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
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
3. 总结
Ubtun24.04 TLS,JDK8,shardingsphere proxy/5.5.0,MySQL Connector/J 8.0.27,仅供学习交流使用。