Exam AWS Certified Solutions Architect - Associate SAA-C02 topic 1 question 48 discussion

A company's web application is using multiple Linux Amazon EC2 instances and storing data on Amazon Elastic Block Store (Amazon EBS) volumes. The company is looking for a solution to increase the resiliency of the application in case of a failure and to provide storage that complies with atomicity, consistency, isolation, and durability (ACID).
What should a solutions architect do to meet these requirements?

Suggested Answer: C 🗳️
How Amazon EFS Works with Amazon EC2
The following illustration shows an example VPC accessing an Amazon EFS file system. Here, EC2 instances in the VPC have file systems mounted.
In this illustration, the VPC has three Availability Zones, and each has one mount target created in it. We recommend that you access the file system from a mount target within the same Availability Zone. One of the Availability Zones has two subnets. However, a mount target is created in only one of the subnets.


Benefits of Auto Scaling -
Better fault tolerance. Amazon EC2 Auto Scaling can detect when an instance is unhealthy, terminate it, and launch an instance to replace it. You can also configure Amazon EC2 Auto Scaling to use multiple Availability Zones. If one Availability Zone becomes unavailable, Amazon EC2 Auto Scaling can launch instances in another one to compensate.
Better availability. Amazon EC2 Auto Scaling helps ensure that your application always has the right amount of capacity to handle the current traffic demand.
Better cost management. Amazon EC2 Auto Scaling can dynamically increase and decrease capacity as needed. Because you pay for the EC2 instances you use, you save money by launching instances when they are needed and terminating them when they aren't.
Reference:
https://docs.aws.amazon.com/efs/latest/ug/how-it-works.html#how-it-works-ec2 https://docs.aws.amazon.com/autoscaling/ec2/userguide/auto-scaling-benefits.html