[obsreport] why the "/" is used for metrics of agent

[yutingcaicyt]

Is your feature request related to a problem? Please describe.
In the Specification of opentelemetry, I haven't seen this usage in any examples or conventions. But in opentelemetry-collecotor, the convention for obsreport metrics is /<metric_name>.

Describe the solution you'd like
Could you let me know whether the convention in opentelemetry-collecotor is consistent with the Specification of opentelemetry?

[codeboten]

I believe this is a side effect of the metrics having been initially instrumented using opencensus. You can see where support for / was added to the specification: open-telemetry/opentelemetry-specification#3422

See open-telemetry/oteps#238 for an OpenTelemetry Enhancement Proposal around semantic conventions for telemetry pipeline monitoring

[codeboten]

The metrics generated have been moved to use _ as a separator. This makes the any metrics generated by the collector consistent regardless of whether the export is done via prometheus (which already did this automatically) or via another exporter (otlp, console).

I'm marking this as done for core. There are a few metrics still being migrated in contrib, but they're being tracked in open-telemetry/opentelemetry-collector-contrib#29867 and open-telemetry/opentelemetry-collector-contrib#33523