Advanced
The celebrity problem
A social network stores profiles in a key-value database that scales almost without limit. Then a celebrity joins: a quarter of all reads now hit one single key, and requests start failing.
Each partition of the store serves at most 3,000 reads per second. A single key always lives on one partition.
What your design must achieve
- Availability ≥ 99.9 %
- Latency p99 < 100 ms
- Infrastructure cost per month < 8,000 $ bonus