AWS Certified Developer – Associate — Question 36

A company experienced partial downtime during the last deployment of a new application. AWS Elastic Beanstalk split the environment's Amazon EC2 instances into batches and deployed a new version one batch at a time after taking them out of service. Therefore, full capacity was not maintained during deployment.
The developer plans to release a new version of the application, and is looking for a policy that will maintain full capacity and minimize the impact of the failed deployment.
Which deployment policy should the developer use?

Answer options

• A. Immutable
• B. All at Once
• C. Rolling
• D. Rolling with an Additional Batch

Correct answer: A

Explanation

The Immutable deployment policy creates new instances for the new version and routes traffic only after they are fully deployed and healthy, ensuring that full capacity is maintained. The All at Once strategy deploys the new version to all instances simultaneously, risking downtime if the deployment fails. The Rolling policy updates instances in batches, which may still lead to reduced capacity during deployment, while the Rolling with an Additional Batch adds extra instances but does not fully prevent capacity issues during the update.