AWS Certified Solutions Architect – Associate (SAA-C02) — Question 448

A company is building its web application by using containers on AWS. The company requires three instances of the web application to run at all times. The application must be highly available and must be able to scale to meet increases in demand.
Which solution meets these requirements?

Answer options

• A. Use the AWS Fargate launch type to create an Amazon Elastic Container Service (Amazon ECS) cluster. Create a task definition for the web application. Create an ECS service that has a desired count of three tasks.
• B. Use the Amazon EC2 launch type to create an Amazon Elastic Container Service (Amazon ECS) cluster that has three container instances in one Availability Zone. Create a task definition for the web application. Place one task for each container instance.
• C. Use the AWS Fargate launch type to create an Amazon Elastic Container Service (Amazon ECS) cluster that has three container instances in three different Availability Zones. Create a task definition for the web application. Create an ECS service that has a desired count of three tasks.
• D. Use the Amazon EC2 launch type to create an Amazon Elastic Container Service (Amazon ECS) cluster that has one container instance in two different Availability Zones. Create a task definition for the web application. Place two tasks on one container instance. Place one task on the remaining container instance.

Correct answer: A

Explanation

Option A is correct because utilizing AWS Fargate allows ECS to manage the underlying infrastructure, and setting the desired task count to three within an ECS service guarantees high availability and automatic scaling. Option C is incorrect because AWS Fargate is serverless, meaning users do not provision or manage 'container instances' themselves. Options B and D fail to meet the high availability and seamless scaling requirements due to limited Availability Zone distribution and manual container instance management.