Prometheus 'equal' comparison binary operator makes labels disappear in Grafana legend

Grafana Prometheus
1

Hi everyone

I’m trying to detect no activity in one of my Gauges in Prometheus using the delta() function. Briefly, if the gauge does not show a change from its value 5 minutes ago - I consider it to be inactive. The query I’m using is thus simply this:

min(delta(metric_name{}[5m])) by (label_name) == 0

However, the graph presented does not show labels in the legend:
image

Contrast that with the ‘<=’ comparison binary operator:
image

The same goes for the ‘>=’ comparison binary operator.
Why am I losing series’ labels when I use ==?

Thanks.

2

Weirder yet: hovering over the == graph always presents the current timestamp and not the time in the x-axis :confused:

image
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This seems like a bug in Grafana, and the hovering time issue may explain why there is no legend or table with values :thinking: