Step 1 of 13 · Intro

Design a distributed lock and leader election

Mutual exclusion that survives crashes, pauses and failovers.

How it works

• ›Acquire: a client gets a lease and a fencing token if the lock is free.
• ›Renew: the holder heartbeats before the lease expires.
• ›Elect: a leader is just the holder of a well-known lock, with a term that increases.

What you'll build

1. The API (acquire, renew, release) and the lock schema
2. A replicated, consensus-style store that survives losing the leader
3. A sharded namespace for 30,000 requests a second
4. A limiter and a breaker against herds and cold caches
5. Reasoning about leases, fencing tokens and durability