`scaleDownDelaySeconds: 0` keeps old ReplicaSet running but should scale it down immediately

[AndiDog]

Summary

With scaleDownDelaySeconds: 0 on a blue-green rollout, and clicking Promote-Full in Argo CD UI for faster deployment, the operator kept the old ReplicaSet running without scaling it down or terminating it (and its pods). We would expect the number of seconds to be respected, so zero means "immediately".

In contrast, any non-zero number like scaleDownDelaySeconds: 1 worked fine in our pre-production testing.

There are other reported issues where the meaning of zero was understood differently, so it's important to document it correctly and fix the behavior accordingly. See https://github.com/argoproj/argo-rollouts/issues/1639 and https://github.com/argoproj/argo-rollouts/issues/1841, for example.

Diagnostics

argo-rollouts v1.1.1

(I cannot offer logs right now)

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[zachaller]

So there is some documentation around this here https://argoproj.github.io/argo-rollouts/features/scaledown-aborted-rs/ but it seems to focus around when it is aborted which it might fall into that logic when clicking full promotion. I will try to take a look at this at some point to see if the behavior is correct and also that it matches what is documented.

[kzcPo]

I think scaleDownDelaySeconds: 0 means permanent retention, and I want to add manual deletion action.

[mitchellhuang]

We have also experience this and were surprised by it. We assumed by setting it to 0, there would be no delay and the ReplicaSet would be terminated immediately. We also ended up changing it to 1 to get closer towards the desired behavior.

[coolbry95]

Another option if you want the replica sets to scale down immediately is to use scaleDownDelaySeconds: -1.

This is what we moved to since 0 keeps them indefinitely.

[kzcPo]

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[kzcPo]

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This issue is stale because it has been open 60 days with no activity.

[kzcPo]

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[github-actions[bot]]

This issue is stale because it has been open 60 days with no activity.

[kzcPo]

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[github-actions[bot]]

This issue is stale because it has been open 60 days with no activity.