Disaster Recovery practice questions

Take regular backups and restore them in AWS during cutover.

Why wrong: This is backup and restore, not pilot light.

Run a scaled-down but fully functional version of the environment in AWS at all times.

Why wrong: This describes warm standby.

Run the application simultaneously in both environments and route traffic to both.

Why wrong: This describes multi-site active-active.

Deploy AD in two Regions and use a VPN connection between the VPCs to replicate data.

Why wrong: VPN traffic would bypass the inspection VPC unless specifically routed, but the requirement mandates transit gateway.

Deploy a single AD domain in one Region and use AD replication over a VPC peering connection to a second Region.

Why wrong: VPC peering does not support transitive routing through a third-party firewall in the transit gateway.

Deploy AD in two Regions, attach both VPCs to the transit gateway, and enable cross-Region transit gateway peering. Use route tables to direct AD traffic through the inspection VPC.

Why wrong: Transit gateway peering does not support transitive routing through a third-party appliance in a different Region; traffic would go directly.

Configure a Multi-AZ deployment for the RDS database in the primary Region.

Why wrong: Multi-AZ is for high availability within a Region, not for cross-Region DR.

Deploy the application on Amazon Aurora Global Database.

Why wrong: Aurora is a different database engine, not RDS MySQL.

Use automated backups with 5-minute retention.

Why wrong: Automated backups are not for failover.

Take manual snapshots every 5 minutes and copy to another region.

Why wrong: Snapshot restore takes longer than 15 minutes.

Create a cross-region read replica in us-west-2.

Why wrong: Asynchronous replication may exceed RPO.

Use Aurora Serverless v2 with data replication across regions using Database Migration Service (DMS).

Why wrong: Aurora Serverless v2 does not support cross-region replication natively; DMS adds complexity and latency.

Deploy Aurora Multi-AZ in the primary region and use a secondary region as a warm standby.

Why wrong: Multi-AZ is within a single region; cross-region failover requires Aurora Global Database.

Configure Aurora Cross-Region Read Replicas and use Amazon Route 53 for DNS failover.

Why wrong: Cross-Region Read Replicas have higher RPO (minutes) and require manual promotion.

RDS Multi-AZ in the same region

Why wrong: Multi-AZ only protects within a region, not cross-region.

Amazon S3

Why wrong: S3 is not a database DR solution.

AWS Database Migration Service

Why wrong: DMS is for migration, not continuous DR.

Use Amazon Aurora Global Database.

Why wrong: Aurora Global Database is for Aurora, not RDS MySQL.

Use Amazon RDS with automated backups and restore in another Region.

Why wrong: Restoring from backup would take longer than 1 minute, not meeting the RTO.

Use Amazon RDS Multi-AZ with a standby in a different AWS Region.

Why wrong: RDS Multi-AZ only supports standby in the same region, not cross-region.

Use AWS Database Migration Service (DMS) for continuous replication to us-west-2

Why wrong: DMS is for migration, not DR, and adds cost.

Use automated backups and restore to us-west-2 when needed

Why wrong: Restore from backup takes longer than 15 minutes.

Use a Multi-AZ deployment in us-east-1 and failover to a standby instance

Why wrong: Multi-AZ is within region, not cross-region DR.

Use EC2 AMI copy to another region and launch instances from the AMI.

Why wrong: AMI copy and instance launch can exceed 15 minutes.

Use RDS cross-region snapshots and restore in the DR region.

Why wrong: Snapshot restore takes longer than 15 minutes.

Configure RDS Multi-AZ in the primary region.

Why wrong: Multi-AZ is for HA within a region, not DR.

Use EC2 Auto Scaling to launch new instances in another Region and use an Application Load Balancer.

Why wrong: Auto Scaling does not address database replication.

Take automated snapshots of the RDS instance every 5 seconds and copy them to another Region.

Why wrong: Snapshots cannot be taken every 5 seconds and restoring snapshot takes longer than 15 minutes.

Deploy RDS Read Replicas in another Region and promote them during a disaster.

Why wrong: Cross-Region Read Replicas have asynchronous replication, resulting in an RPO of seconds to minutes, not 5 seconds.

