Design: build a shortener that handles 38,600 req/s Intermediate
Estimated reading time: 1 min read
You have a list of components and a budget. Drag each component into the right tier. Every time you add or remove one, p99, error rate, database load and cost are recalculated instantly.
- Goal: meet every requirement at the lowest possible cost.
- Try also: find a design that meets the requirements without a CDN, and one without Redis. Which costs more, and why?
Build a URL shortener that handles 38,600 req/s
Your shortener is about to run a big campaign. Per the case study estimate, peak reads are ~38,600 req/s, while writes are only ~39 req/s.
Simplified assumptions for the game: 1 app instance handles ~8,000 req/s, 1 PostgreSQL node handles ~10,000 primary-key lookups/s, the CDN absorbs ~50% of redirects, and Redis hits ~95%. Illustrative numbers, not benchmarks.
Requirements
- No errors at peak load, p99 ≤ 50 ms
- Block bots spamming the link-creation API
- Cost ≤ 20 units/month
Press ＋ Add on each layer to choose a component. On a computer you can drag a component onto a layer. Metrics update right away.
Tap a component to see what it does.
- No PostgreSQL yet: newly created links have nowhere to be stored.
- No App service yet to handle redirects.
- No rate limiter yet: a bot can spam the link-creation API and fill up the database.
The numbers in the game are round assumptions for easy math, not benchmarks. How to estimate peak load is covered in the URL shortener case study.