A financial services company hosts a credit-scoring application in the eu-west-1 Region. T… — AWS Certified Solutions Architect - Associate

A financial services company hosts a credit-scoring application in the eu-west-1 Region. The application uses Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB), and a multi-node Amazon Aurora PostgreSQL DB cluster. The company needs to implement a disaster recovery (DR) strategy in the us-east-1 Region with a Recovery Time Objective (RTO) of $15$ minutes and a Recovery Point Objective (RPO) of $2$ minutes. The solution must minimize ongoing operational costs in the secondary Region during normal operations. Which configuration should a solutions architect recommend to meet these requirements?

A
Set up an Amazon RDS PostgreSQL DB instance in eu-west-1 with a cross-region read replica in us-east-1. In us-east-1, deploy an ALB and an Auto Scaling group with the desired capacity set to $0$ . Configure Amazon Route 53 with active-passive failover routing to automatically promote the cross-region read replica and scale up the Auto Scaling group when health checks fail.
B
Configure daily snapshots of the Aurora DB cluster and copy them to an Amazon S3 bucket in us-east-1, configured to transition snapshots to Amazon S3 Glacier Flexible Retrieval. In us-east-1, deploy an ALB and an Auto Scaling group with a desired capacity of $0$ . During failover, retrieve the snapshot from Glacier, restore the database, and scale up the Auto Scaling group.
Configure an Aurora Global Database with the primary DB cluster in eu-west-1 and a secondary DB cluster in us-east-1. In us-east-1, deploy an ALB and an Auto Scaling group with the minimum and desired capacity set to $0$ . During failover, promote the secondary Aurora DB cluster to primary and update the Auto Scaling group capacity to launch the EC2 instances.Answer
D
Configure an Aurora Global Database with the primary DB cluster in eu-west-1 and a secondary DB cluster in us-east-1. In us-east-1, deploy an ALB and a scaled-down Auto Scaling group with the minimum capacity set to $2$ EC2 instances to run the application at minimal capacity. During failover, promote the secondary database cluster and scale out the Auto Scaling group.

Answer

Configure an Aurora Global Database with the primary DB cluster in eu-west-1 and a secondary DB cluster in us-east-1. In us-east-1, deploy an ALB and an Auto Scaling group with the minimum and desired capacity set to

0

. During failover, promote the secondary Aurora DB cluster to primary and update the Auto Scaling group capacity to launch the EC2 instances.

The correct architecture is a Pilot Light disaster recovery strategy using Aurora Global Database. Aurora Global Database replicates data asynchronously across AWS Regions with a typical latency of less than

1

second, easily meeting the

2

-minute RPO. Since the business requires cost minimization under normal conditions and allows up to

15

minutes for recovery (RTO), keeping the Auto Scaling group in the secondary Region at a desired capacity of

0

ensures no EC2 compute charges are incurred until a disaster occurs. During failover, the secondary Aurora cluster can be promoted to primary in under a minute, and the Auto Scaling group can quickly launch EC2 instances to begin serving traffic within the

15

-minute window.

Step-by-Step Solution

Identify the database replication technology that meets the RPO requirement of

2

minutes.

Aurora Global Database provides sub-second cross-region replication, which easily satisfies the

2

-minute RPO.

Alternative strategies like daily snapshots copied to Amazon S3 would yield an RPO of up to

24

hours, which fails the business requirements.

Determine the minimum compute capacity in the secondary Region that satisfies the RTO of

15

minutes while minimizing costs.

An Auto Scaling group with a desired capacity of

0

instances incurs zero EC2 costs during normal operations and can spin up instances within a few minutes.

This Pilot Light setup meets the

15

-minute RTO upon failover, making it more cost-effective than running instances continuously (Warm Standby).

Analyze the failover automation and network routing capabilities.

Aurora Global Database can be promoted to a standalone primary cluster in less than a minute, fitting well within the

15

-minute RTO.

DNS routing policies alone cannot automatically perform database promotion, meaning a scripted or manual orchestration process is necessary to complete the failover.

Key Concept

Disaster Recovery strategies (Pilot Light vs. Warm Standby) and database cross-region replication capabilities.

Estimated Time:2m 0s

Question

Answer

Step-by-Step Solution

Key Concept

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