Exercise the parallel-check coordinator under reordered failures
Happy-path tests always complete checks in the same order and miss a race between deadline finalization and the last callback.
- Focused work estimate
- 4h + prerequisites
- Priority in the scenario
- Medium
- Engineering practice
- Concurrency testing · Fault injection
Estimated field mix
- Quality engineering50%
- Distributed systems50%
Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence.
Review it, then add it to your workspace.
The board opens an editable draft; nothing is saved until you confirm it. Sign-in and workspace permissions apply, and Demo boards remain ephemeral.
Project context
A fictional vendor portal runs format, policy and duplicate checks in parallel. A slow checker blocks completion, while duplicate callbacks can produce contradictory final summaries.
Setup prerequisites
- Create synthetic document identities and three fake check providers.
- No real risk scoring, hiring decisions or candidate execution is included.
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
- ABATCH-101 · Freeze the required check set when a document review run starts
- ABATCH-102 · Define pass, fail, unavailable and not-applicable check outcomes
- ABATCH-103 · Bound parallel check fan-out per organization and run
- ABATCH-104 · Dispatch each check through a durable deterministic attempt identity
- ABATCH-105 · Deduplicate callbacks without accepting contradictory check results
- ABATCH-106 · Finalize aggregates only from the frozen required check set
- ABATCH-107 · Apply a run deadline without rewriting late check facts
- ABATCH-108 · Recover outstanding checks by querying provider attempt identity
- ABATCH-109 · Produce a result provenance view that names missing and conflicting checks
Acceptance criteria
- Run permutations of declared completion, timeout and conflict events.
- Assert one immutable summary and complete retained check history.
- Record any unsupported adapter guarantee as a failing readiness condition.
Implementation constraints
- Use a deterministic event scheduler; no arbitrary sleeps.
Verification to include
- Run all required checks in several completion orders with equal final semantics.
- Race final callback with deadline and verify the declared single outcome.
Deliverables
- Deterministic coordinator fault harness
Rollout and recovery
Require the harness before adapter changes; retain the prior coordinator version if invariants fail.
Value of the work
For the engineer: Practice fan-out/fan-in, deadline policies and immutable aggregation.
For the team: Review trustworthy partial-result handling and controllable parallel work.
Evidence boundaries
Outcome Evidence: Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.
Ownership Evidence: Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence.