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

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

AWS Config offers a managed rule called CLOUDFORMATION_STACK_DRIFT_DETECTION_CHECK to detect stack drift automatically.

Creating an SNS topic and subscribing the DevOps lead enables simple notification without custom Lambda functions.

An EventBridge rule that triggers on NON_COMPLIANT status (when drift is detected) can send alerts directly to SNS. Option B adds complexity by requiring custom rules and Lambda. Option C incorrectly triggers on COMPLIANT, not NON_COMPLIANT. Option D needs a Lambda for email, while SNS can send email directly. Hence, Option A offers the least operational effort.

S3 RTC ensures ≤15-min replication SLA.

Multi-Region Access Point (MRAP) simplifies active-passive replication access.

SubmitMultiRegionAccessPointRoutes API manages routing changes during failover. This configuration follows AWS DR best practices for S3 active/passive architectures.