Amazon Elastic Container Service (Amazon ECS)

Correct Answer: Amazon ECS Service Auto Scaling

Amazon ECS Service Auto Scaling is the correct answer because it automatically adjusts the number of containers running in an Amazon ECS service based on resource utilization metrics like CPU and memory usage. This allows the service to scale up or down dynamically to meet demand. Amazon ECS Task Placement Constraints are used to control where tasks are placed based on attributes of the container instances, but do not handle automatic scaling. Amazon ECS Container Instance Draining is used to remove a container instance from a cluster for maintenance or scale-in, but does not automatically manage scaling. Amazon ECS Task Definition Versioning and Rollback allows rolling back to a previous version of a task definition, but is not related to automatic scaling of containers based on resource utilization.

Correct Answer: Replica scheduling strategy

The Replica scheduling strategy is the best choice for the given scenario. This strategy allows running and maintaining a specified number of tasks simultaneously in an Amazon ECS service. It ensures that the desired count of tasks is always running across the ECS cluster, providing high availability and scalability. If a task becomes unhealthy or stops, the ECS service scheduler launches another instance of the task to replace it and maintain the desired count. The Daemon scheduling strategy is used to run exactly one task on each active container instance that meets all of the task placement constraints specified in the cluster. It is not suitable for running multiple copies of containers. Custom scheduling strategy using AWS Lambda functions is not a built-in feature of Amazon ECS and would require additional setup and management. Host-based scheduling strategy with instance auto-scaling is not a valid option in Amazon ECS. ECS manages the scheduling of containers on instances within a cluster based on the defined scheduling strategy and does not rely on host-based scheduling.

Correct Answer: Use Amazon Elastic Container Service (ECS) with AWS Fargate to run the containerized application on a serverless infrastructure managed by AWS.

The best approach for the company to containerize their web application and deploy it using a managed container orchestration service on serverless infrastructure is to use Amazon Elastic Container Service (ECS) with AWS Fargate. AWS Fargate is a serverless compute engine for containers that allows running containers without managing the underlying infrastructure. It provides automatic scaling, high availability, and eliminates the need to manage EC2 instances. ECS integrates well with Fargate, enabling the company to focus on their application while AWS manages the container orchestration platform. The other options are not suitable because they either require managing EC2 instances directly (EKS with EC2 worker nodes and deploying containers on existing EC2 instances) or do not provide a fully managed container orchestration solution (Elastic Beanstalk with Docker).