metrics: remove metrics proxy

[GMHDBJD]

What problem does this PR solve?

Issue Number: ref #4287

What is changed and how it works?

• remove metrics proxy
• upgrade promethus and use DeletePartialMatch if we want to delete by partial labels.

Check List

Tests

Manaully test

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• buchuitoudegou
• lance6716

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[GMHDBJD]

/run-all-tests

[codecov-commenter]

Codecov Report

Merging #6948 (bbbfe93) into master (9398176) will increase coverage by 0.0732%.
The diff coverage is 69.1891%.

Additional details and impacted files

Flag	Coverage Δ
cdc	67.2586% <ø> (+0.0626%)	⬆️
dm	51.9451% <25.0000%> (-0.0028%)	⬇️
engine	62.5776% <73.3727%> (+0.3154%)	⬆️

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

@@               Coverage Diff                @@
##             master      #6948        +/-   ##
================================================
+ Coverage   59.8253%   59.8985%   +0.0732%     
================================================
  Files           791        788         -3     
  Lines         90221      90301        +80     
================================================
+ Hits          53975      54089       +114     
+ Misses        31498      31470        -28     
+ Partials       4748       4742         -6     

[GMHDBJD]

/run-engine-integration-test

[CharlesCheung96]

The integration test is fixed in this pr, please rebase this branch and trigger engine tests again.

[GMHDBJD]

cc @D3Hunter @buchuitoudegou

[buchuitoudegou]

Would you mind introduce a bit below this comment about why we used this before and why we abandon it now?

[GMHDBJD]

Would you mind introduce a bit below this comment about why we used this before and why we abandon it now?

see pingcap/dm#575 for more detail. We want to remove metrics when task/source stopped. However, our metrics don't quite fit the specification. e.g. txnHistogram is created with target_schema/target_table label, but we need to remove them when their task/source is deleted, so we need delete the metrics when label is partial match. pingcap/dm#575 wraps metrics and label with a Map, which has perfomance issue. Promethus support DeletePartialMatch now. prometheus/client_golang#1013

[GMHDBJD]

/merge

[ti-chi-bot]

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

Commit hash: d689bae