Controller: Optimize sync process.

[sergeylanzman]

What this PR does / why we need it:

Add many optimization for sync process. On huge cluster with four digit number of ingress and pods controller take up to 50GB memory and sync process too long. This PR try optimize code for less memory and cpu usage

Types of changes

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Local tests

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.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: sergeylanzman
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[k8s-ci-robot]

Hi @sergeylanzman. Thanks for your PR.

I'm waiting for a kubernetes 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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[strongjz]

/ok-to-test
/triage accepted
/kind feature

[Gacko]

/retitle Controller: Optimize sync process.
/triage accepted
/kind bug
/priority backlog

Looks good so far! Please ping us as soon as your WIP is ready for a final review. 🙂

Also I'm tempted to cherry-pick this to release-1.12 and release-1.11. @sergeylanzman @strongjz WDYT?

[strongjz]

I wouldn't consider this a bug like the author says, its an optimization. I am torn, this changes how the sync process works, we do our best to ensure compatibility in patch versions. I can see folks arguing that changing how the sync process works should be in a minor release. We have to remember that folks who do gitops push patch changes almost immediately, so with that in mind we should save it for 1.13.