MySQL主从复制 MySQL主从复制

使用Docker Compose搭建MySQL主从复制架构
环境准备
docker 安装MySQL数据库

docker pull mysql

运行MySQL容器

docker run --name mysql mysql -e MYSQL_ROOT_PASSWORD=123456

使用命令将MySQL配置文件my.cnf 复制出主机上

docker cp mysql:/var/lib/mysql/ D:/docker/mysql_cluster/my.cnf

拿到my.cnf原配置文件，加以改造就可以实现数据库主从同步了
配置文件
创建文件夹在主机创建mysql_cluster 文件夹

mysql_cluster master/ my.cnf mysql/ slave/ my.cnf mysql/ docker-compose.yml

将从容器内复制出来my.cnf分别放入 master、slave 下
文件配置设置 master my.cnf

# 下面配置为主节点设置 #开启二进制日志 log_bin=mysql-bin #为当前节点设置一个全局唯一的ID号 server_id=95 # 不需要同步数据库 binlog-ignore-db = mysql binlog_cache_size = 1M# 二级制自动删除的天数，默认为0，表达没有自动删除，启动时和二级制日志循环可能删除时间 expire_logs_days = 7 log_bin_trust_function_creators = 1 binlog_format=mixed# MySQL 8.x，需要如下配置 default_authentication_plugin=mysql_native_password character-set-server=utf8mb4 collation-server=utf8mb4_unicode_ci

配置 slave my.cnf

server_id = 102 log-bin = mysql-bin relay_log = relicas-mysql-relay-bin log-slave-updates = 1 binlog-ignore-db = mysql log_bin_trust_function_creators = 1 binlog_format=mixed read_only = 1# MySQL 8.x，需要如下配置 default_authentication_plugin=mysql_native_password character-set-server=utf8mb4 collation-server=utf8mb4_unicode_ci

docker-compose.yml 配置

version: '3.8' services: mysql-master: container_name: mysql-master hostname: mysql-master image: mysql restart: always ports: - "3306:3306" volumes: - D:/docker/mysql_cluster/master/my.cnf:/etc/mysql/my.cnf - D:/docker/mysql_cluster/master/mysql:/var/lib/mysql environment: MYSQL_ROOT_PASSWORD: 123456 TZ: Asia/Shanghai command: [ '--character-set-server=utf8mb4', '--collation-server=utf8mb4_general_ci', '--max_connections=3000' ] networks: ## 引入外部预先定义的网段 myweb: ipv4_address: 192.168.102.120#设置ip地址mysql-slave: container_name: mysql-slave hostname: mysql-slave image: mysql restart: always ports: - "3307:3306" volumes: - D:/docker/mysql_cluster/slave/my.cnf:/etc/mysql/my.cnf - D:/docker/mysql_cluster/slave/mysql:/var/lib/mysql environment: MYSQL_ROOT_PASSWORD: 123456 TZ: Asia/Shanghai command: [ '--character-set-server=utf8mb4', '--collation-server=utf8mb4_general_ci', '--max_connections=3000' ] networks: myweb: ipv4_address: 192.168.102.121#设置ip地址networks: myweb: driver: bridge ipam: config: # 自定义网段 - subnet: "192.168.102.0/24"

还用一点值得注意的，如果宿主机上的mysql 文件夹不是空的，配置中MySQL root 密码不生效的。有次我将一个正在运行中/var/lib/mysql copy到宿主机上，使用逻辑卷映射到容器中去，导致MySQL一直登录不上去。
设置主从同步运行容器

docker-compose up -d

查看运行情况

docke ps -a

出现下面状态，表明两个节点都运行成功了

CONTAINER IDIMAGECOMMANDCREATEDSTATUSPORTSNAMES bf3f254d75b2mysql"docker-entrypoint.s…"5 seconds agoUp 4 seconds33060/tcp, 0.0.0.0:3307->3306/tcp, :::3307->3306/tcpmysql-slave691e10949d3fmysql"docker-entrypoint.s…"5 seconds agoUp 4 seconds0.0.0.0:3306->3306/tcp, :::3306->3306/tcp, 33060/tcpmysql-master

登录master节点设置slave 连接master节点

mysql> grant replication client,replication slave on *.* to 'root'@'192.168.102.120'

保存设置

mysql> flush privileges

获取binlog 文件名和Position

mysql> show master status

+------------------+----------+--------------+------------------+-------------------+ | File| Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+-------------------+ | mysql-bin.000003 |156 || mysql|| +------------------+----------+--------------+------------------+-------------------+

登录slave 节点

mysql> reset master; mysql> CHANGE MASTER TO MASTER_HOST='mysql-master',MASTER_USER='root',MASTER_PASSWORD='123456',MASTER_PORT=3306,MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=156 mysql> start slave

查看同步结果

mysql> show slave status \G; *************************** 1. row *************************** Slave_IO_State: Waiting for source to send event Master_Host: mysql-master Master_User: root Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 156 Relay_Log_File: relicas-mysql-relay-bin.000002 Relay_Log_Pos: 324 Relay_Master_Log_File: mysql-bin.000003 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 156 Relay_Log_Space: 541 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Seconds_Behind_Master: 0 Replicate_Ignore_Server_Ids: Master_Server_Id: 95 Master_UUID: 903599fc-0336-11ec-9228-0242adc80678 Master_Info_File: mysql.slave_master_info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Replica has read all relay log; waiting for more updates Master_Retry_Count: 86400

