Apache ShardingSphere Proxy5.5.0实现MySQL分库分表与读写分离

1. 前提准备

1.1 主机IP:192.168.186.77

version: '3.8'

services:
  mysql-master:
    image: mysql:latest
    container_name: mysql-master
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_USER: master
      MYSQL_PASSWORD: 123456
      MYSQL_DATABASE: db1  
    ports:
      - "3306:3306"
    volumes:
      - mysql-master-data:/var/lib/mysql
    command: --server-id=1 --log-bin=mysql-bin --binlog-format=ROW
    cap_add:
      - SYS_NICE
    security_opt:
      - seccomp:unconfined

  mysql-slave:
    image: mysql:latest
    container_name: mysql-slave
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_USER: slave
      MYSQL_PASSWORD: 123456
      MYSQL_DATABASE: db1
    ports:
      - "3307:3306"
    volumes:
      - mysql-slave-data:/var/lib/mysql
    command: --server-id=2 --log-bin=mysql-bin --binlog-format=ROW --relay-log=relay-bin --relay-log-index=relay-bin.index
    depends_on:
      - mysql-master
    cap_add:
      - SYS_NICE
    security_opt:
      - seccomp:unconfined

volumes:
  mysql-master-data:
  mysql-slave-data:

注：3306端口扮演master数据库角色，3307端口扮演salve数据库角色。

1.2 主机IP:192.168.186.216

version: '3.8'

services:
  mysql-master:
    image: mysql:latest
    container_name: mysql-master
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_USER: master
      MYSQL_PASSWORD: 123456
      MYSQL_DATABASE: db2  
    ports:
      - "3306:3306"
    volumes:
      - mysql-master-data:/var/lib/mysql
    command: --server-id=3 --log-bin=mysql-bin --binlog-format=ROW
    cap_add:
      - SYS_NICE
    security_opt:
      - seccomp:unconfined

  mysql-slave:
    image: mysql:latest
    container_name: mysql-slave
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_USER: slave
      MYSQL_PASSWORD: 123456
      MYSQL_DATABASE: db2  
    ports:
      - "3307:3306"
    volumes:
      - mysql-slave-data:/var/lib/mysql
    command: --server-id=4 --log-bin=mysql-bin --binlog-format=ROW --relay-log=relay-bin --relay-log-index=relay-bin.index
    depends_on:
      - mysql-master
    cap_add:
      - SYS_NICE
    security_opt:
      - seccomp:unconfined

volumes:
  mysql-master-data:
  mysql-slave-data:

1.3 主机IP:192.168.186.216

version: '3.8'

services:
  mysql-master:
    image: mysql:latest
    container_name: mysql-master
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_USER: master
      MYSQL_PASSWORD: 123456
      MYSQL_DATABASE: db3  
    ports:
      - "3306:3306"
    volumes:
      - mysql-master-data:/var/lib/mysql
    command: --server-id=5 --log-bin=mysql-bin --binlog-format=ROW
    cap_add:
      - SYS_NICE
    security_opt:
      - seccomp:unconfined

  mysql-slave:
    image: mysql:latest
    container_name: mysql-slave
    environment:
      MYSQL_ROOT_PASSWORD: 123456
      MYSQL_USER: slave
      MYSQL_PASSWORD: 123456
      MYSQL_DATABASE: db3 
    ports:
      - "3307:3306"
    volumes:
      - mysql-slave-data:/var/lib/mysql
    command: --server-id=6 --log-bin=mysql-bin --binlog-format=ROW --relay-log=relay-bin --relay-log-index=relay-bin.index
    depends_on:
      - mysql-master
    cap_add:
      - SYS_NICE
    security_opt:
      - seccomp:unconfined

volumes:
  mysql-master-data:
  mysql-slave-data:

注：每个 MySQL 实例必须有一个唯一的 server-id。这是必要的，因为在主从复制设置中，主服务器和从服务器需要能够互相识别，并避免循环复制和冲突。

1.4 简单主从搭建过程

1.4.1 连接主服务器

1.4.2 连接从服务器

1.4.3 配置主服务器

# 创建一个具有复制权限的用户
CREATE USER 'master_slave'@'%' IDENTIFIED BY '123456' REQUIRE SSL;
GRANT REPLICATION SLAVE ON *.* TO 'master_slave'@'%';
FLUSH PRIVILEGES;
SHOW MASTER STATUS;

