Yes, it’s OK — we can revisit the issue later, the important thing now is to get the MRI patch building and passing its tests.

I decided not to use silent mode and removed all the redundant stubbings . But there seem to false positives in some cases. On removing some stubbings marked unnecessary I'm getting test failures. Is it ok to use lenient for such stubbings?

Yes, using silent mode is OK IMO for the migration. If you do use this though, please file a JIRA so you don’t forget to revisit the issue later — unused stubs mean that there are pieces of code which aren’t exercised by tests .

Have fixed the FB violations. I'm currently facing various test failures due to mockito migration probably. Many tests are failing with the following exception "org.mockito.exceptions.misusing.UnnecessaryStubbingException"

Checking on this I found that "strict" junit runner is default in mockito 2. The fix was to implicitly use "silent" junit runner. Is this fix fine or are we required to remove the unnecessary stubs(which could break some tests?)

I found the above solution here : https://support.intershop.com/kb/index.php/Display/2M8334#Guide-7.10MigrationMockito1toMockito2-MockitoJUnitRunner 

They have some other useful info for mokito migration to 2

no please do not disable FB! The slf4j related problems are really easy to fix, they are simple logging usage API mistakes - these are real logging bugs which make the logs less useful and therefore really should be fixed. They are easy to fix, see here: https://git.opendaylight.org/gerrit/#/c/76389/5..6