The problem that has plagued you for some time finally knows why, and each time you restart the MongoDB server, the service will fail to start.
It was observed that after each reboot, MongoDB would load the memory data and the original server memory configuration was too low, resulting in the memory load not being completed.
So has been unable to use, make a mess to reload MongoDB.
It is observed that the MONGO file storage space around 100GB requires at least 12GB memory configuration to fully load the data.
In order to verify that the result is correctly restarted MongoDB, the result is OK, and soon the data is reloaded back.
This is how the load works.
Final conclusion: In the process of server migration, the server performance configuration requirements are poorly considered, so the memory configuration can not meet the actual use.
Unable to connect issues after MongoDB restart