1.4.4 配置从服务器

CHANGE MASTER TO
    MASTER_HOST ='192.168.186.216', # 主服务器的 IP 地址
    MASTER_USER ='master_slave', # 主服务器上配置的复制用户
    MASTER_PASSWORD ='123456', # 复制用户的密码
    MASTER_LOG_FILE ='mysql-bin.000003', # 主服务器的日志文件名
    MASTER_LOG_POS =920, # 日志文件的位置
    MASTER_SSL=1;
START SLAVE;
SHOW SLAVE STATUS;

其余两台使用同样的方式进行配置。

2. 安装 Apache ShardingSphere Proxy

2.1 安装合适的JDK版本

sudo apt install openjdk-8-jdk -y

2.2 验证JDK版本

java -version

liber@liber-VMware-Virtual-Platform:/home/sp$ java -version
openjdk version "1.8.0_412"
OpenJDK Runtime Environment (build 1.8.0_412-8u412-ga-1~24.04.2-b08)
OpenJDK 64-Bit Server VM (build 25.412-b08, mixed mode)

2.3 使用wget下载Apache ShardingSphere Proxy

sudo wget https://dlcdn.apache.org/shardingsphere/5.5.0/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin.tar.gz

2.4 解压Apache ShardingSphere Proxy文件

 sudo tar -zxvf apache-shardingsphere-5.5.0-shardingsphere-proxy-bin.tar.gz

2.5 进入Apache ShardingSphere Proxy解压后的目录

cd apache-shardingsphere-5.5.0-shardingsphere-proxy-bin

2.5 查看MySQL的版本

找台主服务器或者从服务器输入查看数据库的版本。

SELECT VERSION();

2.6 下载并安装MySQL Connector/J 8.0.27

sudo wget https://downloads.mysql.com/archives/get/p/3/file/mysql-connector-java-8.0.27.tar.gz

2.7 解压MySQL文件

sudo tar -zxvf mysql-connector-java-8.0.27.tar.gz

2.8 进入解压后的MySQL目录

cd mysql-connector-java-8.0.27

2.9 将 JAR 文件放置到合适的位置

需要将JAR文件复制到Apache ShardingSphere-Proxy解压目录的lib 目录中，因为我在Apache ShardingSphere-Proxy的解压目录中下载的MySQL压缩包，解压后只需要将JAR文件移动到上一级的lib目录即可。

sudo mv mysql-connector-java-8.0.27.jar  ../lib

2.10 global.yaml

# 回退上一级目录
cd ..

# 进入conf目录
cd conf

# 编辑global.yaml文件
sudo nano global.yaml

global.yaml 内容如下：

# 释放注解
authority:
  users:
    - user: root@%
      password: 123456
    - user: sharding
      password: 123456
  privilege:
    type: ALL_PERMITTED
sqlParser:
  sqlStatementCache:
    initialCapacity: 2000
    maximumSize: 65535
  parseTreeCache:
    initialCapacity: 128
    maximumSize: 1024
props:
  proxy-default-port: 3308 #修改端口，因为被占用了3307所以我修改了3308
  sql-show: true

2.11 创建物理表

use db1; # 每个主服务器都需要创建，只需要把db1，改db2，db3即可。

CREATE TABLE t_order_0
(
    order_id   INT PRIMARY KEY,
    user_id    INT,
    order_date DATE,
    status     VARCHAR(15)
);

CREATE TABLE t_order_1
(
    order_id   INT PRIMARY KEY,
    user_id    INT,
    order_date DATE,
    status     VARCHAR(15)
);

注：每个主服务器的数据库都需要建立结构相同的物理表，只是库不一样db1，db2，db3。

2.12 database-sharding.yaml

sudo nano database-sharding.yaml

2.1.1 配置数据库源

dataSources:
  # 主库配置
  ds_77_master:
    url: jdbc:mysql://192.168.186.77:3306/db1?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: root  # 数据库用户名
    password: 123456  # 数据库密码
    connectionTimeoutMilliseconds: 30000  # 连接超时时间，单位毫秒
    idleTimeoutMilliseconds: 60000  # 空闲连接超时时间，单位毫秒
    maxLifetimeMilliseconds: 1800000  # 连接最大生命周期，单位毫秒
    maxPoolSize: 50  # 连接池最大连接数
    minPoolSize: 1  # 连接池最小连接数

