Question #991
A healthcare provider operates a patient management system hosted in a single AWS Region. The system uses Amazon EC2 instances behind an Application Load Balancer (ALB) for its frontend, an Amazon RDS for PostgreSQL database for patient records, and stores medical reports in an Amazon S3 bucket. The finance team runs nightly batch queries on the database for billing, which causes significant latency in the application during these periods.
The solutions architect must design a disaster recovery solution that ensures minimal data loss and mitigates the performance impact of the finance team's queries.
Which solution meets these requirements?
Migrate the database to Amazon Aurora Global Database with a secondary cluster in another Region. Instruct the finance team to query the secondary cluster. Use S3 Cross-Region Replication (CRR) to replicate the S3 bucket to the secondary Region. Deploy EC2 instances and an ALB in the secondary Region. Update the application to use the replicated S3 bucket and Aurora secondary cluster.
Deploy additional EC2 instances in the same Region and add them to the existing ALB. Create a read replica of the RDS database in the same Region for the finance team's queries. Configure S3 CRR to a new bucket in another Region. During a disaster, promote the read replica and redeploy the application in the secondary Region using copied AMIs and a new ALB.
Create a cross-Region read replica of the RDS database and direct finance team queries to it. Use AMIs to copy the EC2 instances to the secondary Region. Enable S3 CRR for the medical reports bucket. During a disaster, promote the read replica to primary, launch EC2 instances from the AMIs, and configure the ALB and application to use the new resources.
Implement hourly RDS snapshots copied to another Region. Deploy an Amazon ElastiCache cluster to cache database queries. Copy EC2 AMIs to the secondary Region and configure S3 CRR. During a disaster, restore the database from the latest snapshot and launch instances from the AMIs with a new ALB.
Explanation
Option C is correct because:
1. Cross-Region Read Replica: Directing finance queries to a cross-Region read replica offloads the primary database, mitigating performance impact.
2. Disaster Recovery: Promoting the cross-Region read replica during a disaster ensures minimal data loss (asynchronous replication) and quick recovery.
3. S3 CRR: Replicates medical reports to the secondary Region for data redundancy.
4. AMIs: Pre-configured EC2 instances in the secondary Region enable rapid deployment during failover.
Other options fail because:
- A: Requires migrating to Aurora, which isn't specified.
- B: Uses same-Region read replica, which doesn't reduce primary load effectively.
- D: Hourly snapshots risk up to 1-hour data loss, violating minimal data loss requirements.
Key Points: Use cross-Region read replicas for read-heavy workloads and DR. S3 CRR ensures data redundancy. AMIs enable quick instance deployment.
Answer
The correct answer is: C