Having datasource name in metrics

[stefano-salmaso]

Hello!
I noticed that in the metrics produced there is no tag with the name of the datasource.
In case there are more datasources it becomes impossible to use the metrics correctly.

Is this a desired behavior?
If so... is there a way to have the name of the datasource in the metrics produced?

Thanks

[ttddyy]

Hi @stefano-salmaso

Initially, I thought this could be achieved using a custom ObservationFilter to add the database name as a low-cardinality key-value.

However, the database name is not currently available in the context.

I'll think about adding the database name into the contexts.

[stefano-salmaso]

HI @ttddyy
I looked at the code and I think that adding the datasource name in the context is relatively easy. If I can I could propose you a PR... 😄
But I have some doubts....
Once you add the datasource name in the context it is possible to have it as a metric tag using an ObservationFilter.
But this is not true for all the metrics produced.
For example I have the datasource name for jdbc.query but it is not there for jdbc.query.active, see below:

jdbc_query_active_seconds_active_count{app="my-app"} 0.0 # Missing!!!
jdbc_query_active_seconds_duration_sum{app="my-app"} 0.0 # Missing!!!
jdbc_query_active_seconds_max{app="my-app"} 0.0 # Missing!!!
jdbc_query_seconds_max{app="my-app",name="my-ds"} 0.0 # ok, added with ObservationFilter
jdbc_query_seconds_count{app="my-app",name="my-ds"} 1.0 # ok, added with ObservationFilter
jdbc_query_seconds_sum{app="my-app",name="my-ds",} 0.018519208 # ok, added with ObservationFilter

For jdbc.connection the same thing happens, but here I do not have the name for the managed metrics ObservationHandler also

jdbc_connection_commit_total{app="my-app",} 1.0 # Missing!!!
jdbc_connection_acquired_total{app="my-app",} 3.0 # Missing!!!
jdbc_connection_active_seconds_max{app="my-app",} 0.0 # Missing!!!
jdbc_connection_active_seconds_active_count{app="my-app",} 0.0 # Missing!!!
jdbc_connection_active_seconds_duration_sum{app="my-app",} 0.0 # Missing!!!
jdbc_connection_seconds_count{app="my-app",error="none",name="my-ds",} 2.0 # ok, added with ObservationFilter
jdbc_connection_seconds_sum{app="my-app",error="none",name="my-ds",} 82.99373225 # ok, added with ObservationFilter
jdbc_connection_seconds_max{app="my-app",error="none",name="my-ds",} 0.0 # ok, added with ObservationFilter

I think that having at least the name of the datasource is mandatory to have good metrics.
Do you know if and how to fix this thing?

Stefano.

[ttddyy]

Hi @stefano-salmaso

Did you add the datasource name to low-cardinality key-values?

Those _active_* metrics should be LongTaskTimer instances created by DefaultMeterObservationHandler.
They are tagged using low-cardinality key-values. So, if an ObservationFilter adds the datasource name to low-cardinality key-values, it should automatically be included in LongTaskTimer metrics.
The same applies to observation events for connection commit/acquired counters as well.

Is it not happening?

[stefano-salmaso]

HI @ttddyy
Yes I added the datasource name in the low-cardinality key-values.
I did a little investigation and seems that an ObservationFilter doesn't have effects on metrics created and registered like the LongTaskTimer and observation events.