v3.2.2 — Canary: API v3

The canary release: API v3, rolled out next to v2 and promoted to 100% by the pipeline. It carries everything in v3.2.0 and v3.2.1.

API v3

• /v3/items: every item carries its bin location, readable in GET and writable in POST and PATCH. v1 and v2 never see it.
• /api/... without a version serves v3; every resource is served under /v3.
• Expand/Contract: the canary adds the nullable column before it starts; 3.1.0 keeps working on the same database, and a rollback loses nothing.

Fixed in the pipeline while rehearsing it

• v3.2.1: each stage waits for alarms left by an earlier rollout to clear before moving traffic.
• v3.2.2: both alarms count a minute without canary traffic as healthy (FILL(..., 0)). With no new data, a CloudWatch alarm keeps looking back at the minutes that broke it, so after a rollback it never cleared.

Verified on AWS

Run	Canary share measured	Canary requests	Outcome
promote, fault=error	9.0% at stage 1	399, all 5xx	alarm canary-errors → ABORT → 0%
promote, fault=latency	8.9% at stage 1	397, p95 1,548 ms	alarm canary-latency → ABORT → 0%
promote, no fault	9.5% → 47.9% → 97.3%	426 → 2,140 → 4,354	PROMOTE at every stage; stable rebuilt with 3.2.2

A bin location written through v3 while the canary held 0% survived both aborts and the promotion.