Hi, I'm wondering whether prometheus uses instant queries or range queries when evaluating alert expressions? The context about why I'm asking might help clarify my question.
I'm comparing Grafana Cloud's alerting functionality with prometheus. From Grafana Cloud we're querying Google Cloud Metrics with PromQL (it's Google's Monarch DB with a PromQL interface). Grafana Cloud's alerting system takes your PromQL query and performs a *range query* against Google Cloud Metrics, returning multiple data points over the range you have selected (e.g. 10 minutes ago to now). Then you need to choose a reducer function to turn the time series into an instant scalar (e.g. min, max, last, mean). Prometheus alerts don't seem to have an option for specifying a range and also don't have a reducer option. So this leads me to believe prometheus uses instant queries to evaluate alert expressions. But I'd like to know for sure. Thanks for reading! Here's the Grafana Cloud documentation on alert query ranges and reducers: https://grafana.com/docs/grafana/latest/alerting/alerting-rules/create-grafana-managed-rule/ -- 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 prometheus-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/prometheus-users/ef0e2ee6-a32e-479e-bbe4-10499372715cn%40googlegroups.com.
