That's a good point, Ben and Brian! And thank you both for clarifying! On Saturday 3 February 2024 at 11:24:07 UTC-5 Ben Kochie wrote:
> Yes, that Grafana API seems to be unnecessary complicated compared to just > using PromQL. > > On Sat, Feb 3, 2024, 17:16 'Brian Candler' via Prometheus Users < > [email protected]> wrote: > >> Even without a subquery, a rule can include a range vector expression and >> then reduce it to an instant vector, e.g. >> >> expr: avg_over_time(snmp_scrape_duration_seconds[5m]) >= 3 >> >> On Saturday 3 February 2024 at 16:04:56 UTC Ben Kochie wrote: >> >>> All rule evaluations are instant queries. You do all the "reducer >>> functions" in PromQL itself. >>> >>> For example, you can use subquery syntax to do something like >>> `avg_over_time()`. >>> >>> On Sat, Feb 3, 2024 at 5:02 PM 'Andrew Dedesko' via Prometheus Users < >>> [email protected]> wrote: >>> >>>> 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 [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/prometheus-users/ef0e2ee6-a32e-479e-bbe4-10499372715cn%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/prometheus-users/ef0e2ee6-a32e-479e-bbe4-10499372715cn%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> 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 on the web visit >> https://groups.google.com/d/msgid/prometheus-users/12386cd6-b032-45a6-b755-f0f51551b5d3n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/prometheus-users/12386cd6-b032-45a6-b755-f0f51551b5d3n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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 on the web visit https://groups.google.com/d/msgid/prometheus-users/560144b5-ab8c-4153-9c2a-71c4a6d11510n%40googlegroups.com.
