mysql一主多从 k8s部署实际案例
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: 1selector:matchLabels:app: mysql-mastertemplate:metadata:labels:app: mysql-masterspec:containers:- name: mysqlimage: mysql:8.0env:- name: MYSQL_ROOT_PASSWORDvalue: "root123"- name: MYSQL_DATABASEvalue: "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: 3306volumeMounts:- name: mysql-datamountPath: /var/lib/mysqlvolumeClaimTemplates:- metadata:name: mysql-dataspec: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-slavetemplate:metadata:labels:app: mysql-slavespec:containers:- name: mysqlimage: mysql:8.0env:- name: MYSQL_ROOT_PASSWORDvalue: "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: 3306volumeMounts:- name: mysql-datamountPath: /var/lib/mysqlvolumeClaimTemplates:- metadata:name: mysql-dataspec: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_dbusername: rootpassword: root123driver-class-name: com.mysql.cj.jdbc.Driverslaves:- jdbc-url: jdbc:mysql://mysql-slave-0:3306/app_dbusername: rootpassword: root123- jdbc-url: jdbc:mysql://mysql-slave-1:3306/app_dbusername: rootpassword: 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();}@Beanpublic 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);}@Beanpublic 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<>();@Overrideprotected 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;
四、架构特点说明
- 数据一致性保障:
- 使用GTID实现事务一致性
- 半同步复制配置(需在MySQL配置中额外添加)
- 自动故障转移机制(建议配合k8s探针使用)
- 读写分离策略:
- 写操作强制路由主库
- 读操作自动负载均衡
- 事务中强制使用主库
- 扩展性设计:
- 从库数量可动态调整(修改StatefulSet replicas)
- 自动水平扩展从库集群
- 支持多可用区部署(需配置亲和性策略)
注意事项:
- 生产环境需配置Secret管理数据库密码
- 建议添加MySQL连接池配置(如HikariCP)
- 需要配置合适的持久化存储方案
- 建议添加监控和报警机制(Prometheus+Granafa)