A team must deploy to EC2 instances while keeping the previous application version running on the original fleet until the new fleet passes validation. Which CodeDeploy option matches?
Show answer and explanation
Answer: A
A blue/green deployment in CodeDeploy provisions a replacement fleet, installs the revision there, and shifts traffic through the load balancer or DNS only after the new instances pass health checks. The original fleet can stay available for rollback until it is terminated by the deployment configuration.
In-place deployment updates the existing instances, so the previous version is gone once the revision is installed.
Why the other options are wrong
- B. In-place replaces the application on the same instances, leaving no intact old fleet for instant rollback.
- C. All-at-once in-place is the fastest and riskiest in-place variation, with no parallel environment.
- D. A rolling in-place deployment still overwrites instances in batches and retains no separate old environment.
Exam tip. Blue/green gives a parallel fleet; in-place reuses the same hosts.