How to send big data via SignalR in .NET client

Question

We have a .NET client, which use SignalR to call Server method, but the parameter seems very big, for such scenario how to fix it?

Client code:

public async Task FooAsync()
{
    var hubConnection = new HubConnection(...);
    await hubConnection.Start();

    var hubProxy = hubConnection.CreateHubProcx("ValueHub");
    //the content is very long, about 11776065 bytes (11MB)
    var content = File.ReadAllText(...);
    hubProxy.Invoke("Send", content);
    ...
}

Server code:

[HubName("ValueHub")]
public class ValueHub : Hub
{
    public void Send(string json)
    {

    }
}

From the exception stack and source code, I found the SignalR internally use HttpClient with the FormUrlEncodedContent type HttpContent, and maybe the limitation came from here.

System.UriFormatException was unhandled
  HResult=-2146233033
  Message=Invalid URI: The Uri string is too long.
  Source=System
  StackTrace:
       at System.UriHelper.EscapeString(String input, Int32 start, Int32 end, Char[] dest, Int32& destPos, Boolean isUriString, Char force1, Char force2, Char rsvd)
       at System.Uri.EscapeDataString(String stringToEscape)
       at System.Net.Http.FormUrlEncodedContent.Encode(String data)
       at System.Net.Http.FormUrlEncodedContent.GetContentByteArray(IEnumerable`1 nameValueCollection)
       at System.Net.Http.FormUrlEncodedContent..ctor(IEnumerable`1 nameValueCollection)
       at Microsoft.AspNet.SignalR.Client.Http.DefaultHttpClient.Post(String url, Action`1 prepareRequest, IDictionary`2 postData, Boolean isLongRunning)
       at Microsoft.AspNet.SignalR.Client.Transports.HttpBasedTransport.Send(IConnection connection, String data, String connectionData)
       at Microsoft.AspNet.SignalR.Client.Transports.AutoTransport.Send(IConnection connection, String data, String connectionData)
       at Microsoft.AspNet.SignalR.Client.Connection.Send(String data)
       at Microsoft.AspNet.SignalR.Client.Hubs.HubProxy.Invoke[T](String method, Object[] args)
       at Microsoft.AspNet.SignalR.Client.Hubs.HubProxy.Invoke(String method, Object[] args)

Any good suggestions over this problem?

Honestly I would not do it in a hub. Use the hub as a messaging framework to inform the client that new data has arrived. The client then can fetch the data via web api / webmethod or any other transportation technique. — Schadensbegrenzer, Jun 17 '14 at 11:00
This might help you http://stackoverflow.com/questions/7043566/invalid-uri-the-uri-string-is-too-long — K D, Jun 17 '14 at 11:05
http://stackoverflow.com/questions/13426014/signalr-and-large-data-transfer — st4hoo, Jun 17 '14 at 11:10

score 19 · Answer 1 · answered Oct 04 '16 at 14:29

19

You can add a line that makes the message size 'infinite 'in your Startup.cs by setting the MaxIncomingWebSocketMessageSize to null:

    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
        app.MapSignalR();
        GlobalHost.Configuration.MaxIncomingWebSocketMessageSize = null;
        }
    }
}

Mine works with ~200kb of data, 10 messages send consistently. I don't know how well it works if there is more data send per second though.

answered Oct 04 '16 at 14:29

Alexander

1,286
1
15
21

1

Working great. nice solution. – No1Lives4Ever Feb 07 '17 at 16:03
Didn't wonk for me. May because it's an owin app with Web Api and Signalr and the configuration has to be set up differently – Christoph Adamakis May 31 '17 at 10:46
1

In case SignalR is inside an Owin App, the above answer has to be combined with this http://jerodkrone.com/signalr-2-0-dependency-injection-using-globalhost/ in order to work. So if the hub is using a custom configuration like var hubconfig = new HubConfiguration(); and a custom resolver like hubconfig.Resolver = new AutofacDependencyResolver(lifetimeScope); then the following 2 lines need to be added in StartUp: GlobalHost.DependencyResolver = hubconfig.Resolver; GlobalHost.Configuration.MaxIncomingWebSocketMessageSize = null; – Christoph Adamakis Jun 29 '17 at 10:08
1

For dot net core use - - - - - services.AddSignalR(configure => { configure.MaximumReceiveMessageSize = null; }); – Muhammad Waqas Aziz Feb 25 '20 at 13:09
1

This should really be the accepted answer. It solved the problem for me. Thanks so much @Alexander, I was pulling my hair out over this one! – David R. Oct 12 '20 at 10:03

score 8 · Accepted Answer · answered Jun 17 '14 at 11:05

8

As you have already gathered - this data is too much for SIGNALR by it's own design.

Would it not be a better idea to rather have another process that does this with a normal REST API (GET/POST). Perhaps a message indicating to the user that this needs to be done, as this feels very 'BATCH' like.

Secondly, if it a requirement (possible wrong tool for the job), have you considered compression.

answered Jun 17 '14 at 11:05

Dane Balia

4,259
5
26
48

What about smaller files? I want to send 60KB thumbnails. I can tell my server to accept such a long query string(and it will be quite fast anyway), but SignalR's uri encoding will still block it :S. – tec-goblin Jul 02 '14 at 08:57

score 4 · Answer 3 · edited May 26 '16 at 13:48

4

its easy to do it..

split files into byte Array chunks (my tests shows max 10kb per chunk is enough)
send chunks to client with an invoke like (calculate totalBytes and the chunk data you have) :
```
hubProxy.Invoke("Send", chunk,currentBytes,totalBytes);
```
get the chunks from client and create a byte array and append each chunk, signalr sends files syncronously, this means data will be received as your send order
you have totalbytes and currentBytes data, now you know all data received, save this byte array to a file with stream or whatever you like..

edited May 26 '16 at 13:48

Machavity

28,730
25
78
91

answered May 26 '16 at 13:23

Serkan Polat

61
2

1

You would need to send sequence information along with it as I read that SignalR does not guarantee the order of messages. – TheLegendaryCopyCoder Jan 24 '17 at 13:24
probably sending the stream position number may define the sequence information for each chunk – ASLIM Dec 01 '20 at 16:54

score 2 · Answer 4 · answered Feb 25 '20 at 13:20

2

For dot net core in startup.cs in ConfigureServices(IServiceCollection services) method add the below line

services.AddSignalR(conf =>
{
      conf.MaximumReceiveMessageSize = null;
}

answered Feb 25 '20 at 13:20

Muhammad Waqas Aziz

535
4
8

samad asadi · Answer 5 · 2019-09-30T13:31:22.550

0

add this to web config
<httpRuntime maxRequestLength="1048576" executionTimeout="600" />

then add this code to Startup.cs

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        app.MapSignalR();
        GlobalHost.Configuration.MaxIncomingWebSocketMessageSize = null;
    }
}

edited Sep 30 '19 at 13:31

answered Sep 30 '19 at 12:48

samad asadi

1
1

How to send big data via SignalR in .NET client

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