Orchestrating Web Services

Summary

In this chapter, I examine some of the technologies that will help define the future of Web services. Specifically, I covered .NET My Services, the GXA, and BizTalk Orchestration for Web Services.

.NET My Services provides a set of Web services that allow access and management of personal data associated with a user. You can programmatically query and manipulate the data stored within .NET My Services using the five messages defined by HSDL: queryRequest, deleteRequest, updateRequest, insert Request, and subscriptionResponse. However, you can access only your own data or the data of other users as long as those users have given you the appropriate permissions. Identity of a user is determined by authenticating against the Passport Kerberos domain authority.

In addition to authentication credentials, HSDL messages need to include routing information as well. In an effort not to create a proprietary solution, Microsoft released the GXA. The GXA is currently composed of a set of five specifications: WS-Security, WS-Licensing, WS-Referral, WS-Routing, and WS-Inspection. Each specification is layered on top of SOAP in a modular fashion. Therefore, any GXA specification can be used in combination with any other GXA specification.

Microsoft released the specifications for comment by other leading technology companies as well as customers. Once the specifications have matured, Microsoft intends to hand off the specifications to a standards body. Once the standards body ratifies the specifications, Microsoft has committed to ensure that its product offerings will comply with the specifications.

Finally I examined two infrastructural components for building and deploying Web services. The first was dynamic application topologies, which enable you to deploy your Web service across a geographically distributed network of computers. Requests are routed by the delivery service to the computer most capable of handling the request, which in turn improves both the scalability and the availability of the Web service.

The second infrastructural component I explored was BizTalk Orchestration for Web Services. Orchestration allows the developer to separate the application's workflow from the implementation details. Doing so enables the Orchestration runtime to provide advanced services for the workflow such as hydration and management of long-running transactions.