Question

A SysOps administrator manages an EC2 Auto Scaling group behind an Application Load Balancer. The application takes about 4 minutes to fully initialize and pass the ALB target group health checks after an instance launches. The Auto Scaling group is configured to use ELB health checks. Administrators notice that newly launched instances are being terminated and replaced repeatedly, causing a launch loop that never stabilizes. What is the MOST likely cause and appropriate fix?

Accepted Answer

The Auto Scaling group health check grace period is set too low; increase it to accommodate the application's 4-minute initialization time.

Answer

The ALB target group deregistration delay is too high; reduce it so unhealthy instances are removed faster.

Answer

The scaling policy cooldown period is too short; increase the cooldown to prevent repeated launches.

Answer

The launch template uses an incorrect AMI; rebuild the AMI to reduce boot time.