AWS Certified Solutions Architect Professional SAP-C02 Practice Question
Your organization operates identical production stacks in the us-east-1 and ap-southeast-2 AWS Regions. Client traffic is routed by Amazon Route 53 latency-based routing so that both Regions actively serve users. The company must implement a multi-site disaster-recovery strategy that (1) continuously replicates every Amazon EC2 instance from each Region to the other Region by using AWS Elastic Disaster Recovery (AWS DRS), (2) achieves an RTO of 15 minutes and an RPO of seconds for either Region, and (3) keeps the now-primary Region protected after any Regional failover while avoiding double billing when both Regions are healthy.
Which solution meets these requirements?
Replace AWS Elastic Disaster Recovery with Amazon EBS snapshot policies and AWS Backup cross-Region copy plans for all EC2 volumes in each Region, then use AWS CloudFormation to rebuild the compute environment during a disaster.
Initialize AWS Elastic Disaster Recovery only in us-east-1 and replicate all EC2 instances to ap-southeast-2. After a failover, reinstall the replication agent on the recovered instances and create a new replication job back to us-east-1.
Configure AWS Elastic Disaster Recovery with a single centralized staging account in a third Region and replicate the EC2 instances from both active Regions to that account. Failovers launch the recovery instances in the staging account, and no further action is required to maintain protection.
Initialize AWS Elastic Disaster Recovery in both Regions, install the AWS Replication Agent on every EC2 instance, configure each Region's instances to replicate to a staging subnet in the opposite Region, and after a failover immediately start reversed replication from the recovered instances back to the original Region.