How to configure master-slave databases in Spring Boot?

9 months ago

Jackson Davis

2 minutes

In Spring Boot, configuring master-slave databases can be achieved by setting up multiple data sources in the application.properties file. Here is an example configuration:

Configure the main data source in the application.properties file.

spring.datasource.url=jdbc:mysql://localhost:3306/main_db
spring.datasource.username=root
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

Configure the data source in the application.properties file.

spring.datasource.secondary.url=jdbc:mysql://localhost:3306/secondary_db
spring.datasource.secondary.username=root
spring.datasource.secondary.password=password
spring.datasource.secondary.driver-class-name=com.mysql.cj.jdbc.Driver

3. Create a configuration class to define multiple data source configurations.

@Configuration
public class DataSourceConfig {

    @Primary
    @Bean(name = "mainDataSource")
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource mainDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }
}

Specify the data source in the Repository.

@Repository
public class MainRepository {

    @Autowired
    @Qualifier("mainDataSource")
    private DataSource dataSource;

    // Repository methods
}

@Repository
public class SecondaryRepository {

    @Autowired
    @Qualifier("secondaryDataSource")
    private DataSource dataSource;

    // Repository methods
}

By following the steps above, it is possible to configure master-slave databases in Spring Boot and use different data sources in the Repository for operations.