Azure SignalR Service

ASP.NET SignalR is an open source library for ASP.NET developers to add real-time web functionality to web applications.

For those not clear about the meaning of real-time functionality or what does real-time functionality mean?

Real-time web functionality allows to have server-side code push content to the connected clients as it happens, in real-time.

ASP.NET Web Development Company can help leverage SignalR to support “server push” or “broadcasting” functionality and handles connection management automatically. When it comes to HTTP connections for client-server communication connection is re-established for each request. However, SignalR provides persistent connection between the client and the server. In SignalR with using Remote Procedure Calls (RPC), the server code calls out to a client code in the browser, instead of request-response model.

SignalR Provides Two Models for Communication:

  1. Persistent Connections
    The Persistent Connection API offers developer easy and direct access to the low level communication protocol that SignalR exposes. This API uses the format of the actual message that needs to be specified and if the developer prefers to work with messaging and dispatching model and not remote invocation.
  2. Hubs
    A high-level API written over PersistentConnection allows the client and server to call methods on each other directly. Hubs also allow passing strong parameters to methods, enabling model binding

Official Version of the SignalR Service SDK with ASP.NET Support Released

Microsoft.Azure.SignalR.AspNet v1.0.0

At Ignite 2018, Microsoft announced ASP.NET support preview. Recently, Microsoft announced the release of the generally available version 1.0.0 of service SDK with ASP.NET support! This support will comes across as delightful for customers using the preview version SDK to build ASP.NET SignalR applications.

Azure SignalR Service is a fully managed Azure service for real-time messaging. It is one of the most favorable ways for scaling ASP.NET Core SignalR applications. However, SignalR Service is built on SignalR for ASP.NET Core 2.0, which is not fully compatible with ASP.NET SignalR. This means changes in code are required to make ASP.NET SignalR application work with SignalR Service. The service SDK also needs to add ASP.NET support in detail.

Azure SignalR Service Use Cases

There are several application types that require content updates which are real time. The following are good use cases or examples for using Azure SignalR Service:

  • Apps such as gaming, voting, auction, maps, and GPS apps which need high frequency updates from the server
  • Dashboards and monitoring apps. For instance, corporate dashboards and instant sales updates.
  • Apps for collaborative purpose such as Whiteboard apps and team meeting software.
  • Apps that require notifications. Social networking, email, chat, games, travel alerts, and many other apps use notifications.

Architecture for ASP.NET support

This diagram demonstrates the architecture to use Azure SignalR Service with an application server in either ASP.NET Core or ASP.NET.

Architecture For Support

For self-hosted SignalR application, the application server listens to clients’ connection requests and manages client connections. With SignalR Service, the application server only responds to clients’ requests and redirects clients to SignalR Service to establish consistent client-server connections.

With the ASP.NET support for Azure SignalR Service you can:

  • Keep SignalR application in ASP.NET as well as work with fully managed ASP.NET Core based SignalR Service.
  • Change SignalR API codes to switch and use SignalR Service instead of self-hosted SignalR Hubs.
  • Leverage Azure SignalR Service’s built-in features and tools to operate the SignalR application, with guaranteed SLA.

Several factors both technical and non-technical ones, make migration of the web application from ASP.NET SignalR to ASP.NET Core. The goal of ASP.NET support is to make migration easier with simple changes in code.

Some APIs and features are no longer supported:

  • Automatic reconnects
  • Forever Frame transport
  • HubState
  • PersistentConnection class
  • GlobalHost object
  • HubPipeline module
  • Client-side Internet Explorer support before Microsoft Internet Explorer 11

Today’s modern apps deliver updated information without even the need of hitting a refresh button. Add real-time functionality to your dashboards, maps, games and more.

ASP.NET support is focused on compatibility. As a result, all new features from ASP.NET Core SignalR are not supported. For instance features such as MessagePack, Streaming, etc. are only available for ASP.NET Core SignalR applications.

SignalR Service can be configured for different service mode: Classic/Default/Serverless. In this ASP.NET support, the Serverless mode is not supported. SignalR automatically detects and initializes the relevant and appropriate transport based on the features supported on the server and client.

In addition, SignalR provides a programming model for real-time applications that allows the server to send messages to all connections or to a subset of connections belonging to a specific user or have been placed in an arbitrary group.


If you want to know more about Azure SignalR for ASP.NET, it is important to hire ASP.Net web developers for robust and optimum solutions.

Looking to leverage Azure SignalR service? Get in touch with our team of experts.