Cron scaler - scale by X or % amount

[hawkesn]

Proposal

The cron scaler currently scales by setting the desiredReplicas within a window.
However, in some cases, you want to scale 'up' or 'down' by an amount or fixed percentage.

Use-Case

Say for example, you are running 5 containers and at 10am you want to scale it up to 10 (+5 containers).
This is possible by setting the cron scaler to scale up to 10 at 10am.

Let's say one day, it's currently running at 15 due to unexpected high demand, and the cron scaler unintentionally scales down the container count to 10 instead.

In this case, the load may be variable but the burst up/down is constant.

Is this a feature you are interested in implementing yourself?

No

Anything else?

No response

[JorTurFer]

Let's say one day, it's currently running at 15 due to unexpected high demand, and the cron scaler unintentionally scales down the container count to 10 instead.

I guess that you have 15 instances because any other metric requires them (cpu/memory/other trigger), right? In that case, don't worry because the HPA Controller takes all the metric one by one and then it does a max between them, so if your other trigger requires 15 instances, the cron scaler won't scale in to 10 because max(15,10) is 15

[tomkerkhove]

I still believe the current cron scaler was a good idea, but it's time to replace it with #3566

I definitely get this proposal which I would incorporate in to the above new proposal; however, increasing by % might be a new general feature we want to look in to.