Los Angeles, Calif. – Microsoft's emerging Oslo SOA modeling initiative has just gained a bit more clarity. Part of the package now is M, a modeling language supporting the Oslo community technology preview included in .NET Framework 4.0, released this week at the Microsoft Professional Developers Conference (PDC). Oslo also includes a repository.
Once part of a much broader framework, Oslo as presented at PDC focuses on modeling for composite applications, including service-oriented architecture implementations running on in-house servers, and as part of Windows Azure, Microsoft's new Compute Cloud initiative.
"Initially, Oslo referred to a lot of different things," said David Chappell, principal of Chappell & Associates in San Francisco. "Now, Oslo refers to modeling technologies. and the repository. So just in terms of clarity, that's progress."
Any information stored in the Oslo repository must conform to a schema, said Chappell. The schema can be built using ordinary T-SQL statements, he has written, but the M language is dedicated to creating schemas in the Oslo repository, and can ease the task for developers, especially ones ready to forgo ordinary T-SQL. In effect, it is a declarative language.
"The M language family includes a capability called 'MSchema.' A primary goal of MSchema is to make it easy for developers and architects - not just database administrators - to define new schemas for the Oslo repository. Toward this end, MSchema uses a syntax and a style that will be familiar to most developers."
Oslo as presented at PDC is more focused on modeling than it was in Microsoft's discussions about it earlier this year. At PDC the Oslo theme is "Models Remixed," and focuses on the modeling approach to assembling services into composite applications.
In its current iteration Oslo includes "a repository, providing a common place to store a range of information about your IT environment," the M language for describing that information, and a modeling tool, codenamed Visual Studio "Quadrant," for working with repository information, Chappell explained.
New day for composite apps
"By nature, composite apps are very heterogeneous. You don't know what services you might want to compose into an app," said Burley Kawasaki, director of Microsoft's connected systems division.
"Oslo as a general purpose modeling platform can target any number of environments," he said. He went on to consider the Dublin composite app platform that Microsoft previewed earlier this month. Kawasaki said Dublin will provide a runtime to support composite applications on-premise, while the newly announced Windows Azure will provide a runtime for composite apps in the Compute Cloud. Oslo can be used for the modeling for both, he added.
"That's one of the benefits of using a model to abstract away from the underlying runtime," Kawasaki said. Modeling with Oslo, it will not matter if the eventual runtime is on-premise or in the Cloud or a combination of both, he added.
Oslo will provide a consistent application model across both on-premise and Cloud environments, Kawasaki said, which will be helpful to Microsoft partners such as AmberPoint, which provides runtime governance on Windows Communications Foundation (WCF). Ed Horst, AmberPoint's chief marketing officer, said that in working with Microsoft as Oslo emerges, his company also sees a future where customers will be moving to a mix of on-premise and Cloud-based applications.
"As an outside observer one of the big breakthroughs that we see is that Oslo was built from the ground up assuming there was going to be this composite world," Horst said. "The applications or compositions that we're going to be working with are going to be diving in and out of different places. Some may be on the Cloud side and then you're back to a service running in-house."
Although gaining clarity, Oslo is still perhaps a moving target. As if to defend Microsoft's evolving Oslo initiative from criticism, Ray Ozzie, Chief Software Architect at Microsoft, ended his PDC keynote on Tuesday by cautioning that the new technology is "nascent." He told the developers and architects in attendance to expect changes as projects mature to include feedback from those working with the preview editions.
Workflows, Services, and Models: A First Look at WF 4.0, Dublin, and Oslo by David Chappell, on MSDN.