简介
Apache ShardingSphere 是一套开源的分布式数据库中间件解决方案组成的生态圈,它由 JDBC、Proxy 和 Sidecar,这 3 款相互独立,却又能够混合部署配合使用的产品组成。 它们均提供标准化的数据分片、分布式事务和数据库治理功能,目前,数据分片、读写分离、数据加密、影子库压测等功能,以及 MySQL、PostgreSQL、SQLServer、Oracle 等 SQL 与协议的支持,均通过插件的方式织入项目,ShardingSphere 已于2020年4月16日成为 Apache 软件基金会的顶级项目。
背景
公司项目随着业务数据不断增多,单表数量达到五百W以上,查询新增速度不断变慢,严重影响客户使用,分库分表势在必行,大概看了下相关的技术,果断选择了ShardingJDBC(使用人多,稳定成熟,加Apache加持),本文主要围绕ShardingSphere 做单库分表,简单介绍下ShardingSphere。
公司先做的分表,后来数据增多,存储磁盘满足不了单个数据库的大小,后来才做的分库,所以可以结合着自己的实际业务去做考虑是否做需要做分库,如果分表已经能满足自己的三年内的业务需求,可以不做分库操作,直接分表即可,本文主要围绕单库分表进行讲述,如想了解分库分表,可参考 https://www.jianshu.com/p/2e8bafd888d0
分片场景
策略 | 表名称 | 分片字段 | 表数量 |
---|---|---|---|
某字段分表 | sh_in_conf | task_id | 6 |
某字段分表 | sh_in_log | company_id | 4 |
通用默认某字段分表 | sh_in_toll | biz_id | 2 |
不分表 | sh_in_info | 无 | 1 |
库结构
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Pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.sharding.test</groupId>
<artifactId>sharding-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>sharding-demo</name>
<description>分库分表Demo</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<sharding.jdbc.version>4.0.0</sharding.jdbc.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>com.github.ulisesbocchio</groupId>
<artifactId>jasypt-spring-boot-starter</artifactId>
<version>1.16</version>
</dependency>
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>4.0.0</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.74</version>
</dependency>
<!-- 与swagger一起使用,需要注意-->
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.8.0</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.8.0</version>
</dependency>
<!--mybatis plus-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.0</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-generator</artifactId>
<version>3.3.0</version>
</dependency>
<dependency>
<groupId>org.freemarker</groupId>
<artifactId>freemarker</artifactId>
<version>2.3.29</version>
</dependency>
<!--前端-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!-- hutool 工具包-->
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>4.6.1</version>
</dependency>
<!-- lang包-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.4</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
分片算法测试
public static void main(String[] args) {
//分表表数量
Integer table_num = 4;
//分库数量
Integer ds_num = 2;
//分片内容
String content = "a1922929222a1";
Integer table = HashUtil.fnvHash(content) % table_num;
Integer data = HashUtil.fnvHash(content) % ds_num;
System.out.println("存入表:"+table);
System.out.println("存入库:"+data);
}
application.properties
server.port=8080
spring.application.name=sharding-demo
swagger2.enable=true
spring.profiles.active=sharding
##单数据库
spring.shardingsphere.datasource.names=ds0
spring.shardingsphere.datasource.ds0.type=com.zaxxer.hikari.HikariDataSource
spring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.ds0.jdbc-url=jdbc:mysql://172.21.16.52:3306/release_degree?characterEncoding=UTF-8&serverTimezone=UTC
spring.shardingsphere.datasource.ds0.username=dev
spring.shardingsphere.datasource.ds0.password=21758E78331B20E4
spring.shardingsphere.datasource.ds0.maximum-pool-size=64
spring.shardingsphere.datasource.ds0.connection-timeout=30000
spring.shardingsphere.datasource.ds0.max-lifetime=1200000
spring.shardingsphere.datasource.ds0.connection-test-query=SELECT 'X'
spring.shardingsphere.datasource.ds0.minimum-idle=10
##是否打印SQL
spring.shardingsphere.props.sql.show=true
application-sharding.properties
#分表时使用
# 默认数据库
spring.shardingsphere.sharding.default-data-source-name=ds0
###################################################### sub table rules ######################################################
#根据某字段进行分片
#根据biz_id分片
spring.shardingsphere.sharding.tables.sh_in_conf.actual-data-nodes=ds0.sh_in_conf_$->{0..5}
spring.shardingsphere.sharding.tables.sh_in_conf.table-strategy.standard.sharding-column=task_id
spring.shardingsphere.sharding.tables.sh_in_conf.table-strategy.standard.precise-algorithm-class-name=com.sharding.test.sharding.OtherPreciseShardingAlgorithm
#根据company_id分片
spring.shardingsphere.sharding.tables.sh_in_log.actual-data-nodes=ds0.sh_in_log_$->{0..3}
spring.shardingsphere.sharding.tables.sh_in_log.table-strategy.standard.sharding-column=company_id
spring.shardingsphere.sharding.tables.sh_in_log.table-strategy.standard.precise-algorithm-class-name=com.sharding.test.sharding.OtherPreciseShardingAlgorithm
#默认分片策略
spring.shardingsphere.sharding.tables.sh_in_toll.actual-data-nodes=ds0.sh_in_toll_$->{0..1}
#用于单分片键的标准分片场景
spring.shardingsphere.sharding.default-table-strategy.standard.sharding-column=biz_id
spring.shardingsphere.sharding.default-table-strategy.standard.precise-algorithm-class-name=com.sharding.test.sharding.DefaultPreciseShardingAlgorithm
#绑定表规则列表 涉及到关联查询的同分片规则的绑定
spring.shardingsphere.sharding.binding-tables=sh_in_toll
自定义分片类
package com.sharding.test.sharding;
import cn.hutool.core.util.HashUtil;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.shardingsphere.api.sharding.standard.PreciseShardingAlgorithm;
import org.apache.shardingsphere.api.sharding.standard.PreciseShardingValue;
import java.util.Collection;
/**
* @author leijie.gao
* @since 2020-05-27
*/
public class DefaultPreciseShardingAlgorithm implements PreciseShardingAlgorithm<String> {
/**
* @param targetTableNames sharding 逻辑表 分表规则
* @param shardingVal PreciseShardingValue(logicTableName=真实表, columnName=company_id, value=company_id_value)
* @return {{@link String}}
*/
@Override
public String doSharding(Collection<String> targetTableNames, PreciseShardingValue<String> shardingVal) {
final String[] tables = targetTableNames.toArray(new String[targetTableNames.size()]);
return ArrayUtils.isEmpty(tables) ? tables[0] : tables[HashUtil.fnvHash(shardingVal.getValue()) % targetTableNames.size()];
}
}
结束语
- 每张表可以按照不同的分片策略,保存或者更新查询操作时,必须带着分片策略的条件。
- 建表时,建议为偶数表,方便分库时,为数据迁移做准备,后期分库时,只需要在偶数库中保留偶数表数据,奇数库中保留奇数表数据
5.代码地址 https://gitee.com/G_YutianMusi/sharding-demo.git
测试
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