Scheduled Scaling and Predictive Scaling

Dynamic scaling policies (target tracking and step scaling) are reactive—they respond after a metric threshold is already breached. For known, predictable traffic patterns like business-hours peaks, end-of-month batch runs, or Black Friday sales, reactive scaling is too slow because instances take minutes to launch and warm up. Scheduled Scaling and Predictive Scaling address this by proactively adjusting capacity before the load arrives.

A Scheduled Scaling Action changes the ASG's min, max, or desired capacity at a specific date and time, or on a recurring cron schedule. This is ideal when you know exactly when load will increase—for example, pre-warming before a planned marketing event, or scaling down overnight when traffic is minimal to save costs. Scheduled actions override the current desired capacity at the specified time.