A lease expires, but the old process can resume#
A receives a lease, then pauses. The lease expires and B receives ownership. When A resumes, it may still issue a write based on stale local state. An increasing fencing token lets the protected resource reject an older owner after it has accepted a newer token.
Pause a lock owner beyond its lease
Advance the scenario to see why expiration alone cannot stop a stale process from acting.
A acquires lease
Worker A receives fencing token 41.
accepted token: 41Related practice problems
Use the manifest-backed prompts below to apply this lesson in a complete design.
- In Search of an Understandable Consensus AlgorithmUSENIX / Stanford
- Reliability design patternsMicrosoft Azure Architecture Center
Reach this point to mark the lesson as read.