collector: add more retry when collect metrics

[nexustar]

What problem does this PR solve?

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

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

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (88122e8) 30.19% compared to head (b08d351) 30.19%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #455 +/- ## ======================================= Coverage 30.19% 30.19% ======================================= Files 52 52 Lines 4362 4362 ======================================= Hits 1317 1317 Misses 2874 2874 Partials 171 171 ``` | [Flag](https://app.codecov.io/gh/pingcap/diag/pull/455/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/pingcap/diag/pull/455/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap) | `30.19% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pingcap#carryforward-flags-in-the-pull-request-comment) to find out more.

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