A regional bank runs its online banking web tier on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. Releases currently use CodeDeploy in-place deployments, and a failed release has left some instances serving the old and new code at once.
The release manager wants each release to build a complete replacement fleet, check it before any customer traffic reaches it, and keep the original fleet running for an hour so that a rollback is only a traffic change. After that hour, the original instances must be terminated without anyone doing it by hand.
The team wants to keep using CodeDeploy for the application package and lifecycle hooks.
Which approach meets these requirements?
Choose one answer.
AA. Change the deployment group to use an in-place deployment with the OneAtATime configuration and a longer ValidateService hook, so that each instance is checked before the next one is updated.
BB. Create a second Auto Scaling group by hand for each release, copy the application package onto its instances with a Run Command document, and point the load balancer at the new group after the health checks pass.
CC. Configure a CodeDeploy blue/green deployment for the group, with CodeDeploy provisioning a replacement fleet, shifting load balancer traffic after the checks pass, and terminating the old instances after a wait.
DD. Replace the CodeDeploy deployment with a rolling instance refresh of the Auto Scaling group, using a launch template that points at the new application package in Amazon S3.
B. Wrong: This keeps two fleets, but the team would coordinate the copy, the health checks and the traffic change by hand. It also gives up the CodeDeploy deployment record and its automatic rollback. Learn more: AWS Systems Manager Run Command (opens in a new tab)
CodeDeploy blue/green deployments for EC2 Auto Scaling groups build a separate replacement fleet and move traffic to it only after the deployment succeeds. The original fleet stays available for a rollback window before it is terminated, which turns a rollback into a traffic change. In-place updates, hand-built fleets and instance refreshes each miss part of this.
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