[gRPC-C++] Using channelZ with OpenTelemetry metrics

[Ben Harkins]

Hi all. I'm currently tasked with improving general telemetry support in a C++ library, where one of the primary goals is to expose some of gRPC's metrics to the top-level application via OpenTelemetry.

One proposed idea was to expose channelZ's metrics to OpenTelemetry, however, I'm not familiar enough with how channelZ operates to know if this is fundamentally sound. Does it seem feasible to access information from the channelZ service through OpenTelemetry instruments? I get the feeling that this may be an unusual use-case based on the research I've done so far.

[yas...@google.com]

Hey Ben, what kind of metrics are you looking for?

We already have gRPC metrics exposed via OpenTelemetry. Please take a look at -

https://github.com/grpc/proposal/blob/master/A66-otel-stats.md

https://github.com/grpc/proposal/blob/master/A78-grpc-metrics-wrr-pf-xds.md