Your company has an application sitting on EC2 Instances behind an Elastic Load balancer. The EC2 Instances are being launched as part of an Autoscaling Group. Which of the following is an example of Blue Green Deployments in AWS?

Answer options:

A.Use a Cloudformation stack to deploy your resources. Use 2 Cloudformation stacks. Whenever you want to switch over, deploy and use the resources in the second Cloudformation stack.
B.Use the Elastic beanstalk service to deploy your resources. Use 2 Elastic beanstalk environments. Use Rolling deployments to switch between the environments.
C.Re-deploy your application behind a load balancer that uses Auto Scaling groups, create a new Auto Scaling group, and associate it to the load balancer. After the new environment is up and running, set the desired number of instances on the old Auto Scaling group to zero, and when all instances have terminated, delete the old Auto Scaling group.
D.Use the Opsworks service to deploy your resources. Use 2 Opswork layers to deploy 2 versions of your application. When the time comes for the switch, change to the alternate layer in the Opswork stack

Answer – C
This deployment technique is given in the AWS Whitepaper
As you scale up the green Auto Scaling group, you can take blue Auto Scaling group instances out of service by either terminating them or putting them in Standby state. Standby is a good option because if you need to roll back to the blue environment, you only have to put your blue server instances back in service and they`re ready to go.1 4 As soon as the green group is scaled up without issues, you can decommission the blue group by adjusting the group size to zero. If you need to roll back, detach the load balancer from the green group or reduce the group size of the green group to zero.
For more information on Blue Green deployments, please visit the below URL:
https://d0.awsstatic.com/whitepapers/AWS_Blue_Green_Deployments.pdf