fix(tianmu): the instance crashed while exporting data (#1961)

[TomeC]

Summary about this PR

Issue Number: close #1961

Tests Check List

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

Changelog

• [ ] New Feature
• [x] Bug Fix
• [ ] Performance Improvement
• [ ] Build/Testing/CI/CD
• [ ] Documentation
• [ ] Not for changelog (changelog entry is not required)

Documentation

• [ ] Affects user behaviors
• [ ] Contains syntax changes
• [ ] Contains variable changes
• [ ] Contains experimental features