"dead" metrics

[Christian]

Hi @all,

don't know if this is the right place to ask.

How does Prometheus in general deal with "dead" metrics.
With "dead" I mean the node exporter will deliver the same value over and over again,
because the logic behind is broken for some reason.

From a developer perspective this would be easy to deal with by putting a timestamp inside the metric to check if we are looking on old values and then raise an alert.

I guess that's a complete newbie question and there is something in place already ?

Thanks for your answer.

[Stuart Clark]

I think it really depends on what you mean by "dead metrics" from the
node exporter. Are you meaning custom metrics you are adding via the
textfile collector? If so, you also get a timestamp metric for when the
file last changed, which you could alert against (if not changed within
a certain time period). If you are meaning something different you could
alert using the changes function - alert if the changes over the past
time period were 0.

--
Stuart Clark