AWS DevOps Engineer Professional Practice Test

What should be included in the appspec.yml file for rolling back CodeDeploy deployments?

1. Lambda triggers for rollback

2. ValidateService hook with health checks

3. Success criteria for deployment completion

4. Manual approval process for deployment

The correct answer is: ValidateService hook with health checks

The appspec.yml file plays a crucial role in defining how AWS CodeDeploy interacts with the application during deployment. Including a ValidateService hook with health checks is essential for rolling back CodeDeploy deployments. The ValidateService hook allows CodeDeploy to verify whether the application is functioning correctly after a deployment. When a deployment occurs, health checks determine if the application is operating as expected. If the health checks fail, the deployment process can be automatically rolled back to ensure minimal disruption to users and services. This helps in maintaining application availability and reliability. The other options, while they may have relevance in different contexts, do not directly ensure an effective rollback mechanism in CodeDeploy deployments. Lambda triggers, success criteria, and manual approval processes serve distinct purposes but do not focus solely on monitoring application health post-deployment, which is critical for determining if a rollback is necessary.