Question #827
A company operates a real-time inventory management system in a single AWS Region. The system uses a five-node Amazon Aurora PostgreSQL DB cluster to handle high-frequency updates for stock levels and order fulfillment. The database experiences a continuous stream of write operations during peak hours. The company must replicate the data to another Region to meet disaster recovery requirements with an RPO of 1 hour. Which solution will meet these requirements with the LOWEST cost?
Modify the Aurora database to be an Aurora global database. Deploy a secondary cluster in another Region.
Enable the Backtrack feature with a 1-hour window. Use an AWS Lambda function to export snapshots to another Region every hour.
Use AWS Database Migration Service (AWS DMS) to create a CDC task that replicates ongoing changes to an Amazon S3 bucket in the destination Region.
Configure cross-region automated backups with a 1-hour retention period and disable continuous backups.
Explanation
Option C is correct because AWS Database Migration Service (DMS) with Change Data Capture (CDC) replicates only incremental changes to Amazon S3, minimizing data transfer and storage costs while meeting the 1-hour RPO.
- Option A (Aurora Global Database) offers low-latency replication but is more expensive due to dedicated infrastructure in the secondary Region, exceeding the cost requirements.
- Option B (Backtrack + Lambda) involves hourly full snapshots, which are storage-intensive and costly compared to incremental CDC.
- Option D (Cross-region backups) relies on automated backups with a 1-hour retention period, which may not guarantee continuous replication and disables point-in-time recovery, risking data loss.
Key Points:
1. RPO of 1 hour allows for incremental replication (CDC) instead of real-time solutions.
2. Cost efficiency is achieved by using DMS (pay-per-use) and S3 (low-cost storage).
3. Disaster Recovery requires reliable cross-region replication, which DMS provides via continuous CDC tasks.
Answer
The correct answer is: C