Cache, security, WAF, and purge

Cache, security, WAF, and purge

This section covers how the CDN stores, protects and refreshes your content — the three things that decide whether visitors get a fast, safe and up-to-date site. Cache rules control what is cached and for how long, security controls and the WAF filter out malicious traffic, and purge clears cached content the moment you publish a change.

Caching is what makes a CDN fast: a cached response is served from the edge, close to the visitor, without touching your origin server. You shape it with cache rules — the cache key, TTL, which HTTP methods and status codes to cache, and header/cookie handling — and you confirm it is working by reading the X-Proxy-Cache-MT response header, which shows HIT, MISS, BYPASS or EXPIRED for every request.

Security runs at the same edge. The WAF (Web Application Firewall) blocks common attacks such as SQL injection and cross-site scripting before they ever reach your server, and the WAF logs let you see exactly what was blocked or challenged and why. When content looks stale after an update, a purge removes the old copy from the edge cache so the next visitor gets the new version immediately.