placement: do not delete orphan peers if some peers selected by RuleFit is down or pending (#4067)

[ti-chi-bot]

This is an automated cherry-pick of #4067

What problem does this PR solve?

fixes #4045

Related changes

• Need to cherry-pick to the release-5.0

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• nolouch

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

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

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[nolouch]

/merge

[ti-chi-bot]

@nolouch: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 83b3382

[nolouch]

/rebuild

[nolouch]

/test

[nolouch]

/rebuild

[nolouch]

/rebuild

[nolouch]

/rebuid

[nolouch]

/retest

[nolouch]

/rebuild

[codecov]

Codecov Report

Merging #4073 (83b3382) into release-5.0 (b1adc27) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@               Coverage Diff               @@
##           release-5.0    #4073      +/-   ##
===============================================
- Coverage        74.79%   74.77%   -0.03%     
===============================================
  Files              245      245              
  Lines            24321    24327       +6     
===============================================
- Hits             18192    18191       -1     
- Misses            4514     4519       +5     
- Partials          1615     1617       +2     

Flag	Coverage Δ
unittests	74.77% <100.00%> (-0.03%)	⬇️

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

Impacted Files	Coverage Δ
server/schedule/checker/rule_checker.go	83.11% <100.00%> (+2.03%)	⬆️
server/member/member.go	63.04% <0.00%> (-7.07%)	⬇️
server/region_syncer/server.go	83.08% <0.00%> (-5.89%)	⬇️
server/election/leadership.go	83.52% <0.00%> (-2.36%)	⬇️
server/tso/allocator_manager.go	75.24% <0.00%> (-0.84%)	⬇️
server/schedule/operator_controller.go	82.60% <0.00%> (-0.38%)	⬇️
server/grpc_service.go	46.94% <0.00%> (+0.33%)	⬆️
server/cluster/cluster.go	82.40% <0.00%> (+0.38%)	⬆️
server/handler.go	42.46% <0.00%> (+0.49%)	⬆️
server/tso/tso.go	72.39% <0.00%> (+0.61%)	⬆️
... and 4 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c98de48...83b3382. Read the comment docs.