前提seata必须实现高可用，请查看seata注册到nacos，实现高可用

添加依赖,此处采用seata1.3版本

        <!-- seata -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-seata</artifactId>
            <version>2.2.0.RELEASE</version>
            <exclusions>
                <exclusion>
                    <groupId>io.seata</groupId>
                    <artifactId>seata-spring-boot-starter</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>io.seata</groupId>
            <artifactId>seata-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>

添加seata配置，修改application.yml

seata:
  enabled: true
  application-id: anyouliang-user-service
  tx-service-group: my_test_tx_group    #此处配置自定义的seata事务分组名称
  enable-auto-data-source-proxy: true    #开启数据库代理
  config:
    type: nacos
    nacos:
      namespace:
      server-addr: 192.168.101.50:8848
      group: SEATA_GROUP
      username: nacos
      password: nacos
  registry:
    type: nacos
    nacos:
      application: seata-server
      server-addr: 192.168.101.50:8848
      namespace:
      username: nacos
      password: nacos

配置数据源

/**
 *  @author: haodongdong
 *  @Date: 2020/7/22 17:25
 *  @Description:  数据源代理
 */
@Configuration
public class DataSourceConfiguration {

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource druidDataSource(){
        DruidDataSource druidDataSource = new DruidDataSource();
        return druidDataSource;
    }

    /**
     * 创建DataSourceProxy
     */
    @Primary
    @Bean("dataSource")
    public DataSourceProxy dataSourceProxy(DataSource druidDataSource){
        return new DataSourceProxy(druidDataSource);
    }

    /**
     * 将原有的DataSource对象替换为DataSourceProxy
     */
    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSourceProxy dataSourceProxy)throws Exception{
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSourceProxy);
        sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:/mapper/*.xml"));
        sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory());
        return sqlSessionFactoryBean.getObject();
    }

}

在对应业务库建立undo_log

CREATE TABLE IF NOT EXISTS `undo_log`
(
   `id`            BIGINT(20)   NOT NULL AUTO_INCREMENT COMMENT 'increment id',
   `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     NOT NULL COMMENT 'create datetime',
   `log_modified`  DATETIME     NOT NULL COMMENT 'modify datetime',
   PRIMARY KEY (`id`),
   UNIQUE KEY `ux_undo_log` (`xid`, `branch_id`)
) ENGINE = InnoDB
 AUTO_INCREMENT = 1
 DEFAULT CHARSET = utf8 COMMENT ='AT transaction mode undo table';

在需要分布式事务的业务上添加@GlobalTransactional