Add native histogram support for histogram metrics

[rabenhorst]

This PR exposes native histogram configuration for histogram metrics as flags. Without setting the flags, behavior won't change. Native histograms are only scraped when both Prometheus and the client support it and have it enabled, otherwise classic histograms will be scraped.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• CVE Report (Scanner found CVE and adding report)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

How Has This Been Tested?

Ran ingress-nginx in a local Kubernetes cluster using make dev-env and scraped it with Prometheus with native histograms enabled and disabled.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added unit and/or e2e tests to cover my changes.
• All new and existing tests passed.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: rikatz / name: Ricardo Katz (ca29f06)
• ✅ login: rabenhorst / name: Sebastian Rabenhorst (fcbcc7b)

[k8s-ci-robot]

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[rabenhorst]

/auto-cc @ElvinEfendi

[github-actions]

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/remove-lifecycle frozen

[Cheshirez]

Assuming a huge metrics cardinality from ingress controllers, exposing native histogram would help a lot.

[longwuyuan]

@Cheshirez for the readers who know nothing about the histograms and the variants like native or classic, this PR is hard to wrap one's head around.

What is required is the screesnhots, data and explaining all together, copy/paste here for everyone to read and understand. That will likely cause a thought on what the improvement is and how its relevant to what group of users. It also requires to help out with info on the impact of maintaining & supporting. That kind of insight is missing here. It requires the rare prometheus maintainer level experts and they are hard to come by, to spend their time here.

Any help is appreciated.

[tiithansen]

@rabenhorst Any plans to continue with this PR?

[rabenhorst]

@rabenhorst Any plans to continue with this PR?

Sry I was on holiday. Yes I can work on this. I'm not a Prometheus maintainer, but added (partial) native histogram support for Thanos and know my way around in Prometheus.

@longwuyuan I will rebase and update the PR description accordingly in the coming days.

[rikatz]

@rabenhorst are you still willing to work on this?
@longwuyuan should we proceed once this is rebased?

[longwuyuan]

@rikatz ,if rebased and passing tests, then its ok to accept this because optional observabiity flag being added here helps because it is optional.

[netlify]

✅ Deploy Preview for kubernetes-ingress-nginx canceled.

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[longwuyuan]

Hi Sebastian, thanks for the contribution. Hoping you will copy paste some screenshots of histograms resulting from your changes. Helps get perspective. Also requesting you squash commits kindly.

[rabenhorst]

Hi Sebastian, thanks for the contribution. Hoping you will copy paste some screenshots of histograms resulting from your changes. Helps get perspective. Also requesting you squash commits kindly.

I will. There also will be a talk about our migration to native histograms on PromCon https://promcon.io/2024-berlin/talks/shopifys-journey-from-conventional-to-native-histograms/ if you are interested in the wider topic of native histograms.

Will squash all commits now.

Is the failing lint expected?

[longwuyuan]

That is awesome. Will try to sync. I hope you will put in some brief description in docs about how native histograms are different and their benefits. Thanks again for this contribution being optional config.

[longwuyuan]

I am on phone. Will get on computer and comment on lint.

[longwuyuan]

@rikatz linter caught 2 deprecations. Needs your comment

Error: internal/task/queue.go:39:8: SA1019: workqueue.RateLimitingInterface is deprecated: Use TypedRateLimitingInterface instead. (staticcheck)
  	queue workqueue.RateLimitingInterface

@tao12345666333 PTAL

[rikatz]

Yeah these linter comments are new and unrelated. I am fixing those on another PR, let me see if I can expedite these fixes and then merge this one

[rikatz]

#11853 fixing the linter here, then we can rebase and re-run this test

[rikatz]

/ok-to-test

[rikatz]

/lgtm
/approve
Thank you

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: rabenhorst, rikatz

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