Microsoft ASP.NET SignalR

Yes, you read that right, Microsoft.AspNet.SignalR. It’s been a while since I last blogged as we’re super busy trying to make SignalR rock solid and 1.0 quality for you all to use. I’ve also given my first talk ever at Monkeyspace and then BUILD - both on SignalR. SignalR 1.0 alpha has been live for just over 2 weeks on NuGet, and a few seconds ago I just published alpha2. A lot has changed since 0.5.3 and there have been several people poking around trying to find out what’s changed and what’s new in the alpha. There’s also been lots of confusion about what to use, so I’m going to clear things up by enumerating the list of major changes.

New Packages

There are new packages that you can use today in your applications.

  • Microsoft.AspNet.SignalR – meta package (use this)
  • Microsoft.AspNet.SignalR.Client – .NET 4 and WinRT client
  • Microsoft.AspNet.SignalR.JS – The Javascript client.
  • Microsoft.AspNet.SignalR.Core – Core server package with no host implementation
  • Microsoft.AspNet.SignalR.Hosting.AspNet – The ASP.NET host
  • Microsoft.AspNet.SignalR.Hosting.Utils – utilities for signalr (signalr.exe)
  • Microsoft.AspNet.SignalR.Redis – Redis message bus implementation
  • Microsoft.AspNet.SignalR.ServiceBus – Service bus message bus implementation

If you’re using the NuGet dialog, pick the IncludePrerelease in the dropdown to see them. If you’re using the package manager console, use the –pre flag to install it.

Install-Package Microsoft.AspNet.SignalR –pre

Visual Studio Integration

When you install the ASP.NET 2012 Fall Update, you’ll see a few new things in your Add New Item menu.


These will bring in the alpha1 packages but you can update them using NuGet to get the latest and greatest.

Hub API changes

First thing to notice is the client and server members on the hub object. This came about because there was a subtle issue with naming methods on the client and server. If they were called the same thing it just wouldn’t work so we decided to separate the namespaces. As you already guessed, you can declare methods that the server calls on the client object and call methods that exist on the server with the server object.

On the server side we’ve added quite a few new APIs for hubs after lots of feedback and discussion.

This is a dump of all the new surface we’ve added for hubs. The comments are pretty self explanatory but as part of this work we resolved this long standing feature request (it’s almost a year old!).

Connected, Disconnected and Reconnected

Before we had these awful interfaces you had to implement to detect this, now it’s just an override on the Hub itself.

No more magic?

There’s obviously still some magic, just a bit less than before. When using hubs, people always wondered how this magic ~/signalr/hubs url was getting registered. This is now an explicit call the developer has to make to enable this route. When you install the new package, it’ll add a RegisterHubs.cs file to the project in the App_Start folder.

There's even a little comment telling you what MapHubs does. If you want to, you can remove this file and just add the call to your global asax with the rest of your route registration.

Hub Pipeline

This is the most powerful feature we’ve added in the new release. Think of the hub pipeline like mvc filters but more powerful. You get to inject any piece of code anywhere in the hub pipeline for incoming and outgoing calls. Here’s an example of a hub pipeline module that logs all outgoing and incoming calls.

The module has a bunch of different methods you can override, the above sample only shows 2 of them. Each method takes the appropriate context so you can get whatever information you want about the incoming or outgoing invocation. The next feature on the list builds on the pipeline implementation.


Many of you wanted an easy way to mark a hub as requiring authorization and now you can do that by just specifying an attribute similar to MVC.

Now you can decorate your hubs or hub methods or both to get different granularities of security. The first example shows requires authorization for all connections to the hub and calls to any incoming methods. In the second example, any connection to the hub as well as calls to Send require authorization, but calls to Send2 do not.

Client side keep alive

This feature allows clients to react to slow/buggy networks that drop connectivity often. The JavaScript client checks for a keep alive ping from the server on a configurable interval and raises the “connection slow” event before it drops the connection and starts reconnecting.

Rejoining Groups

There’s tons of confusion about how groups work in SignalR and how it works in scaled out environments ( SignalR stores enough state on the server to make groups work, but all groups that a client is a member of is round-tripped with that client. This of course means that any client can claim they are in a group and spy on your messages. Groups are not a security feature, it’s about message filtering. By default, SignalR will ignore groups that are sent from client to server (to be secure by default). Clients will not be able to receive messages for groups they were in after a reconnect for most transports, but for longpolling it will be immediate. Developers can re-enable the default behavior by enabling a pipeline module that trusts the client’s groups.

If you’re more advanced and want to apply a custom filter to pre-process groups for particular clients, you can write a custom pipeline module to do so.

New Scale Out Providers

We’ve completely re-worked the scale out providers for service bus and redis and added sql server to the list (not shipping with this release but you can use the source). As part of this work, we’ve abstracted a ScaleOutMessageBus base class that each of these providers derive from in order to cleanly plug into SignalR. Check out the class for more details.

More Memory Efficient and huge throughput gains

The MessageBus was complete re-written and optimized for small messages (we normally test with 32 byte sized message payloads) and high throughput. More memory efficient means that we can get more connections on a single node. By the time we RTM, we’ll have documentation and guidance on how to do capacity planning on your webservers and on azure.

Performance Counters

We have a utility called signalr.exe (in the Microsoft.AspNet.SignalR.Hosting.Utils package) that you can use to do a few things.

  • Install/Uninstall SignalR performance counters
  • Generate a static js file for the magic ~/signalr/hubs url.

You can install the performance counters if you want to see more detailed information about your SignalR applications. Here’s a view of what that looks like:



NOTE: To use these on full IIS you need to add the app pool user for your application to the Performance Monitor Users group.

