When using horizon on a moderately loaded RHOS 7.0.3 installation, if you browse to the url http://openstack.example.com/dashboard/admin/metering/ the page sits there taking forever to load, eventually timing out with a 504 error. This 504 error is coming from haproxy which has a hard limit set to time out pages that take longer than 1 minute to load. The underlying issue looks like this page and the way it interacts with ceilometer is simply sub par.
Raising the priority / severity as it affecting our internal central CI environment.