Cianplan

Level 6: Applied: cases, FDE scenarios, mocks · L6.1 Classic cases I

Rate limiter (walkthrough)

Design a distributed rate limiter with Redis.

15 min · Pro

What you take away

  • Purely local counters across a fleet of 500 servers allow 500× the intended limit, which is why the counter has to be shared or reconciled.

And 3 more inside the class, in Pro.

How the class is laid out

  1. The prompt
  2. Requirements and numbers
  3. Pick the algorithm, which is really a burst policy
  4. Where the counter lives
  5. The twist
  6. Check your understanding