SOA-C02 Question 80
Select 2A company hosts a critical application on Amazon EC2 instances running in a single Availability Zone within an Auto Scaling group behind an Application Load Balancer (ALB). The SysOps Administrator is tasked with improving the application's high availability and resilience to minimize downtime in case of an Availability Zone failure. Which of the following actions should the SysOps Administrator take?
- A
Configure the Auto Scaling group to span multiple Availability Zones.
- B
Add a second Application Load Balancer in a different Availability Zone.
- C
Enable Cross-Zone Load Balancing on the Application Load Balancer.
- D
Configure Amazon Route 53 with a failover routing policy for the ALB.
- E
Launch a read replica of the EC2 instances in a different Availability Zone.
Show answer and explanation
Correct answers: A, C
Explanation
To improve high availability and resilience, the Auto Scaling group must span multiple Availability Zones to ensure instances are available even if an AZ fails. Enabling Cross-Zone Load Balancing on the ALB ensures that traffic is evenly distributed across all instances, providing better resource utilization and reducing the risk of overload in one zone. These combined actions address the high availability and resilience requirements for the given setup.
- A. Correct.
Configuring the Auto Scaling group to span multiple Availability Zones ensures that EC2 instances can be launched in healthy Availability Zones if one fails, thereby increasing the application's high availability.
- B. Incorrect.
Adding a second Application Load Balancer in a different Availability Zone is unnecessary since ALBs can already distribute traffic across multiple Availability Zones when configured correctly.
- C. Correct.
Enabling Cross-Zone Load Balancing on the Application Load Balancer allows traffic to be distributed evenly across instances in all connected Availability Zones, improving resilience and ensuring optimal usage of resources.
- D. Incorrect.
Configuring Amazon Route 53 with a failover routing policy would help in disaster recovery scenarios involving multiple regions rather than improving high availability within a single region.
- E. Incorrect.
Launching a read replica of the EC2 instances does not apply in this scenario as the focus is on improving high availability and resilience, not database replication or read performance.