Name each task tolerance
At synthetic 14:12, read-only snapshot is from 14:00. Local policy allows catalogue browsing up to 15-minute age, but booking availability only up to 2-minute age. No writes or live refresh are available. The exercise does not claim that a cached availability result can reserve anything.
| Task | Snapshot age | Allowed age |
|---|---|---|
| Catalogue browse | 12 min | ≤15 min |
| Booking availability | 12 min | ≤2 min |
Compare one snapshot with both limits
- Fix read time and snapshot time
- Calculate age once
- Apply each task-specific tolerance
Missing snapshot time cannot demonstrate that an age-limited read is eligible.
Which read is eligible and how far does availability exceed its limit?
Show the worked answer
Catalogue browsing is eligible. Availability exceeds its limit by 10 minutes:12−2. The same snapshot cannot be approved for both tasks.
Expose the stale decision
| Case | Decision | Reason |
|---|---|---|
| Browse catalogue | Allow under local policy | 12≤15 |
| Show bookable availability | Withhold this result | 12>2 |
Keep the snapshot time beside the permitted catalogue output and name availability as unavailable. Do not imply an unavailable write can confirm a slot.