Details about the meaning of the “Busy Sensors” value in PRTG Traffic Grapher
While you are using the Windows GUI of PRTG you will see a “Busy Sensors” value in the statusbar. In larger installations or installations with small intervalls you should have an eye on this value because it can tell you wether your PRTG setup may be close to an overload.
The maximum number of SNMP sensors that you can monitor with PRTG depends - apart from other aspects - on the latency of the devices that you want to scan (=the time it takes a device to answer the SNMP requests from PRTG). Especially if many SNMP requests fail and cause a timeout (due to devices being powered off, packet loss in your network and failing data lines) the “busy sensors” value can jump to high values.
Read more in the new Knowledgebase Article about this topic.