DVA-C02 Deployment Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The instances in the Auto Scaling group are not running a supported operating system.

  Why it's wrong here

  If instances were running an unsupported operating system, the AWS CodeDeploy agent would likely fail to install, start, or communicate with the CodeDeploy service. This would typically result in errors indicating agent connectivity issues, instances not registering for deployment, or immediate deployment failures due to an inability to reach target instances, rather than a 'too many instances failed' error after deployment initiation.

• ✗

  The deployment configuration should be changed to AllAtOnce to avoid this error.

  Why it's wrong here

  Changing the deployment configuration to AllAtOnce would instruct CodeDeploy to deploy the application to all target instances simultaneously. If the underlying issue causing instance failures persists, deploying to all instances at once would likely result in a complete failure across the entire fleet, rather than avoiding the error. This configuration does not prevent failures; it merely changes the deployment strategy, potentially exacerbating the impact of a widespread issue.

• ✗

  The IAM role for CodeDeploy does not have sufficient permissions.

  Why it's wrong here

  Insufficient IAM permissions for the CodeDeploy service role or the EC2 instance profile would typically manifest as explicit 'Access Denied' errors. These errors would prevent CodeDeploy from performing actions like reading from S3, interacting with EC2 instances, or updating deployment statuses. Such permission-related failures are distinct from a deployment successfully initiating on instances but then failing due to application-level issues or lifecycle hook failures, which would lead to a 'too many instances failed' message.

• ✓

  The deployment failed on a single instance, causing the overall deployment to fail because the minimum number of healthy hosts was not maintained.

  Why this is correct

  CodeDeploy deployment configurations, such as `CodeDeployDefault.OneAtATime`, often specify a minimum healthy host threshold, which can be 100%. If a deployment fails on even a single instance due to issues like a failed lifecycle hook or an application startup problem, it immediately violates this strict healthy host requirement. This single failure is sufficient to cause the entire deployment to stop or roll back, triggering an error that indicates the minimum number of healthy hosts could not be maintained.