浅谈订单重构之 MySQL 分库分表实战篇

吾爱主题阅读：180 2024-04-02 08:04:25 评论：0

一、背景

发布上篇文章浅谈订单重构之路之后，有很多小伙伴想知道，分库分表具体是如何实现的。那么这篇文章具体介绍下，分库分表实战。

二、目标

本文将完成如下目标:

* 分表数量: 256 分库数量: 4

* 以用户ID(user_id) 为数据库分片Key

* 最后测试订单创建，更新，删除, 单订单号查询，根据user_id查询列表操作。

架构图:

表结构如下:

CREATE TABLE `order_XXX` (
`order_id` bigint(20) unsigned NOT NULL,
`user_id` int(11) DEFAULT '0' COMMENT '订单id',
`status` int(11) DEFAULT '0' COMMENT '订单状态',
`booking_date` datetime DEFAULT NULL,
`create_time` datetime DEFAULT NULL,
`update_time` datetime DEFAULT NULL,
PRIMARY KEY (`order_id`),
KEY `idx_user_id` (`user_id`),
KEY `idx_bdate` (`booking_date`),
KEY `idx_ctime` (`create_time`),
KEY `idx_utime` (`update_time`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

注: 000<= XXX <= 255, 本文重点在于分库分表实践, 只保留具有代表性字段，其它场景可以在此基础上做改进。

全局唯一ID设计

要求:1.全局唯一 2:粗略有序 3:可反解出库编号

1bit + 39bit时间差 + 8bit机器号 + 8bit用户编号(库号) + 8bit自增序列

订单号组成项	保留字段	毫秒级时间差	机器数	用户编号(表编号)	自增序列
所占字节(单位bit)	1	39	8	8	8

单机最大QPS: 256000 使用寿命: 17年

订单号生成规则说明详见浅谈分布式唯一Id生成器之最佳实践

三、环境准备

1. 基本信息

2. 数据库环境准备

温馨提示：使用docker-compose快速搭建了4主4从数据库集群，实现本地快速一键部署，生产环境一般由DBA同学搭建。

具体实现请移步查看: https://gitee.com/bytearch_admin/docker-app/tree/main/mysql-cluster

3. 建库 & 导入分表

* 在mysql master实例分别建库

172.30.1.21( o rder_db_ 1) , 172.30.1.22( order_db_2) ,

172.30.1.23( ord er_db_3) , 172.30.1.24( order_db_4 )

* 依次导入建表SQL 命令为

mysql -uroot -pbytearch -h172.30.1.21 order_db_1<fast-cloud-mysql-sharding/doc/sql/order_db_1.sql;
mysql -uroot -pbytearch -h172.30.1.22 order_db_2<fast-cloud-mysql-sharding/doc/sql/order_db_2.sql;
mysql -uroot -pbytearch -h172.30.1.23 order_db_3<fast-cloud-mysql-sharding/doc/sql/order_db_3.sql;
mysql -uroot -pbytearch -h172.30.1.24 order_db_4<fast-cloud-mysql-sharding/doc/sql/order_db_4.sql;

四、配置&实践

1. pom文件

<dependency>
<groupId>org.jfaster</groupId>
<artifactId>mango-spring-boot-starter</artifactId>
<version>2.0.1</version>
</dependency>
<dependency>
<groupId>com.bytearch</groupId>
<artifactId>fast-cloud-id-generator</artifactId>
<version>${version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.6</version>
</dependency>

2. 常量配置

package com.bytearch.fast.cloud.mysql.sharding.common;
/**
* 分库分表策略常用常量
*/
public class ShardingStrategyConstant {
/**
* database 逻辑名称，真实库名为 order_db_XXX
*/
public static final String LOGIC_ORDER_DATABASE_NAME = "order_db";
/**
* 分表数 256，一旦确定不可更改
*/
public static final int SHARDING_TABLE_NUM = 256;
/**
* 分库数, 不建议更改，可以更改，但是需要DBA迁移数据
*/
public static final int SHARDING_DATABASE_NODE_NUM = 4;
}

