Similarly to #1 in my case this is related to the pause/resume functionality. It seems like when we pause the principle unit (nova-compute) in order to perform the OpenStack upgrade, the ceilometer-agent-compute gets properly stopped and successfully terminates (exits 0). But later on nothing seems to re-attempt to restart that service, although we resume the principle unit. So it seems like we "forget" to restart that service somewhere. Investigating.
Similarly to #1 in my case this is related to the pause/resume functionality. It seems like when we pause the principle unit (nova-compute) in order to perform the OpenStack upgrade, the ceilometer- agent-compute gets properly stopped and successfully terminates (exits 0). But later on nothing seems to re-attempt to restart that service, although we resume the principle unit. So it seems like we "forget" to restart that service somewhere. Investigating.