Registry + Repository = SOA Platform

There's a deafening buzz in service-oriented architecture around repositories, which appear to be emerging as a core component of SOA. What is actually emerging, says Miko Matsumura, is an integrated registry-repository model, which could serve as the core technology of what amounts to an SOA platform.

“Up to now, SOA has mostly been about point-to-point Web services integration,” Matsumura tells SOATrends. “If you’re connecting one point to another point, there’s no need for any kind of platform. It’s really just a cat’s-cradle kind of series of connections between everything and everything else. But people are starting to get interested in connecting things in a way that creates direction, coherence or intention.”

Matsumura is the former vice president of product marketing at Systinet, co-creator of The Middleware Company's SOA Blueprints (the first complete, vendor-neutral specification of an SOA application set), and the original Java evangelist at Sun Microsystems.

He recently signed on as VP of marketing at Infravio, a provider of SOA Web services management products, where he is expected to advance his Intentional SOA methodology.

Intentional SOA is about ensuring the business value of SOA, using best practices and principles, Matsumura explains. It raises key questions to help SOA builders stay on course during design and implementation. Intentional SOA moves beyond ad hoc Web services enablement, mandating a strategic, enterprise-wide view that directly addresses the gamut of business, technology, security and governance concerns posed by SOA.

Matsumura says the roles of registry and repository are sometimes confusing. That confusion, he says, is understandable.

"People like to say that registries hold metadata and repositories hold data," he says. "That's a handy explanation, I suppose, but it really taxes the semantics. Data and metadata are determined by relationship; one person's data is another person's metadata."

A simpler and clearer definition, he suggests, is "registries hold references to things, and repositories hold the things."

It is this inherent "permeability of the data-metadata boundary" that will lead, as the market matures, to more integrated registry-repository solutions, he says.

Matsumura credits analyst group Zapthink with originating the SOA platform concept. During one of their recent Webcast seminars, "End-to-End Metadata Management: Registries, Repositories, and Governance," Zapthink analysts Jason Bloomberg and Ron Schmelzer identified the metadata registry-repository as "a key to making loosely coupled SOAs work and to providing the necessary infrastructure for SOA governance." (Matsumura served as a guest expert for the event.)

Whether the two technologies actually come together to form an SOA platform or not, Gartner analyst Yefim Natis also believes that an integrated registry-repository is a key SOA enabler. “It is safe to say that no long-term enterprise SOA initiative can succeed without an integrated and searchable registry-repository,” he says.

And vendors are getting on board with the reg-rep integration strategy, though few are calling their offerings SOA platforms. Sun Microsystems's new Sun Service Registry includes an integrated repository for storing service metadata, and providing additional capabilities such as Web services lifecycle management. Systinet’s new Blizzard platform extends the capabilities of Systinet Registry to include a unified registry and repository. And Matsumura's company Infravio’s X-Registry is designed to provide a single point of access for information about all Web services in an enterprise.

Infravio has supported an integrated registry-repository model since its X-Registry was first released, Matsumura says. The X-Registry platform uses the Java API for XML Registries, which is the Java programmatic API for developing applications on top of standard Registries including UDDI and the ebXML Registry Information Model.

Matsumura sees support for the platform idea in work under way at the OASIS standards group, which is developing a registry information model that integrates the registry and repository within ebXML. Matsumura is developing a technical committee at OASIS to create a mechanism for standardizing the SOA Blueprint.

The current Web services registry standard is Universal Description, Discovery and Integration, but the repository field is still wide open. "UDDI is pretty core," Matsumura says. "It’s mostly about discovery, and it leaves a lot of room for interpretation on the repository side. That’s where the frontier is."

About the Author

John K. Waters is a freelance writer based in Silicon Valley. He can be reached at [email protected].