3. yml 配置

4主4从数据库配置，这里仅测试默认使用root用户密码，生产环境不建议使用root用户。

mango:
scan-package: com.bytearch.fast.cloud.mysql.sharding.dao
datasources:
- name: order_db_1
master:
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.21:3306/order_db_1?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
slaves:
- driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.31:3306/order_db_1?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
- name: order_db_2
master:
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.22:3306/order_db_2?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
slaves:
- driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.32:3306/order_db_2?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
- name: order_db_3
master:
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.23:3306/order_db_3?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
slaves:
- driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.33:3306/order_db_3?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
- name: order_db_4
master:
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.24:3306/order_db_4?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 3000
slaves:
- driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://172.30.1.34:3306/order_db_4?useUnicode=true&characterEncoding=utf8&autoReconnect=true&rewriteBatchedState&connectTimeout=1000&socketTimeout=5000&useSSL=false
user-name: root
password: bytearch
maximum-pool-size: 10
connection-timeout: 300

4. 分库分表策略

1). 根据order_id为shardKey分库分表策略

package com.bytearch.fast.cloud.mysql.sharding.strategy;
import com.bytearch.fast.cloud.mysql.sharding.common.ShardingStrategyConstant;
import com.bytearch.id.generator.IdEntity;
import com.bytearch.id.generator.SeqIdUtil;
import org.jfaster.mango.sharding.ShardingStrategy;
/**
* 订单号分库分表策略
*/
public class OrderIdShardingStrategy implements ShardingStrategy<Long, Long> {
@Override
public String getDataSourceFactoryName(Long orderId) {
if (orderId == null || orderId < 0L) {
throw new IllegalArgumentException("order_id is invalid!");
}
IdEntity idEntity = SeqIdUtil.decodeId(orderId);
if (idEntity.getExtraId() >= ShardingStrategyConstant.SHARDING_TABLE_NUM) {
throw new IllegalArgumentException("sharding table Num is invalid, tableNum:" + idEntity.getExtraId());
}
//1. 计算步长
int step = ShardingStrategyConstant.SHARDING_TABLE_NUM / ShardingStrategyConstant.SHARDING_DATABASE_NODE_NUM;
//2. 计算出库编号
long dbNo = Math.floorDiv(idEntity.getExtraId(), step) + 1;
//3. 返回数据源名
return String.format("%s_%s", ShardingStrategyConstant.LOGIC_ORDER_DATABASE_NAME, dbNo);
}
@Override
public String getTargetTable(String logicTableName, Long orderId) {
if (orderId == null || orderId < 0L) {
throw new IllegalArgumentException("order_id is invalid!");
}
IdEntity idEntity = SeqIdUtil.decodeId(orderId);
if (idEntity.getExtraId() >= ShardingStrategyConstant.SHARDING_TABLE_NUM) {
throw new IllegalArgumentException("sharding table Num is invalid, tableNum:" + idEntity.getExtraId());
}
// 基于约定，真实表名为 logicTableName_XXX， XXX不足三位补0
return String.format("%s_%03d", logicTableName, idEntity.getExtraId());
}
}

2). 根据user_id 为shardKey分库分表策略

package com.bytearch.fast.cloud.mysql.sharding.strategy;
import com.bytearch.fast.cloud.mysql.sharding.common.ShardingStrategyConstant;
import org.jfaster.mango.sharding.ShardingStrategy;
/**
* 指定分片KEY 分库分表策略
*/
public class UserIdShardingStrategy implements ShardingStrategy<Integer, Integer> {
@Override
public String getDataSourceFactoryName(Integer userId) {
//1. 计算步长即单库放得表数量
int step = ShardingStrategyConstant.SHARDING_TABLE_NUM / ShardingStrategyConstant.SHARDING_DATABASE_NODE_NUM;
//2. 计算出库编号
long dbNo = Math.floorDiv(userId % ShardingStrategyConstant.SHARDING_TABLE_NUM, step) + 1;
//3. 返回数据源名
return String.format("%s_%s", ShardingStrategyConstant.LOGIC_ORDER_DATABASE_NAME, dbNo);
}
@Override
public String getTargetTable(String logicTableName, Integer userId) {
// 基于约定，真实表名为 logicTableName_XXX， XXX不足三位补0
return String.format("%s_%03d", logicTableName, userId % ShardingStrategyConstant.SHARDING_TABLE_NUM);
}
}

