Grpc.Core.RpcException: Status(StatusCode=\"Internal\", Detail=\"Error starting gRPC call. HttpRequestException: An HTTP/2 connection could not be established because the server did not complete the HTTP/2 handshake

What version of gRPC and what language are you using?

Grpc.Net.Client / 2.56.0-dev202307260702

What operating system (Linux, Windows,…) and version?

Linux containers in debian

What runtime / compiler are you using (e.g. .NET Core SDK version dotnet --info)

.NET SDK 6.0.600

What did you do?

If possible, provide a recipe for reproducing the error. Try being specific and include code snippets if helpful.

var services = new ServiceCollection();
        services.AddScoped<ClientLoggingInterceptor>();
        AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);
        AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2Support", true);
        services.AddSingleton<ResolverFactory>(sp => new DnsResolverFactory(TimeSpan.FromSeconds(10)));
        services
             .AddGrpcClient<TClient>(factoryOptions =>
             {
                 factoryOptions.Address = new Uri("dns://");
             })
            .ConfigureChannel(channelOptions =>
            {
                channelOptions.Credentials = ChannelCredentials.Insecure;
                channelOptions.ServiceConfig = new ServiceConfig
                {
                    LoadBalancingConfigs =
            {
                new RoundRobinConfig()
            }
                };
                channelOptions.HttpHandler = new SocketsHttpHandler()
                {
                    EnableMultipleHttp2Connections = true,
                    SslOptions = new SslClientAuthenticationOptions
                    {
                        RemoteCertificateValidationCallback = delegate { return true; }
                    }
                };
            }).AddInterceptor<ClientLoggingInterceptor>(); 
public class ClientLoggingInterceptor : Interceptor
{
    private readonly ILogger _logger;

    public ClientLoggingInterceptor(ILoggerFactory loggerFactory)
    {
        _logger = loggerFactory.CreateLogger<ClientLoggingInterceptor>();
    }

    public override AsyncUnaryCall<TResponse> AsyncUnaryCall<TRequest, TResponse>(TRequest request, ClientInterceptorContext<TRequest, TResponse> context, AsyncUnaryCallContinuation<TRequest, TResponse> continuation)
    {
        var call = continuation(request, context);

        return new AsyncUnaryCall<TResponse>(
            HandleResponse(context, call.ResponseAsync),
            call.ResponseHeadersAsync,
            call.GetStatus,
            call.GetTrailers,
            call.Dispose);
    }

    private async Task<TResponse> HandleResponse<TRequest, TResponse>(ClientInterceptorContext<TRequest, TResponse> context, Task<TResponse> inner)
        where TRequest : class
        where TResponse : class
    {
        try
        {
            return await inner;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "error");
            throw;
        }
    }
}

public class Client
{
    private readonly TClient _client
    public Client(TClient client)
    {
        _client = client;
    }
    public async Task Test()
    {
        await _client.sendAsync();
    }
}

The following exceptions occasionally occur when the client calls the .net Grpc method

{ "date": "2023-07-26 05:45:27.9186", "logger": "Middleware.ExceptionHandleMiddleware", "severity": "Error", "environment": "Production", "appdomain": "0001:", "hostname": "g", "token": "access-token=57A54F9C92181F86D41F8C69265FDF3B", "request-url": "", "request-ip": "", "localIP": "", "message": "Convert error from exception handle middleware", "exception": "Grpc.Core.RpcException: Status(StatusCode=\"Internal\", Detail=\"Error starting gRPC call. HttpRequestException: An HTTP/2 connection could not be established because the server did not complete the HTTP/2 handshake.\", DebugException=\"System.Net.Http.HttpRequestException: An HTTP/2 connection could not be established because the server did not complete the HTTP/2 handshake.\")\n ---> System.Net.Http.HttpRequestException: An HTTP/2 connection could not be established because the server did not complete the HTTP/2 handshake.\n   at System.Net.Http.HttpConnectionPool.ReturnHttp2Connection(Http2Connection connection, Boolean isNewConnection)\n   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)\n   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)\n   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)\n   at System.Threading.Tasks.Task`1.InnerInvoke()\n   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)\n   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)\n   at System.Threading.ThreadPoolWorkQueue.Dispatch()\n   at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()\n--- End of stack trace from previous location ---\n   at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken)\n   at System.Net.Http.HttpConnectionPool.GetHttp2ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)\n   at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at Grpc.Net.Client.Balancer.Internal.BalancerHttpHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\n   at System.Net.Http.HttpMessageInvoker.<SendAsync>g__SendAsyncWithTelemetry|6_0(HttpMessageHandler handler, HttpRequestMessage request, CancellationToken cancellationToken)\n   at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request, Nullable`1 timeout)\n   --- End of inner exception stack trace ---\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Logged|12_1(ControllerActionInvoker invoker)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)\n   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)\n at lambda_method132(Closure , Object )\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Logged|12_1(ControllerActionInvoker invoker)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)\n   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)\n  System.Private.CoreLib\nSystem.Net.Http.HttpRequestException: An HTTP/2 connection could not be established because the server did not complete the HTTP/2 handshake.\n   at System.Net.Http.HttpConnectionPool.ReturnHttp2Connection(Http2Connection connection, Boolean isNewConnection)\n   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)\n   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)\n   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)\n   at System.Threading.Tasks.Task`1.InnerInvoke()\n   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)\n   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)\n   at System.Threading.ThreadPoolWorkQueue.Dispatch()\n   at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()\n--- End of stack trace from previous location ---\n   at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken)\n   at System.Net.Http.HttpConnectionPool.GetHttp2ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)\n   at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at Grpc.Net.Client.Balancer.Internal.BalancerHttpHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\n   at System.Net.Http.HttpMessageInvoker.<SendAsync>g__SendAsyncWithTelemetry|6_0(HttpMessageHandler handler, HttpRequestMessage request, CancellationToken cancellationToken)\n   at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request, Nullable`1 timeout)    at System.Net.Http.HttpConnectionPool.ReturnHttp2Connection(Http2Connection connection, Boolean isNewConnection)\n   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)\n   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)\n   at System.Net.Http.HttpConnectionPool.AddHttp2ConnectionAsync(HttpRequestMessage request)\n   at System.Threading.Tasks.Task`1.InnerInvoke()\n   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)\n   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)\n   at System.Threading.ThreadPoolWorkQueue.Dispatch()\n   at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()\n--- End of stack trace from previous location ---\n   at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken)\n   at System.Net.Http.HttpConnectionPool.GetHttp2ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)\n   at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)\n   at Grpc.Net.Client.Balancer.Internal.BalancerHttpHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\n   at System.Net.Http.HttpMessageInvoker.<SendAsync>g__SendAsyncWithTelemetry|6_0(HttpMessageHandler handler, HttpRequestMessage request, CancellationToken cancellationToken)\n   at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request, Nullable`1 timeout) System.Private.CoreLib" }

What did you expect to see?

no error

What did you see instead?

Make sure you include information that can help us debug (full error message, exception listing, stack trace, logs).

See TROUBLESHOOTING.md for how to diagnose problems better.

Anything else we should know about your project / environment?

[kalduzov]

While monitoring the logs of our services, I noticed a similar problem on a nightly build. This error message only comes from services that are on build 2.56.0-dev202307240701.

Services with versions 2.43.0 and 2.55.0 do not throw such an error.

The error is very rare. This error cannot be reproduced.

[kalduzov]

@kalduzov Do your call java grpc server?

No. .net and Go server.