Interoperability Guide to WS-I Basic Profile

The first formal docs for building integratable -- and interoperable -- web services are available free from the Web Services Interoperability Organization (WS-I). IDN goes in-depth on the WS-I Basic Profile, to show devs how they can best use the docs, which reflects 1000s of hours of development and testing by teams from IBM, Microsoft, Oracle among others.

Tags: Basic Profile, Web Services, Interoperability, WS-I, Van Roekel, Developers, Vendors,

The Web Services Interoperability Organization, a group of more than 150 web services vendors, including the warring factions of Microsoft, IBM, Sun and Oracle, have formally reached final agreement on the WS-I Basic Profile for combining interoperable web services.

As a result, WS-I's Basic Profile 1.0 was made public this week with a general-availability release, providing final guidelines to devs for building the core plumbing elements of their web services codesets (including SOAP 1.1, WSDL 1.1, UDDI 2.0 and XML 1.0 and XML Schema). Follow the guidelines, and these plumbing or framework components should interoperate, enabling web services to communicate across products and platforms from different vendors.

The Basic Profile has been in interop review for more than nine months, during which time, WS-I reviewers found some 200-250 areas where fixes were needed, the WS-I said. While many were minor, special attention was paid to areas related to state management, including error handling and fault tolerance.

Now that the work is done, the Basic Profile 1.0 provides a "common framework for implementing interoperable solutions," said Tom Glover, WS-I Chair, in a statement. In specific, he added, "The Basic Profile 1.0 will significantly simplify the task of implementing interoperable web services solutions within and across enterprise boundaries."

Inside the WS-I Basic Profile -
Defining Interoperable Plumbing

The WS-I focused on four (4) key web services operations in which they considered interoperability a must. These include:
  • Messaging -- Exchange of web service protocol elements, usually over a network;
  • Description -- Enumeration of the messages associated with a web service, along with implementation details;
  • Discovery -- Metadata that enables the advertisement of a web service's capabilities; and
  • Security -- Use of HTTPS for integrity, privacy, authentication and authorization.
With these guidelines for web services plumbing provided in the Basic Profile, devs working with the specifications can focus on their core competencies rather than worrying about basic plumbing. Secondly, devs can look forward to a core set of implementations that will be compatible across products and different dev environments (such as Java and C#). Moreover, there are three categories of "web services plumbing" that the Basic Profile will impact, Steven Van Roekel, Microsoft's Director of Web Services and WS-I spokesperson, told IDN.
  1. Development tools --"We're making it easier for developers to write web services applications that will have interoperability at the end of the build process. The key here is that a variety of development tools will all have some Basic Profile capabilities," Van Roekel added. In specific, the WS-I will be shipping its own set of development tools, along with its testing tools later this year, Van Roekel told IDN. In addition, Van Roekel said he expected the major tools vendors to include Basic Profile support, including tools from IBM, Borland, Oracle and Microsoft's Visual Studio,

  2. Platforms -- These include enterprise servers, web servers, application servers and the like. "Platforms will be able to understand web services and how they will send messages back and forth, how they read a message, etc," Van Roekel said. .NET already supports this, Sun has announced J2EE 1.4 will support it in the next version, so all J2EE app servers should also support this, he said, "and more vendors will be building platforms that understand the Basic Profile."

  3. Web Services -- Van Roekel expects that WS-I members, along with many end-user companies, will re-examine their existing XML and/or SOAP-based web services, at least many that will, over time, need to be connected to other platforms or services. "I expect that you'll see a retesting of those services to verify they conform to the Basic Profile, and even a modification to them where they do not conform." As an example, Van Roekel pointed to Google's famed Web Services API. "This is just an example, but I'm hoping that they're testing their [work] against the Basic Profile and confirming their compliance.
"Enterprise developers should start reading the Basic Profile 1.0 documentation and gaining an understanding of that," Van Roekel advised. "By building the Basic Profile, WS-I is defining what a web service is. And, by participation from a large breadth of the industry we are agreeing to the definitions of a web service. So, the Basic Profile is a good educational tool just to gain a deeper understanding of web services, so that when tools and other products come out they can make sure they are Basic Profile-compliant."

A Holistic View of Interoperability
The Basic Profile also aims to do more than simply define SOAP, WSDLs and XML components, Van Roekel added. The Basic Profile shows how these components will depend upon and interoperate, with one another.

The idea of "whole is greater than the sum of its parts is very much a part of the Basic Profile [work], Van Roekel told IDN. He explains it this way: "We just don't look at spec-by-spec interoperability," he said, "In the Basic Profile, we also take a holistic look to say what is the interrelationship of all these different pieces. In that way we can build the profile or the patterns for how devs will build a [web services] foundation layer that will enable interoperable applications." The Basic Profile then also offers insights and advice for helping devs build WSDLS that take full advantage of their other SOAP and XML web services components.

