scheduler: reduce GetStore in hot-region-scheduler

[HunDunDM]

Signed-off-by: HunDunDM [email protected]

What problem does this PR solve?

• fix hot scheduler causes pd panic when scale out #3868

What is changed and how it works?

Reduce GetStore in hot-region-scheduler. In addition to preventing panic caused by data inconsistency, it can also reduce the use of BasicCluster locks.

Check List

Tests

• Unit test

Code changes

Side effects

Related changes

• Need to cherry-pick to the release branch

Release note

Fix the bug that PD may panic during scaling out TiKV.

[codecov]

Codecov Report

Merging #3870 (e703e79) into master (d02f0a9) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #3870      +/-   ##
==========================================
+ Coverage   74.49%   74.52%   +0.03%     
==========================================
  Files         246      246              
  Lines       24846    24854       +8     
==========================================
+ Hits        18509    18523      +14     
+ Misses       4682     4676       -6     
  Partials     1655     1655              

Flag	Coverage Δ
unittests	74.52% <100.00%> (+0.03%)	⬆️

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

Impacted Files	Coverage Δ
server/schedulers/utils.go	93.06% <ø> (ø)
server/schedulers/hot_region.go	85.38% <100.00%> (+0.87%)	⬆️
server/schedulers/shuffle_hot_region.go	65.30% <100.00%> (+10.56%)	⬆️
server/tso/local_allocator.go	64.86% <0.00%> (-13.52%)	⬇️
pkg/etcdutil/etcdutil.go	82.35% <0.00%> (-5.89%)	⬇️
server/tso/tso.go	60.22% <0.00%> (-3.32%)	⬇️
server/server.go	72.23% <0.00%> (-0.92%)	⬇️
server/config/persist_options.go	91.50% <0.00%> (-0.78%)	⬇️
server/tso/allocator_manager.go	66.77% <0.00%> (-0.67%)	⬇️
server/member/member.go	64.70% <0.00%> (-0.54%)	⬇️
... and 9 more

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[rleungx]

Do we need unit tests?

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• lhy1024
• nolouch

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[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: ff84f4e

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #3909.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #3910.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #3911.