SAA-C03 Question 341
Select 3A company is migrating its on-premises web application to AWS and wants to ensure high availability and fault tolerance. The application consists of a front-end hosted on virtual machines and a back-end relational database. Which combination of services and features should the company use to meet its requirements?
- A
Deploy the front-end on Amazon EC2 instances in an Auto Scaling group across multiple Availability Zones
- B
Use an Application Load Balancer to distribute traffic to the front-end EC2 instances
- C
Host the database on a single Amazon RDS instance in one Availability Zone
- D
Enable Multi-AZ deployment for the Amazon RDS database
- E
Store session state locally on each EC2 instance
Show answer and explanation
Correct answers: A, B, D
Explanation
To achieve high availability and fault tolerance, the company should deploy the front-end on EC2 instances in an Auto Scaling group across multiple Availability Zones and use an Application Load Balancer to distribute traffic. For the back-end database, enabling Multi-AZ deployment for Amazon RDS ensures redundancy and failover capabilities. Hosting the database on a single instance or storing session state locally on EC2 instances introduces single points of failure, which should be avoided.
- A. Correct.
This is correct because deploying EC2 instances in an Auto Scaling group across multiple Availability Zones ensures high availability and fault tolerance for the front-end.
- B. Correct.
This is correct because an Application Load Balancer enables load distribution across the EC2 instances, improving availability and handling traffic spikes.
- C. Incorrect.
This is incorrect because hosting the database on a single RDS instance in one Availability Zone creates a single point of failure, which does not meet the high availability requirement.
- D. Correct.
This is correct because enabling Multi-AZ deployment for Amazon RDS ensures that a standby database is available in another Availability Zone for failover, enhancing fault tolerance.
- E. Incorrect.
This is incorrect because storing session state locally on EC2 instances can lead to issues during failover or scaling. Using a centralized session management solution like Amazon ElastiCache or Amazon DynamoDB would be more appropriate.