SOA-C02 Reliability and Business Continuity 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.

• ✗

  Deploy the application across multiple Availability Zones using an Auto Scaling group and an Application Load Balancer.

  Why it's wrong here

  Deploying across multiple Availability Zones within a single region provides high availability against AZ-level failures, but it cannot protect against a regional disaster that impairs or destroys all AZs in that AWS Region. An Auto Scaling group and Application Load Balancer distribute traffic among local AZs, yet they have no awareness or failover capability beyond the region boundary. Therefore, this approach would not satisfy a disaster recovery plan that requires recovery in a separate region with defined RTO/RPO goals.

• ✗

  Use AWS Database Migration Service (DMS) for continuous replication to an EC2 instance in the DR region.

  Why it's wrong here

  AWS DMS is a database migration and continuous replication service that works with supported database engines, not a general-purpose EBS volume or EC2 instance replication tool. Pointing DMS at an EC2 instance in the DR region would either require the source to be a supported database or would fail to capture OS, files, and application configuration from the source server. Additionally, maintaining a continuously replicated standby EC2 instance is significantly more expensive and still leaves the problem of restoring the entire application stack, so it does not cover the full scope of disaster recovery for the application.

• ✓

  Take automated EBS snapshots every 15 minutes and copy them to the DR region. Use a pre-configured Amazon Machine Image (AMI) to launch EC2 instances from the latest snapshot.

  Why this is correct

  Automated EBS snapshots taken every 15 minutes and copied to the DR region deliver a consistent, block-level backup of the instance's data with a recoverable point objective of at most 15 minutes. Because EBS snapshots are stored in Amazon S3 and support cross-region copying, you can recreate the volume in the DR region. Launching EC2 instances from a pre-configured AMI that uses the latest restored snapshot as its root volume minimizes the recovery time objective by avoiding manual OS and application provisioning, making this a cost-effective and reliable DR strategy.

• ✗

  Use S3 Cross-Region Replication to replicate the EBS volume data to an S3 bucket in the DR region.

  Why it's wrong here

  S3 Cross-Region Replication replicates objects from one S3 bucket to another, but EBS volumes are block-level storage devices, not object storage, and cannot be directly replicated to an S3 bucket. To use S3 for DR, you would have to create an EBS snapshot (which itself is stored in S3) and then copy that snapshot to the destination region—you cannot simply 'replicate the EBS volume' through existing CRR. Even if you manually uploaded the volume's files, you would still need to rebuild a block device from those objects, which would be slower and more error-prone than using EBS snapshots directly.

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