Microsoft's 'Dublin' App Server Tied to .NET 4.0

New Windows Server and .NET Framework 4.0 technologies aimed at developers who are building composite applications will be released at Microsoft's Professional Developers Conference, Oct. 26-30. The server technologies are the first to support Microsoft's upcoming "Oslo" modeling platform, according to Microsoft.

The community technology previews (CTPs) will include early looks at new app server technologies, codenamed "Dublin," designed to increase the performance, scalability and operations of service-oriented software. Dublin is designed to host apps built using the next generation of the .NET Framework's messaging and workflow APIs. The final release will integrate with BizTalk Server, but BizTalk is not required. For now, Dublin will be offered as extensions to Windows Server 2008.

While the concepts behind Windows Communication Foundation (WCF) and Windows Workflow Foundation (WF), launched in .NET 3.0, were applauded, the early versions of the technologies meant steep learning curves, little to no support for REST principles -- the common architecture on the World Wide Web -- and frustrating workarounds for developers. Earlier this year, .NET 3.5 added some support for RESTful Web Services to WCF.

Microsoft's moves toward further embracing RESTful principles after an allegiance to SOAP was foreshadowed in its ADO.NET Data Services (codenamed "Astoria") available in .NET 3.5 Service Pack 1 released in August. .NET 4.0 leaps into Web 2.0 territory by enhancing WCF with REST, ATOM, POX and additional support for the WS*-stack: WS-Discovery, WS-BusinessActivity, WS-I BP 1.2 and SOAP over UDP.

"With Windows Communication Foundation, one of the things that we are seeing from customers is that they are doing a lot of work around Web 2.0 with things like REST, ATOM and POX," said Burley Kawasaki, director of product management in Microsoft's Connected Systems Division. "Investments we are making in the 4.0 release are making it even easier to build these RESTful services as a seamless extension of .NET."

Toward that goal, Microsoft is releasing a WCF REST Starter Kit on CodePlex this month and asking developers for feedback on its preview technologies. The starter kit offers developers Visual Studio 2008 tooling, integration with ASP.NET, and guidance on common server and client-related issues such as caching, security and error handling, as well as templates for REST Singleton Service, REST Collection Service, ATOM Feed Service, ATOM Publishing Protocol Service and HTTP Plain XML Service.

In addition to messaging and communication, composite apps often require more complex operations in the form of transaction flows, data binding and declarative application logic (HTML and XAML). To that end, Microsoft is improving the integration between WCF and WF, and ratcheting up the performance and flexibility of its WF tooling.

"Today you can model parts of the applications and then you still have to drop into code, so one of the big focuses of the 4.0 release is trying to create a much broader set of apps that you can build entirely just using declarative programming," Kawasaki explained. "We are adding workflow models. We are adding all these pre-built activities, so it is not 100 percent, but something close to 80 to 90 percent of apps that you can write without having to write code."

Better performance and scalability are also expected in WF 4.0. The early previews of the workflow engine are clocking 10X better performance during benchmark testing in certain scenarios, according to Kawasaki.

Early adopters of "Dublin" and its related dev frameworks include the Microsoft Dynamics team, who have committed to using the new technologies in the next releases of AX and CRM.

About the Author

Kathleen Richards is the editor of and executive editor of Visual Studio Magazine.