client: support configuring backoff

[rleungx]

What problem does this PR solve?

Issue Number: Close #xxx

What is changed and how does it work?

Check List

Tests

• Unit test

Release note

None.

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[ti-chi-bot]

[FORMAT CHECKER NOTIFICATION]

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[codecov]

Codecov Report

Attention: Patch coverage is 58.33333% with 50 lines in your changes missing coverage. Please review.

Project coverage is 71.78%. Comparing base (26ced22) to head (41384b9).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8679      +/-   ##
==========================================
- Coverage   77.54%   71.78%   -5.76%     
==========================================
  Files         474      517      +43     
  Lines       62359    67452    +5093     
==========================================
+ Hits        48358    48423      +65     
- Misses      10441    15434    +4993     
- Partials     3560     3595      +35     

Flag	Coverage Δ
unittests	71.78% <58.33%> (-5.76%)	⬇️

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