[Feature] How to evaluate whether to scale-out or scale-in, and what is the number of nodes to scale-out or scale-in

[renajin]

Feature Request

Is your feature request related to a problem? Please describe:
Middleware need to evaluate whether to scale-out or scale-in, and what is the number of nodes to scale-out or scale-in, what is the detailed strategy about this?

Describe the feature you'd like:

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: