Design a system for managing a content delivery network (CDN).

Question

Anonymous · Accepted Answer

Functional Requirements

1. Upload content (images, videos, static files) → get a globally served URL

2. Serve from nearest edge server, not origin

3. Cache miss → pull from origin, cache locally, serve

4. Purge/invalidate cached content on demand

5. Analytics -- hit/miss ratios, bandwidth, latency per region

6. Custom domains with TLS

Non-Functional Requirements

- Sub-50ms on cache hits -- that's the whole point of a CDN

- 99.99% uptime, edge goes down → DNS reroutes automatically

- Millions of req/sec, petabyte-scale storage, heavily read-biased

- Eventual consistency on cache propagation (5-10s purge delay is fine)

- DDoS protection at edge, TLS everywhere, signed URLs for private content

Core Entities

- Asset : file being served (ID, origin URL, content type, size, hash, TTL,
owner)

- EdgeNode : server at a geographic location (region, IP, health, load,
capacity)

- CacheEntry : asset to edge mapping (cached when, expires when, hit count,
evicted via LRU)

- Distribution : customer's CDN config (custom domain, origin server, TLS cert,
caching rules)

- PurgeRequest :invalidation job (URL pattern, status, edge confirmations)

Anonymous · Answer

on the front you will have something like api gateway. Which will route to local
CDN service which will be geologically close server that has cached data of the
contents that you are looking for, then this cdn server will first check local
cache to find the contents if there is, return the contents, if not, call
original db, return it, and put it in cache with some timeout value.

Design a system for managing a content delivery network (CDN).

Practice this question with AI

Go Premium

Community Answers

Unlock Full Access

Unlock Full Access

Practice More Questions