A company runs a large workload every Friday evening on Amazon EC2 instances in two Availability Zones in the us-east-1 Region. Normally no more than two instances run, but the company wants to scale to six instances each Friday for the recurring workload. Which solution meets this requirement with the least operational overhead?

An Auto Scaling group with a scheduled action is the most efficient solution. Scheduled actions allow you to define scaling activities (like changing desired, minimum, or maximum capacity) to occur at specific times or on a recurring schedule, perfectly suiting the weekly workload. This automates the scaling process, minimizing operational overhead. Manual scaling would require someone to manually adjust the instance count every Friday, which is inefficient and prone to human error. Automatic scaling (e.g., based on CPU utilization) might not reliably scale to six instances precisely when needed if the workload doesn't immediately trigger the metrics, or it might scale down prematurely. Creating a reminder in EventBridge would still require a separate mechanism (like a Lambda function) to perform the scaling, adding complexity compared to the built-in scheduled action of an Auto Scaling group.