SAA-C03 Question 478
Select 2You are designing a highly available web application for your organization using AWS. The application requires a minimum of two instances running at all times to handle traffic. Additionally, the application must be resilient to a single Availability Zone failure. Which combination of components will best meet these requirements?
- A
Launch an Auto Scaling group with a desired capacity of 2, minimum capacity of 2, and deploy the instances across multiple Availability Zones.
- B
Use an Elastic Load Balancer to distribute traffic across instances in multiple Availability Zones.
- C
Deploy all instances in a single Availability Zone and increase the instance size to handle peak traffic.
- D
Launch an Auto Scaling group with a desired capacity of 2 and deploy the instances in a single Availability Zone.
- E
Use an Elastic Load Balancer to distribute traffic but restrict it to a single Availability Zone for lower latency.
Show answer and explanation
Correct answers: A, B
Explanation
To achieve high availability and resilience to an Availability Zone failure, you should use an Auto Scaling group to ensure a minimum of two instances are running and deploy them across multiple Availability Zones. An Elastic Load Balancer is essential to distribute traffic across multiple instances and Availability Zones, ensuring traffic is routed to healthy instances even if one Availability Zone goes down.
- A. Correct.
This is correct because an Auto Scaling group can ensure that at least two instances are always running and deploying them across multiple Availability Zones ensures high availability.
- B. Correct.
This is correct because an Elastic Load Balancer can distribute traffic across instances in multiple Availability Zones, which helps maintain availability during an Availability Zone failure.
- C. Incorrect.
This is incorrect because deploying all instances in a single Availability Zone creates a single point of failure, making the application vulnerable to an Availability Zone outage.
- D. Incorrect.
This is incorrect because deploying instances in a single Availability Zone fails to meet the requirement of resilience against an Availability Zone failure.
- E. Incorrect.
This is incorrect because restricting the Elastic Load Balancer to a single Availability Zone eliminates the resilience benefit it provides in multi-AZ deployments and does not meet the high availability requirement.