Make HighNodeUtilization select 1 node if all nodes are underutilized

[zoonage]

Eventually reconcile the issue in #725 by tainting and removing 1 node at a time on each run.

There's definitely a more efficient way by working out how many nodes could be removed to achieve a certain resource utilisation density on the remaining nodes, however this is a quick fix that eventually reconciles the cluster into the desired state

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[zoonage]

This is the first time I've tried to use the de-scheduler, how are the *NodeUtilization plugins preventing pods from being re-scheduled onto the node they've just been evicted from?

[zoonage]

This is the first time I've tried to use the de-scheduler, how are the *NodeUtilization plugins preventing pods from being re-scheduled onto the node they've just been evicted from?

I've added PreferredNoSchedule tainting to nodes now to avoid scheduling on nodes we're trying to remove

[zoonage]

Just realised the tainting has an unintended effect on LowNodeUtilization, will give this a rethink

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PR needs rebase.

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/lifecycle stale

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/lifecycle rotten

[ricardomaraschini]

Hi @zoonage , do you have any plans on moving this forward ? I think this is a very nice addition to the plugin.

[zoonage]

Hi @zoonage , do you have any plans on moving this forward ? I think this is a very nice addition to the plugin.

Heya, yeah I do, I've just been time constrained a lot this year. Hoping to get some time for it in August to wrap this up

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/close

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@k8s-triage-robot: Closed this PR.

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/close

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[SarCode]

/remove-lifecycle rotten

[SarCode]

Hey @zoonage, this feature sounds what I was trying with #1766, but your integration is much better

[zoonage]

Hey @zoonage, this feature sounds what I was trying with #1766, but your integration is much better

Skimming your change description it looks like what this needs is a combination of the two to work, my approach was flawed because it assumes you can treat each node as identical, however there are so many cases where that isn't true (e.g. node groups, pods with AZ bound PVs etc)

Currently the place I'm working isn't using k8s so I don't have the time (or infrastructure) to test these changes right now unfortunately, however if you want to take any of my changes please feel free to use them