Which Statement is Incorrect About Auto-Scaling Group Termination Policy?

Answer: B.

Option B is the only false statement, the rest of them are true statements.

The default termination policy applies multiple termination criteria before selecting an instance to terminate.

When Amazon EC2 Auto Scaling terminates instances, it first determines which Availability Zones have the most instances, and it finds at least one instance that is not protected from scale-in.

Determine whether any of the instances eligible for termination use the oldest launch template or configuration:

[For Auto Scaling groups that use a launch template]

Determine whether any of the instances use the oldest launch template unless there are instances that use a launch configuration.

Amazon EC2 Auto Scaling terminates instances that use a launch configuration before it terminates instances that use a launch template.

[For Auto Scaling groups that use a launch configuration]

Determine whether any of the instances use the oldest launch configuration.

After applying the preceding criteria, if there are multiple unprotected instances to terminate, determine which instances are closest to the next billing hour.

If there are multiple unprotected instances closest to the next billing hour, terminate one of these instances at random.

Reference:

https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-termination-policies.html

Auto Scaling group is a service provided by AWS which enables users to launch or terminate EC2 instances automatically based on pre-defined rules, in order to handle changes in demand for an application or service.

When creating an Auto Scaling group, users can define a Launch Configuration, which defines the configuration of the instances launched by the Auto Scaling group. Additionally, users can define a Termination Policy, which specifies the order and criteria for selecting instances to terminate when scaling in.

The provided options are all related to the default termination policy for scale in. The default termination policy selects instances for termination based on the criteria listed below:

A. Determine unprotected instances in the selected Availability Zone which uses the oldest launch configuration. If there is one such instance, terminate it.

This statement is correct. The default termination policy selects the unprotected instances in the selected Availability Zone which use the oldest launch configuration for termination.

B. Determine unprotected instances in the selected Availability Zone use the newest launch configuration. If there is one such instance, terminate it.

This statement is incorrect. The default termination policy selects the instances which use the oldest launch configuration for termination, not the newest.

C. If multiple instances use the oldest launch configuration, determine which unprotected instances are closest to the next billing hour and terminate it.

This statement is correct. If multiple instances use the oldest launch configuration, the default termination policy selects the unprotected instances which are closest to the next billing hour for termination.

D. If there is more than one unprotected instance closest to the next billing hour, select one of the instances randomly.

This statement is correct. If there is more than one unprotected instance closest to the next billing hour, the default termination policy selects one of the instances randomly for termination.

In conclusion, the correct statement is A, while the incorrect statement is B. The default termination policy selects unprotected instances using the oldest launch configuration for termination, not the newest.