Alert status "no data" even though query returns data

  • What Grafana version and what operating system are you using?

Grafana v7.4.1 (07649d1313) on Ubuntu

  • What are you trying to achieve?

Set up an alarm

  • How are you trying to achieve it?

  • What happened?

Alarm status is “no data”

  • What did you expect to happen?

Alarm status to be “OK”

  • Can you copy/paste the configuration(s) that you are having problems with?

  • Did you receive any errors in the Grafana UI or in related logs? If so, please tell us exactly what they were.

  • Did you follow any online instructions? If so, what is the URL?

I have set up an alert for a query that clearly has data within the last 24 hours, but even though I set up the alert condition as WHEN max() OF query (A, 24h, now) it shows status “no_data” when I test the alert. And it also shows “UNKNOWN” in my alert list panel.

One thing I notice in the test result is that the values that are reported are actually all null, but viewing the panel graph we can clearly see that the query does return results for the given time period. What am I missing?