AWS Certified Solutions Architect – Associate (SAA-C03)Design Resilient ArchitecturesMedium
A financial institution requires a highly available and fault-tolerant architecture for its critical transaction processing system. The system uses an Amazon RDS for PostgreSQL database. In the event of an Availability Zone (AZ) outage, the database must fail over to a standby instance with minimal data loss and disruption. Which RDS deployment option meets these requirements?
- ASingle-AZ deployment with automated backups.
- BSingle-AZ deployment with a manual snapshot strategy.
- CMulti-AZ deployment with a synchronous standby replica.
- DMulti-Region deployment with read replicas.
Show answer & explanationAnswer & explanation
Correct answer: C. Multi-AZ deployment with a synchronous standby replica.
Amazon RDS Multi-AZ deployments provide high availability and fault tolerance by synchronously replicating data to a standby instance in a different Availability Zone. In case of an AZ outage or primary instance failure, RDS automatically fails over to the standby, minimizing downtime and data loss.
Why the other options are wrong
- A. Single-AZ deployment does not provide fault tolerance against an AZ outage and requires manual recovery.
- B. Manual snapshots provide point-in-time recovery but do not offer automatic failover or high availability during an outage.
- D. Multi-Region deployment offers disaster recovery across geographies but is not the primary mechanism for AZ-level fault tolerance for a single database, and read replicas are asynchronous.
RDS Multi-AZ
Amazon RDS Multi-AZ deployments create a synchronous standby replica of your database in a different Availability Zone for high availability and automatic failover.
- Synchronous replication to a standby instance.
- Automatic failover in case of primary instance or AZ failure.
- Enhances fault tolerance and minimizes downtime.
Memory trick: Multi-AZ is like having a perfect twin ready to take over instantly.