server: implement for BucketStatInformer

[bufferflies]

What problem does this PR solve?

Issue Number: Close #4991

What is changed and how does it work?

Check List

Tests

• Unit test
• Integration test

Code changes

Side effects

Related changes

Release note

 None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• HunDunDM
• nolouch

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[ti-chi-bot]

@bufferflies: PR needs rebase.

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 kubernetes/test-infra repository.

[ti-chi-bot]

@bufferflies: PR needs rebase.

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 kubernetes/test-infra repository.

[nolouch]

rest LGTM

[codecov]

Codecov Report

Merging #4992 (431d7be) into master (61842c3) will decrease coverage by 0.12%.
The diff coverage is 79.48%.

@@            Coverage Diff             @@
##           master    #4992      +/-   ##
==========================================
- Coverage   75.54%   75.42%   -0.13%     
==========================================
  Files         306      307       +1     
  Lines       30194    30230      +36     
==========================================
- Hits        22811    22800      -11     
- Misses       5394     5431      +37     
- Partials     1989     1999      +10     

Flag	Coverage Δ
unittests	75.42% <79.48%> (-0.13%)	⬇️

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

Impacted Files	Coverage Δ
pkg/mock/mockcluster/mockcluster.go	94.07% <33.33%> (-0.68%)	⬇️
server/cluster/cluster.go	82.78% <50.00%> (+0.32%)	⬆️
server/statistics/buckets/hot_bucket_task.go	85.71% <85.71%> (+35.71%)	⬆️
server/grpc_service.go	52.78% <100.00%> (-0.14%)	⬇️
server/metrics.go	100.00% <100.00%> (ø)
server/statistics/buckets/bucket_stat_informer.go	94.20% <100.00%> (+3.02%)	⬆️
server/statistics/buckets/hot_bucket_cache.go	90.09% <100.00%> (+7.68%)	⬆️
server/statistics/buckets/metric.go	100.00% <100.00%> (ø)
pkg/tempurl/tempurl.go	45.00% <0.00%> (-25.00%)	⬇️
server/storage/leveldb_backend.go	76.00% <0.00%> (-8.00%)	⬇️
... and 25 more

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[nolouch]

LGTM

[HunDunDM]

/merge

[ti-chi-bot]

@HunDunDM: 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: 431d7be