Thank you for the detailed explanation. Since the only thing you need is the method name, consider adding a methodName parameter to your marshaller class. Then, when building the service definition, you can create an instance of your marshaller per method, and provide the method name as a constructor/builder argument. Would this solution work for you? If not, I'd be curious to know why.
- Sergii On Monday, February 19, 2024 at 6:37:49 AM UTC-8 R Chinmay wrote: > Thanks for your reply. > Since the exception from the marshaller in server does not reach the > client, and the exception logged in server does not contain any information > about microservice method which was invoked, I wanted to log microservice > method name along with the parsing exception, so that we can track the > microservice methods which are incompatible with the new marshaller and > allow fallback to default marshaller (which is comparitively slower) for > further calls. > > On Friday 16 February 2024 at 01:28:15 UTC+5:30 Sergii Tkachenko wrote: > >> You are correct, the Marshaller won't be able to access the Context from >> the interceptor. Though not exactly for the reasons you mentioned. >> Unmarshalling happens prior to `ServerCall.Listener.onMessage` callback >> is executed: >> >> 1. io.grpc.MethodDescriptor.Marshaller unmarshaller the message --> >> 2. Contexts.interceptCall interceptor (ContextualizedServerCallListener >> <https://github.com/grpc/grpc-java/blob/f20c853c40ef620e79b01ebcec6fcf0f667cab61/api/src/main/java/io/grpc/Contexts.java#L63>) >> >> restores the contexts --> >> 3. ServerCall.Listener.onMessage callbacks are executed (with the context >> attached). >> >> To answer your question, could you please provide a bit more info on what >> you're trying to achieve? Why do you need microservice method name in the >> marshaller? >> There are a few possible approaches, but it really depends on your goals. >> >> Best Regards, >> Sergii >> >> On Monday, February 12, 2024 at 8:07:03 AM UTC-8 R Chinmay wrote: >> >>> I have a custom implementation of request marshaller (overriding >>> io.grpc.MethodDescriptor.Marshaller) >>> which I want to use, but I would need context information related to the >>> microservice call (specifically microservice method name being invoked). I >>> tried populating it in ServerInterceptor's interceptCall. My interceptor >>> code looks like this: >>> @Override >>> >>> public <ReqT, RespT> Listener<ReqT> interceptCall(ServerCall<ReqT, RespT> >>> serverCall, Metadata metadata, ServerCallHandler<ReqT, RespT> >>> serverCallHandler) { >>> >>> Context context = Context.current().withValue(MS_METHOD_NAME, >>> call.getMethodDescriptor().getFullMethodName()); >>> >>> return Contexts.interceptCall(context, serverCall, metadata, >>> serverCallHandler); >>> } >>> >>> But the context populated does not persist when unmarshalling of the >>> request stream takes place. >>> >>> This is because >>> io.grpc.internal.ServerImpl.ServerTransportListenerImpl#streamCreatedInternal >>> >>> creates new >>> io.grpc.internal.ServerImpl.JumpToApplicationThreadServerStreamListener and >>> populates context using >>> io.grpc.internal.ServerImpl.ServerTransportListenerImpl#createContext which >>> just adds deadline and serverImpl instance fields over rootContext. So, the >>> information I populated was not available during unmarshalling. Also, >>> populating it in onMessage would not be useful too, since >>> io.grpc.internal.ServerCallImpl.ServerStreamListenerImpl#messagesAvailableInternal >>> >>> uses >>> listener.onMessage(call.method.parseRequest(message)); >>> >>> so parseRequest executes before onMessage is triggered. >>> >>> Is there some way to pass context information to marshaller, or maybe >>> use method name there. I am constructing methodDescriptor using >>> io.grpc.MethodDescriptor.Builder >>> >> -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to grpc-io+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/1941cf8f-7ee8-489a-9751-f71c3228ed27n%40googlegroups.com.
