A Company Runs a Database on a Single Amazon EC2

question 186

Multiple Choice

A company runs a database on a single Amazon EC2 instance in a development environment. The data is stored on separate Amazon EBS volumes that are attached to the EC2 instance. An Amazon Route 53 A record has been created and configured to point to the EC2 instance. The company would like to automate the recovery of the database instance when an instance or Availability Zone (AZ) fails. The company also wants to keep its costs low. The RTO is 4 hours and the RPO is 12 hours. Which solution should a DevOps Engineer implement to meet these requirements?

• A) Run the database in an Auto Scaling group with a minimum and maximum instance count of 1 in multiple AZs. Add a lifecycle hook to the Auto Scaling group and define an Amazon CloudWatch Events rule that is triggered when a lifecycle event occurs. Have the CloudWatch Events rule invoke an AWS Lambda function to detach or attach the Amazon EBS data volumes from the EC2 instance based on the event. Configure the EC2 instance UserData to mount the data volumes (retry on failure with a short delay), then start the database and update the Route 53 record.
• B) Run the database on two separate EC2 instances in different AZs with one active and the other as a standby. Attach the data volumes to the active instance. Configure an Amazon CloudWatch Events rule to invoke an AWS Lambda function on EC2 instance termination. The Lambda function launches a replacement EC2 instance. If the terminated instance was the active node, then the function attaches the data volumes to the standby node. Start the database and update the Route 53 record.
• C) Run the database in an Auto Scaling group with a minimum and maximum instance count of 1 in multiple AZs. Create an AWS Lambda function that is triggered by a scheduled Amazon CloudWatch Events rule every 4 hours to take a snapshot of the data volume and apply a tag. Have the instance UserData get the latest snapshot, create a new volume from it, and attach and mount the volume. Then start the database and update the Route 53 record.
• D) Run the database on two separate EC2 instances in different AZs. Configure one of the instances as a master and the other as a standby. Set up replication between the master and standby instances. Point the Route 53 record to the master. Configure an Amazon CloudWatch Events rule to invoke an AWS Lambda function upon the EC2 instance termination. The Lambda function launches a replacement EC2 instance. If the terminated instance was the active node, the function promotes the standby to master and points the Route 53 record to it.

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Definitions:

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