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@guettli guettli commented Aug 13, 2025

There is a common misunderstanding about SyncPeriod. It does not sync between api-server and local cache.

This PR updates the docs to make this more clear.

Related: #3269 (comment)

@k8s-ci-robot k8s-ci-robot added the cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. label Aug 13, 2025
@k8s-ci-robot k8s-ci-robot added the needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. label Aug 13, 2025
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Hi @guettli. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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@k8s-ci-robot k8s-ci-robot added the size/XS Denotes a PR that changes 0-9 lines, ignoring generated files. label Aug 13, 2025
@guettli guettli force-pushed the syncPeriod-docs--sync-between-local-cache-and-reconciler-not-apiserver branch from f9eb09f to 18df20d Compare August 13, 2025 07:18
Comment on lines 151 to 154
// reconciled. It causes all resources in the local cache to be re-enqueued
// for reconciliation, even if there are no new events. It does
// not sync between the api-server and the local cache.
// A lower period will correct entropy more quickly, but reduce
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I am not a fan of changing this part of the paragaph, because the godoc goes from the big picture to the details/the why to the how, we are now adding parts of the how to the why.

Also it would IMHO be better to explain what does happen, rather than what does not.

WDYT about leaving this part be and changing L176 till the end of the godoc to:

	// SyncPeriod will locally trigger an artificial Update event with the same
	// object in both ObjectOld and ObjectNew for everything that is in the
	// cache.
	//
	// Predicates or Handlers that expect ObjectOld and ObjectNew to be different
	// (such as GenerationChangedPredicate) will filter out this event, preventing
	// it from triggering a reconciliation.

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@alvaroaleman Thank you for your feedback. Yes, I am fine with your suggestion. For people like me (who are slow on the uptake), I added a final note stating that there is no sync between the server and the local cache. Is that okay for you now?

@guettli guettli force-pushed the syncPeriod-docs--sync-between-local-cache-and-reconciler-not-apiserver branch from 18df20d to 897454a Compare August 20, 2025 07:35
@k8s-ci-robot k8s-ci-robot added size/S Denotes a PR that changes 10-29 lines, ignoring generated files. and removed size/XS Denotes a PR that changes 0-9 lines, ignoring generated files. labels Aug 20, 2025
@k8s-ci-robot k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Aug 20, 2025
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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: alvaroaleman, guettli

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LGTM label has been added.

Git tree hash: cc8dbd69fe315fb4ecd6ee801771147cf3b3c3aa

@k8s-ci-robot k8s-ci-robot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Aug 20, 2025
@k8s-ci-robot k8s-ci-robot merged commit 525d541 into kubernetes-sigs:main Aug 20, 2025
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Thank you very much!!
/lgtm

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4 participants