Examkin

Question

Difficulty: MediumEnhancing Reliability and Disaster Recovery

An enterprise has a multi-tier web application running in a primary AWS Region (us-east-1). The web tier is deployed on Amazon EC2 instances inside an Auto Scaling group behind an Application Load Balancer (ALB). The database tier uses an Amazon Aurora PostgreSQL Provisioned DB cluster. The enterprise needs to implement a disaster recovery (DR) solution in a secondary AWS Region (us-west-2) using a warm standby approach. The business requires a Recovery Point Objective (RPO) of less than 15 minutes and a Recovery Time Objective (RTO) of less than 30 minutes. Which combination of actions should a solutions architect recommend to meet these requirements? (Select TWO.)

  1. Create an Amazon Aurora Global Database by adding a secondary DB cluster in the secondary region, and deploy the application tier in the secondary region using an Auto Scaling group with a minimum capacity of at least one instance.Answer
  2. Configure Amazon Route 53 active-passive failover routing with Route 53 health checks associated with each Application Load Balancer endpoint to automatically redirect traffic to the standby region during an outage.Answer
  3. C
    Implement a pilot light disaster recovery strategy by copying daily Amazon Aurora DB cluster snapshots to the secondary region and restoring the database cluster from the snapshot only during a failover event.
  4. D
    Configure Amazon Route 53 failover routing records pointing to the regional Application Load Balancers, but disable Route 53 health checks to avoid split-brain scenarios and instead manually change DNS records during an outage.
  5. E
    Reduce disaster recovery standby costs in the secondary region by deploying a single NAT Gateway in one Availability Zone and directing outbound traffic from all secondary private subnets to this gateway.

Answer

The correct approach is to set up an Amazon Aurora Global Database for database replication with minimal latency, maintain a scaled-down Auto Scaling group of application instances in the secondary region for the warm standby application tier, and implement Amazon Route 53 active-passive failover routing linked with ALB health checks to automate failover.
To meet the RPO of less than 15 minutes and RTO of less than 30 minutes, the architecture must support low-latency database replication and pre-provisioned application resources. Creating an Amazon Aurora Global Database ensures sub-second replication (satisfying the RPO). Keeping a minimum of one instance running in the secondary region's Auto Scaling group satisfies the warm standby model. Finally, configuring Amazon Route 53 active-passive failover routing with health checks ensures that traffic is automatically redirected to the healthy secondary region within minutes, satisfying the RTO.

Step-by-Step Solution

1
Address the database tier RPO and RTO requirements by setting up replication.
Amazon Aurora Global Database replicates data to the secondary region with sub-second latency, satisfying the RPO of less than 15 minutes.
This guarantees minimal data loss and makes the database available in the secondary region for rapid promotion.
2
Configure the application tier in the standby region to support a warm standby posture.
An Auto Scaling group is provisioned in the secondary region with a minimum capacity of at least one instance to process traffic immediately upon failover.
This avoids the delay of starting instances from scratch, keeping RTO under 30 minutes.
3
Establish the traffic routing mechanism for the disaster recovery architecture.
Route 53 active-passive failover routing records are configured with health checks targeting the Application Load Balancer endpoints in both regions.
This automates the redirection of client requests to the secondary region's ALB during a failure in the primary region.

Key Concept

Enhancing Reliability and Disaster Recovery via Multi-Region Database Replication and Automated Traffic Failover
Rate this question

Topics

Enhancing Reliability and Disaster Recovery