Internal metrics support. about volo

[PureWhiteWu]

export runtime metrics, like eventloop delay

Hi, seems you are asking for some metrics of tokio? https://tokio.rs/blog/2022-02-announcing-tokio-metrics

We also have some apis for tracing, such as stat_tracer/span_provider of server, and you can also use a layer to get the stats of client from client context.

There's CommonStats in the context and also server and client specified stats in their own context.

Is this what you want?

[PureWhiteWu]

Hi, do you have any further question or something that need to be improved?