An Auto Scaling Group (ASG) automatically manages the number of EC2 instances in a group to maintain application performance and availability.
It ensures you always have the right number of instances running based on demand.
Example (kaptaindevops):
His app traffic spikes during office hours. ASG launches more EC2s automatically and scales down at night to save cost.
| Component | Description |
|---|---|
| Launch Template | Blueprint for EC2 (AMI, instance type, security, etc.) |
| Desired Capacity | Target number of instances |
| Minimum Capacity | Minimum instances to run |
| Maximum Capacity | Upper limit of scaling |
| Health Checks | Replace unhealthy instances automatically |
Example: