[proposal] Collect metrics in an internal format #345
Description
It would be useful if opamp-go could report metrics about its internal operations. For example:
- total message bytes transmitted and received
- count of messages transmitted and received
- message latency distribution
- message metadata, for instance type (ServerToAgent vs AgentToServer), instance uid, etc.
I think it would be nice to have some support for user labels as well, which can be scoped to the client process or however the user wishes.
Using a standard format would place dependencies on the library which may be difficult to accommodate. A way to avoid this is to use a bespoke format, and provide converters for this format elsewhere as needed. This is the approach the Go standard library used for runtime stats, and I think there is some merit for adopting it here too.
Draft PR of a possible implementation: #344