amazon-web-services - AWS ASG 冷却期和扩展策略中的预热期有什么区别？

Question

AWS ASG 冷却期(当我想更新我的自动扩展组时可以编辑)和扩展策略中的预热期有什么区别？

Answer 1

冷却时间防止失控的缩放事件。如果您的系统在 CPU 上运行很高，并且您的自动缩放规则添加了一个实例，则需要 5 分钟左右的时间才能使实例完全启动并帮助负载。如果没有冷却时间，规则将继续触发，并可能在 CPU 指标下降之前添加 4 或 5 个实例，从而导致浪费的过度配置。或者在缩减的情况下，超调并导致供应不足。

with a cooldown period in place, the Auto Scaling group launches aninstance and then suspends scaling activities due to simple scalingpolicies or manual scaling until the specified time elapses. (Thedefault is 300 seconds.) This gives newly launched instances time tostart handling application traffic. After the cooldown period expires,any suspended scaling actions resume. If the CloudWatch alarm firesagain, the Auto Scaling group launches another instance, and thecooldown period takes effect again. If, however, the additionalinstance was enough to bring the CPU utilization back down, then thegroup remains at its current size.

Cooldown
实例预热
实例的预热值允许您控制新启动的实例可以贡献 CloudWatch 指标的时间，因此当预热时间到期时，实例被视为 Auto Scaling 组的一部分并将接收流量。

With step scaling policies, you can specify the number of seconds thatit takes for a newly launched instance to warm up. Until its specifiedwarm-up time has expired, an instance is not counted toward theaggregated metrics of the Auto Scaling group. While scaling out, AWSalso does not consider instances that are warming up as part of thecurrent capacity of the group. Therefore, multiple alarm breaches thatfall in the range of the same step adjustment result in a singlescaling activity. This ensures that we don't add more instances thanyou need.

as-scaling-target-tracking