Sonarqube is going in maintenance mode while upgrading


We are having sonarqube 7.1 in our production server (docker container), with mysql 5.7 (on base machine).
Now when we upgrading our sonarqube to 7.8 (container) with existing mysql 5.7 (base machine), it is going into maintenance mode. And again if we revert back to sonarqube 7.1 then it is working again.
So do we have to upgrade something from mysql side (schema), or is there any steps in mysql that we have to follow while upgrading to 7.8 version.