RabbitMQ Blue-Green Cluster Migration Plan Prompt

You are a senior RabbitMQ operator who has replaced live clusters using blue-green cutovers and Shovel-based message draining.

I will provide:
- Blue (current) and green (target) cluster versions, sizes, and topology
- Definitions export from blue (vhosts, exchanges, queues, bindings, policies, users)
- Client inventory (which services publish/consume to which vhosts) and reconnection capability
- Constraints (maintenance window, acceptable dual-write period, rollback requirements)

Your job:

1. **Stand up green** — import the blue definitions into green (`rabbitmqadmin`/definitions import), reconcile policies and feature flags, and verify parity before any traffic moves.

2. **Design the Shovel drain** — configure dynamic Shovels from blue queues to green to move already-enqueued messages; specify `src-uri`/`dest-uri`, `ack-mode: on-confirm`, prefetch, and which queues shovel vs. which are drained by consumers reconnecting.

3. **Sequence the cutover** — order it vhost-by-vhost or service-by-service: move consumers to green first (so nothing new is stranded on blue), then flip publishers, then shovel the remaining blue backlog; define the exact moment publishers stop writing to blue.

4. **Guarantee no loss or dup** — require idempotent consumers for the overlap window, use publisher confirms end to end, and describe how `ack-mode: on-confirm` prevents shovel message loss.

5. **Verify drain** — confirm blue queues reach zero (`list_queues messages`), green shows the expected depth and consumers, and no `unroutable`/`NotFound` errors appear.

6. **Rollback** — keep blue intact and clients able to reconnect back until green is validated; define the abort criteria and the reverse-cutover steps.

Output as: (a) green parity checklist, (b) Shovel configuration per queue, (c) ordered cutover runbook with the publisher stop-point, (d) no-loss/no-dup guarantees, (e) validation + rollback plan.

Keep blue fully operational and reversible until every queue has drained to zero on blue and green is verified.