Which set of steps should the solutions architect take to meet these requirements?
Delete the existing ALB. Create an Auto Scaling group that is configured to handle the web application traffic. Attach a new launch template to the Auto Scaling group. Create a new ALB. Attach the Auto Scaling group to the new ALB. Attach the existing EC2 instances to the Auto Scaling group.
Create an Auto Scaling group that is configured to handle the web application traffic. Attach a new launch template to the Auto Scaling group. Attach the Auto Scaling group to the existing ALAttach the existing EC2 instances to the Auto Scaling group.
Delete the existing ALB and the EC2 instances. Create an Auto Scaling group that is configured to handle the web application traffic. Attach a new launch template to the Auto Scaling group. Create a new ALB. Attach the Auto Scaling group to the new ALB. Wait for the Auto Scaling group to launch the minimum number of EC2 instances.
Create an Auto Scaling group that is configured to handle the web application traffic. Attach a new launch template to the Auto Scaling group. Attach the Auto Scaling group to the existing ALB. Wait for the existing ALB to register the existing EC2 instances with the Auto Scaling group.
Explanations:
Deleting the existing ALB and manually attaching EC2 instances to the new Auto Scaling group is not efficient. The solution requires attaching the existing EC2 instances to the Auto Scaling group, but the instances are already behind the ALB, and this step could cause unnecessary downtime.
Creating an Auto Scaling group with a new launch template and attaching it to the existing ALB ensures that the solution leverages the existing infrastructure, allowing for automatic scaling and replacement of instances without downtime.
Deleting both the ALB and EC2 instances and creating a new ALB introduces unnecessary complexity and potential downtime. Waiting for the Auto Scaling group to launch instances also introduces delays that could cause downtime.
Although attaching the Auto Scaling group to the existing ALB is correct, waiting for the ALB to register the instances with the Auto Scaling group would not be as effective as the approach in option B, which eliminates potential delays.