planning.md

gRPC-dotnet future planning (for ASP.NET Core 5.0)

Schedule and versioning

The work described here targets the ASP.NET Core 5.0 release which is currently scheduled for November 2020: https://github.com/dotnet/core/blob/master/roadmap.md. The version of the gRPC-dotnet release will follow the rules laid out in https://github.com/grpc/grpc-dotnet/blob/master/doc/versioning.md.

Runtime

• Linker-friendly gRPC

  • As part of positioning .NET as a viable technology for cloud native, we should ensure we are linker-friendly and audit any possible future usage of reflection/ref-emit

  • Optimize for working-set memory/published output size

    • See https://github.com/rynowak/link-a-thon/blob/master/Findings.md for comparison

  • Additional Server

    • HttpSysServer
    • IIS In-proc

• Introduce additional transports on the server

  • Unix-domain sockets
  • Named pipes (on Windows)
  • [Stretch] QUIC

• Introduce additional transports on the client

  • Unix-domain sockets
  • Named pipes (on Windows)
  • [Stretch] QUIC

• Serializer/de-serializer performance improvements

  • protocolbuffers/protobuf#5888

• HTTP/2 performance on the server

  • HPACK Static dictionary
  • HPACK Dynamic dictionary
  • Pooling of HTTP/2 Streams
  • [Stretch] Window update tuning

• Ensure code-first gRPC is successful

• Marc Gravell is using protobuf.net to build a code-first gRPC experience on grpc-dotnet. Ensure our abstractions allow him to be successful.

• Ensure WCF to gRPC ebook is successful

• Provide SME guidance where applicable

• Testing existing client libraries on both implementations

  • There are APIs and SDKs to share between the implementations
  • https://github.com/grpc/grpc-dotnet/blob/master/doc/implementation_comparison.md
  • Here is the list of client libraries that grpc-dotnet should work with
    • https://github.com/googleapis/google-cloud-dotnet
    • there's an add-on library https://github.com/GoogleCloudPlatform/grpc-gcp-csharp that is used to provide some of the functionality (like channel affinity) for some of the APIs.

It would also be useful to help with figuring out a way to make the client libraries not depend on Grpc.Core directly (which is currently the case).

• Load balancing

  • Integration with XDS load balancing APIs
  • May need Connectivity APIs work in HttpClient
  • We should start with supporting round_robin loadbalancing as a first step. The features needed for that are very likely to be needed for XDS loadbalancing as well.

• Connection Features

  • Keep alive, without keepalive support it can be difficult to have long-lived streaming call that only rarely sends messages (e.g. "client subscribes for receiving updates from server " scenario)
  • Connection idle: https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md
  • Wait for ready
  • These features are often needed for production ready services

• Support status.proto

  • Trailing rich metadata for error details
  • Works across different implementation
  • For details, see "Richer error model" here: https://grpc.io/docs/guides/error/ and also https://cloud.google.com/apis/design/errors#error_model example what we've done for e.g. python: https://github.com/grpc/proposal/blob/master/L44-python-rich-status.md the expectation is that we'll ship this as a separate nuget (e.g. "Grpc.StatusProto")

• Channelz support

  • Observability of server status

• gRPC web

Tooling

• [Stretch] Build a LSP for protobuf

• [Stretch] VS Code extension to consume LSP

  • [More Info Needed] Possibly partner with VS Code team here

• [Stretch] VS Extension to consume LSP

• Tooling for working with gRPC services without building a client project

  • Integration with HttpREPL or something like WCFTestClient?

• Generating and working with client certificates

• Publishing to AKS

Ecosystem

• Envoy integration
  • [Stretch] Integration with Envoy XDS APIs for client-side load balancing
• Kubernetes/AKS
  • [More Info Needed] Helm charts for CLI publish
• Xamarin apps support

Documentation/Samples

• OAuth E2E
• More AuthN/AuthZ coverage
• gRPC specific features
  • Deadlines
  • Cancellation
• Distributed Tracing
  • OpenCenus/Open Telemetry
• Interceptors

Intentional cuts/omissions

• gRPC with JSON (as opposed to protobuf)