I am working on an ASP.NET Core application which consumes a GraphQL
endpoint via RestSharp
to retrieve the data. This is an intranet type application, deployed on a Windows 2016 IIS Server and we are utilizing Windows Authentication. The problem we are encountering is that a certain user, who belongs to a large number of active directory groups is getting intermittent 431 Request headers too long errors.
I have attempted the following:
I am setting the IISDefaults
in the startup.cs
for both the application and service:
services.AddAuthentication(IISDefaults.AuthenticationScheme);
I am passing UseDefaultCredentials in the RestRequest
var client = new RestClient(endpoint);
var request = new RestRequest(Method.POST);
request.UseDefaultCredentials = true;
request.AddHeader("content-type", "application/json");
request.AddParameter("application/json", data, ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
return response.Content;
Set the registry entries for MaxFieldLength
and MaxRequestBytes
to the max allowed.
Log from stdout:
info: Microsoft.AspNetCore.Server.Kestrel[17] Connection id "0HLIABLA41UKH" bad request data: "Request headers too long." Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Request headers too long. at Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException.Throw(RequestRejectionReason reason) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.Http1Connection.TakeMessageHeaders(ReadOnlySequence
1 buffer, SequencePosition& consumed, SequencePosition& examined) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.Http1Connection.ParseRequest(ReadOnlySequence
1 buffer, SequencePosition& consumed, SequencePosition& examined) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.Http1Connection.TryParseRequest(ReadResult result, Boolean& endConnection) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication1 application) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequestsAsync[TContext](IHttpApplication
1 application) info: Microsoft.AspNetCore.Hosting.Internal.WebHost[1]
This was resolved by setting the MaxRequestHeadersTotalSize Kestrel option. This defaults to 32768.
public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
.UseKestrel(options =>
{
options.Limits.MaxRequestHeadersTotalSize = 1048576;
});