Internal metrics support.

[fly3366]

Feature Request

Crates

volo-otel? volo-var?

Motivation

like bvar in brpc. support export to otel or openmetrics format to prometheus easy.

export runtime metrics, like eventloop delay.

Proposal

like bvar. write metrics var to thread local storage. and merge all tls on read.

Alternatives

if not impl it in framework. user may need do it on application layer and hard to monitor runtime metrics. may conflict with volo's better perf. such like some prom client use one instance and need mutex. it may conflict with volo's slogan lock free.

[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?