AWS Certified Solutions Architect – Associate (SAA-C03) — Question 201

A company needs to run a critical application on AWS. The company needs to use Amazon EC2 for the application’s database. The database must be highly available and must fail over automatically if a disruptive event occurs.

Which solution will meet these requirements?

Answer options

• A. Launch two EC2 instances, each in a different Availability Zone in the same AWS Region. Install the database on both EC2 instances. Configure the EC2 instances as a cluster. Set up database replication.
• B. Launch an EC2 instance in an Availability Zone. Install the database on the EC2 instance. Use an Amazon Machine Image (AMI) to back up the data. Use AWS CloudFormation to automate provisioning of the EC2 instance if a disruptive event occurs.
• C. Launch two EC2 instances, each in a different AWS Region. Install the database on both EC2 instances. Set up database replication. Fail over the database to a second Region.
• D. Launch an EC2 instance in an Availability Zone. Install the database on the EC2 instance. Use an Amazon Machine Image (AMI) to back up the data. Use EC2 automatic recovery to recover the instance if a disruptive event occurs.

Correct answer: A

Explanation

Option A is the correct choice as it provides high availability through the use of two EC2 instances across different Availability Zones, allowing for automatic failover. Option B does not ensure high availability since it relies on a single instance, and provisioning through AWS CloudFormation does not provide immediate failover. Option C is incorrect as it uses different Regions, which can introduce latency and complexity for failover. Option D also relies on a single instance and automatic recovery, which does not guarantee high availability.