Question

A company runs a web application behind an Application Load Balancer (ALB) in a single Availability Zone. All EC2 instances in the Auto Scaling group are also in that one AZ. During a recent AZ impairment, the entire application became unreachable for several hours. The CloudOps team must redesign the architecture to survive the loss of a single Availability Zone with minimal manual intervention. Which change BEST achieves this goal?

Accepted Answer

Enable the ALB in subnets across at least two Availability Zones and configure the Auto Scaling group to launch instances into those multiple AZs.

Answer

Create a second ALB in another Region and use Route 53 failover routing to redirect traffic when the primary AZ fails.

Answer

Increase the desired capacity of the Auto Scaling group in the existing single AZ so more instances are available during an impairment.

Answer

Enable ALB access logging and configure a CloudWatch alarm to notify the team so they can manually launch instances in another AZ.