Fix danger in replicas documentation #1866
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| Setting both static replicas and HPA Replicas may lead to undefined behaviors | ||
| When the HPA is not active, the static replicas setting will determine the number of replicas. | ||
| If the HPA is active, the [static replicas](/development_suite/api-console/api-design/services.md#microservice-configuration) setting will serve as a baseline, but it must be configured with a non-zero value to ensure a minimum number of replicas. |
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This is not how k8s works in terms of HPA/deployment.spec.replicas collision, thought.
If you are using HPA you should not be using static replicas as this will lead to undefined behaviours, such as k8s scaling to the value defined in the replicas field during an apply, regardless of any currently active HPA.
e.g.
Assuming you have an HPA between 2 and 4 and the current scaling is at 3.
if you release the deployment with the replicas field set to 2, the pods will be scaled from 3 down to 2 and then, after a while, the HPA will kick-in again scaling back to 3.
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Description
Description
This pull request aims to improve the clarity of the documentation regarding managing static replicas and horizontal pod autoscalers (HPA). The current documentation might be confusing for users trying to understand the difference between these two approaches to scaling deployments.
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