Which of the following is not a characteristic of the Auto Scaling service on AWS?

The correct answer indicates a characteristic that does not align with the core functions of the Auto Scaling service. The Auto Scaling service on AWS is primarily designed to automatically adjust the number of EC2 instances in response to changing demand. This includes scaling the capacity up when the demand increases and scaling it down when demand decreases, ensuring optimal resource utilization and cost management.

While Auto Scaling works closely with other AWS services, the action of sending traffic to healthy instances is primarily a function of the Elastic Load Balancing (ELB) service. ELB distributes incoming application traffic across multiple targets, such as EC2 instances, in a variety of availability zones to ensure higher levels of availability and fault tolerance. Although Auto Scaling can work in conjunction with ELB to ensure instances are available for load balancing, the responsibility of directing traffic lies with the load balancer, not with the Auto Scaling service itself.

The other characteristics listed reflect the true capabilities of Auto Scaling: it automatically adjusts capacity based on demand, it allows scaling both up and down, and it integrates seamlessly with Elastic Load Balancing for optimal performance and availability.