chore(pd): add UT; update data path

[csuzhangxc]

What problem does this PR solve?

What is changed and how does it work?

Code changes

• Has Go code change
• Has CI related scripts change

Tests

• Unit test
• E2E test
• Manual test
• No code

Side effects

• Breaking backward compatibility
• Other side effects:

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

Release Notes

Please refer to Release Notes Language Style Guide before writing the release note.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 90.90909% with 1 line in your changes missing coverage. Please review.

Project coverage is 21.14%. Comparing base (4e07af2) to head (c508b2f).

Additional details and impacted files

@@              Coverage Diff               @@
##           feature/v2    #6000      +/-   ##
==============================================
+ Coverage       20.36%   21.14%   +0.78%     
==============================================
  Files             152      152              
  Lines           10371    10379       +8     
==============================================
+ Hits             2112     2195      +83     
+ Misses           8052     7972      -80     
- Partials          207      212       +5     

Flag	Coverage Δ
unittest	21.14% <90.90%> (+0.78%)	⬆️

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: liubog2008

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