AWS DevOps Engineer Professional DOP-C01 – Question520

You currently have the following setup in AWS:
1) An Elastic Load Balancer
2) Auto Scaling Group which launches EC2 Instances
3) AMIs with your code pre-installed You want to deploy the updates of your app to only a certain number of users. You want to have a cost-effective solution. You should also be able to revert back quickly.
Which of the below solutions is the most feasible one?

A.
Create a second ELB, and a new Auto Scaling Group assigned a new Launch Configuration. Create a new AMI with the updated app. Use Route53 Weighted Round Robin records to adjust the proportion of traffic hitting the two ELBs.
B. Create new AMIs with the new app. Then use the new EC2 instances in half proportion to the older instances.
C. Redeploy with AWS Elastic Beanstalk and Elastic Beanstalk versions. Use Route 53 Weighted Round Robin records to adjust the proportion of traffic hitting the two ELBs
D. Create a full second stack of instances, cut the DNS over to the new stack of instances, and change the DNS back if a rollback is needed.

Correct Answer: A

Explanation:

Explanation:
The Weighted Routing policy of Route53 can be used to direct a proportion of traffic to your application. The best option is to create a second CLB, attach the new Autoscaling Group and then use Route53 to divert the traffic. Option B is wrong because just having EC2 instances running with the new code will not help.
Option C is wrong because Clastic beanstalk is good for development environments, and also there is no mention of having 2 environments where environment urls can be swapped. Option D is wrong because you still need Route53 to split the traffic.