Helios: A Owin-based ASP. NET Web hosting framework that runs on IIS

Author Abel Avram, translator Yao Qirin released on March 29, 2014

Microsoft has released the Helios Project, a lightweight Owin-based web hosting framework that runs on IIS.

Helios, another project released last summer by Microsoft following Katana, made it possible for. NET Web developers to bypass Asp.net/iis, by providing widgets that can be installed, used, and managed independently, running on web hosting services that implement the Owin specification.

Asp. NET is a drawback of being included in the. NET Framework, bundled with the release cycle of. Net. The latter only releases a major version in a few years and is subject to a specific test and defect repair process. In order to make the development of Web tools more agile and more responsive, ASP. NET team created a number of slightly smaller components--asp.net MVC, ASP. api--They are not dependent on System.Web.dll, have a faster development cycle and are able to fix defects in a timely manner. Furthermore, developers can deploy such Web applications on custom Owin managed services or katana (a reference Owin implementation).

Helios is a Web runtime running on IIS, but not a fully fledged Microsoft Web server, Rick Strahl explains:

Helios does not use System.Web.dll, it hooks directly onto the native interface of IIS, providing basic Owin interfaces and contextual semantics. It runs completely outside of the normal ASP. NET HTTP runtime environment, bypassing the module pipeline and the default ASP. NET Runtime processing ... Helios is a lightweight, short-circuited version of the web hosting service that is booting from native IIS. Keep in mind that although IIS and ASP. NET are closely connected, the IIS kernel itself is very lightweight and runs completely above the native code. Only after an ASP. NET module or handler is installed does it interact with ASP., and this interaction is quite slow compared to the native kernel and native modules.

The idea behind Helios is that a mature and feature-rich environment based on IIS (excluding legacy ASP. NET attachments) provides a runtime. In addition, as security engineer Levi Broderick of ASP., the goal is to provide "high-density Web servers", "simulate the behavior of self-hosting more than analog web hosting", and "reduce the hassle of deploying Web apps". However, it does not "have compatibility with existing application 100%." In particular,. aspx and. ashx or other ASP. NET-related endpoints are not supported.

At development time, Helios requires the following environments: Windows 8 or Windows Server 2012,.net Framework 4.5.1,visual Studio 2012 or 2013. Broderick said they would "relax this requirement in a future preview" and might allow developers to use Windows 7 for development. Helios applications can be deployed in Windows Azure or any managed environment that has Windows Server 2012,. NET Framework 4.5.1, and Full trust.

On the performance side, for a "Hello world" application, the Helios throughput is 2-3 times more than the standard ASP. But Broderick that this is not the basis for comparing the two Web solutions, because the actual application is far more complex than the introductory application. But in terms of memory footprint, Helios is superior to system.web:

In terms of absolute numbers, the sample application can achieve 50,000 concurrent requests under the Helios architecture, saving approximately 1GB of memory footprint compared to standard ASP. Since the sample application is designed with minimal baselines, we have reason to believe that this absolute number can be maintained in other complex applications.

It should be noted that Broderick in the comments, Microsoft has not yet submitted Helios:

If people do not actually need Helios, or if the team is disbanded, or have a better idea, or have other reasons to think otherwise, we may stop working and not release it. We don't want it to work only under Azure.

Once the developer installs the Microsoft.Owin.Host.IIS NuGet package, it is possible to create a Helios-based ASP. NET application directly in Visual Studio.

Original English Link: Project helios:an ASP. NET owin-based Web Host Running on IIS

Helios: A Owin-based ASP. NET Web hosting framework that runs on IIS