DOP-C02 Exam Dumps : AWS Certified DevOps Engineer - Professional

AWS CodeDeploy natively supports automatic rollback based on CloudWatch alarms . To use this capability, you define an alarm that indicates unhealthy behavior (for example, increasing application error rate) and attach that alarm to the deployment group in CodeDeploy. If the alarm goes into ALARM state during or after a deployment, CodeDeploy automatically rolls back to the last known good revision when auto rollback is enabled.

Option A correctly implements this pattern:

Derive a CloudWatch metric from application logs (e.g., count of error-level log entries or HTTP 5xx responses).

Create a CloudWatch alarm on that metric with appropriate thresholds.

Configure the deployment group to use the alarm as part of its alarm configuration and enable auto rollback .

Option B uses CodeDeploy agent logs, which may not directly reflect true application health and couples rollback logic tightly to deployment internals rather than application behavior. Options C and D implement custom rollback logic with Lambda and EventBridge, which re-create behavior that CodeDeploy already provides natively and add unnecessary operational and code complexity.

Therefore, Option A is the simplest and most aligned with built-in CodeDeploy features for automated rollback based on application errors.

To restrict access to S3 buckets so that only IAM principals from within the AWS Organization can access them, an SCP (Service Control Policy) with conditions using the aws:PrincipalAccount or preferably aws:PrincipalOrgID can be applied at the OU level.

SCPs restrict the maximum permissions for IAM entities in member accounts and can be used to enforce access control policies across accounts.

The aws:PrincipalAccount condition restricts access to principals from specific accounts, while aws:PrincipalOrgID restricts based on the organization ID.

IAM permissions boundaries (Option B) cannot be applied organization-wide and do not enforce restrictions across accounts.

AWS RAM (Option C) is for sharing resources but does not restrict S3 bucket access based on organizational principals.

There is no such thing as an RCP in AWS Organizations (Option D is invalid).

The best solution to implement failover for the application is to use CloudFront origin groups. Origin groups allow CloudFront to automatically switch to a secondary origin when the primary origin is unavailable or returns specific HTTP status codes that indicate a failure1. This way, CloudFront can serve the requests from the secondary ALB in the secondary Region without any delay or redirection. To set up origin groups, the DevOps engineer needs to create a new origin on the distribution for the secondary ALB, create a new origin group with the original ALB as the primary origin and the secondary ALB as the secondary origin, and configure the origin group to fail over for HTTP 5xx status codes. Then, the DevOps engineer needs to update the default behavior to use the origin group instead of the single origin2.

The other options are not as effective or efficient as the solution in option B. Option A is not suitable because creating a second CloudFront distribution will increase the complexity and cost of the application. Moreover, using Route 53 alias records with a failover policy will introduce some delay in detecting and switching to the secondary CloudFront distribution, which may not meet the zero-second RTO requirement. Option C is not feasible because CloudFront does not support using Route 53 alias records as origins3. Option D is not advisable because using a CloudFront function to redirect the requests to the secondary ALB will add an extra round-trip and latency to the failover process, which may also not meet the zero-second RTO requirement.

1: Optimizing high availability with CloudFront origin failover - Amazon CloudFront

2: Creating an origin group - Amazon CloudFront

3: Values That You Specify When You Create or Update a Web Distribution - Amazon CloudFront