Implementing label_value does not work

[ambuznego]

I have the instrumenter working fine w/ default settings and I see my Ecto metrics come through prometheus:

# TYPE ecto_db_query_duration_microseconds histogram
# HELP ecto_db_query_duration_microseconds The time spent executing the DB query in microseconds.
ecto_db_query_duration_microseconds_bucket{result="ok",le="10"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="100"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="1000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="10000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="100000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="300000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="500000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="750000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="1000000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="1500000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="2000000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="3000000"} 49
ecto_db_query_duration_microseconds_bucket{result="ok",le="+Inf"} 49
ecto_db_query_duration_microseconds_count{result="ok"} 49
ecto_db_query_duration_microseconds_sum{result="ok"} 89.833

In looking for a way to identify which queries are taking how long, I am trying to implement the label_value function as suggested and just logging the 2nd argument so I can see what I can use:

defmodule App.Repo.Instrumenter do
  use Prometheus.EctoInstrumenter

  def label_value(:source, log_entry) do
   IO.
    IO.inspect log_entry
    true
  end
end

But it doesn't seem to ever enter this function... It doesn't log anything and I don't see "source" in the labeling as I would expect...

Is there any additional steps to get this to work?

[ambuznego]

@deadtrickster any insight? thanks!!