Sharding-JDBC教程：Spring Boot整合Sharding-JDBC实现分库分表+读写分离

在上一篇文章介绍了如何 使用Sharding-jdbc进行分库+读写分离，这篇文章将讲述如何使用Sharding-jdbc进行分库分表+读写分离。

架构回顾

在数据量不是很多的情况下，我们可以将数据库进行读写分离，以应对高并发的需求，通过水平扩展从库，来缓解查询的压力。如下：

在数据量达到500万的时候，这时数据量预估千万级别，我们可以将数据进行分表存储。

在数据量继续扩大，这时可以考虑分库分表，将数据存储在不同数据库的不同表中，如下：

案例详解

本案例有6个数据库，两个主库，四个从库，信息如下：

在主库主机的Mysql执行以下脚本，分别为数据库cool和cool2创建5个表，这5个表分别为user_0、user_1、user_2、user_3、user_4。
执行的脚本如下：

USE `cool`;


/*Table structure for table `user_0` */

DROP TABLE IF EXISTS `user_0`;

CREATE TABLE `user_0` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=149 DEFAULT CHARSET=utf8;

/*Table structure for table `user_1` */

DROP TABLE IF EXISTS `user_1`;

CREATE TABLE `user_1` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=150 DEFAULT CHARSET=utf8;

/*Table structure for table `user_2` */

DROP TABLE IF EXISTS `user_2`;

CREATE TABLE `user_2` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=147 DEFAULT CHARSET=utf8;

/*Table structure for table `user_3` */

DROP TABLE IF EXISTS `user_3`;

CREATE TABLE `user_3` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=148 DEFAULT CHARSET=utf8;
CREATE TABLE `user_4` (
  `id` INT(12) NOT NULL AUTO_INCREMENT,
  `username` VARCHAR(12) NOT NULL,
  `password` VARCHAR(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=INNODB AUTO_INCREMENT=148 DEFAULT CHARSET=utf8;


USE `cool2`;


/*Table structure for table `user_0` */

DROP TABLE IF EXISTS `user_0`;

CREATE TABLE `user_0` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=149 DEFAULT CHARSET=utf8;

/*Table structure for table `user_1` */

DROP TABLE IF EXISTS `user_1`;

CREATE TABLE `user_1` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=150 DEFAULT CHARSET=utf8;

/*Table structure for table `user_2` */

DROP TABLE IF EXISTS `user_2`;

CREATE TABLE `user_2` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=147 DEFAULT CHARSET=utf8;

/*Table structure for table `user_3` */

DROP TABLE IF EXISTS `user_3`;

CREATE TABLE `user_3` (
  `id` int(12) NOT NULL AUTO_INCREMENT,
  `username` varchar(12) NOT NULL,
  `password` varchar(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=InnoDB AUTO_INCREMENT=148 DEFAULT CHARSET=utf8;

CREATE TABLE `user_4` (
  `id` INT(12) NOT NULL AUTO_INCREMENT,
  `username` VARCHAR(12) NOT NULL,
  `password` VARCHAR(30) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `idx-username` (`username`)
) ENGINE=INNODB AUTO_INCREMENT=148 DEFAULT CHARSET=utf8;

案例的工程是在上一篇文章的工程基础上进行改造，其中pom文件的依赖包不变，详情可见源码。

在工程的application中做sharding-jdbc的分库分表配置，代码如下：

sharding.jdbc.datasource.names=ds-master-0,ds-master-1,ds-master-0-slave-0,ds-master-0-slave-1,ds-master-1-slave-0,ds-master-1-slave-1

sharding.jdbc.datasource.ds-master-0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.ds-master-0.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds-master-0.url=jdbc:mysql://10.0.0.3:3306/cool?useUnicode=true&characterEncoding=utf8&tinyInt1isBit=false&useSSL=false&serverTimezone=GMT
sharding.jdbc.datasource.ds-master-0.username=root
sharding.jdbc.datasource.ds-master-0.password=

sharding.jdbc.datasource.ds-master-0-slave-0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.ds-master-0-slave-0.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds-master-0-slave-0.url=jdbc:mysql://10.0.0.13:3306/cool?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT
sharding.jdbc.datasource.ds-master-0-slave-0.username=root
sharding.jdbc.datasource.ds-master-0-slave-0.password=
sharding.jdbc.datasource.ds-master-0-slave-1.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.ds-master-0-slave-1.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds-master-0-slave-1.url=jdbc:mysql://10.0.0.17:3306/cool?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT
sharding.jdbc.datasource.ds-master-0-slave-1.username=root
sharding.jdbc.datasource.ds-master-0-slave-1.password=

