Autoscaling Group Settings

Answer - C.

You should make a copy of the launch configuration, add the new instance type.

The change the Autoscaling Group to include the new instance type.

Then change the Desired number of the Autoscaling Group to 4 so that instances of new instance type can be launched.

Once launched, change the desired size back to 2 so that Autoscaling will delete the instances with the older configuration.

Note that the assumption here is that the current instances are equally distributed across multiple AZ's because Autoscaling will first use the AZRebalance process to terminate instances.

Option A is invalid because you cannot make changes to an existing Launch configuration.

Option B is invalid because if you delete the existing launch configuration, your application will not be available.

You need to ensure a smooth deployment process.

Option D is invalid because you should change the desired size to 4 after attaching the new launch configuration.

For more information on Changing the Launch Configuration for an Auto Scaling Group, please visit below AWS Docs:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/change-launch-config.html

For more information on Autoscaling Suspend and Resume, please visit the below URL:

http://docs.aws.amazon.com/autoscaling/latest/userguide/as-suspend-resume-processes.html

The scenario described in the question is that you have an Autoscaling group with a certain configuration, and you need to change the instance type and launch new instances with the updated configuration. The goal is to have a total of 4 instances in the group.

Option A suggests changing the instance type in the current launch configuration and changing the desired value of the Autoscaling Group to 4. This approach will launch new instances with the updated configuration, but it may not be the best option if you want to revert to the previous configuration later. Also, it may not be practical to change the instance type of an existing instance.

Option B suggests deleting the current Launch configuration and creating a new one with the updated instance type. This approach will launch new instances with the updated configuration, and you can easily revert to the previous configuration by deleting the new launch configuration. However, this approach will also terminate the existing instances in the Autoscaling Group, which may not be desirable.

Option C suggests making a copy of the Launch configuration and changing the instance type in the new configuration. You can then attach the new launch configuration to the Autoscaling Group and change the maximum and desired size to 4. This will launch new instances with the updated configuration. Once the new instances are launched, you can change the desired and maximum size back to 2. This approach will allow you to test the updated configuration without terminating the existing instances, and you can easily revert to the previous configuration by deleting the new launch configuration.

Option D suggests changing the desired and maximum size of the Autoscaling Group to 4 and then making a copy of the Launch configuration and changing the instance type in the new configuration. You can then attach the new launch configuration to the Autoscaling Group and change the maximum and desired size back to 2. This approach is similar to option C, but it may result in unnecessary instances being launched if the desired and maximum size are set to 4.

In summary, option C is the best approach as it allows you to test the updated configuration without terminating the existing instances, and you can easily revert to the previous configuration by deleting the new launch configuration.