Message payload size

We’ve made some changes (not in alpha2 but later) to reduce the size of our payload dramatically and as a result changed the protocol for 1.0 as well. I’ll talk about this more in a later post.


We’re in the process of updating it as well as preparing content for Stay tuned!


Thank you all for being a part of this amazing journey from side project to official project. Thanks to your enthusiasm it has has grown rapidly into a framework that people just love to use! Keep giving us feedback! Ping me on jabbr or twitter if you have any questions!


  • Great job!
    I still waiting for Scaleout through sql server.


  • Great post! Thanks man.

  • Nice job getting this out.

    Except for the fact SignalR just rocks, I'm also learning so much just by following the commits, comments and discussions on github.

    Thanks for that.

    You forgot one package tough: Microsoft.AspNet.SignalR.Js

    I used it to get the static jquery.signalr.*.js file into a web project.

    I didn't want to use the meta package, because the infra/web/hub code files live in a seperate class library.

  • Hi,

    I don't see a Silverlight client package there, is it dropped?

  • Awesome @davidfowl ! Given that our project is still in initial stages of development using 0.5.3, do you think this is the time to embrace SignalR 1.0 alpha? I see that you have 2.0 alpha is out too..

  • Congrats David and Damian for the success. You have included most of the features that anyone using SignalR in any application would need.

    Thanks to both of you for bringing this amazing gift for developers and Thanks to Microsoft for adding it to ASP.NET.

  • What about self hosting? has that been dropped from 1.0?

  • Great job on the updates to SignalR and also becoming official!

    One thing, in your hub example, you might want to change the client method to addMessage. (e.g. Clients.All.addMessage(message);)

    It's a little confusing using 'send' as your client method, since that's also the name of the server method, and it doesn't fit with the earlier Javascript example.

    Anyway, awesome work!

  • The pipeline filter is intercepting outgoing and incoming traffic.

    I wonder how much increase in cpu this causes?

  • @redmond0712 I'd suggest using alpha2 as we're fixing lots of bugs and improving it constantly. 0.5.3 Will never be updated again so if you want an upgrade path we'd suggest using alpha2.

    @Remco Ros Fixed!

    @Martin Rothschink We won't be shipping the self hosting package in it's current form. In the latest changes we're focused on OWIN (, which will have support for self host and an ASP.NET host.

    @Geir-Tore Lindsve Silverlight 5 support will be there for RC and RTM.

    @Kiliman Fixed!! Nice to see you're still around :).

    @Jeevan You'd have to measure that.

    @Paul Batum Man, that's an old bug ;). Not sure it's a good place to implement it but it would be interesting to see if you could.

  • Any update about signalr ninject package?

  • @Scott Xu We won't be officially shipping anymore DI containers. That's the community's job. I will however personally take over the ninject piece.

  • I assume Visual Studio Express won't get the Fall update, does this mean Express users won't get these added benefits or will updating NuGet do this?

  • to be clear, what client browswer can be used with SignalR. more specifically, which legacy versions of IE can be used. Hopefully, IE8 ?

  • @breath2k Did the installer fail for express? I think most of the ASP.NET updates work with VWD Express and full VS but I can check to make sure.

    @mikeJ Yes you can use IE8. When we ship 1.0 RTW, we'll have a graded support matrix with browsers. So things like IE6 might work but we won't be making major investments in making it work well with IE6 (as an example).

  • @davidfowl you say SL5 support will come with the RC/RTM.
    Any idea how long will we have to wait ?

  • @Bob If you don't want to wait you can always build from source :).

  • @davidfowl No it was ok, worked fine for Express I was getting confused with Web Essentials

  • @davidfowl you mean the current source on git have a full working project for silverlight ?

  • Big congrats for the release, its brilliant. Loved the way all connections method are changed.

    I just upgraded from 0.5.3 to the latest version.
    After upgrading , its not working. Here are the details of my implementation:

    1. Signalr server is hosted as a REST service( web api)

    2. xyzHub class has implemented onConnected,ondisconnected methods.

    3. Client = is doing a cross domain request for loading all signalr stuff.

    When my webpage loads, i can see the connection done but cannot see any of my hub(s).

    Also cannot see the onconnected event fired on server side in the hub class.

    Any idea?


  • Maybe good to mention is the casing change. The hub name on the server was camel cased in the javascript client, but not anymore, it's just the exact hub name on the server.

  • @chmarsh That would imply that you don't have any subscriptions on the client.

  • @Scott Xu: I have a solution:

    1. Create other NinjectDependencyResolver
    public class SignalRNinjectDependencyResolver : Microsoft.AspNet.SignalR.DefaultDependencyResolver
    private readonly IKernel _kernel;

    public SignalRNinjectDependencyResolver(IKernel kernel)
    if (kernel == null)
    throw new ArgumentNullException("kernel");

    _kernel = kernel;

    public override object GetService(Type serviceType)
    return _kernel.TryGet(serviceType) ?? base.GetService(serviceType);

    public override IEnumerable GetServices(Type serviceType)
    return _kernel.GetAll(serviceType).Concat(base.GetServices(serviceType));

    2. Configure in RegisterHubs.Start()
    public static class RegisterHubs
    public static void Start()
    GlobalHost.DependencyResolver = new SignalRNinjectDependencyResolver(NinjectFactory.Kernel);
    RouteTable.Routes.MapHubs(new SignalRNinjectDependencyResolver(NinjectFactory.Kernel));
    I'm using SignalR 1.0 alpha
    Hope this help.

  • In case you have multiple web servers to keep in sync and using Redis for that, is it possible to switch to another Redis Master server on the fly without having to restart application?

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