docs(10_Wiki): Topic_Business/General/Graphic/Programming을 Topics/ 하위로 이동

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+---
+id: wiki-2026-0508-case-study-skybound-asset-cache-
+title: "Case Study: Skybound Asset Cache Busting"
+category: 10_Wiki/Topics
+status: verified
+canonical_id: self
+aliases: [Cache Busting, Asset Versioning Case Study]
+duplicate_of: none
+source_trust_level: B
+confidence_score: 0.85
+verification_status: applied
+tags: [case-study, caching, deployment, web-performance]
+raw_sources: []
+last_reinforced: 2026-05-10
+github_commit: pending
+tech_stack:
+  language: TypeScript
+  framework: Vite
+---
+
+# Case Study: Skybound Asset Cache Busting
+
+## 매 한 줄
+> **"매 stale-asset bug 매 production"**. 매 Skybound (fictional internal codename) 매 CDN-cached JS bundle 매 user device 매 days-old version 의 root-cause hunt → 매 content-hash filename + immutable cache-control headers 의 conventional fix.
+
+## 매 핵심
+
+### 매 problem
+- 매 deploy → 매 some users 매 broken UI (stale `app.js` mismatched with new `api.js` schema).
+- 매 CDN-edge 매 7-day cache, browser 매 1-day cache, 매 union 매 race.
+
+### 매 root cause
+- 매 fixed filename `/static/app.js` 매 invalidation 매 manual.
+- 매 `Cache-Control: max-age=86400` 매 too aggressive for mutable name.
+
+### 매 fix layers
+1. Content-hash in filename: `app.[hash].js`.
+2. `Cache-Control: public, max-age=31536000, immutable` for hashed assets.
+3. Short TTL on `index.html` (entry point) only.
+
+## 💻 패턴
+
+### Vite hashed output (default)
+```ts
+// vite.config.ts
+export default {
+  build: {
+    rollupOptions: {
+      output: {
+        entryFileNames: 'assets/[name].[hash].js',
+        chunkFileNames: 'assets/[name].[hash].js',
+        assetFileNames: 'assets/[name].[hash][extname]',
+      },
+    },
+  },
+};
+```
+
+### CDN cache-control (Cloudflare worker)
+```js
+addEventListener('fetch', (e) => e.respondWith(handle(e.request)));
+async function handle(req) {
+  const url = new URL(req.url);
+  const res = await fetch(req);
+  const r = new Response(res.body, res);
+  if (/\.[a-f0-9]{8,}\.(js|css|png|webp)$/.test(url.pathname)) {
+    r.headers.set('Cache-Control', 'public, max-age=31536000, immutable');
+  } else if (url.pathname.endsWith('.html') || url.pathname === '/') {
+    r.headers.set('Cache-Control', 'public, max-age=60, must-revalidate');
+  }
+  return r;
+}
+```
+
+### Service worker cache cleanup
+```ts
+self.addEventListener('activate', (e) => {
+  e.waitUntil(
+    caches.keys().then(keys =>
+      Promise.all(keys.filter(k => k !== CURRENT_VERSION).map(k => caches.delete(k)))
+    )
+  );
+});
+```
+
+### Deployment 매 atomic swap (S3 + CloudFront)
+```bash
+aws s3 sync ./dist s3://bucket --cache-control 'public,max-age=31536000,immutable' \
+  --exclude 'index.html'
+aws s3 cp ./dist/index.html s3://bucket/index.html \
+  --cache-control 'public,max-age=60,must-revalidate'
+aws cloudfront create-invalidation --distribution-id $ID --paths '/index.html' '/'
+```
+
+### Verification 매 post-deploy
+```bash
+curl -I https://app.example.com/assets/app.abc123.js | grep -i cache-control
+# expect: cache-control: public, max-age=31536000, immutable
+```
+
+## 매 결정 기준
+| Asset type | Strategy |
+|---|---|
+| Hashed JS/CSS/images | `immutable, max-age=1y` |
+| HTML entry | `max-age=60, must-revalidate` |
+| API JSON | `no-store` or `stale-while-revalidate` |
+
+**기본값**: Vite/Webpack hashed output + 1y immutable for hashed, short TTL for HTML.
+
+## 🔗 Graph
+- 변형: [[ETag]]
+- Adjacent: [[Vite]]
+
+## 🤖 LLM 활용
+**언제**: deploy-time stale-asset bug, CDN config debugging.
+**언제 X**: server-rendered no-cache responses (caching irrelevant).
+
+## ❌ 안티패턴
+- **Fixed filenames + long cache**: 매 production-broken-on-deploy guarantee.
+- **Cache-busting via querystring `?v=2`**: 매 some CDNs ignore query.
+- **Forgetting HTML cache TTL**: hashed assets 매 useless if entry HTML cached.
+
+## 🧪 검증 / 중복
+- Verified (MDN Cache-Control, Vite docs, Web.dev caching guide).
+- 신뢰도 B+.
+
+## 🕓 Changelog
+| 날짜 | 변경 |
+|---|---|
+| 2026-05-08 | Phase 1 |
+| 2026-05-10 | Manual cleanup — Skybound case study FULL with Vite + CDN patterns |