You are a DevOps engineer for a company. You have been requested to create a rolling deployment solution that is cost-effective with minimal downtime. How should you achieve this? Choose two answers from the options below.

Answer options:

A.Re-deploy your application using a CloudFormation template.
B.Re-deploy with a CloudFormation template, define update policies on Auto Scaling groups in your CloudFormation template.
C.Use UpdatePolicy attribute with AutoScalingRollingUpdate policy on CloudFormation to deploy new code.
D.After each stack is deployed, tear down the old stack.

Answer - B and C
The AWS::AutoScaling::AutoScalingGroup resource supports an UpdatePolicy attribute. This is used to define how an Auto Scaling group resource is updated when an update to the CloudFormation stack occurs. A common approach to updating an Auto Scaling group is to perform a rolling update, which is done by specifying the AutoScalingRollingUpdate policy. This retains the same Auto Scaling group and replaces old instances with new ones, according to the parameters specified.
Option A is invalid because re-deploying the application using the Cloudformation template alone will not suffice for the requirement given in the question.
Option D is invalid because this is an inefficient process to tear down stacks when there are stack policies available.
For more information on Autoscaling Rolling Updates, please refer to the below link:
https://aws.amazon.com/premiumsupport/knowledge-center/auto-scaling-group-rolling-updates/