Add gRPC Instrumentation

[lalitb]

Add support for gRPC C++ client and server api calls instrumentation either using

• gRPC C++ interceptors ( if available - seems to be experimental support for now : https://grpc.github.io/grpc/cpp/classgrpc_1_1experimental_1_1_interceptor.html )
• gRPC channel filters - similar to how it is done for OpenCensus ( https://github.com/grpc/grpc/tree/master/src/cpp/ext/filters/census ).

[ovidiubuligan]

I see a B3Propagator was commited today , Is this the recomended format for trace propagation? Or should the W3C format be used ?

[lalitb]

I see a B3Propagator was commited today , Is this the recomended format for trace propagation? Or should the W3C format be used ?

From instrumentation library prospective, it can be assumed that the right type of propagator would be already set ( refer : https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/context/api-propagators.md#global-propagators ). While it is not yet implemented for C++ ( #540), there would be api to set and get default propagator, which would be usable from instrumentation library.

[bryanuribe]

Is this still open/available? Would I be able to pick this up?
cc: @alolita

[maxgolov]

I see a B3Propagator was commited today , Is this the recomended format for trace propagation? Or should the W3C format be used ?

Depends on your cloud service provider. w3c TraceContext is the default endorsed and recommended:
https://www.w3.org/blog/2019/12/trace-context-enters-proposed-recommendation/

B3 is optional and supposed to live in external package.

[maxgolov]

@bryanuribe - in terms of gRPC w3c context propagation, I think @Hablapatabla is already working in this direction:
#729
You can join our channel on Slack to discuss more. Slack channel has more context.

[maxgolov]

@alolita - let's discuss this item during C++ SIG call. I guess what we need to achieve:

• generic example that shows how to use ANY propagator: standard + extended set.
• possibly a helper template / utility class that allows our customers to plug in any propagator of their choice.
• validation effort associated with verifying E2E that all propagators are functional.

I can help with W3C Trace Context validation, early customer feedback, etc. I have customers lined up for that already.

[maxgolov]

@bryanuribe - would you be able to join the next C++ SIG meeting? It would be immensely helpful if you can help us with B3 context propagator validation, and maybe covering Amazon-specific context propagator in contrib repo. Slack channel where we can discuss it:
https://cloud-native.slack.com/archives/C01SM7Y71DJ

[bryanuribe]

@maxgolov Yes, I will be at the next SIG meeting. Awesome, I will reach out to you over slack

[alolita]

@maxgolov will join in for the next SIG meeting - let's discuss.

[lalitb]

#729 closes this