When using Horizon as Admin user, you probably saw the metering dashboard, also known as "Resource Usage".
It internally uses Ceilometer; Ceilometer continuously collects data from configured data sources. In a cloud environment, this can quickly grow enormously. When someone visits the metering dashboard in Horizon, Ceilometer then will accumulate requested data on the fly.
On the medium term, Horizon should switch to use gnocchi; in between, if you're tired on waiting, just disable metering dasboard e.g by placing the file like _99_disable_metering_dashboard.py to /usr/share/openstack-dashboard/openstack_dashboard/local/enabled
# The slug of the panel to be added to HORIZON_CONFIG. Required. PANEL = 'metering' # The slug of the dashboard the PANEL associated with. Required. PANEL_DASHBOARD = 'admin' # The slug of the panel group the PANEL is associated with. PANEL_GROUP = 'admin' REMOVE_PANEL = True
Finally, restart httpd:
systemctl restart httpd