Netreo uses an adaptive polling system to manage devices that may be responding slowly, so that they do not interfere with data collection on devices that are responding normally. This feature was introduced in version 7.2.
When the polling process detects that a device is taking more than 100 seconds to complete a full data poll (the “critically slow” threshold), it flags the device as a “slow” device. Polling for that device is then handed over to the slow-device poller process. On the device dashboard, the poll time will display “Slow” when this happens. The polling speed flag for the device is also set to 5.
The device will continue to be polled by the slow poller process until Netreo detects that the device is responding in under 30 seconds (the “recovery” threshold). When the device responds faster than the recovery threshold, the polling speed flag for the device is reduced by one. If the device completes a poll above the recovery timer, but below the critical timer, Netreo will increase the polling speed flag by 1. When the polling speed flag is less than 5 (critically slow) but greater than 1 (normal), the device dashboard will display “Slow, Recovering.” The slow polling process will continue to manage the device until it has fully recovered.
If the device completes any poll above the critical threshold, the polling speed flag is set back to 5.
When the polling speed flag returns to 1, the regular polling process will resume polling of the device, and the device dashboard will display “Normal” for poll speed.
Therefore a device must complete 4 successful polls in a row faster than the recovery threshold to return to normal operation. This minimizes the net shift between slow and normal devices.