Panko is barely maintained upstream and offer no interesting feature. Plus, it does not scale. The feature it offers can be achieve by using Gnocchi and Aodh. Therefore Panko should be deprecated in OSP as of OSP12. (there's no openstack-panko component there so setting to openstack-ceilometer for now)
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2017:3462