Pattern 63 / COORD

Fencing Token

Use this when Preventing an old owner from writing after a newer owner appears.

Pressure
Preventing an old owner from writing after a newer owner appears
Mechanism
Attach monotonically increasing tokens to operations and reject stale tokens downstream
Toll
Every protected resource must validate tokens for the guarantee to hold
Architecture plate63
Diagram for Fencing Token
Executive brief

Fencing Token fits when Preventing an old owner from writing after a newer owner appears. Mechanism: Attach monotonically increasing tokens to operations and reject stale tokens downstream. Use it for Distributed locks, storage writers, leader failover. The toll: Every protected resource must validate tokens for the guarantee to hold.

Use when

Distributed locks, storage writers, leader failover.

Example

Use fencing token when distributed locks, storage writers, leader failover..

Review framing

Describe the pressure first, then the mechanism, then the cost. That keeps the design grounded.

Same pressure family

Coordination

60Leader Election61Distributed Lock62Lease
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