Use of Steata distributed transactions

The use scenario of Steata distributed transactions is a back-end management system where the amount of concurrency is not very large.
Steate introduces and uses the official website: http://seata.io/zh-cn/docs/overview/what-is-seata.html
The distributed transaction solution we use here is the AT mode, which is the 2pc mode
we use It is version 0.7.1. Different versions may use different ways.

• seata wants to control distributed transactions

• 1) Every microservice database must create a uodo_log table
  – note that 0.7.1+ adds the field context
  CREATE TABLE undo_log(
  idbigint(20) NOT NULL AUTO_INCREMENT,
  branch_idbigint(20) NOT NULL,
  xidvarchar(100) NOT NULL,
  contextvarchar (128) NOT NULL,
  rollback_infolongblob NOT NULL,
  log_statusint(11) NOT NULL,
  log_createddatetime NOT NULL,
  log_modifieddatetime NOT NULL,
  PRIMARY KEY ( id),
  UNIQUE KEY ux_undo_log( xid, branch_id)
  ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
  

• 2), install the transaction coordinator seata-server https://github.com/seata.seata/releases
  
  registry.conf registry configuration modification registry type=nacos, the address is changed to the connection address of nacos.
  
  Then start the service

• 3) Integration
  1. Import dependency spring-cloud-starter-alibaba-seata ｜ seata-all-0.7.1

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

• 3. All microservices that want to use distributed transactions use seata DataSourceProxy

@Configuration
public class MySeataConfig {
    
    

    @Autowired
    DataSourceProperties dataSourceProperties;

    @Bean
    public DataSource dataSource(DataSourceProperties dataSourceProperties) {
    
    
        HikariDataSource dataSource = dataSourceProperties.initializeDataSourceBuilder().type(HikariDataSource.class).build();
        if (StringUtils.hasText(dataSourceProperties.getName())) {
    
    
            dataSource.setPoolName(dataSourceProperties.getName());
        }
        return new DataSourceProxy(dataSource);
    }
}

• 4. Import
  registry.conf for each service.
  
  The service.vgroup_mapping configuration of file.conf file.conf must be
  set consistent with spring.application.name: vgroup_mapping.gulimall-order-fescar-service-group = "default", or Modify the suffix by configuring spring.cloud.alibaba.seata.tx-service-group, but it must be consistent with the configuration in file.conf
  
• 5. Big transaction: @GlobalTransactional
• 6. Remote small transactions: @Transactional
  is used at the entrance of @Transactional , while other remote calls to open transactions are local transactions @Transactional.