During the coverage of EC2 Auto-Scaling, you refer to two cooldown periods, one for health checks which allows a new instance to fully launch before being required to respond to health checks and another for how long scaling should wait before making a scaling decision after the launch of the instance. Both of these are referred to in the videos as "cooldowns", but isn’t the 300 seconds wait before scaling decisions are made called a "Warm-Up"? Just wondering if referring to both as cooldowns is acceptable or if the default 300 seconds pause for scaling decisions after a scaling event would be known as a "Warm-Up" period on the exam. Thanks!
I think I do eventually use distinct terms in the lecture, but Warm-Up is more associated with the time it takes a new instance to get stable before we expect it to start responding to health checks. Cooldown period is the "timeout" before responding to new scaling events. You can read in more detail here: https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-scaling-simple-step.html
I got a bit confused. From what I understood is that Cooldown period has nothing to do with health check grace-period. These are two separate things. The cooldown period helps you prevent your Auto Scaling group from launching or terminating additional instances before the effects of previous activities are visible.
While the health check grace-period is the amount of time until Amazon EC2 Auto Scaling checks the health of instances after they are put into service. The intention of this setting is to prevent Amazon EC2 Auto Scaling from marking instances as unhealthy and terminating them before they have time to come up.
But the health check grace-period and the warm-up, are basically the same thing, since AWS defines the warm-up as the number of seconds that it takes for a newly launched instance to warm up. Until its specified warm-up time has expired, an instance is not counted toward the aggregated metrics of the Auto Scaling group.
Thank you for your insights