Need help on building an alerting rule

I’m trying to setup some new alerting. I have a device that gets me the following info for wireless_sensors:

            sensor_id: 12605
       sensor_deleted: 0
         sensor_class: power
            device_id: 3435
         sensor_index: 268451970
          sensor_type: ceraos-rx
         sensor_descr: Radio: Slot 2, Port 2 RX Level
       sensor_divisor: 1
    sensor_multiplier: 1
    sensor_aggregator: sum
       sensor_current: -48
          sensor_prev: -49

What I’m looking to do is setup an alert so if I see say a 10% drop between sensor_current and sensor_prev that I get an alert.

What is the best way to attack this?

For (say) a >10% drop I use variations on:

wireless_sensors.sensor_current < wireless_sensors.sensor_prev * 0.9


I’m trying a few things, here’s the query I’m doing:

wireless_sensors.sensor_class = “power” AND wireless_sensors.sensor_current < “wireless_sensors.sensor_prev * 1.1”

The * 1.1 is to account for RSSI values being negative. When I put that in and apply it to a couple of radios I get an alert even though the values are not changing and when I hover over the graph, I get graphs named sensor*power and they have no data, it shows the value underneath that not in a graph properly but I must have something goofed up. Any other suggestions?

Not sure - the wireless point-to-point kit I have under monitoring has separate sensor classes for transmit power and RSSI:

wireless_sensors.sensor_class = “power”
wireless_sensors.sensor_class = “rssi”

For this kit power is a +ve dBm vs -ve dBm for RSSI.

What can you see under https://yourserver/wireless/metric=power and https://yourserver/wireless/metric=rssi?