Looks like bug 1532661; the Liberty UCA has Ceilometer 5.0.5 which should include the fixes to the stable/liberty branch upstream.
Unfortunately I can't tell which version of ceilometer you're using from this bug report - please could you confirm the version of the ceilometer-common package installed on your ceilometer units.
Either way, this is a ceilometer bug not a charm bug - so moving the target directly to the Ubuntu Cloud Archive.
Looks like bug 1532661; the Liberty UCA has Ceilometer 5.0.5 which should include the fixes to the stable/liberty branch upstream.
Unfortunately I can't tell which version of ceilometer you're using from this bug report - please could you confirm the version of the ceilometer-common package installed on your ceilometer units.
Either way, this is a ceilometer bug not a charm bug - so moving the target directly to the Ubuntu Cloud Archive.
Marking 'Incomplete' and 'Low' for now.