Cloudflare年内第三次宕机：单点依赖真的是架构设计的"原罪"吗?

用户请求
    ↓
[DNS查询] → Cloudflare DNS (❌故障)
    ↓
无法获取IP地址
    ↓
[CDN节点] → 找不到源站位置 (❌失效)
    ↓
[Workers边缘计算] → 依赖DNS的业务逻辑 (❌瘫痪)
    ↓
整个服务链路崩溃

[用户] 
  → 腾讯云DNS (￥50/月)
  → 阿里云CDN (按流量￥0.24/GB)
  → AWS Shield (DDoS防护,￥3000/月起)
  → 自建边缘计算服务器 (运维成本...)

[用户]
  → Cloudflare一站式服务
  → 月费: $0 (免费版) / $20 (Pro版)

// DNS健康检查 + 自动切换
const dnsProviders = [
  { name: 'Cloudflare', server: '1.1.1.1', priority: 1 },
  { name: 'Route53', server: '8.8.8.8', priority: 2 },
  { name: 'DNSPod', server: '119.29.29.29', priority: 3 }
];

asyncfunction resolveWithFallback(domain) {
for (const provider of dnsProviders) {
    try {
      const result = await dns.resolve(domain, provider.server);
      if (result) return result;
    } catch (error) {
      console.warn(`${provider.name} DNS failed, trying next...`);
      continue;
    }
  }
thrownewError('All DNS providers failed');
}

// Service Worker实现CDN降级
self.addEventListener('fetch', event => {
  const cdnUrl = event.request.url.replace('origin.com', 'cdn.cloudflare.com');
  
  event.respondWith(
    fetch(cdnUrl, { timeout: 3000 }) // 3秒超时
      .catch(() => {
        console.warn('CDN timeout, fallback to origin');
        return fetch(event.request.url); // 直接访问源站
      })
  );
});

// ❌ 危险:业务逻辑完全依赖Workers
export default {
  async fetch(request) {
    // 鉴权、路由、业务逻辑全在这
    const user = await authenticate(request);
    return handleRequest(user);
  }
}

// ✅ 安全:源站保留完整能力
exportdefault {
async fetch(request) {
    try {
      // Workers只做加速和缓存
      const cached = await CACHE.get(request.url);
      if (cached) returnnew Response(cached);
      
      // 源站保留完整业务逻辑
      return fetch('https://origin-server.com' + request.url);
    } catch {
      // Workers挂了?直接透传到源站
      return fetch(request);
    }
  }
}

传统方式(危险):
[用户] → [Workers独立处理业务] → (Workers挂了=服务挂了)

推荐方式(安全):
[用户] → [Workers加速层] → [源站完整服务]
          ↓ (故障时)
       [直接访问源站]

import requests
import time

# 多地域探测节点
PROBE_LOCATIONS = [
'us-east', 'eu-west', 'asia-southeast', 'china-beijing'
]

def check_availability(url, timeout=5):
    results = {}
    for location in PROBE_LOCATIONS:
        try:
            start = time.time()
            resp = requests.get(url, timeout=timeout, 
                              headers={'X-Probe-Location': location})
            latency = (time.time() - start) * 1000
            results[location] = {
                'status': resp.status_code,
                'latency': f'{latency:.2f}ms'
            }
        except Exception as e:
            results[location] = {'status': 'FAILED', 'error': str(e)}
    
    return results

# 实时监控
whileTrue:
    status = check_availability('https://your-site.com')
    if any(r['status'] != 200for r in status.values()):
        send_alert('WARNING: Service degradation detected')
    time.sleep(60)  # 每分钟检查一次

成本:$20/月 (Pro版)
风险:一年宕机3次,每次影响时长1-4小时
损失:假设每小时业务损失$1000,年损失≈$6000+

Cloudflare Pro: $20/月
腾讯云CDN (备份): 100GB流量 ≈ ￥24/月 ($3.5)
DNSPod (备份DNS): ￥50/月 ($7)
------
总成本: $30.5/月 (增加50%)
------
收益:
- 国内访问速度提升60%
- 故障自动切换,损失降低90%
- 年节省损失: $5400+

额外投入: $30.5 - $20 = $10.5/月 = $126/年
故障损失减少: $6000 × 90% = $5400/年
------
净收益: $5274/年

2010年代早期: Docker一家独大
      ↓
2015年: Kubernetes出现,定义了容器编排标准
      ↓
现在: Docker、containerd、CRI-O 可互换