dotnet protocol_error ai_generated true

Grpc.Core.RpcException: Status(StatusCode="Unimplemented", Detail="Method service.MethodName is unimplemented.")

ID: dotnet/grpc-unsupported-protocol

Also available as: JSON · Markdown · 中文
85%Fix Rate
87%Confidence
1Evidence
2024-01-10First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
gRPC C# 2.46.0 active — — —
Grpc.AspNetCore 2.57.0 active — — —
Google.Protobuf 3.24.0 active — — —
.NET 6.0 active — — —
.NET 7.0 active — — —
.NET 8.0 active — — —

Root Cause

The gRPC client is calling a method that the server does not have a handler for, often due to mismatched service definitions, missing method implementation, or incorrect proto file compilation.

generic

中文

gRPC 客户端调用了服务器没有处理程序的方法，通常是由于服务定义不匹配、缺少方法实现或 proto 文件编译错误导致的。

Official Documentation

https://learn.microsoft.com/en-us/aspnet/core/grpc/troubleshoot?view=aspnetcore-8.0

Workarounds

  1. 90% success Regenerate both client and server stubs from the same .proto file. Example command: protoc --csharp_out=./Client --grpc_out=./Client --plugin=protoc-gen-grpc=grpc_csharp_plugin service.proto 
    Regenerate both client and server stubs from the same .proto file. Example command: protoc --csharp_out=./Client --grpc_out=./Client --plugin=protoc-gen-grpc=grpc_csharp_plugin service.proto
  2. 85% success Verify the server implements all methods defined in the proto file by checking the generated service base class. Ensure no method is missing or commented out. 
    Verify the server implements all methods defined in the proto file by checking the generated service base class. Ensure no method is missing or commented out.
  3. 75% success Ensure the client is using the correct service address and port. Test with grpcurl: grpcurl -plaintext localhost:50051 list 
    Ensure the client is using the correct service address and port. Test with grpcurl: grpcurl -plaintext localhost:50051 list

中文步骤

  1. Regenerate both client and server stubs from the same .proto file. Example command: protoc --csharp_out=./Client --grpc_out=./Client --plugin=protoc-gen-grpc=grpc_csharp_plugin service.proto
  2. Verify the server implements all methods defined in the proto file by checking the generated service base class. Ensure no method is missing or commented out.
  3. Ensure the client is using the correct service address and port. Test with grpcurl: grpcurl -plaintext localhost:50051 list

Dead Ends

Common approaches that don't work:

  1. Restarting the server without updating the proto files or regenerating the client stub. 95% fail

    The issue is a mismatch between client and server definitions; restarting alone does not synchronize them.

  2. Adding a catch-all method in the server that returns an empty response. 90% fail

    gRPC relies on strict method contracts; a catch-all violates the protocol and may cause other errors.

  3. Changing the client to use a different HTTP version (e.g., HTTP/1.1). 100% fail

    gRPC requires HTTP/2; HTTP/1.1 is not supported and will cause a different error.