Q11 — AWS SAA-C03 Ch.13

Question 11 of 100 | ← Chapter 13

Q911. A company is migrating a data center from its on-premises location to AWS. The company has several legacy applications that are hosted on individual virtual servers. Changes to the application designs cannot be made.Each individual virtual server currently runs as its own EC2 instance. A solutions architect needs to ensure that the applications are reliable and fault tolerant after migration to AWS. The applications will run on Amazon EC2 instances.Which solution will meet these requirements?

• A. Create an Auto Scaling group that has a minimum of one and a maximum of one. Create an Amazon Machine Image (AMI) of each application instance. Use the AMI to create EC2 instances in the Auto Scaling group Configure an Application Load Balancer in front of the Auto Scaling group.
• B. Use AWS Backup to create an hourly backup of the EC2 instance that hosts each application. Store the backup in Amazon S3 in a separate Availability Zone. Configure a disaster recovery process to restore the EC2 instance for each application from its most recent backup.
• C. Create an Amazon Machine Image (AMI) of each application instance. Launch two new EC2 instances from the AMI. Place each EC2 instance in a separate Availability Zone. Configure a Network Load Balancer that has the EC2 instances as targets. ✓
• D. Use AWS Mitigation Hub Refactor Spaces to migrate each application off the EC2 instance. Break down functionality from each application into individual components. Host each application on Amazon Elastic Container Service (Amazon ECS) with an AWS Fargate launch type.

Correct Answer: C. Create an Amazon Machine Image (AMI) of each application instance. Launch two new EC2 instances from the AMI. Place each EC2 instance in a separate Availability Zone. Configure a Network Load Balancer that has the EC2 instances as targets.

Explanation

To ensure that the legacy applications are reliable and fault-tolerant after migrating to AWS, the most suitable solution is:C. Create an Amazon Machine Image (AMI) of each application instance. Launch two new EC2 instances from the AMI. Place each EC2 instance in a separate Availability Zone. Configure a Network Load Balancer that has the EC2 instances as targets.By creating an AMI of each application instance, the company can replicate the existing virtual server configuration in AWS. Launching two new EC2 instances from the AMI ensures redundancy and fault tolerance by distributing the application across multiple instances.Placing each EC2 instance in a separate Availability Zone enhances availability and resilience. In the event of an issue or failure in one Availability Zone, the application can continue running from the other Availability Zone.Configuring a Network Load Balancer with the EC2 instances as targets allows for load distribution and automatic failover. The load balancer monitors the health of the instances and routes traffic to the healthy instances, ensuring reliable access to the applications.Option A suggests creating an Auto Scaling group with a minimum and maximum of one instance, using an AMI for each application. While this approach provides some level of fault tolerance, it does not provide the same level of redundancy as having multiple instances in separate Availability Zones.Option B suggests using AWS Backup to create backups of the EC2 instances and store them in Amazon S3. While backups are important for data protection, it does not directly address the requirement of application reliability and fault tolerance.Option D suggests migrating the applications to Amazon Elastic Container Service (Amazon ECS) with an AWS Fargate launch type. This option would require significant changes to the application design, which is explicitly mentioned as not possible in the scenario.In summary, option C, which involves creating AMIs, launching multiple EC2 instances in separate Availability Zones, and configuring a Network Load Balancer, is the most appropriate solution. It ensures reliability, fault tolerance, and high availability for the company's legacy applications hosted on EC2 instances.