Added KEP for Node Resource Score Strategy

[ahg-g]

#2458

/sig scheduling

[alculquicondor]

In the default profile, this plugin is enabled along with NodeResourcesLeastAllocated. It's optimization objective is complementary to the other plugins, it should remain separate.

[ahg-g]

I am hoping we can express everything using the plugin config, the idea is to have a path to mirror this into the pod spec. I guess we need to answer the following questions:

1. Is it useful to use balanced allocation on its own
2. What other plugins benefit from having balanced allocation enabled?
3. For plugins identified in (2), is it always better to have balanced allocation enabled?

answering those questions will help us understand if its scoring behavior can be expressed in the unified configuration (e.g., either bake it into existing strategies always or as a flag that can be enabled on demand with other strategies)

[alculquicondor]

cc @Huang-Wei

[ahg-g]

I removed the balanced strategy for now, we can come back to it later if we find a good API to integrate it.

[alculquicondor]

/lgtm

[ahg-g]

Thanks, squashed for now.

[alculquicondor]

/lgtm

[damemi]

Would this be better as ResourceScoringStrategy? Or is this planned to be used for other scoring plugins besides resource allocation?

[ahg-g]

may be, lets leave that to the api review.

[Huang-Wei]

Is this plugin flexible to support internal combination of sub-fit strategy? Like a user may want to combine 2 strategies: least (absolute) available resource plus most allocated resource (ratio).

[ahg-g]

For new ones, we need to understand if they should be baked into existing scoring strategies, or add knobs to enable them on demand if they are cross cutting (or have keep them in separate plugin).

[Huang-Wei]

/approve

[ahg-g]

/hold

[wojtek-t]

/approve PRR

Please squash commits.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ahg-g, Huang-Wei, wojtek-t

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• keps/prod-readiness/OWNERS [wojtek-t]
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[ahg-g]

/milestone v1.21

[annajung]

Hi @ahg-g, would you be able to expand this a bit more? A little more detail here would really help. You can take a look at the comment of what test plan should consider in the KEP template as well.

[ahg-g]

there is nothing particularly challenging to test here, we are proposing a new config parameter to an existing logic, so this doesn't really include complex interactions; I added some clarification.

[Huang-Wei]

/lgtm

[ahg-g]

/hold cancel

[alculquicondor]

/lgtm