BAC-L2-COSMOS-116Cosmos SDK
Coordinated upgrades and migrations
A sovereign chain upgrades at an agreed block height: a validator running the wrong version forks alone.
- Level
- L2 — Appchain developer
- Duration
- 4 h
- Track
- Cosmos SDK
- Maintainer
- Cosmos Lead Architect
Learning objectives
- 01Schedule an upgrade at a block height
- 02Write a storage migration between two module versions
- 03Run the validator-side procedure without downtime
Guided lab
Execute a coordinated upgrade across the four-validator local network.
Independent lab
Deliberately fail one validator's upgrade and document its recovery.
Security angle
A validator left on the old version produces a competing chain: detection and recovery.
Assessment
Successful upgrade plus a verified recovery procedure.