MSDN Magazine - June 2008 - (Page 46)

Figure 4 Building on the New Internet Service Bus However, it’s important to remember that, as a CTP, the bits made available today are only meant for experimentation and gathering feedback—they are not meant for production use. Microsoft provides no quality guarantees at this point. Also, Microsoft has not yet announced how it will charge for ISB usage once it’s ready for production use. BizTalk Services BizTalk Services is the initial implementation of the ISB components that reside on the Web. Today BizTalk Services consists of a few core services including BizTalk Connectivity Services and BizTalk Identity Services. Another key service called BizTalk Workflow Services will become available in the very near future. More services will be added by Microsoft over time, and additional services might also be placed on the ISB by third parties. Let’s discuss each of the current core services in more detail. One of the most challenging problems when creating loosely coupled composite apps is managing how services will connect at the network level. For example, you might have one service that resides in the network perimeter and another service that resides inside the firewall, and they need to communicate with each other. Or you might want to expose a service to business partners, but those partner services are behind firewalls of their own or other network devices such as proxies or NATs. BizTalk Connectivity Services simplifies many of these communication challenges by providing a universal naming convention for services along with a mechanism for direct/indirect communication between two nodes independent of network topology and configuration. It does this by providing a controlled mechanism for securely relaying connections through network devices. That said, in the cases where a direct connection can be made, BizTalk Connectivity Services can also get out of the way and let the nodes connect without relaying traffic. You can certainly write this type of code yourself, although it can be challenging and cumbersome. The main advantage of letting BizTalk Services provide this functionality is that you don’t have to write or maintain that code, which is often customized 46 msdn magazine per endpoint. This frees you to concentrate on writing the code to solve your business problem rather than coding around these infrastructure problems. BizTalk Connectivity Services also provides other key features such as a global naming convention based on uniform resource identifiers (URIs), a simple publish/subscribe mechanism, and even multicast capabilities. Another core part of BizTalk Services is the BizTalk Identity Services, a publicly accessible Security Token Service (STS) that conforms to the WS-Trust standard. WS-Trust is an interoperable standard for negotiating security based on trust relationships between parties. For example, one party can authenticate a client and issue a token that contains a set of claims about the client. That token can then be presented securely to other parties who also happen to trust the original party that issued the token. This approach makes it possible to federate valuable identity information across organizational boundaries. Given this, BizTalk Identity Services can be used as a third-party identity and authentication management service even if you don’t employ any other features like BizTalk Connectivity Services. However, when using the other BizTalk Services, BizTalk Identity Services will always be used to authenticate and authorize users. When using BizTalk Connectivity Services, both the client and the service will be authenticated against BizTalk Identity Services using either a username/password, client certificate, or a managed card. Once authenticated, a set of authorization rules are processed to issue a new token that will be supplied to BizTalk Connectivity Services. The BizTalk Services Web site provides a user interface for managing your authorization rules along with a few programmatic APIs including a RESTful interface. BizTalk Workflow Services has not yet been released for public consumption. However, a future release of BizTalk Services is expected to provide the capability to host workflow services based on Windows® Workflow Foundation (WF) on ISB. Workflows will activate based on messages received by ISB at a particular URI. These are the only details currently available. BizTalk Identity Services can be used by itself as a third-party identity and authentication management service. BizTalk Services SDK The BizTalk Services SDK is a free download available from biztalk.net that will enable you to get started programming against ISB. Before you can get started, you’ll need to install the BizTalk Services SDK and create a user account on the BizTalk Services site. BizTalk Services is built on Windows Communication Foundation (WCF). The SDK is just a set of assemblies built on the Microsoft .NET Framework 3.0 that allows you to use ISB via the WCF programming model. Most of the BizTalk Services SDK is found in the System.ServiceBus assembly. System.ServiceBus uses standard WCF extensibility points to define a new binding named RelayBinding. For those not familiar with WCF, a binding determines what kind of communication will be exposed or used by a service endpoint. Bindings are used by the WCF BizTalk Services http://biztalk.net

Table of Contents Feed for the Digital Edition of MSDN Magazine - June 2008

MSDN Magazine - June 2008 Contents Toolbox CLR Inside Out Cutting Edge Patterns In Practice SAAS Concurrency Robotics Form Filler GUI Library Service Station Foundations Windows With C++ Concurrent Affairs Going Places { End Bracket }

MSDN Magazine - June 2008

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