Difference between a launch template and a launch configuration.
AWS · Basic level
Answer
Launch templates are the modern EC2 launch definition with versioning and support for newer features. Launch configurations are legacy and less capable, so I use launch templates for ASGs and controlled rollouts.
Technical explanation
Launch template versioning enables safe AMI and bootstrap rollouts with ASG instance refresh.
Compute design should balance availability, scaling speed, startup time, instance limits, health checks, and deployment rollback, not just raw instance size.
Autoscaling and load balancing only work well when health checks reflect readiness and when applications externalize state.
Cost optimization should be tied to utilization data and workload tolerance for interruption, commitment, and architecture changes.
Hands-on example
1. Build a launch template or workload definition with IAM role, security groups, user data/bootstrap, health endpoint, and CloudWatch metrics.
2. Place compute behind an ALB/NLB or scaling group and run a controlled load test to observe scaling and health behavior.
3. Tune scaling policy, warmup/cooldown, target group health checks, and rollback procedure.
4. Compare cost and reliability after the test, then promote the configuration through IaC.
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