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Build a Better Enterprise Application

Posted by Eric A. Marks on August 1, 2004

With plans for Web services still in their early stages, most organizations are cautiously enhancing their IT infrastructure to accommodate the move. At least, that's the philosophy behind Service-Oriented Architecture (SOA), the hottest idea being pushed by Web services vendors, analysts, and visionaries. It might just be a good one, too--if implemented properly.

Strictly speaking, SOA isn't a new concept. It's simply a way of making application functionality available through shared services discoverable on a network. The theory is that by abstracting applications away from the underlying hardware, resources can be used more efficiently. Having reusable software components can also simplify the development of custom applications, allowing IT to more closely match the needs of end users than it could with services that depend on specific servers.

Until now, that theory has been difficult to put into practice, mainly because SOAs have traditionally depended on proprietary middleware that often erased any efficiency gains made. The advent of Web services changes this. Thanks to industry-wide standardization on XML, Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL), and Universal Description, Discovery, and Integration (UDDI), services can be published, discovered, and invoked using interfaces that are supported by all competing vendors.

An SOA is more than a collection of Web services. It's also the technical architecture required to publish, discover, operate, and manage services in support of enterprise applications. And while Web services do make SOA rollout simpler than it used to be, it still involves critical decisions that impact network performance and IT security.

Designing an SOA is further complicated by the immaturity of Web services. Enterprises still grappling with XML are bombarded by continued standards volatility. Vendors from previously separate markets are jockeying to provide SOA solutions, each claiming to offer the architecture's most important component, whether that be management, security, development tools, or the Enterprise Service Bus (ESB), the middleware that distinguishes an SOA from standalone Web services. Some of these solutions are critical in an SOA, while others will depend on the existing IT architecture and the organization's goals.