A company uses an Amazon RDS for PostgreSQL database as the backend for its critical e-commerce application. To meet a strict Recovery Time Objective (RTO) of less than 5 minutes and a Recovery Point Objective (RPO) of less than 1 minute in case of a regional disaster, the SysOps Administrator needs to implement a robust disaster recovery strategy. Which combination of RDS features provides the most effective solution?
- ACross-Region Automated Backups with a Read Replica in the DR region.
- BRDS Custom with a manual standby replica in a different region.
- CAmazon Aurora Global Database with a PostgreSQL-compatible engine.
- DMulti-AZ deployment with automated daily snapshots.
Show answer & explanationAnswer & explanation
Correct answer: A. Cross-Region Automated Backups with a Read Replica in the DR region.
For a non-Aurora RDS PostgreSQL database, Cross-Region Automated Backups combined with a Read Replica in the DR region offers the best RTO/RPO. The Read Replica can be promoted to a standalone instance quickly (minutes RTO) with minimal data loss (minutes RPO due to asynchronous replication of the Read Replica). Automated snapshots alone would lead to a much higher RTO. Aurora Global Database is not directly applicable to standard RDS for PostgreSQL, and RDS Custom is not designed for this specific DR scenario.
Why the other options are wrong
- B. RDS Custom databases offer more control but are not inherently designed for sub-5-minute RTO/RPO cross-region DR out-of-the-box in the same way as native RDS features. Manual standby replica setup would be complex and prone to higher RTO/RPO.
- C. Amazon Aurora Global Database provides excellent RTO/RPO for Aurora databases, but the question specifies 'Amazon RDS for PostgreSQL database', not Aurora PostgreSQL. While Aurora PostgreSQL is compatible, it's a different service and not what's currently being used.
- D. Multi-AZ deployment provides high availability within a single region, not cross-region disaster recovery. Automated daily snapshots would result in an RPO of potentially 24 hours and an RTO of hours to restore, failing to meet the strict requirements.
RDS Cross-Region DR
For standard Amazon RDS, cross-region disaster recovery with low RTO/RPO is best achieved by combining Cross-Region Automated Backups with a Read Replica in the disaster recovery region.
- Cross-Region Automated Backups enable PITR to another region.
- Read Replica in DR region provides near real-time data copy.
- Read Replica can be quickly promoted to primary (low RTO).
- Asynchronous replication means RPO is typically minutes.
- Specific to standard RDS, not Aurora.
Memory trick: RDS Cross-Region DR: Backup + Read Replica = Fast Recovery, Minimal Loss.