When snmpcollector generates lots of qos messages based on metrics configured in template, how do I know which device is generating more messages than others? It is difficult to identify that with Dr.Nimbus.
Did you check the "view message statistics" option in Dr.Nimbus? Set the path to the HUB where the snmpcollector is installed and that should give you the number of QoS generated per device on that HUB