mysql一主多从 k8s部署实际案例

news2025/6/2 4:00:18

一、Kubernetes配置（MySQL主从集群）

主库StatefulSet配置（master-mysql.yaml）：

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql-master
spec:
  serviceName: "mysql-master"
  replicas: 1
  selector:
    matchLabels:
      app: mysql-master
  template:
    metadata:
      labels:
        app: mysql-master
    spec:
      containers:
      - name: mysql
        image: mysql:8.0
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: "root123"
        - name: MYSQL_DATABASE
          value: "app_db"
        # 主库配置参数
        args:
        - "--server-id=1"
        - "--log-bin=mysql-bin"
        - "--binlog_do_db=app_db"
        - "--gtid-mode=ON"
        - "--enforce-gtid-consistency=ON"
        ports:
        - containerPort: 3306
        volumeMounts:
        - name: mysql-data
          mountPath: /var/lib/mysql
  volumeClaimTemplates:
  - metadata:
      name: mysql-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "standard"
      resources:
        requests:
          storage: 20Gi

从库StatefulSet配置（slave-mysql.yaml）：

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mysql-slave
spec:
  serviceName: "mysql-slave"
  replicas: 2  # 两个从库实例
  selector:
    matchLabels:
      app: mysql-slave
  template:
    metadata:
      labels:
        app: mysql-slave
    spec:
      containers:
      - name: mysql
        image: mysql:8.0
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: "root123"
        # 从库配置参数
        args:
        - "--server-id=$HOSTNAME_SLICE"  # 动态生成唯一server-id
        - "--relay-log=mysql-relay"
        - "--read-only=ON"
        - "--gtid-mode=ON"
        - "--enforce-gtid-consistency=ON"
        - "--skip-slave-start"  # 等待手动配置主从复制
        ports:
        - containerPort: 3306
        volumeMounts:
        - name: mysql-data
          mountPath: /var/lib/mysql
  volumeClaimTemplates:
  - metadata:
      name: mysql-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "standard"
      resources:
        requests:
          storage: 20Gi

二、Java读写分离实现（Spring Boot示例）

数据源配置（application.yml）：

spring:
  datasource:
    master:
      jdbc-url: jdbc:mysql://mysql-master:3306/app_db
      username: root
      password: root123
      driver-class-name: com.mysql.cj.jdbc.Driver
    slaves:
      - jdbc-url: jdbc:mysql://mysql-slave-0:3306/app_db
        username: root
        password: root123
      - jdbc-url: jdbc:mysql://mysql-slave-1:3306/app_db
        username: root
        password: root123

动态数据源配置类：

/**
 * 动态数据源配置
 */
@Configuration
@EnableTransactionManagement
@MapperScan("com.example.mapper")
public class DynamicDataSourceConfig {

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public DataSource slaveDataSource() {
        // 创建从库数据源列表
        List<DataSource> slaves = new ArrayList<>();
        // 这里需要根据实际配置动态加载从库数据源
        // ...（具体实现根据配置加载多个从库）

        // 负载均衡策略（轮询）
        return new LoadBalancedDataSource(slaves);
    }

    @Bean
    public DataSource dynamicDataSource(
            @Qualifier("masterDataSource") DataSource master,
            @Qualifier("slaveDataSource") DataSource slave) {
        
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put("master", master);
        targetDataSources.put("slave", slave);
        
        dynamicDataSource.setTargetDataSources(targetDataSources);
        dynamicDataSource.setDefaultTargetDataSource(master);
        
        return dynamicDataSource;
    }
}

数据源路由实现：

/**
 * 动态数据源路由器
 */
public class DynamicDataSource extends AbstractRoutingDataSource {

    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();

    @Override
    protected Object determineCurrentLookupKey() {
        return CONTEXT_HOLDER.get();
    }

    public static void setDataSource(String dataSource) {
        CONTEXT_HOLDER.set(dataSource);
    }

    public static void clearDataSource() {
        CONTEXT_HOLDER.remove();
    }
}

自定义注解实现读写分离：

/**
 * 数据源选择注解
 */
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
    DataSourceType value() default DataSourceType.MASTER;
}

public enum DataSourceType {
    MASTER, SLAVE
}

AOP切面实现：

@Aspect
@Component
public class DataSourceAspect {

    @Before("@annotation(dataSource)")
    public void beforeSwitchDS(JoinPoint point, DataSource dataSource) {
        DataSourceType value = dataSource.value();
        if (value == DataSourceType.MASTER) {
            DynamicDataSource.setDataSource("master");
        } else {
            DynamicDataSource.setDataSource("slave");
        }
    }

    @Before("execution(* com.example.service..*.save*(..)) || " +
            "execution(* com.example.service..*.update*(..)) || " +
            "execution(* com.example.service..*.delete*(..))")
    public void writeOperations() {
        DynamicDataSource.setDataSource("master");
    }

    @AfterReturning("execution(* com.example.service..*.*(..))")
    public void afterReturning() {
        DynamicDataSource.clearDataSource();
    }
}

三、部署说明

集群初始化步骤：

# 部署主库
kubectl apply -f kubernetes/mysql/master-mysql.yaml

# 等待主库启动完成后部署从库
kubectl apply -f kubernetes/mysql/slave-mysql.yaml

# 验证Pod状态
kubectl get pods -l app=mysql-master
kubectl get pods -l app=mysql-slave

主从复制配置（在从库Pod中执行）：

# 进入从库容器
kubectl exec -it mysql-slave-0 -- bash

# 在MySQL中执行
CHANGE MASTER TO
MASTER_HOST='mysql-master',
MASTER_USER='root',
MASTER_PASSWORD='root123',
MASTER_AUTO_POSITION=1;

START SLAVE;