Compute
CoreAmazon EC2 Auto Scaling
Managed EC2 fleet capacity that replaces unhealthy instances and adjusts desired count from policy or schedule.
Key points
- Distribute groups across AZs to match the required failure boundary.
- Scale from workload-relevant metrics and account for warm-up, cooldown, and downstream limits.
- Auto Scaling replaces instances; it does not externalize application state or create database capacity.
Best-known use cases
- Maintain a healthy multi-AZ web or worker fleet.
- Add and remove EC2 capacity for variable demand.
What candidates often confuse it with
- Auto Scaling changes instance count; ELB routes traffic and health-checks targets.
- EC2 Auto Scaling manages EC2 groups; AWS Auto Scaling coordinates scaling plans across supported resource types.
Key takeaway
Choose EC2 Auto Scaling for replaceable elastic fleets, paired with the right traffic or queue signal.
Related services
- Amazon EC2
- Elastic Load Balancing (ELB)
- Amazon CloudWatch
Relevant exam tasks
- D2.1
- D2.2
- D3.2
- D4.2