[大数据]【Mysql】基于tkmapper实现Mysql主从模式

1.实现原理（核心）

动态切换数据源（实现AbstractRoutingDataSource类基于本地副本动态切换数据源）

上述动态切换数据源时机，，最好的时机就是拦截mybatis的操作，写走主库读走从库
（此处要谈从库读性能，有兴趣可了解下clickhouse）

2.实现（此处着重描述动态数据源切换实现）

其他配置可参考
【shardingjdbc&Mysql】基于springboot+shardingjdbc+tkmapper实现mysql分库分表

DynamicDataSource.java

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

import javax.sql.DataSource;
import java.util.Map;

/**
 * 动态数据源
 *
 * @author kdniao
 */
public class DynamicDataSource extends AbstractRoutingDataSource {
    public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources) {
        super.setDefaultTargetDataSource(defaultTargetDataSource);
        super.setTargetDataSources(targetDataSources);
        super.afterPropertiesSet();
    }

    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}

TmsDataSourceConfiguration.java

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class TmsDataSourceConfiguration {

    @Bean(name = "tmsMasterDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.tms.master")
    @Primary
    public DataSource tmsMasterDataSource(DruidProperties druidProperties) {
        DruidDataSource dataSource = DruidDataSourceBuilder.create().build();
        return druidProperties.dataSource(dataSource);
    }

    @Bean(name = "tmsSlaveDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.tms.slave")
    public DataSource tmsSlaveDataSource(DruidProperties druidProperties) {
        DruidDataSource dataSource = DruidDataSourceBuilder.create().build();
        return druidProperties.dataSource(dataSource);
    }

    @Bean(name = "tmsDynamicDataSource")
    public DataSource tmsDynamicDataSource(@Qualifier("tmsMasterDataSource") DataSource tmsMasterDataSource,
                                           @Qualifier("tmsSlaveDataSource") DataSource tmsSlaveDataSource) {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DataSourceTypeEnum.MASTER.name(), tmsMasterDataSource);
        targetDataSources.put(DataSourceTypeEnum.SLAVE.name(), tmsSlaveDataSource);
        return new DynamicDataSource(tmsMasterDataSource, targetDataSources);
    }

}

3.实现效果