# Relay / checkout returns.

Fictional practice records — no customer incident.

A checkout interruption, reconstructed from the request log, alert record and response notes. Review the exact 24-minute window without turning a hypothesis into a fact.

## Reviewed milestone intervals

- Impact to detection: 4m
- Detection to mitigation: 11m
- Impact to resolution: 24m

Intervals are computed from the explicitly selected event IDs. Reported timestamps remain reported; chronological proximity does not establish causation.

## Timeline (UTC)

| Time | Phase / status | Event | Evidence |
| --- | --- | --- | --- |
| 2026-10-06T09:00:00Z | impact / observed | relay-01: First rejected checkout request recorded | relay-source (CSV row 2) |
| 2026-10-06T09:02:00Z | note / observed | relay-02: Additional checkout retries appear in the log | relay-source (CSV row 3) |
| 2026-10-06T09:04:00Z | detected / observed | relay-03: Alert threshold crosses the reviewed limit | relay-source (CSV row 4) |
| 2026-10-06T09:05:00Z | note / observed | relay-04: Response lead opens the incident record | relay-source (CSV row 5) |
| 2026-10-06T09:08:00Z | note / reported | relay-05: Support relays a customer checkout report | relay-source (CSV row 6) |
| 2026-10-06T09:10:00Z | note / hypothesis | relay-06: Cache-expiry interaction proposed for investigation | relay-source (CSV row 7) |
| 2026-10-06T09:12:00Z | note / observed | relay-07: Rollback request acknowledged | relay-source (CSV row 8) |
| 2026-10-06T09:15:00Z | mitigated / observed | relay-08: New checkout route enabled as mitigation | relay-source (CSV row 9) |
| 2026-10-06T09:18:00Z | note / observed | relay-09: Fresh checkouts return accepted responses | relay-source (CSV row 10) |
| 2026-10-06T09:20:00Z | note / observed | relay-10: Retries continue through the legacy route | relay-source (CSV row 11) |
| 2026-10-06T09:24:00Z | resolved / observed | relay-11: Both reviewed routes pass the recovery check | relay-source (CSV row 12) |
| 2026-10-06T09:30:00Z | note / observed | relay-12: Follow-up review scheduled in the exercise | relay-source (CSV row 13) |

## Cause statement — hypothesis

Cache-expiry behavior may have amplified stale checkout requests. A controlled reproduction and configuration review are still required.

## Owned follow-ups

- **Reproduce the cache-expiry interaction** — Mira / platform; due 2026-10-16; open; event relay-06
  Acceptance: Record a controlled check with before/after evidence. Review the working hypothesis before changing production.
- **Update the detection and handoff checklist** — Jon / response; due 2026-10-19; in-progress; event relay-03
  Acceptance: Run one fictional drill; preserve reviewed milestone IDs, source offsets and an explicit backup owner.

## Source files

- relay-source: [Relay checkout / exercise record](evidence/source-01.txt); SHA-256 `58fd3f2a812bacd97d24ea662a0a1693e678f6fe6755d0d68f79a070690f1d27`
  Authored fictional exercise log. Event IDs and timestamp strings are preserved; source hash checks file integrity only.