Question #874
A European company with headquarters in Frankfurt is deploying a new web application running on Amazon EC2 in the eu-west-1 Region. The application must dynamically scale to handle traffic spikes and ensure high availability. Additionally, it requires disaster recovery capabilities in an active-passive configuration with the eu-central-1 Region.
Which steps should a solutions architect take after creating a VPC in the eu-west-1 Region?
Create a VPC in the eu-central-1 Region. Establish inter-Region VPC peering between the two VPCs. Deploy an Application Load Balancer (ALB) across multiple Availability Zones (AZs) in the eu-west-1 VPC. Deploy EC2 instances across multiple AZs in both Regions as part of a single Auto Scaling group spanning both VPCs, linked to the ALB.
Deploy an Application Load Balancer (ALB) spanning multiple AZs in the eu-west-1 VPC. Configure EC2 instances across multiple AZs using an Auto Scaling group served by the ALB. Replicate the same architecture in the eu-central-1 Region. Set up an Amazon Route 53 record with a failover routing policy and health checks to route traffic between the two Regions.
Create a VPC in the eu-central-1 Region. Use inter-Region VPC peering to connect the VPCs. Deploy a global ALB across both Regions. Configure EC2 instances in each Region as part of separate Auto Scaling groups linked to the ALB. Create a Route 53 alias record pointing to the ALB.
Deploy an ALB spanning multiple AZs in the eu-west-1 VPC. Configure EC2 instances using an Auto Scaling group in eu-west-1. Replicate the solution in eu-central-1. Create separate Route 53 records for each Region with latency-based routing and health checks to distribute traffic.
Explanation
The correct answer is B. Here's why:
- High Availability & Scaling: Deploying an ALB and Auto Scaling group across multiple AZs in eu-west-1 ensures dynamic scaling and fault tolerance within the primary Region.
- Disaster Recovery (Active-Passive): Replicating the architecture in eu-central-1 creates a standby environment. Route 53 failover routing with health checks ensures traffic shifts to the passive Region only if the active Region fails.
- Why Other Options Fail:
- A: Auto Scaling groups (ASGs) cannot span multiple Regions/VPCs. ALBs are regional, not cross-region.
- C: 'Global ALB' does not exist; ALBs are regional. Inter-Region VPC peering is unnecessary for this architecture.
- D: Latency-based routing is for active-active setups, not active-passive disaster recovery.
Key Points:
- Use Route 53 failover routing for active-passive DR.
- ALB and ASG are regional resources.
- Active-passive requires health checks to trigger failover.
Answer
The correct answer is: B