Distributed locking for shared, limited resources is a perennial problem. Common approaches such as a database, cache-layer, or a central rate-limiter services introduce extra infrastructure and new failure modes. Holders of locks die without releasing leak orphan locks. Lock state drifts out of sync with the Workflows that hold them. Capacity changes require restarting limiter services.
The Temporal Validated Pattern “Coordinate access to shared resources with a distributed lock” details a reusable, durable distributed lock for Temporal Workflows. The design doesn't rely on an external database, a central limiter, or any shared state outside Temporal itself.
This pattern represents each held permit or lock as its own short-lived child Workflow. The child Workflow's ID includes the resource and slot. Temporal does not allow two running Workflows with the same ID, so acquiring a permit is an atomic operation using Temporal's own state. The Workflow releases on a Signal pinned to the run. If no release Signal is received, the permit Workflow's lease timeout handles orphan recovery.