AWS Auto Scaling
AWS Auto Scaling is a Amazon Web Services service that monitors applications and automatically adjusts capacity to maintain steady performance at the lowest possible cost — but, critically, it is a different service from Amazon EC2 Auto Scaling. Amazon EC2 Auto Scaling only scales fleets of EC2 instances within an Auto Scaling group; AWS Auto Scaling sits a level above it, letting a single scaling plan coordinate scaling across several resource types at once.
Key points
- Not the same service as Amazon EC2 Auto Scaling. Amazon EC2 Auto Scaling manages EC2 Auto Scaling groups only. AWS Auto Scaling is a unified orchestration layer built on top of the Amazon EC2 Auto Scaling API (for EC2) and the separate Application Auto Scaling API (for everything else), exposed through one console and one scaling plan.
- Resource types AWS Auto Scaling can scale, in a single plan: EC2 Auto Scaling groups, EC2 Spot Fleet requests, Amazon ECS services, Amazon DynamoDB tables and global secondary indexes, and Amazon Aurora read replicas.
- A scaling plan groups the resources for an application (often discovered via tags) and automatically generates the underlying target-tracking and predictive scaling policies for each one, based on a chosen strategy — optimize for availability, optimize for cost, or a balanced default.
- Predictive scaling uses machine learning on historical load data to forecast upcoming traffic and scale resources ahead of the demand spike, rather than only reacting after a Amazon Cloudwatch metric crosses a threshold — the same predictive-scaling capability that Amazon EC2 Auto Scaling now also offers natively as its own scaling policy type.
- No additional charge for AWS Auto Scaling itself; you pay only for the underlying resources it provisions (EC2 instances, DynamoDB throughput, and so on).
- Exam framing: a question about scaling only EC2 instances in one Auto Scaling group points to Amazon EC2 Auto Scaling. A question about scaling multiple different resource types together (e.g. EC2 + ECS + DynamoDB) from one unified interface points to AWS Auto Scaling.
- AWS publishes a guide for migrating an existing scaling plan’s settings directly onto native Amazon EC2 Auto Scaling and Application Auto Scaling policies — evidence that AWS now steers customers toward configuring target-tracking and predictive scaling on each service directly, with the AWS Auto Scaling scaling-plan layer as the older, higher-level convenience wrapper around them.