springboot多数据源配合docker部署mysql主从实现读写分离效果

docker pull mysql:5.7.23 #拉取镜像文件

docker images #查看镜像文件

docker run --name mysql-master --privileged=true -v F:\dockerV\mysql:/var/lib/mysql -p 3307:3306 -e MYSQL_ROOT_PASSWord=654321 -d mysql:5.7.23

docker exec -it mysql-master bash #进入容器内部

apt-get install vim

apt-get update

apt-get install vim

vim mysqld.cnf #修改cnf文件，添加 server-id 表示master服务标识,同一局域网内注意要唯一 和 log-bin=mysql-bin 开启二进制日志功能，可以随便取，用来完成主从复制

service MySQL restart # 重启mysql服务时会使得docker容器停止，我们还需要docker start mysql-master启动容器

docker start mysql-master #启动容器

mysql -uroot -p654321 #连接mysql

grant replication slave on *.* to 'slaveaccount'@'%' identified by '654321'; #账号slaveaccount 密码654321

flush privileges; #刷新用户权限表

show master status #查看mysql master的状态

docker run --name mysql-slave --privileged=true -v F:\dockerV\mysql-slave:/var/lib/mysql -p 3308:3306 --link mysql-master:master -e MYSQL_ROOT_PASSWORD=654321 -d mysql:5.7.23

docker exec -it mysql-slave /bin/bash #进入mysql salve容器

vim mysqld.cnf #修改cnf文件，添加 server-id 表示slave服务标识，如果此salve需要作为其他mysql的主，那么就需要配置log-bin=mysql-bin

service MySQL restart # 重启mysql服务时会使得docker容器停止，我们还需要docker start mysql-slave启动容器

docker start mysql-master #启动容器

mysql -uroot -proot #连接mysql服务

change master to master_host='172.17.0.2', master_user='slaveaccount', master_password='654321', master_port=3306, master_log_file='mysql-bin.000001', master_log_pos=2272, master_connect_retry=30;

start slave; #以slave模式运行

show salve status \G; #查看slave的状态

mysql> create database test;
Query OK, 1 row affected (0.01 sec)

mysql> use test;
Database changed

mysql> create table t_user(id bigint, name varchar(255));
Query OK, 0 rows affected (0.02 sec)

mysql> insert into t_user(id, name) value (1, 'cgg');
Query OK, 1 row affected (0.01 sec)
mysql> select * from test.t_user;
+------+------+
| id   | name |
+------+------+
|    1 | cgg |
+------+------+
1 row in set (0.00 sec)

server:
  port: 8888
  servlet:
    encoding:
      charset: UTF-8
      force: true
      enabled: true
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://127.0.0.1:3307/test?serverTimezone=GMT%2B8&characterEncoding=utf-8&autoReconnect=true&failOverReadOnly=false&useSSL=false
    username: root
    password: 654321
slave:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://127.0.0.1:3308/test?serverTimezone=GMT%2B8&characterEncoding=utf-8&autoReconnect=true&failOverReadOnly=false&useSSL=false
    username: root
    password: 654321

@Configuration
@EnableTransactionManagement
public class DynamicDataSourceConfig {


    @Bean(name = "slaveDatasource")
    @ConfigurationProperties(prefix = "slave.datasource")
    public DataSource dbSlave() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean(name = "dataSource")
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource dbMaster() {
        return DruidDataSourceBuilder.create().build();
    }


    @Bean
    @Primary
    public DataSource multipleDataSource(@Qualifier("dataSource") DataSource db,
                                         @Qualifier("slaveDatasource") DataSource slaveDatasource) {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        Map<Object, Object> targetDataSources = new HashMap<>(16);
        targetDataSources.put("dataSource", db);
        targetDataSources.put("slaveDatasource", slaveDatasource);
        dynamicDataSource.setTargetDataSources(targetDataSources);
        //设置默认数据源为从库，如果写操作业务多，可以默认设置为主库
        dynamicDataSource.setDefaultTargetDataSource(slaveDatasource);
        return dynamicDataSource;
    }

    @Bean("sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        mybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(multipleDataSource(dbSlave(), dbMaster()));
        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setCacheEnabled(false);
        sqlSessionFactory.setConfiguration(configuration);
        sqlSessionFactory.setMapperLocations((new PathMatchingResourcePatternResolver()).getResources(DEFAULT_MAPPER_LOCATION));
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        paginationInterceptor.setOverflow(false);
        paginationInterceptor.setLimit(-1);
        paginationInterceptor.setCountSqlParser(tenantSqlParserCountOptimize());
        Interceptor[] plugins = new Interceptor[]{new ShardTableInterceptor(), paginationInterceptor};
        sqlSessionFactory.setPlugins(plugins);
        return sqlSessionFactory.getObject();
    }

}


@Slf4j
public class DynamicDataSource  extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        return DbContextHolder.getDbType();
    }
}

@Component
@Order(value = -100)
@Slf4j
@Aspect
public class DataSourceSwitchAspect {

    //master 包下的操作都是操作主库业务
    @Pointcut("execution(* com.master..*.*(..))")
    private void db1Aspect() {
    }

    //slave 包下的操作都是操作从库业务
    @Pointcut("execution(* com.slave.*.*(..))")
    private void db2Aspect() {
    }


    @Before("db1Aspect()")
    public void dbMaster() {
        log.debug("切换到Master 数据源...");
        DbContextHolder.setDbType("dataSource");
    }

    @Before("db2Aspect()")
    public void dbSlave() {
        log.debug("切换到Slave 数据源...");
        DbContextHolder.setDbType("slaveDatasource");
    }
}



public class DbContextHolder {
    private static final ThreadLocal contextHolder = new ThreadLocal<>();
    
    public static void setDbType(String dbType) {
        contextHolder.set(dbType);
    }

    
    public static String getDbType() {
        return (String) contextHolder.get();
    }

    
    public static void clearDbType() {
        contextHolder.remove();
    }
}