PromQL query to detect the creation of new time series

Question

I have a metric with counters type. For a given metric and label combination, I need to detect if a new time series is created for the last one day. If yes, the query should return 1, else return 0 or empty.

I used the below query.

count by(label_1, label_2) count_over_time(My_metric{label_1="v1",label_2="v2"}[1d]) > 0 

This works partly as it detects the new time series but after a day of creation, it still returns 1.

My_metric{label_1="v1",label_2="v2"}

Time series

count by(label_1, label_2) count_over_time(My_metric{label_1="v1",label_2="v2"}[1d]) > 0 

Time series with the above the above query

This timeseries is created around Jan 1, 10AM. From Jan 1, 10AM - Jan 2 10AM, promQL query should return 1 and rest of time, it should return 0 or empty. Could someone help on this? Any help on this is greatly appreciated.

Answer 1

The following query returns 0 if there were no new time series matching the My_metric{label_1="v1",label_2="v2"} series selector during the last day. Otherwise it returns 1:

count(
  My_metric{label_1="v1",label_2="v2"}
    unless
  (
    My_metric{label_1="v1",label_2="v2"} offset 1d
  )
) >bool 0

The query uses the following PromQL features:

• offset modifier
• unless binary operator
• bool modifier for > operator