Take daily automated snapshots of the RDS DB instance and copy them to the DR Region. In the DR Region, restore the DB instance from the latest snapshot.

Why wrong: Daily snapshots provide RPO of up to 24 hours, exceeding 15 minutes.

Use Amazon Aurora Global Database to replicate data across Regions.

Why wrong: Aurora Global Database is for Aurora, not RDS MySQL, and is more expensive.

Use AWS Backup to copy backups to the DR Region and set up EC2 Image Builder for application recovery.

Why wrong: AWS Backup for RDS provides point-in-time recovery but RTO may be longer; Image Builder is for AMIs, not database.

Pre-warm a standby EC2 instance in the DR region.

Why wrong: EC2 warm standby alone does not address database failover.

Take hourly snapshots of RDS and copy them to the DR region.

Why wrong: Snapshot restore takes more than 15 minutes.

Use Amazon S3 Cross-Region Replication for application data.

Why wrong: S3 CRR is for object storage, not database.

Configure a cross-region read replica in the DR region and promote it during failover.

Why wrong: Promoting a read replica takes longer than 15 minutes.

Take frequent snapshots of the Aurora cluster and copy them to the DR region.

Why wrong: Snapshot restore takes too long (more than 15 minutes).

Use backup and restore: take hourly snapshots of EBS volumes and copy to us-west-2, then restore EC2 instances from snapshots.

Why wrong: Restoring from snapshots takes longer than 15 minutes.

Implement a pilot light strategy: replicate data to us-west-2 and keep a minimal stack running.

Why wrong: Pilot light requires provisioning resources during failover, which may exceed 15 minutes.

Deploy a multi-site active-active configuration with full capacity in both regions.

Why wrong: This is costly and may not be necessary; also failover could be complex.

Single-AZ RDS instance with cross-Region snapshot copy

Why wrong: RPO is hours (snapshot interval), RTO is minutes to restore.

Multi-AZ RDS instance in us-east-1

Why wrong: Does not provide cross-Region failover.

Amazon Aurora Global Database

Why wrong: Aurora Global Database is for Aurora, not RDS MySQL.

Use S3 Cross-Region Replication for application data and launch EC2 instances from AMIs copied to the secondary Region

Why wrong: S3 CRR replicates objects but not EC2 instance state; launching from AMIs may take time and not meet RPO/RTO.

Take hourly snapshots of EBS volumes and copy them to another Region; use AWS CloudFormation to launch instances from the snapshots

Why wrong: Hourly snapshots may not achieve 15-minute RPO; also restoring from snapshots may exceed 2-hour RTO.

Configure an Active-Passive failover using Route 53 with health checks within the same Region

Why wrong: Single Region does not protect against region-wide failure.

Deploy the RDS instance in Multi-AZ configuration and take frequent snapshots to another Region.

Why wrong: Multi-AZ does not protect against Region failure; cross-Region snapshots would not meet RPO of 15 minutes if taken less frequently.

Use AWS Database Migration Service (DMS) for continuous replication to an RDS instance in another Region.

Why wrong: DMS can replicate but adds cost and complexity; not the lowest cost option.

Use Amazon Aurora Global Database, which provides global replication with typical RPO of 1 second.

Why wrong: Aurora Global Database is more expensive than using RDS read replicas.

Use Amazon RDS Multi-AZ with synchronous replication. Use Elastic Load Balancing with cross-zone load balancing.

Why wrong: Multi-AZ is within a single region, not multi-region DR.

Use Amazon DynamoDB global tables. Use an Application Load Balancer in each region with Route 53 weighted routing.

Why wrong: DynamoDB global tables are for NoSQL, not MySQL; weighted routing is not for failover.

Use Amazon RDS for MySQL with a cross-region read replica. Use Amazon Route 53 failover routing with a health check on port 8080.

Why wrong: Cross-region read replica RPO is typically seconds, not sub-second.

Use cross-Region Read Replicas with automatic failover.

Why wrong: Asynchronous replication may cause data loss.

Use a Multi-AZ RDS instance with a standby in another Region.

Why wrong: Multi-AZ is only within one Region.

Use AWS Database Migration Service for continuous replication.

Why wrong: DMS is not designed for low-RTO failover.