Custom instruments?

[agr]

I have an Azure Function with a timer trigger that does "something useful". While doing that something it produces several numbers indicating the health of the process it interacts with, so I want to produce metrics out of those values. The values are useful by themselves individually. I don't need to add them, I don't want to see any histograms with it. Gauge feels like the right type of metric for those, but unfortunately there is only ObservableGauge which wants a callback that would return those values. I don't have a continuous process that I could sample at any moment. I have a function that works and at some point produces a few numbers. At that point (and only at that point) I want metric samples produced.

I tried to create my own Instrument<T> implementation, but it seems whatever samples I produce with that are just dropped. Do I have to do some additional setup besides inheriting from Instrument<T> and calling Publish() in constructor? "Standard" instruments work fine (both standard and my instruments use the same Meter object).

In Application Insights .net API terms, I am looking for equivalent of TelemetryClient.TrackMetric function. How do I do that?

[cijothomas]

I tried to create my own Instrument implementation, but it seems whatever samples I produce with that are just dropped. Do I have to do some additional setup besides inheriting from Instrument and calling Publish() in constructor?

OpenTelemetry does not support any newly created instruments. It only supports the ones specified in OTel specification, and adding a new one has to go through OpenTelemetry specification process. (There were discussions around sync version of Gauge earlier, but no actual spec is made to support that yet)

[agr]

Should the Instrument class be marked as internal then?

[cijothomas]

Instrument is not part of this repo. Its part of DiagnosticSource package from .NET runtime, and it needs to be public to enable building OpenTelemetry instruments in this repo.