata.mapper
  configuration:
    cache-enabled: true
    lazy-loading-enabled: true
    multiple-result-sets-enabled: true
    use-column-label: true
    default-executor-type: reuse
    default-statement-timeout: 25000

第四步：配置seata

seata:
  registry:
    # 配置seata的注册中心， 告诉seata server 这么去访问seata server(TC)
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848  # seata server 所在的nacos服务地址
      application: seata-server    # seata server 的服务名为seata-server， 如果没有修改可以不配
      username: nacos
      password: nacos
      group: SEATA_GROUP           # seata server 所在的组，默认就是SEATA_GROUP， 没有修改也可以不配
  config:
    # 配置seata的配置中心， 可以读取关于seata client的一些配置
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      username: nacos
      password: nacos
      group: SEATA_GROUP

第五步：开启分布式事务 @GlobalTransactional

@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    OrderMapper orderMapper;

    @Autowired
    StockService stockService;

    /**
     * 下单
     * @param order
     */
    @GlobalTransactional
    @Override
    public Order create(Order order) {
        //插入能否成功
        orderMapper.insert(order);

        stockService.reduct(order.getProductId());

        //异常
        int a = 1/0;

        return order;
    }

}