Long max-age biggest win and biggest footgun; no-cache vs no-store; ETag costs RTT; CDN uses s-maxage separately.
Разбор
- Long max-age pure upside on content-hashed URLs; footgun on stable URL — can't invalidate million browsers.
no-cache vs no-store. no-cache stores, fast 304s; no-store re-downloads every time — secrets only.- ETag costs RTT. 304 cheap bytes but full network trip;
immutable skips trip for never-changing assets.
- CDNs cache with
s-maxage/public separately. private blocking CDN kills edge hit rate quietly.
Итог
Match directive to URL mutability; no-store sparingly; align browser and CDN cache policy.
HTTP / REST · senior · сложность 7