There are at least two places listing events in ceilometer. However, this is far from extensive since the services in OpenStack could emit arbitrary events. It is near to impossible to keep the list up to date. The event definitions for ceilometer to act on is in this config file https://github.com/openstack/ceilometer/blob/master/ceilometer/pipeline/data/event_definitions.yaml (meaning, it can be enhanced/changed) For sending/updating gnocchi resources, there is also https://github.com/openstack/ceilometer/blob/master/ceilometer/publisher/data/gnocchi_resources.yaml which describes what to submit/update in gnocchi on given events. These are far from complete, events are hidden in the OpenStack services source code.