MSDN Magazine - June 2008 - (Page 45)

make up a business process—this layer is often referred to as orchestration or workflow. One way to build systems that employ the ESB pattern on the Microsoft platform is to use BizTalk® Server. BizTalk Server provides all of the ESB features we’ve discussed here out of the box. investment and financial risk associated with adopting a significant piece of infrastructure like an ESB. Instead, many companies end up creating their own custom—and often more costly— systems integration infrastructure. This happens to be one of the biggest impediments to BizTalk Server adoption today. Software as a Service Further, companies able to implement an ESB Figure 1 Managing While ESBs have been growing in popularity Point-to-Point Connections are still challenged with trying to make their ESB within the enterprise, another business trend has in Composite Applications talk to their partners’ ESBs. No two ESB instances also been blossoming on the Web that will surely are alike, making cross-enterprise integration difimpact enterprise systems in the years ahead. This trend, referred ficult, even when embracing the loosely coupled ESB pattern. to as Software as a Service (SaaS), revolves around companies exThe Microsoft ISB platform addresses these realities by placing posing complete applications or services on the Web—sometimes key service bus components in the Internet cloud for public conreferred to as the Internet cloud—that other companies can simply sumption regardless of the platform using the components. Mipay to use. This allows consumers to avoid the complexities and crosoft is essentially making the service bus available through the costs associated with building or managing a similar piece of soft- SaaS model, thereby allowing companies of any size to jump on the ware (design, development, operational, and maintenance costs), bus. ISB offers a publish/subscribe architecture and the necessary which usually require large initial investments. messaging infrastructure for traversing enterprise firewalls and The SaaS model essentially allows consumers to remotely access network address translators (NATs). ISB also offers federated idensoftware hosted by another company with expertise in a particular tity management and a workflow services layer for hosting custom area (such as CRM, accounting, payroll, data storage, e-mail, and business processes on the Web, as illustrated in Figure 4. so on), as illustrated in Figure 3. With SaaS, the provider usually Microsoft is actively working on making ISB a reality, and you offers a complete solution for a particular software need, allowing can follow its work on the BizTalk Services Web site (see labs.biz the consumer to outsource that particular part of the system. The talk.net). The current Community Technology Preview (CTP) offers service provider manages the software over time and simply charges several fundamental services that you can begin experimenting the consumer for usage, which means the consumer no longer has with today. In the years ahead, Microsoft plans for this initiative to manage those software services locally. to blossom into a rich communication fabric capable of providThe applications or services offered by SaaS providers typically ing powerful building blocks for a wide variety of modern conembrace standard Web protocols and data formats in order to in- nected applications. crease their ease-of-use and potential reach. Today they tend to rely heavily on HTTP and on common Web data formats like XML, RSS, and JSON, which are ubiquitous today. Although SaaS does not constrain a provider to these specific choices, reach requirements often force providers in that direction. Some architects may question how smart it is to take on the external dependencies that are inherent in an SaaS system architecture. Although they might raise concerns around connectivity and service level agreements (SLA), with the ubiquity of Internet connections today, it seems that exposing software on the Web has almost become completely acceptable and even extremely advan- Figure 2 Building Composite Applications with an ESB tageous given the new doors it opens. Internet Service Bus Microsoft has embraced these popular ideas—ESB and SaaS— and has blended their most compelling characteristics into a new idea it calls the Internet Service Bus (ISB). The ISB model is similar to ESB in terms of functionality. However, ISB is made available at the broader Internet scope, so it’s similar to the SaaS model in terms of standards, reach, and scalability. The Microsoft® ISB, in a nutshell, makes it easier for companies to adopt ESB infrastructure. Although ESB functionality is compelling to a wide range of companies, it seems that only larger companies have significantly taken advantage of them today. This is mostly due to the upfront msdnmagazine.com Figure 3 Outsource Software Needs with SaaS June 2008 45 http://labs.biztalk.net http://labs.biztalk.net http://msdnmagazine.com

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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