AZ400-Q: Blue-green deployment
Q: A team runs two identical production stacks (blue and green) behind a load balancer. The new version is fully deployed and smoke-tested on the idle stack, then the load balancer switches traffic to it. If something goes wrong, traffic is switched back to the previous stack. Which deployment pattern is this?
- A) Blue-green deployment ✓
- B) Canary deployment
- C) Rolling deployment
- D) Feature-flag rollout
Answer: A. Blue-green keeps two complete production environments; you deploy to the idle one, validate it, then flip traffic via the router, giving an instant, complete rollback by flipping back. Canary and rolling shift traffic gradually; feature flags toggle functionality at runtime rather than swapping environments.
Why it helps
Recognizing deployment patterns and their rollback characteristics is a direct “deployment patterns” AZ-400 objective.
Related
blue-green-deployment · cd · release-strategy · rollback-strategy