Polling
Most network devices and servers use counters and gauges to track performance and network activity against a variety of hardware and software resources inside of the node. The data from each of these counters and gauges can be extracted by Orion NPM using industry standard protocols such as WMI and SNMP and presented in an easy-to-understand format through the Orion dashboard. The process for extracting the counter and gauge data from a node is called polling. There are two reasons why you poll nodes, they are as follows:
To verify the node's status
To gather statistics
Orion NPM polls for status to know if the node is available or if there is a problem. A common node status is if it is up or down. If the node is up, it is usually operating normally. If the node is down, then there is a good chance there is a problem with that device.
The second reason why we poll nodes is to gather statistics from the node's counters and gauges. We can gather CPU usage, free space available on storage...