proposal: introducing a scheduling strategy to customize cluster propagation priorities

[chaosi-zju]

What type of PR is this?

/kind feature
/kind design

What this PR does / why we need it:

This proposal introduces a new user scenario for scheduling, where users have preferences for clusters with
varying priorities and want replicas assigned to their preferred clusters.

To support this scenario, we propose two alternative solutions: one is adding aggregatePreference to the existing
Weighted replica scheduling strategy, and the other is enhancing the capability of multiple scheduling groups.

Ultimately, we compare these two options and decide on the best implementation to provide a scheduling strategy
that allows users to customize cluster propagation priorities.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

[karmada-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign kevin-wangzefeng for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 43.18%. Comparing base (32c2ef7) to head (368a6ae).
Report is 369 commits behind head on master.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #5512       +/-   ##
===========================================
+ Coverage   31.70%   43.18%   +11.48%     
===========================================
  Files         643      656       +13     
  Lines       44445    55921    +11476     
===========================================
+ Hits        14090    24149    +10059     
- Misses      29325    30214      +889     
- Partials     1030     1558      +528     

Flag	Coverage Δ
unittests	43.18% <ø> (+11.48%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[chaosi-zju]

/retest

[RainbowMango]

Suggested change

	+ // ReplicaDivisionPreferencePriorityAggregated assigns replicas to higher-priority clusters first,
	+ // then to lower-priority clusters if resources are insufficient.
	+ ReplicaDivisionPreferencePriorityAggregated ReplicaDivisionPreference = "PriorityAggregated"
	// ReplicaDivisionPreferencePriorityAggregated assigns replicas to higher-priority clusters first,
	// then to lower-priority clusters if resources are insufficient.
	ReplicaDivisionPreferencePriorityAggregated ReplicaDivisionPreference = "PriorityAggregated"

[RainbowMango]

Does the PriorityAggregated still honor the score plugins in the scheduler? In another world, what's the relationship of them?

[chaosi-zju]

The sign "+" can reflect which lines are newly added. Does this need to be removed?

[chaosi-zju]

Does the PriorityAggregated still honor the score plugins in the scheduler? In another world, what's the relationship of them?

I have updated the doc, this answer is in Controller logic changes paragraph.