Safety Invariants in Distributed Rate Limiters
This day launches phase-4 by establishing the core safety properties (consistency, availability under partition, monotonicity) that any distributed safety mechanism must preserve. It directly informs later days on failure modes and mitigation patterns the learner will implement.
Resources
- 25 min
- 20 min
Deliverable
Journal entry listing three safety invariants for the rate-limiter with one concrete violation scenario
Quiz · 3 questions
1. Which property is violated when two replicas of a rate-limiter allow the same token to be consumed twice under partition?
2. Name one safety invariant that a distributed rate-limiter must maintain even when the network is partitioned.
3. Describe how the tail-latency behavior described in 'The Tail at Scale' could cause a safety violation in a token-bucket limiter.