Spring Boot + MyBatis로 두 개의 데이터소스 쓰기

여러 DB를 한 애플리케이션에서 다룰 때, MyBatis의 MapperScan을 패키지 단위로 나누고 각 패키지에 별도 SqlSessionFactory를 매핑한다.

yaml

spring:
  datasource:
    hikari:
      primary:
        driver-class-name: org.h2.Driver
        jdbc-url: jdbc:h2:file:./build/h2db/db/primary;DB_CLOSE_DELAY=-1
        username: primary_user
        password:
      secondary:
        driver-class-name: org.h2.Driver
        jdbc-url: jdbc:h2:file:./build/h2db/db/secondary;DB_CLOSE_DELAY=-1
        username: secondary_user
        password:

Primary DataSource

@Primary가 붙은 빈이 기본 주입 대상이 된다.

@Configuration
@EnableTransactionManagement
@MapperScan(value = "com.test.dao.primary", sqlSessionFactoryRef = "primarySqlSessionFactory")
public class PrimaryDatasourceConfiguration {

    @Bean @Primary
    @ConfigurationProperties("spring.datasource.hikari.primary")
    public HikariConfig primaryHikariConfig() {
        return new HikariConfig();
    }

    @Bean @Primary
    public DataSource primaryDataSource() {
        return new HikariDataSource(primaryHikariConfig());
    }

    @Bean(name = "primarySqlSessionFactory") @Primary
    public SqlSessionFactory sqlSessionFactory(
            @Qualifier("primaryDataSource") DataSource dataSource,
            ApplicationContext applicationContext) throws Exception {
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        factory.setDataSource(dataSource);
        factory.setMapperLocations(applicationContext.getResources("classpath:mapper/primary/*.xml"));
        factory.setTypeAliasesPackage("com.test.service.dto");
        return factory.getObject();
    }

    @Bean(name = "primarySqlSessionTemplate") @Primary
    public SqlSessionTemplate sqlSessionTemplate(
            @Qualifier("primarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

Secondary DataSource

@Primary만 빠진 같은 구조.

@Configuration
@EnableTransactionManagement
@MapperScan(value = "com.test.dao.secondary", sqlSessionFactoryRef = "secondarySqlSessionFactory")
public class SecondaryDatasourceConfiguration {

    @Bean
    @ConfigurationProperties("spring.datasource.hikari.secondary")
    public HikariConfig secondaryHikariConfig() {
        return new HikariConfig();
    }

    @Bean
    public DataSource secondaryDataSource() {
        return new HikariDataSource(secondaryHikariConfig());
    }

    @Bean(name = "secondarySqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory(
            @Qualifier("secondaryDataSource") DataSource dataSource,
            ApplicationContext applicationContext) throws Exception {
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        factory.setDataSource(dataSource);
        factory.setMapperLocations(applicationContext.getResources("classpath:mapper/secondary/*.xml"));
        factory.setTypeAliasesPackage("com.test.service.dto");
        return factory.getObject();
    }

    @Bean(name = "secondarySqlSessionTemplate")
    public SqlSessionTemplate sqlSessionTemplate(
            @Qualifier("secondarySqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

패키지 분리 규칙

• DAO/Mapper 인터페이스는 com.test.dao.primary, com.test.dao.secondary로 분리
• XML mapper도 classpath:mapper/primary/*.xml, classpath:mapper/secondary/*.xml로 분리
• 트랜잭션은 보통 Primary 기준. Secondary 쪽에 별도 트랜잭션이 필요하면 @Transactional("secondaryTransactionManager")로 명시 주입