EC2 Auto Scaling With QuickInfra: Handle Traffic Spikes Without Manual Intervention

An EC2 Auto Scaling Group that's misconfigured is sometimes worse than no Auto Scaling at all. Groups that scale up on the wrong metric, use stale launch configurations, or don't drain connections properly before terminating instances can cause more downtime than a fixed-size deployment. QuickInfra generates Auto Scaling configurations that actually work under production conditions.

Launch Templates Instead of Launch Configurations

AWS deprecated Launch Configurations in favour of Launch Templates. Launch Templates support versioning — you can update the template while the ASG continues running the previous version, then roll out the new version in a controlled way. QuickInfra generates Launch Templates exclusively, with a pinned version reference in the ASG configuration so version updates don't apply automatically.

Scaling Policies

QuickInfra supports two scaling policy types: Target Tracking and Step Scaling.

Target Tracking is the recommended starting point for most workloads. You declare a target metric and value — "keep average CPU utilisation at 60%" — and AWS calculates the exact scaling actions needed. QuickInfra sets this up with a 300-second scale-in cooldown to prevent thrashing.

Step Scaling is useful when you want different scaling aggressiveness at different load levels — scale by 2 instances when CPU hits 70%, by 4 instances when it hits 85%. QuickInfra generates the step scaling policy with configurable thresholds.

Health Checks

The default ASG health check uses EC2 status checks. For instances behind an Application Load Balancer, you want ELB health checks — the ASG will terminate and replace instances that the ALB considers unhealthy, not just instances with failed hardware checks. QuickInfra configures ELB health checks automatically when an ASG is associated with a load balancer target group.

Connection Draining

When an instance is scaled in (terminated), the ALB needs time to drain existing connections before the instance is removed. QuickInfra sets a deregistration delay on the target group (default 30 seconds) so in-flight requests complete cleanly rather than getting a connection reset.

Multi-AZ Placement

QuickInfra distributes ASG instances across all available AZs in the selected region. The Availability Zone rebalancing feature is enabled so the group re-distributes when one AZ has more instances than others after scaling events.