Good to hear some of it worked. I don't know how to make the time midnight in Grafana. Probably better asking in a Grafana forum. You can use the Grafana 'query inspector' to see what the front-end is sending; you'd need to turn on query-logging in Prometheus to see exactly what is sent by the Grafana back-end.
Bryan On Tuesday, 7 January 2025 at 00:02:29 UTC [email protected] wrote: > Wow! Both of these methods work perfectly, with Grafana step set to 24h. > It was initially hard for me to wrap my head around this but after > thinking about your examples it makes sense now. Thanks Bryan! > > One more piece that's not working: Even with the time ranges set as you > described (from: now-31d/d, to: now-1d/d), it looks like each measurement > is taken at the current time instead of midnight. Response data looks like > this, at 14:27 local time. > > "Time","Spa" > 2024-12-24 14:27:14,5.15 kWh > 2024-12-25 14:27:14,7.62 kWh > 2024-12-26 14:27:14,7.41 kWh > > Grafana’s time picker says midnight as shown in this screenshot. > > On Monday, January 6, 2025 at 2:01:26 AM UTC-8 Bryan Boreham wrote: > >> Off the top of my head it seems this should be: avg_over_time(watts[24h]) >> * 24 >> If you tried this please say what went wrong. >> >> An alternative would be: sum_over_time(watts[24h:1m]) / 60. >> This uses a subquery to produce a value every 1 minute, adds them all up >> to give a total in Watt-minutes, then divides to get Watt-hours. >> >> Using the counter: increase(watt_hours_total[24h]). >> >> Set the Step in Grafana to 24h to get one point per day. >> Set an "Absolute time range" with From=now-31d/d and To=now-1d/d to get >> 30 days ending midnight yesterday. >> >> Bryan >> >> On Monday, 6 January 2025 at 09:45:21 UTC [email protected] wrote: >> >>> Is there a way to do something like GROUP BY in PromQL? My use case is >>> to convert Watts to Watt-Hours. I have a gauge metric measuring >>> instantaneous power consumption every minute. I want to calculate the >>> daily consumption to display in Grafana as a time series with one bar per >>> day over a 30 day period. >>> >>> I found a thread here describing how to do this with Influx, but I can't >>> figure out how to do this in Prometheus. I've tried a bunch of variations >>> of sum_over_time and avg_over_time. >>> https://community.grafana.com/t/calculate-energy-consumsion-manually/45739/2 >>> >>> Alternatively, my energy monitor device also records Watt-hours as a >>> counter metric which resets every day. I'm not sure if that would make >>> this any easier... >>> >> -- You received this message because you are subscribed to the Google Groups "Prometheus Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/prometheus-users/bf5428cc-8cae-4e44-9075-d631259017cbn%40googlegroups.com.
