UPDATE

1) We made the experimental function to reboot rig, when the speed slowdown.
Compare the average speed for the last 5 minutes with the average speed for the last 6-10 minutes.
And if the first number is lower by X%, then the reboot command is sent.
The threshold of operation in % is set in the options of the rig (click edit). Soon mass change of % through Multiple edit will be available.

2) If the fan speed drops to 0, or the speed of any of the rigs drops to 0, then change the color of the record to red for clarity.