5. dao层编写

1). OrderPartitionByIdDao

package com.bytearch.fast.cloud.mysql.sharding.dao;
import com.bytearch.fast.cloud.mysql.sharding.common.ShardingStrategyConstant;
import com.bytearch.fast.cloud.mysql.sharding.pojo.entity.OrderEntity;
import com.bytearch.fast.cloud.mysql.sharding.strategy.OrderIdShardingStrategy;
import org.jfaster.mango.annotation.*;
@DB(name = ShardingStrategyConstant.LOGIC_ORDER_DATABASE_NAME, table = "order")
@Sharding(shardingStrategy = OrderIdShardingStrategy.class)
public interface OrderPartitionByIdDao {
@SQL("INSERT INTO #table (order_id, user_id, status, booking_date, create_time, update_time) VALUES" +
"(:orderId,:userId,:status,:bookingDate,:createTime,:updateTime)"
)
int insertOrder(@TableShardingBy("orderId") @DatabaseShardingBy("orderId") OrderEntity orderEntity);
@SQL("UPDATE #table set update_time = now()" +
"#if(:bookingDate != null),booking_date = :bookingDate #end " +
"#if (:status != null), status = :status #end" +
"WHERE order_id = :orderId"
)
int updateOrderByOrderId(@TableShardingBy("orderId") @DatabaseShardingBy("orderId") OrderEntity orderEntity);
@SQL("SELECT * FROM #table WHERE order_id = :1")
OrderEntity getOrderById(@TableShardingBy @DatabaseShardingBy Long orderId);
@SQL("SELECT * FROM #table WHERE order_id = :1")
@UseMaster
OrderEntity getOrderByIdFromMaster(@TableShardingBy @DatabaseShardingBy Long orderId);

6. 单元测试

@SpringBootTest(classes = {Application.class})
@RunWith(SpringJUnit4ClassRunner.class)
public class ShardingTest {
@Autowired
OrderPartitionByIdDao orderPartitionByIdDao;
@Autowired
OrderPartitionByUserIdDao orderPartitionByUserIdDao;
@Test
public void testCreateOrderRandom() {
for (int i = 0; i < 20; i++) {
int userId = ThreadLocalRandom.current().nextInt(1000,1000000);
OrderEntity orderEntity = new OrderEntity();
orderEntity.setOrderId(SeqIdUtil.nextId(userId % ShardingStrategyConstant.SHARDING_TABLE_NUM));
orderEntity.setStatus(1);
orderEntity.setUserId(userId);
orderEntity.setCreateTime(new Date());
orderEntity.setUpdateTime(new Date());
orderEntity.setBookingDate(new Date());
int ret = orderPartitionByIdDao.insertOrder(orderEntity);
Assert.assertEquals(1, ret);
}
}
@Test
public void testOrderAll() {
//insert
int userId = ThreadLocalRandom.current().nextInt(1000,1000000);
OrderEntity orderEntity = new OrderEntity();
orderEntity.setOrderId(SeqIdUtil.nextId(userId % ShardingStrategyConstant.SHARDING_TABLE_NUM));
orderEntity.setStatus(1);
orderEntity.setUserId(userId);
orderEntity.setCreateTime(new Date());
orderEntity.setUpdateTime(new Date());
orderEntity.setBookingDate(new Date());
int i = orderPartitionByIdDao.insertOrder(orderEntity);
Assert.assertEquals(1, i);
//get from master
OrderEntity orderInfo = orderPartitionByIdDao.getOrderByIdFromMaster(orderEntity.getOrderId());
Assert.assertNotNull(orderInfo);
Assert.assertEquals(orderInfo.getOrderId(), orderEntity.getOrderId());
//get from slave
OrderEntity slaveOrderInfo = orderPartitionByIdDao.getOrderById(orderEntity.getOrderId());
Assert.assertNotNull(slaveOrderInfo);
//update
OrderEntity updateEntity = new OrderEntity();
updateEntity.setOrderId(orderInfo.getOrderId());
updateEntity.setStatus(2);
updateEntity.setUpdateTime(new Date());
int affectRows = orderPartitionByIdDao.updateOrderByOrderId(updateEntity);
Assert.assertTrue( affectRows > 0);
}
@Test
public void testGetListByUserId() {
int userId = ThreadLocalRandom.current().nextInt(1000,1000000);
for (int i = 0; i < 5; i++) {
OrderEntity orderEntity = new OrderEntity();
orderEntity.setOrderId(SeqIdUtil.nextId(userId % ShardingStrategyConstant.SHARDING_TABLE_NUM));
orderEntity.setStatus(1);
orderEntity.setUserId(userId);
orderEntity.setCreateTime(new Date());
orderEntity.setUpdateTime(new Date());
orderEntity.setBookingDate(new Date());
orderPartitionByIdDao.insertOrder(orderEntity);
}
try {
//防止主从延迟引起的校验错误
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
List<OrderEntity> orderListByUserId = orderPartitionByUserIdDao.getOrderListByUserId(userId);
Assert.assertNotNull(orderListByUserId);
Assert.assertTrue(orderListByUserId.size() == 5);
}
}