AWS Certified DevOps Engineer - Professional Exam Preparation

Answer - A.

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 ELB, attach the new Autoscaling Group, and then use Route53 to divert the traffic.

Option B is wrong because it does not mention how to divide the instances.

If it is the same Auto Scaling group, it will be difficult to revert the configurations back.

Option C is wrong because Elastic beanstalk is good for development environments.

Also, there is no mention of having 2 environments where environment URLs can be swapped.

Option D is wrong because you cannot control the weight for either the Blue or Green stack with this method.

For more information on Route53 routing policies, please refer to the below link:

http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/routing-policy.html

The scenario described suggests that you currently have an AWS setup that includes an Elastic Load Balancer (ELB), an Auto Scaling group, and a Launch Configuration with an Amazon Machine Image (AMI) running your application. Now you want to update your application to a new version and deploy it with minimal downtime.

Option A:

This option suggests creating a second ELB, a new Auto Scaling Group, and a new Launch Configuration with the new AMI. The Route53 Weighted Routing policy will then be used to adjust the proportion of traffic hitting the two ELBs.

The benefit of this option is that you can deploy the new version alongside the old version, ensuring that there is no downtime. The weighted routing policy allows you to control the proportion of traffic hitting the two ELBs, which is useful for testing the new version before you fully migrate to it.

Option B:

This option suggests creating new AMIs with the new application version and using the new EC2 instances alongside the older instances. The proportion of traffic hitting the new instances will be set to half.

The benefit of this option is that you can deploy the new version alongside the old version, ensuring that there is no downtime. However, you'll have to carefully manage the proportion of traffic hitting the two groups of instances. It might also be difficult to rollback if there are issues with the new version.

Option C:

This option suggests redeploying with AWS Elastic Beanstalk and Elastic Beanstalk versions. Route53 Weighted Round Robin Records will be used to adjust the proportion of traffic hitting the two ELBs.

The benefit of this option is that AWS Elastic Beanstalk can manage the deployment for you, making the process easier. The weighted round-robin records can also be used to manage traffic proportion. However, it might take more time to set up the Elastic Beanstalk environment, and there may be a learning curve involved.

Option D:

This option suggests creating a full second stack of instances, cutting the DNS over to the new stack of instances, and changing the DNS back if a rollback is needed.

The benefit of this option is that you can completely separate the new version from the old version, reducing the risk of issues. However, there will be some downtime during the DNS switch, and it might be difficult to rollback if there are issues with the new version.

In conclusion, option A is the most optimal solution. It allows you to deploy the new version alongside the old version, control the proportion of traffic hitting the two ELBs, and quickly rollback if there are issues.