sharding.jdbc.datasource.ds-master-1.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.ds-master-1.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds-master-1.url=jdbc:mysql://10.0.0.3:3306/cool2?useUnicode=true&characterEncoding=utf8&tinyInt1isBit=false&useSSL=false&serverTimezone=GMT
sharding.jdbc.datasource.ds-master-1.username=root
sharding.jdbc.datasource.ds-master-1.password=

sharding.jdbc.datasource.ds-master-1-slave-0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.ds-master-1-slave-0.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds-master-1-slave-0.url=jdbc:mysql://10.0.0.13:3306/cool2?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT
sharding.jdbc.datasource.ds-master-1-slave-0.username=root
sharding.jdbc.datasource.ds-master-1-slave-0.password=
sharding.jdbc.datasource.ds-master-1-slave-1.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.ds-master-1-slave-1.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.ds-master-1-slave-1.url=jdbc:mysql://10.0.0.17:3306/cool2?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT
sharding.jdbc.datasource.ds-master-1-slave-1.username=root
sharding.jdbc.datasource.ds-master-1-slave-1.password=

sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column=id
sharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=ds_$->{id % 2}

sharding.jdbc.config.sharding.tables.user.actual-data-nodes=ds_$->{0..1}.user_$->{0..4}
sharding.jdbc.config.sharding.tables.user.table-strategy.inline.sharding-column=id
sharding.jdbc.config.sharding.tables.user.table-strategy.inline.algorithm-expression=user_$->{id % 5}
sharding.jdbc.config.sharding.tables.user.key-generator-column-name=id

sharding.jdbc.config.sharding.master-slave-rules.ds_0.master-data-source-name=ds-master-0
sharding.jdbc.config.sharding.master-slave-rules.ds_0.slave-data-source-names=ds-master-0-slave-0, ds-master-0-slave-1
sharding.jdbc.config.sharding.master-slave-rules.ds_1.master-data-source-name=ds-master-1
sharding.jdbc.config.sharding.master-slave-rules.ds_1.slave-data-source-names=ds-master-1-slave-0, ds-master-1-slave-1

• 在上面的配置中，其中sharding.jdbc.datasource部分是配置数据库的信息，配置了6个数据库。
• sharding.jdbc.config.sharding.master-slave-rules.ds_0.master-data-source-name配置的是ds_0区的的主库名称，同理ds_1。
• sharding.jdbc.config.sharding.master-slave-rules.ds_0.slave-data-source-names配置的是ds_0区的的从库名称，同理ds_1。
• sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column配置的分库的字段，本案例是根据id进行分。
• sharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression配置的分库的逻辑，根据id%2进行分。
• sharding.jdbc.config.sharding.tables.user.actual-data-nodes配置的是user表在真实数据库中的位置，ds_->{0..1}.user_->{0..4}表示
  数据在ds_0和ds_1中的user_0、user_1、user_2、user_3、user_4中。
• sharding.jdbc.config.sharding.tables.user.table-strategy.inline.sharding-column，配置user表数据切分的字段
• sharding.jdbc.config.sharding.tables.user.table-strategy.inline.algorithm-expression=user_$->{id % 5}，配置user表数据切分的策略。
• sharding.jdbc.config.sharding.tables.user.key-generator-column-name=id 自动生成id。

然后在Spring Boot启动类的注解@SpringBootApplication，加上exclude={DataSourceAutoConfiguration.class}，代码如下：

@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
@EnableConfigurationProperties
public class ShardingJdbcDbMsTblApplication {

    public static void main(String[] args) {
        SpringApplication.run(ShardingJdbcDbMsTblApplication.class, args);
    }

}

测试

测试同上一篇文章，这里不在重复。

源码下载

https://github.com/forezp/SpringBootLearning/tree/master/sharding-jdbc-example/sharding-jdbc-db-ms-tbl

资料参考

https://github.com/apache/incubator-shardingsphere-example/releases/tag/3.1.0.M1

https://shardingsphere.apache.org/document/current/cn/overview/

https://github.com/apache/incubator-shardingsphere