Q: The code coverage for my microservice is always low, even for some classes the code coverage is 0%, how come? since when I run it locally it is 100% code coverage, it should not have such a big gap.
A: According to https://github.com/powermock/powermock/issues/422 it seems like Jacoco is not very friend with PowerMock. Unfortunately my test cases are using PowerMock (since I can test private method through Powermock)
After switch from Powermock to Mockito, my problem fixed.