fix(table): reclaim a cascade lock a timed-out acquire may have taken

[waleedlatif1]

Summary

• A client-side timeout does not mean Redis declined the SET. The command can still be parked in the offline queue and take the lock once the connection completes, leaving the row's cascade held for the full 30s TTL by an owner that already threw — no heartbeat, no release
• Every other cell task for that row then reads contended and bails on the silent path, so one stalled connection quietly drops later cells rather than just failing the one run
• Releasing after a failed acquire is what Redlock prescribes: a client that fails to acquire "will try to unlock all the instances (even the instances it believed it was not able to lock)", and the docs stress releasing ASAP so nobody waits out the TTL
• Both preconditions the option documents hold here — ownerId is the cell task's unique executionId, and a throw means fn never runs, so the reclaim cannot cut under a caller still doing work

Verified against a local ioredis harness: at the moment the caller sees the timeout the server has only seen the handshake, and the SET arrives afterwards — so the lock really is taken by a caller that gave up. With the reclaim, the compare-and-delete lands behind it and frees the key.

The option stays opt-in rather than becoming the default: withLeaderLock and the MCP OAuth refresh mutex both return fn() when acquisition throws, so freeing a lock under them would admit a second concurrent runner.

Type of Change

• Bug fix

Testing

Adds the cascade lock's first tests — acquire, contention, reclaim, release on throw, and heartbeat teardown. The reclaim test was verified to fail when the option is flipped off.

bun run type-check clean. 1,775 tests pass across lib/table and background. bun run lint, docs-manifest:check, and all 46 audits in check:audits pass.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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1 Skipped Deployment

Project	Deployment	Actions	Updated
docs	Skipped		Sep 9, 2026 8:39pm UTC

[greptile-apps]

Greptile Summary

This PR enables failed-acquisition reclamation for row cascade locks, preventing a Redis command that completes after a client-side timeout from silently holding the row lock until its TTL expires.

• Opts only the cascade-lock acquisition path into reclaimOnFailure.
• Documents why the cascade owner ID and execution flow make reclamation safe.
• Adds coverage for acquisition, contention, failed-acquisition configuration, work failure, release, and heartbeat teardown.

Confidence Score: 5/5

The PR appears safe to merge; the reclamation path is owner-checked, limited to callers with unique execution IDs, and does not run concurrently with abandoned work.

No actionable failures remain: cleanup can only delete a lock carrying the failed caller’s unique owner ID, cleanup errors cannot replace the original acquisition error, and the relevant integration and lock-helper behavior are covered by tests.

Important Files Changed

Filename	Overview
apps/sim/lib/table/cascade-lock.ts	Safely opts cascade acquisition into owner-checked reclamation when Redis acquisition throws.
apps/sim/lib/table/cascade-lock.test.ts	Adds focused tests for cascade-lock lifecycle behavior and verifies failed acquisitions request reclamation.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[Cell task requests cascade lock] --> B{Redis SET result}
    B -->|Acquired| C[Run cascade work]
    C --> D[Stop heartbeat and release owned lock]
    B -->|Contended| E[Return contended]
    B -->|Client-side error| F[Compare lock owner with execution ID]
    F -->|Matches| G[Delete potentially late-acquired lock]
    F -->|Does not match| H[Leave current holder untouched]
    G --> I[Rethrow original acquisition error]
    H --> I

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