Add default metrics

[jamescrosswell]

There are various metrics that have already been instrumented in .NET which users might be interested in sending to Sentry:

• Built In Metrics that are accessible via the System.Diagnostics.Metrics API.
• Well known Counters
• Polly resilience metrics
• Available Threads
• FirstChanceException
• ObservableInstruments

We'll likely resolve this issue in multiple Pull Requests:

• Capture built in metrics from System.Diagnostics.Metrics API #3052
• Spike: Capture well known EventSource counters #3100

[bruno-garcia]

Furthermore, the Polly.Extensions package now provides seamless integration with IServiceCollection and facilitates the export of Polly’s telemetry events into .NET metrics.

https://devblogs.microsoft.com/dotnet/building-resilient-cloud-services-with-dotnet-8/

maybe something interesting to tap into

[jamescrosswell]

See Built in Metrics

I think we can tap into these using the MeterListner API.

[bruno-garcia]

Added FirstChanceException to the list (I recall we talked about it but I couldn't find a ticket)

[jamescrosswell]

Added FirstChanceException to the list (I recall we talked about it but I couldn't find a ticket)

Yeah I remember discussing it. Were we just thinking of a counter for that one (# of first chance exceptions)?

[optical]

I wanted to double check that sampling of Observable instruments (eg ObservableCounter) is on the radar for this? Just had a play with the experimental feature and noticed it wasn't reporting any of the observable instruments yet (MeterListener.RecordObservableInstruments is never invoked)

We are otherwise looking forward to trying out Metrics with Sentry

[bitsandfoxes]

I wanted to double check that sampling of Observable instruments (eg ObservableCounter) is on the radar for this?

It is now!

[bitsandfoxes]

Sorry, we won't address this.
Superseded by #3597