Display query duration in logs

[reubano]

Is your feature request related to a problem? Please describe.

I'm always frustrated when I'm not able to figure out how long it took a job to run its queries.

Describe the solution you'd like

I want to be able to see the total query duration in the logs so that I can know what value to set scrape_timeout.

Describe alternatives you've considered

When I get a timeout error, I have to use trial and error to figure out the maximum number of queries I can run without timing out.

[burningalchemist]

Hey @reubano, there's already scrape_duration_seconds metric, which is exposed when you use jobs. It's not exposed for a single target mode, though.

I've prepared a small adjustment, so if the target name is provided in the config (this field is unavailable for now), you get the above and also up metrics.

For unnamed single targets we preserve current operations to avoid any surprises for users.