看见 Slave_IO_Running: Yes Slave_SQL_Running: Yes这两个都是Yes 说明同步已经成功了。
验证同步
连接master 节点，创建一个数据库，在新数据库下再创建一个新表。再连接slave 节点可以看见再master 创建数据库下的新表，这样就表明数据已经实现同步了。
使用springboot 搭建读写分离
maven pox.xml

org.springframework.boot spring-boot-starter-parent 2.5.1 org.mybatis.spring.boot mybatis-spring-boot-starter 2.2.0 com.alibaba druid-spring-boot-starter 1.2.3 mysql mysql-connector-java runtime org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-test org.springframework.boot spring-boot-starter-aop org.projectlombok lombok true

主要原来就是利用org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource可以将不同连接设置到Map 根据key 获取获取dataSource ,重写determineCurrentLookupKey() ,实现对读取数据库时，切换到读库，写操作切换到写库。下面会贴出全部代码
application.yml 配置

server: port: 8001 spring: datasource: druid: master: url: jdbc:mysql://127.0.0.1:3306/example?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&failOverReadOnly=false&useSSL=false&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true username: root password: 123456 slave: url: jdbc:mysql://127.0.0.1:3307/example?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&failOverReadOnly=false&useSSL=false&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true username: root password: 123456

多数据库druid 设置

@Configuration public class DataSourceConfig {@Bean @ConfigurationProperties(prefix = "spring.datasource.druid.master") public DataSource master() { return DruidDataSourceBuilder.create().build(); }@Bean @ConfigurationProperties(prefix = "spring.datasource.druid.slave") public DataSource slave(){ return DruidDataSourceBuilder.create().build(); }@Bean("dynamicDB") public DataSourceRouter dynamicDB(@Qualifier("master") DataSource master, @Qualifier("slave") DataSource slave){ DataSourceRouter router = new DataSourceRouter(); Map map = new HashMap<>(2); map.put(SLAVE,slave); map.put(MASTER,master); router.setTargetDataSources(map); router.setDefaultTargetDataSource(slave); return router; } }

创建枚举类用作数据库路由Key

public enumClusteEnum { SLAVE, MASTER; }

重写路由数据库实现根据key 切换数据库

public class DataSourceRouter extends AbstractRoutingDataSource { @Override protected Object determineCurrentLookupKey() { return DataSourceContextHolder.get(); } }

DataSourceContextHolder 提供线程安全方式返回不同连接切换key

public class DataSourceContextHolder{private static ThreadLocal contextHolder = new ThreadLocal<>(); public static voidsetEnum(ClusteEnum clusteEnum){ contextHolder.set(clusteEnum); }public staticvoidremove(){ contextHolder.remove(); }public static ClusteEnum get(){ return contextHolder.get(); } }

设置了多数据源，需要手上生成SqlSessionFactory,SqlSessionTemplate bean，让Mybatis 生效。

@Configuration public class MybatisConfig {@Resource(name = "dynamicDB") private DataSource dataSource; @Bean("sqlSessionFactory") public SqlSessionFactory sessionFactory() throws Exception { SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean(); factoryBean.setDataSource(dataSource); factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/*Mapper.xml")); return factoryBean.getObject(); }@Bean public PlatformTransactionManager transactionManager(){ return new DataSourceTransactionManager(dataSource); }@Bean("sqlSessionTemplate") public SqlSessionTemplate sqlSessionTemplate( @Qualifier("sqlSessionFactory") SqlSessionFactory sqlSessionFactory){ return new SqlSessionTemplate(sqlSessionFactory); } }

自定义注解声明需要切换数据源

@Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface DatabaseSelector {ClusteEnum value() default SLAVE; boolean clear() default true; }

最后一步，设置AOP 环绕通知，动态修改数据库路由Key

@Slf4j @Aspect @Component @Order(1)//这个注解很关键，如果没有不能成功切换数据源 public class DatabaseAopPointCut { @Around("@annotation(tk.shenyifeng.study.bean.DatabaseSelector)") public Object setDynamicDataSource(ProceedingJoinPoint pjp) throws Throwable { boolean clear = true; try { MethodSignature signature = (MethodSignature) pjp.getSignature(); Method method = signature.getMethod(); DatabaseSelector databaseSelector = method.getAnnotation(DatabaseSelector.class); clear = databaseSelector.clear(); log.info("set cluster db => {}",databaseSelector.value().name()); DataSourceContextHolder.setEnum(databaseSelector.value()); return pjp.proceed(); }finally { if (clear) DataSourceContextHolder.remove(); } } }

b编写一个简单service 验证成果

@Component public class UserService {@Autowired private UserMaper userMaper; @Transactional(rollbackFor = Exception.class) @DatabaseSelector(MASTER) public void insert(UserModel userModel){ userMaper.insert(userModel); }public UserModel findOne(int id){ return userMaper.findOne(id); }@DatabaseSelector(MASTER) public void updateOne(UserModel userModel){ userMaper.updateOne(userModel); } }

编写测试类

@ExtendWith(SpringExtension.class) @SpringBootTest(classes = RunApp.class) @Slf4j public class ClusterServiceTest {@Autowired private UserService userService; @Test public void insertTest(){ UserModel userModel = new UserModel(); userModel.setName("神易风"); userModel.setAge(8848); userService.insert(userModel); }@Test public void findOne(){ UserModel one = userService.findOne(1); log.info("user data {}",one); }@Test public void integrationTest(){ UserModel userModel = userService.findOne(1); userModel.setName("神易风02"); userModel.setAge(18); userService.updateOne(userModel); } }

【MySQL主从复制】运行insert 插入结果如下