Advanced
A replica set that survives a zone
Orders live in a three-member document database. At 09:00 the primary will crash, and at 13:00 zone A will go dark for an hour. Keep taking orders and never lose an acknowledged one.
A replica set needs a majority of members to elect a primary and accept writes. Every minute is simulated.
What your design must achieve
- Availability ≥ 99.9 %
- Lost writes = 0
- Latency p99 < 120 ms