Structural tracing for Cloud Hypervisor

[liuw]

At the moment we can only rely on the output from the log crate for debugging. When there are multiple components that dump into the log, it is not easy to understand what thread does what.

The tracing crate provides structural output. It also can be easily integrated with the OpenTelemetry framework.

[liuw]

The log crate also seems to support structural logging with kv feature enabled per its document. Not sure how easy that is to integrate with OpenTelemetry yet.

[weltling]

The opentelemetry-rust project states logs are alpha, but it seems that logs have a good chance to be integrated depending on the current logging library in use.

For the traces, indeed the opentelemetry-rust project recommends using the tracing crate on their readme. Actually it seems strange, as the OpenTelemetry framework could be used directly. But one could also wrap both somehow and chose at the compile time, if needed.

It seems it need some exercise also to ensure the solution plays ok with OpenTelemetry.

Thanks

[weltling]

It also seems the tracing project would be useful even by itself? Thanks