【Java高阶面经：微服务篇】9.微服务高可用全攻略：从架构设计到自动容灾

一、架构层：构建抗故障的分布式基石

1.1 多维度冗余设计

1.1.1 跨可用区部署策略

# Kubernetes跨可用区反亲和性配置
apiVersion: apps/v1
kind: Deployment
metadata:
  name: product-service
spec:
  replicas: 3
  template:
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
          - labelSelector:
              matchExpressions:
              - key: app
                operator: In
                values: [product-service]
            topologyKey: topology.kubernetes.io/zone  # 按可用区隔离
      containers:
      - name: product
        image: product-service:v1

1.1.2 无状态服务设计模式

• 会话管理：
  用户会话存储于Redis集群，避免实例绑定

  // Spring Session Redis配置
  @Bean
  public RedisHttpSessionConfiguration sessionConfiguration() {
       
      RedisHttpSessionConfiguration config = new RedisHttpSessionConfiguration();
      config.setEnableTransactionSupport(true);
      return config;
  }
  

1.2 流量调度与容灾架构

1.2.1 多活数据中心设计

1.2.2 智能DNS解析策略

# 基于延迟的DNS动态解析（Go语言示例）
package main

import (
    "net"
    "sort"
)

func selectHealthyServer(servers []string) string {
   
    var healthy []string
    for _, s := range servers {
   
        if isHealthy(s) {
   
            healthy = append(healthy, s)
        }
    }
    sort.Slice(healthy, func(i, j int) bool {
   
        return getLatency(healthy[i]) < getLatency(healthy[j])
    })
    return healthy[0]
}

二、服务治理层：弹性防御体系构建

2.1 注册中心混合架构

2.1.1 CP与AP模式协同

// Spring Cloud混合注册配置
@Configuration
public class RegistryConfig {
   
    @Bean
    @ConditionalOnProperty(name="service.type", havingValue="core"