I use Ubuntu 16.04 to install https://docs.openstack.org/ceilometer/queens/install/install-base-ubuntu.html (ceilometer)
When I run service gnocchi-api restart, I get Failed to restart gnocchi-api.service: Unit gnocchi-api.service not found.
I find related info https://bugs.launchpad.net/ceilometer/+bug/1750933 (here), it says

latest release does not have gnocchi-api

but I still don't know how to fix the problem in detail.