Ceilometer receives volume.create/volume.delete events, along with volume detail ('volume' and 'volume.size' meters). The problem is not information was received  about the current existence of a volume. The openstack documentation states that a 'volume.exists' event/meter should exist, but it is not reported.

Add the following properties in /etc/cinder/cinder.conf
cinder_volume_usage_audit=True
cinder_volume_usage_audit_period=hour
notification_driver=cinder.openstack.common.notifier.rpc_notifier // this does not work for volume.exists events
control_exchange=cinder
Then you can either run manually Or set a cronjob for "cinder-volume-usage-audit" ref link
also check if there is cinder time mismatch as reported here

For the above issue I added the below 2 properties:
cinder_volume_usage_audit=True
cinder_volume_usage_audit_period=hour

and changed the
 notification_driver=messaging
 property as well.
Te default value was
notification_driver=cinder.openstack.common.notifier.rpc_notifier.



The above changes resolved the issue.