A CDN (Content Delivery Network) is a set of edge nodes worldwide that cache your site's static assets close to users. Visitors fetch data from a nearby server, so it loads faster and your origin handles less load.
1. What a CDN solves
- Global speed: overseas users don't hit your origin every time.
- Resilience: traffic spikes are absorbed at the edge, sparing the origin.
- Bandwidth savings: most requests hit cache, cutting origin egress sharply.
- Security: hides your origin IP and adds DDoS/WAF protection.
2. When you need one
If any apply, it's worth it: global or multi-region users; lots of static assets (images, video, JS, CSS); spikes from launches or sales; or a need to hide the origin and add protection. For a small single-city site, the gains are limited.
3. Free vs paid
Cloudflare's free tier covers most personal and small sites; commercial sites with strict origin-pull, hit-rate or China-route needs may want a paid CDN.
4. How to set it up
- Move your DNS to the CDN and enable proxying.
- Set cache rules: long cache for static assets, short/no cache for HTML and APIs.
- Enable HTTPS, HTTP/3 and Brotli compression.
- Restrict the origin to CDN pull IPs to further hide it.
5. Watch out for
Caching dynamic content causes bugs — separate static from dynamic carefully. For mainland-China audiences, ordinary overseas CDNs have mediocre return quality; evaluate premium routes or a China CDN. To plan a CDN around your VPS, contact sales @aliyun370.