Keep edge-job priority from starving lower-priority maintenance
Frequent urgent cache checks prevent cleanup from ever running. Add bounded fairness to the ready queue.
- Focused work estimate
- 3h + prerequisites
- Priority in the scenario
- Medium
- Engineering practice
- Scheduling · Fairness
Estimated field mix
- Embedded and edge60%
- Performance engineering40%
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
Fictional kiosk software schedules cache refresh and display housekeeping. Build a software clock and job adapter; do not control real machinery or purchase hardware.
Setup prerequisites
- Implement injected wall and monotonic clocks.
- Create synthetic jobs with controllable completion and failure.
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
- CTIMER-101 · Use monotonic time for edge-job timeout deadlines
- CTIMER-102 · Validate emulated edge-job intervals before scheduling
- CTIMER-103 · Specify fixed-delay behavior for periodic kiosk maintenance
- CTIMER-104 · Cancel emulated edge jobs without accepting late callbacks
- CTIMER-105 · Prevent overlapping edge jobs that share one local resource
- CTIMER-106 · Bound emulated edge-job execution attempts after failure
- CTIMER-107 · Recover due edge jobs after restart without a catch-up storm
Acceptance criteria
- High priority gets documented preference
- Low priority eventually runs under bounded arrivals
- Queue size remains capped
Implementation constraints
- State workload assumptions used for fairness checks.
Verification to include
- Run mixed-priority fixture
- Continuously enqueue within supported arrival bound
Deliverables
- Fair queue and execution trace
Rollout and recovery
Use simple round-robin while priority fairness is uncertain.
Value of the work
For the engineer: Practice timer semantics, cancellation and bounded scheduling.
For the team: Inspect predictable edge resource use and honest execution status.
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.