Recover edge-journal page generation selection after power loss
A cut during page-header activation leaves two pages claiming to be newest. Resolve generations through a declared ordering rule.
- Focused work estimate
- 4h + prerequisites
- Priority in the scenario
- High
- Engineering practice
- Crash consistency · Sequence arithmetic
Estimated field mix
- Storage systems60%
- Embedded and edge40%
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 edge display gateway stores noncritical synthetic readings while disconnected. Implement a byte-array flash emulator with explicit erase/write behavior and injected power cuts; no physical storage device is required.
Setup prerequisites
- Specify emulator page size write rules and erase behavior.
- Generate synthetic records and deterministic power-cut schedules.
Preceding work
Complete these dependencies, or supply their agreed outputs before taking this ticket.
- CJOUR-101 · Model edge-journal flash writes with explicit emulator constraints
- CJOUR-102 · Encode edge-journal records with bounded length and checksum
- CJOUR-103 · Assign edge-journal event identities independently from delivery attempts
- CJOUR-104 · Commit edge-journal records only after their marker is durable
- CJOUR-105 · Recover edge-journal scanning after a torn final record
- CJOUR-106 · Roll edge-journal writes onto a new page without overwriting unread events
Acceptance criteria
- Recovery chooses valid committed generation
- Incomplete header cannot supersede valid page
- Ambiguous generations fail visibly
Implementation constraints
- Include wrap behavior in generation comparison.
Verification to include
- Cut header activation
- Exercise generation wrap fixture
Deliverables
- Generation selection and boundary tests
Rollout and recovery
Preserve both pages and stop writes on unresolved ambiguity.
Value of the work
For the engineer: Practice torn writes, wear-aware batching and acknowledged durability.
For the team: Inspect whether offline device records remain recoverable within stated constraints.
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.