gRPC AsyncServerInterceptor throws an exception when opentelemetry-javaagent is enabled

[kabigon-sung]

Hi team,
I found that the AsyncServerInterceptor throws an exception when opentelemetry-javaagent is enabled.
Here is the exception and stacktrace:

Armeria Version - 1.30.1

Possible root cause:
The default method interceptCall in AsyncServerInterceptor creates an instance of DeferredListener. The constructor of DeferredListener performs checking on the ServerCall<I, O> call parameter. The checking requires that the passed call should be a subclass of com.linecorp.armeria.internal.server.grpc.AbstractServerCall.
When opentelemetry-javagent is enabled, the original com.linecorp.armeria.server.grpc.UnaryServerCall object is replaced by io.opentelemetry.javaagent.shaded.instrumentation.grpc.v1_6.TracingServerInterceptor$TracingServerCall. Since TracingServerCall is not a subclass of AbstractServerCall , the constructor of DeferredListener throws an exception.

How to reproduce the problem

1. Implement a AsyncServerInterceptor

public static class MyInterceptor implements AsyncServerInterceptor {
        @Override
        public <I, O> CompletableFuture<Listener<I>> asyncInterceptCall(ServerCall<I, O> call,
                                                                        Metadata headers,
                                                                        ServerCallHandler<I, O> next) {
            final Context context = Context.current();
            return CompletableFuture.supplyAsync(() -> {
                try {
                    return context.call(() -> next.startCall(call, headers));
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }
            });
        }
    }

2. Add the interceptor to the GrpcService

sb.service(GrpcService.builder()
                                        .intercept(new MyInterceptor()) // add the interceptor
                                        .addService(new MyHelloService())
                                        .build());

4. Download the opentelemetry-javaagent from https://github.com/open-telemetry/opentelemetry-java-instrumentation.
5. Run the server with opentelemetry-javaagent.
6. Sending a gRCP request causes the error.

[jrhee17]

Did a local check, and it seems like the delegate method cannot be found for some reason:

[jrhee17]

I realized delegateMH doesn't work as expected 😅 We'll fix this from armeria-side in the next version 🙏

[kabigon-sung]

Hi @jrhee17 , I think you are right. Thanks for checking the issues.