Data failure modes
How validation, requests, stale data, and halts fail safely.
#Failure matrix
| Failure | UI | Engine |
|---|---|---|
| Asset API failure | MARKET API UNAVAILABLE | No cycle observations |
| Quote missing | β / NO DATA | Symbol omitted; gate incomplete |
| Invalid numeric string | β | Rejected |
| Stale generatedAt | STALE | Rejected |
| Halt flag | MARKET HALTED | Rejected |
| Duplicate generatedAt | Existing quote may render | Unique row ignored |
#Recovery
A later valid response resumes collection without deleting the durable history. Health records retain the last failed and successful cycle times.
#Diagnosis
Use /status, quote provenance, engine heartbeat, logs, and observation counts. Do not seed rows to make calibration appear healthy.