Add metrics to understand cost of telemetry

[pavolloffay]

Component(s)

No response

Is your feature request related to a problem? Please describe.

I would like to use the collector to understand the cost of telemetry data collection. Usually, observability vendors charge per ingest volume.

Describe the solution you'd like

I would like to have internal telemetry metrics that will help me understand how much data is collector processing/sending.

I want to understand how much each instrumented process (service) reports bytes. What is average span size and attribute cardinality?

Describe alternatives you've considered

No response

Additional context

No response

[crobert-1]

Am I correct in understanding that you're proposing to add these to the internal metrics the collector exposes? Would these values be per telemetry pipeline, or for the running collector as a whole?

[crobert-1]

Related: open-telemetry/oteps#249

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

[github-actions]

This issue has been closed as inactive because it has been stale for 120 days with no activity.