Soru

Zorluk: OrtaEnhancing Reliability and Disaster Recovery

An enterprise runs a critical web application in the us-east-1 Region. The architecture consists of an Application Load Balancer (ALB), an Auto Scaling group of Amazon EC2 instances, and an Amazon RDS for PostgreSQL Multi-AZ database. The database endpoint is resolved via a Route 53 Private Hosted Zone. To enhance reliability and meet compliance mandates, the enterprise needs to establish a pilot light disaster recovery (DR) solution in the us-west-2 Region. The solution must achieve a Recovery Point Objective (RPO) of 1515 minutes and a Recovery Time Objective (RTO) of 3030 minutes. Which strategy should a solutions architect recommend to meet these requirements with the lowest operational overhead?

  1. Configure a cross-region read replica of the RDS database in us-west-2. Deploy the application infrastructure in us-west-2 with the Auto Scaling group desired capacity set to 00. Associate the Route 53 Private Hosted Zone with the VPC in us-west-2. Set up Route 53 Active-Passive failover routing pointing to the primary ALB, and associate it with a Route 53 health check that monitors the primary application. During DR activation, promote the read replica and scale up the Auto Scaling group.Cevap
  2. B
    Configure a cross-region read replica of the RDS database in us-west-2. Deploy the application infrastructure in us-west-2 with the Auto Scaling group desired capacity set to 00. Configure Route 53 Active-Passive failover routing pointing to the primary ALB, but do not associate a Route 53 health check with the primary record, relying instead on the ALB's internal health check status to trigger DNS routing changes during an outage.
  3. C
    Implement a backup-and-restore strategy. Schedule daily manual snapshots of the RDS database and replicate them to us-west-2 using AWS Backup. Use AWS CloudFormation to deploy the ALB and Auto Scaling group in us-west-2 only after a disaster is declared. Restore the database from the copied snapshot and update Route 53 failover routing records manually.
  4. D
    Configure a cross-region read replica of the RDS database in us-west-2. Deploy the application infrastructure in the secondary VPC in us-west-2 with the Auto Scaling group desired capacity set to 00. Configure Route 53 Active-Passive failover routing pointing to the primary ALB with an associated health check. Do not associate the Route 53 Private Hosted Zone with the secondary VPC in us-west-2, assuming the replica endpoint resolves via public DNS.

Cevap

Configure a cross-region read replica of the RDS database in us-west-2. Deploy the application infrastructure in us-west-2 with the Auto Scaling group desired capacity set to 00. Associate the Route 53 Private Hosted Zone with the VPC in us-west-2. Set up Route 53 Active-Passive failover routing pointing to the primary ALB, and associate it with a Route 53 health check that monitors the primary application. During DR activation, promote the read replica and scale up the Auto Scaling group.
The correct strategy combines RDS cross-region replication (to achieve the 1515-minute RPO), keeping the secondary Auto Scaling group scaled to 00 (establishing a low-cost pilot light architecture), associating the Route 53 Private Hosted Zone with the secondary VPC (to ensure database resolution), and configuring a Route 53 health check on the active failover record (to enable automatic DNS redirection).

Adım Adım Çözüm

1
Select a disaster recovery pattern that meets the 1515-minute RPO and 3030-minute RTO constraints.
Identify that the Pilot Light pattern meets the RTO/RPO target by replicating data continuously and keeping compute resources shut down or scaled to zero in the secondary region.
Establishing database replication ensures data loss is minimal, while keeping application servers scaled down reduces operational costs.
2
Ensure DNS resolution is configured correctly across regions.
Associate the Route 53 Private Hosted Zone hosting the database endpoint with the VPC in the secondary region (us-west-2).
Without this association, the application servers running in the secondary region will not be able to resolve the database DNS name to connect to the promoted RDS instance.
3
Configure DNS failover routing.
Set up Route 53 failover records pointing to the primary ALB and associate a Route 53 health check with the primary record.
Route 53 requires a health check to detect that the primary region's endpoint is degraded in order to automatically direct client requests to the secondary region.

Anahtar Kavram

Disaster Recovery pattern selection (Pilot Light) combined with cross-region DNS and database replication configurations in AWS.

Alternatif Yöntem

Instead of setting the Auto Scaling group capacity to 00, a Warm Standby strategy could keep a minimal number of instances running to further reduce RTO, though at a slightly higher cost. However, the pilot light requirement is fully satisfied by a capacity of 00 since the 3030-minute RTO permits the time needed to spin up instances.
Tahmini Süre:2m 0s
Bu soruyu puanla