关于自动扩缩容策略配置UI及控制台操作的技术疑问

Hey there, let's unpack your confusion step by step—this interface design can feel counterintuitive at first, but each part serves a specific purpose:

1. Can you override the alarm's lower threshold by modifying the "trigger condition" value? #

Yes and no—let me break it down clearly:

• The initial value (81) is pulled directly from your linked CPU alarm (≥81% usage). When you change it to something like 123, you are effectively setting a higher activation bar for this scaling step.
• But the UI's validation prompt (The lower bound of the first step must be greater than or equal to the alarm threshold) is critical here: you can't set this value below the alarm's threshold. So you can only raise the bar, not lower it past the alarm's trigger point.

2. What's the purpose of this editable field? #

It's not exactly a "temporary manual override"—instead, it's a tool to add granularity to your scaling strategy on top of the alarm:

• Your alarm acts as the gatekeeper: it has to trigger first (CPU ≥81%) before any scaling rules even come into play.
• The editable trigger condition in the scaling step lets you refine the logic: "Okay, the alarm is tripped, but only start this scaling action when CPU hits even higher (like 123%)".
• This is perfect for tiered scaling: e.g., first scale out when CPU hits 90% (after the 81% alarm triggers), then scale out again at 95%, etc.

3. What does < +infinity mean? #

That's just a shorthand way of saying "all values above the lower bound of this step". For example:

• If your first step has a lower bound of 81, < +infinity means any CPU usage value ≥81% (up to 100%, since CPU can't exceed that) will trigger this scaling action.
• If you add a second step with a lower bound of 90, then < +infinity for that step would cover 90% to 100% CPU, while the first step handles 81% to 89%.

To sum it up: the alarm is the minimum requirement for scaling to kick in, and the editable trigger conditions let you fine-tune when exactly each scaling step activates once the alarm is already triggered.

内容的提问来源于stack exchange，提问作者red888