  # 从库配置
  ds_77_slave:
    url: jdbc:mysql://192.168.186.77:3307/db1?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: slave  # 数据库用户名
    password: 123456  # 数据库密码
    connectionTimeoutMilliseconds: 30000  # 连接超时时间，单位毫秒
    idleTimeoutMilliseconds: 60000  # 空闲连接超时时间，单位毫秒
    maxLifetimeMilliseconds: 1800000  # 连接最大生命周期，单位毫秒
    maxPoolSize: 50  # 连接池最大连接数
    minPoolSize: 1  # 连接池最小连接数

  ds_216_master:
    url: jdbc:mysql://192.168.186.216:3306/db2?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1

  ds_216_slave:
    url: jdbc:mysql://192.168.186.216:3307/db2?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: slave
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1

  ds_18_master:
    url: jdbc:mysql://192.168.186.18:3306/db3?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1

  ds_18_slave:
    url: jdbc:mysql://192.168.186.18:3307/db3?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: slave
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1

# 设置逻辑数据库名称
databaseName: my_database

2.1.2 读写分离规则

rules:
  - !READWRITE_SPLITTING
    # 定义用于读写分离的数据源配置
    dataSources:
      # 第一组读写分离规则，命名为 "readwrite_77"
      readwrite_77:
        writeDataSourceName: ds_77_master  # 指定写操作的数据源为 ds_77_master（主库）
        readDataSourceNames:
          - ds_77_slave  # 指定读操作的数据源列表，这里只包括 ds_77_slave（从库）
        transactionalReadQueryStrategy: PRIMARY  # 事务中的读查询策略设为 PRIMARY，即事务中所有读操作都将指向主库
        loadBalancerName: random  # 使用随机策略从可用的从库中选择

      readwrite_216:
        writeDataSourceName: ds_216_master  
        readDataSourceNames:
          - ds_216_slave  
        transactionalReadQueryStrategy: PRIMARY 
        loadBalancerName: random  

      readwrite_18:
        writeDataSourceName: ds_18_master  # 主库
        readDataSourceNames:
          - ds_18_slave  
        transactionalReadQueryStrategy: PRIMARY  
        loadBalancerName: random  

    # 定义负载均衡器的配置
    loadBalancers:
      random:
        type: RANDOM  # 指定负载均衡器的类型为 RANDOM，随机选择读库

2.1.3 分库分表规则

- !SHARDING
  # 分片表的配置
  tables:
    t_order:
      # 定义分片表t_order在各个数据源的具体分布
      actualDataNodes: readwrite_77.t_order_${0..1}, readwrite_216.t_order_${0..1}, readwrite_18.t_order_${0..1}
      # 表的分片策略配置
      tableStrategy:
        standard:
          shardingColumn: order_id  # 使用订单ID作为分片键
          shardingAlgorithmName: t_order_inline  # 分片算法名称，指向后面定义的内联算法
      # 主键生成策略，用于插入操作时自动生成主键
      keyGenerateStrategy:
        column: order_id  # 主键列
        keyGeneratorName: snowflake  # 使用雪花算法生成主键

  # 默认数据库分片策略
  defaultDatabaseStrategy:
    standard:
      shardingColumn: user_id  # 使用用户ID作为分片键
      shardingAlgorithmName: database_inline  # 数据库分片使用的算法名称，指向后面定义的内联算法

  # 默认的表分片策略，此处未定义分片策略
  defaultTableStrategy:
    none:

  # 绑定表组，确保相互关联的表在同一数据库分片中
  bindingTables:
    - t_order  # 把t_order表标记为绑定表

  # 定义使用的分片算法
  shardingAlgorithms:
    # 定义数据库分片的内联算法
    database_inline:
      type: INLINE
      props:
        algorithm-expression: "readwrite_${(user_id % 3 == 0) ? '77' : ((user_id % 3 == 1) ? '216' : '18')}"
        # 根据用户ID的值进行模3运算来决定数据分配到哪个数据源

    # 定义表分片的内联算法
    t_order_inline:
      type: INLINE
      props:
        algorithm-expression: "t_order_${order_id % 2}"
        # 根据订单ID的值进行模2运算来决定数据存储在哪个分表

  # 主键生成器配置，指定使用雪花算法生成主键
  keyGenerators:
    snowflake:
      type: SNOWFLAKE
      props:
        worker-id: 123  # 设置雪花算法的工作节点ID

2.1.4 完整配置信息

dataSources:
  ds_77_master:
    url: jdbc:mysql://192.168.186.77:3306/db1?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1
  ds_77_slave:
    url: jdbc:mysql://192.168.186.77:3307/db1?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: slave
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1
  ds_216_master:
    url: jdbc:mysql://192.168.186.216:3306/db2?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1
  ds_216_slave:
    url: jdbc:mysql://192.168.186.216:3307/db2?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: slave
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1
  ds_18_master:
    url: jdbc:mysql://192.168.186.18:3306/db3?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: root
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1
  ds_18_slave:
    url: jdbc:mysql://192.168.186.18:3307/db3?serverTimezone=UTC&useSSL=false&allowPublicKeyRetrieval=true
    username: slave
    password: 123456
    connectionTimeoutMilliseconds: 30000
    idleTimeoutMilliseconds: 60000
    maxLifetimeMilliseconds: 1800000
    maxPoolSize: 50
    minPoolSize: 1
databaseName: my_database
rules:
  - !READWRITE_SPLITTING
    dataSources:
      readwrite_77:
        writeDataSourceName: ds_77_master
        readDataSourceNames:
          - ds_77_slave
        transactionalReadQueryStrategy: PRIMARY
        loadBalancerName: random
      readwrite_216:
        writeDataSourceName: ds_216_master
        readDataSourceNames:
          - ds_216_slave
        transactionalReadQueryStrategy: PRIMARY
        loadBalancerName: random
      readwrite_18:
        writeDataSourceName: ds_18_master
        readDataSourceNames:
          - ds_18_slave
        transactionalReadQueryStrategy: PRIMARY
        loadBalancerName: random
    loadBalancers:
      random:
        type: RANDOM
  - !SHARDING
    tables:
      t_order:
        actualDataNodes: readwrite_77.t_order_${0..1}, readwrite_216.t_order_${0..1}, readwrite_18.t_order_${0..1}
        tableStrategy:
          standard:
            shardingColumn: order_id
            shardingAlgorithmName: t_order_inline
        keyGenerateStrategy:
          column: order_id
          keyGeneratorName: snowflake
    defaultDatabaseStrategy:
      standard:
        shardingColumn: user_id
        shardingAlgorithmName: database_inline
    defaultTableStrategy:
      none:
    bindingTables:
      - t_order
    shardingAlgorithms:
      database_inline:
        type: INLINE
        props:
          algorithm-expression: "readwrite_${(user_id % 3 == 0) ? '77' : ((user_id % 3 == 1) ? '216' : '18')}"
      t_order_inline:
        type: INLINE
        props:
          algorithm-expression: "t_order_${order_id % 2}"
    keyGenerators:
      snowflake:
        type: SNOWFLAKE
        props:
          worker-id: 123

注：分片规则根据 user_id 的值对3取模，决定将数据分片到哪个数据库，根据 order_id 的值对2取模，决定将数据分片到哪个表。

2.1.5 参考教程文献

数据分片 :: ShardingSphere

读写分离 :: ShardingSphere

混合规则 :: ShardingSphere

2.13 启动程序

# 回退上一级
cd ..
# 进入bin目录
cd bin
# 启动程序
sudo ./start.sh

liber@liber-VMware-Virtual-Platform:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/conf$ cd ..
liber@liber-VMware-Virtual-Platform:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin$ cd bin
liber@liber-VMware-Virtual-Platform:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/bin$ sudo ./start.sh
/usr/bin/java
we find java version: java8, full_version=1.8.0_412, full_path=/usr/bin/java
The classpath is /home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/conf:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/conf:.:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/lib/*:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/ext-lib/*
main class org.apache.shardingsphere.proxy.Bootstrap -1 /home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/conf 0.0.0.0 false
Starting the ShardingSphere-Proxy ... PID: 128452
Please check the STDOUT file: /home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/logs/stdout.log #日志路径可以通过cat进行查看
liber@liber-VMware-Virtual-Platform:/home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/bin$

2.15 查看日志

cat /home/sp/apache-shardingsphere-5.5.0-shardingsphere-proxy-bin/logs/stdout.log

#显示该信息代表成功
[INFO ] 2024-07-25 15:39:09.724 [main] o.a.s.d.p.c.l.PipelineContextManagerLifecycleListener - mode type is not Cluster, mode type='Standalone', ignore
[INFO ] 2024-07-25 15:39:09.933 [main] o.a.s.p.v.ShardingSphereProxyVersion - Database type is `MySQL`, version is `8.0.27`, database name is `my_database`
[INFO ] 2024-07-25 15:39:09.966 [main] o.a.s.p.frontend.ssl.ProxySSLContext - Proxy frontend SSL/TLS is not enabled.
[INFO ] 2024-07-25 15:39:12.683 [main] o.a.s.p.frontend.ShardingSphereProxy - ShardingSphere-Proxy Standalone mode started successfully

2.16 测试连接

2.17 分库分表验证

在ShardingSphere-Proxy连接的客户端进行操作，因为t_order是ShardingSphere-Proxy创建的逻辑表，所以实际上通过第三方连接工具是看不到存在的实体表，比如我使用的是IDEA自带的MySQL的连接管理工具。

use my_database;

INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (1, 10, '2023-07-01', 'NEW');
INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (2, 20, '2023-07-02', 'SHIPPED');
INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (3, 30, '2023-07-03', 'DELIVERED');
INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (14, 40, '2023-07-04', 'RETURNED');

运行日志：

[INFO ] 2024-07-25 15:43:21.874 [ShardingSphere-Command-1] ShardingSphere-SQL - Logic SQL: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (1, 10, '2023-07-01', 'NEW')
[INFO ] 2024-07-25 15:43:21.874 [ShardingSphere-Command-1] ShardingSphere-SQL - Actual SQL: ds_216_master ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order_1 (order_id, user_id, order_date, status) VALUES (1, 10, '2023-07-01', 'NEW')
解释：分片规则根据 user_id 的值对3取模，决定将数据分片到哪个数据库， 根据 order_id 的值对2取模，决定将数据分片到哪个表。数据库取模顺序：77=>0,216=>1,18=>2
user_id: 10%3=1，order_id: 1%2=1，所以分片到第2个数据库ds_216_master，t_order_1表。 

[INFO ] 2024-07-25 15:43:21.976 [ShardingSphere-Command-1] ShardingSphere-SQL - Logic SQL: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (2, 20, '2023-07-02', 'SHIPPED')
[INFO ] 2024-07-25 15:43:21.976 [ShardingSphere-Command-1] ShardingSphere-SQL - Actual SQL: ds_18_master ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order_0 (order_id, user_id, order_date, status) VALUES (2, 20, '2023-07-02', 'SHIPPED')
解释：分片规则根据 user_id 的值对3取模，决定将数据分片到哪个数据库， 根据 order_id 的值对2取模，决定将数据分片到哪个表。数据库取模顺序：77=>0,216=>1,18=>2
user_id: 20%3=2，order_id: 2%2=0，所以分片到第3个数据库ds_18_master，t_order_0表。
[INFO ] 2024-07-25 15:43:22.108 [ShardingSphere-Command-1] ShardingSphere-SQL - Logic SQL: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (3, 30, '2023-07-03', 'DELIVERED')
[INFO ] 2024-07-25 15:43:22.108 [ShardingSphere-Command-1] ShardingSphere-SQL - Actual SQL: ds_77_master ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order_1 (order_id, user_id, order_date, status) VALUES (3, 30, '2023-07-03', 'DELIVERED')
解释：分片规则根据 user_id 的值对3取模，决定将数据分片到哪个数据库， 根据 order_id 的值对2取模，决定将数据分片到哪个表。数据库取模顺序：77=>0,216=>1,18=>2
user_id: 30%3=0，order_id: 3%2=1，所以分片到第1个数据库ds_77_master，t_order_1表。

[INFO ] 2024-07-25 15:43:22.248 [ShardingSphere-Command-1] ShardingSphere-SQL - Logic SQL: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order (order_id, user_id, order_date, status) VALUES (14, 40, '2023-07-04', 'RETURNED')
[INFO ] 2024-07-25 15:43:22.248 [ShardingSphere-Command-1] ShardingSphere-SQL - Actual SQL: ds_216_master ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ INSERT INTO t_order_0 (order_id, user_id, order_date, status) VALUES (14, 40, '2023-07-04', 'RETURNED')
解释：分片规则根据 user_id 的值对3取模，决定将数据分片到哪个数据库， 根据 order_id 的值对2取模，决定将数据分片到哪个表。数据库取模顺序：77=>0,216=>1,18=>2
user_id: 40%3=1，order_id: 14%2=0，所以分片到第2个数据库ds_216_master，t_order_0表。

2.18 读写分离验证

select *from t_order;

运行日志：
[INFO ] 2024-07-25 15:57:22.968 [ShardingSphere-Command-2] ShardingSphere-SQL - Logic SQL: /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order
[INFO ] 2024-07-25 15:57:22.969 [ShardingSphere-Command-2] ShardingSphere-SQL - Actual SQL: ds_77_slave ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order_0 UNION ALL /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order_1
[INFO ] 2024-07-25 15:57:22.969 [ShardingSphere-Command-2] ShardingSphere-SQL - Actual SQL: ds_216_slave ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order_0 UNION ALL /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order_1
[INFO ] 2024-07-25 15:57:22.973 [ShardingSphere-Command-2] ShardingSphere-SQL - Actual SQL: ds_18_slave ::: /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order_0 UNION ALL /* ApplicationName=IntelliJ IDEA 2024.1 */ select *from t_order_1