I was installing CE CPU MapD on AWS LightSail instance following instructions step by step.
All went prettty well until I entered
sudo ufw disable sudo ufw enable sudo ufw allow 9092/tcp
It was pretty obvious in hidsight that I shot myself into foot by denying access with ssh (I was unable to connect to this particular instance ever again, so I just deleted it and created another anew), I should have added
sudo ufw allow 22
at that step. But maybe there should be some warning for inexperienced users like me