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Fix danger in replicas documentation #1866

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Fix danger in replicas documentation #1866

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5 changes: 2 additions & 3 deletions docs/development_suite/api-console/api-design/replicas.md
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Expand Up @@ -13,9 +13,8 @@ Based on your release pipeline, the `ENABLE_HPA` environment variable could need
:::

:::danger
The replicas configured will not work properly if the [static replicas](/development_suite/api-console/api-design/services.md#microservice-configuration) is set to 0.

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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@fredmaggiowski fredmaggiowski Dec 19, 2024 •
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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.

:::

## Configure Replicas
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