Application Versions

Correct Answer: Create a new application version in Elastic Beanstalk and deploy it to the existing environment, allowing for easy rollback.

Creating a new application version in Elastic Beanstalk and deploying it to the existing environment retains the old version, allowing for easy rollback in case of any issues. All the other methods involve manual steps, disrupt the existing environment, or are not suitable for quick rollback.

Correct Answer: Create a new environment with the new application version, then swap CNAMEs between environments.

Blue/green deployment on Elastic Beanstalk is implemented by running two parallel environments: the current (blue) and a new one (green). You deploy and validate the new version in the green environment and then use Elastic Beanstalk's built-in CNAME swap to shift production traffic instantly with minimal downtime. This also enables immediate rollback by swapping back if needed. Deploying directly to the production environment is an in-place update, not blue/green, and risks downtime. Creating a new application and manually redirecting traffic bypasses Elastic Beanstalk's native CNAME swap and is more error-prone. Using CodeDeploy to update instances behind the load balancer is an in-place deployment approach and not the standard Elastic Beanstalk blue/green pattern.

Correct Answer: AllAtOnce

The AllAtOnce deployment policy updates all instances simultaneously, which is suitable for testing new application code in a non-production environment. The other policy options are used for controlled, gradual deployments and to avoid downtime in production environments.