Any web services solution is easily going to use more than one of these listed components in the Basic Profile. Van Roekel offers this example: SOAP is built on XML; and you're going to use both XML and SOAP, not just SOAP alone. Looking at the Basic Profile and the testing tools that will follow this fall, developers will understand that they're looking at the complete solution scenario for ensuring the interoperability of the integrated web service.

We asked Van Roekel if that was just a "nice-to-have" aspect of web services, or if that's what enterprise devs and managers want.

"When we at Microsoft interviewed IT professionals, CIO, architects and the like, we asked them what were their biggest pain points. I would have thought security issues would be the Number One," Van Roekel went on, "but they always come back and say integration, and the high cost of integration."

Not Just "Chalk-Talk"
The 200-250 fixes or modifications made to the Basic Profile aren't simply the result of proofreading the spec. These revisions are real areas of non-interoperability that were found by WS-I vendors during their hands-on building of sample apps to test the Basic Profile.

"If you and I were to both take the 25-page SOAP spec and go off to our respective offices and say we're going to write an app to that spec, there's enough ambiguity and 'openness' or 'flexibility' in the spec that it would be very unlikely that our two solutions would interoperate, unless we talked to each other beforehand. The Basic Profile now gives developers guidelines that say the likelihood of interoperability between two solutions is high, without the need to talk beforehand."

Van Roekel shared some of the inside operations that went into finalizing the Basic Profile, and finding -- and eliminating -- the 200+ inconsistencies in the document.

"A lot of vendors and customers involved in the WS-I have done a lot of work around the Basic profile. We got a lot of input as we built the applications as we went along." In fact, Van Roekel said, there were up to 10 vendors that were building sample apps to track the usefulness and effectiveness of the Basic Profile.

In specific, the process worked like this, Van Roekel told IDN:

"We started with a use case, a multi-hop e-commerce scenario, and then started building to that using the same Basic Profile guidelines and the same schema and everything. Then, from time to time we would look at where we are and found that sometimes there would be areas where interoperability between the sample app would start breaking down. Then we'd say, 'We need to be clear about the way we define certain aspects. ' Then we would build another rev of the sample app, and test again for interoperability and do that over and over until we feel really good about the level at which we're really addressing the problems that existed in the Basic Profile."

Analyst Look to Today, Future WS-I Profiles
Vendors can use the Basic Profile to build software products that are guaranteed to interoperate with other software that supports the Profile, and IT end-users can also build custom software that supports the Profile to guarantee interoperability with software products that support the Profile, Jason Bloomberg, a senior analyst at ZapThink, told IDN.

The Basic Profile will ensure devs that their primary web services components will interoperate across vendors' platforms. "It's important to point out that the WS-I basic profile isn't a spec or standard in its own right, but rather a set of guidelines and tools for using certain standards, in this case SOAP and WSDL," Bloomberg added.

Could Basic Profile 1.0 be a "starter gun" for enterprise developers looking to begin to build complex point-to-multipoint web services for their enterprise or B2B needs.

"I wouldn't go so far as to say that the release of the Basic Profile is the starter gun for enterprise developers, but maybe a sign that the warm-up lap is complete," Bloomberg told IDN. "Keep in mind that there are many standards and specs that haven't yet made it into a WS-I profile, including security, management and reliability specs. "

While these more complex specs are on the WS-I's near-term road map, ZapThink founder and senior analyst, Ronald Schmelzer, emphasizes the Profile's rudimentary nature at present.

"The Basic Profile is just that -- basic. It just addresses the primary and most basic interoperability concerns of getting SOAP 1.2, WSDL 1.1, and UDDI 2.0 to work together. Most real-world implementations of web services are already well beyond these basic requirements," he added. "Developers will have to wait until the WS-I includes them in future Profiles before the developers can be assured of interoperability out of the box."

And those areas are among the next stops on the WS-I roadmap.

Next Steps - Confirming Interoperability; Moving Up the Stack
Here's what's on the WS-I's calendar for later this year, and into early 2004:

  • The Test Tools for Basic Profile 1.0 will be available in both C# and Java implementations, and will inspect and validate that a web service meets the interoperability requirements of the Basic Profile.

  • The Sample Applications for Basic Profile 1.0 will demonstrate the Basic Profile at work, including the design, implementation, test and deployment of web services based upon selected business scenarios and implemented on 10 different platforms.

  • A first Basic Security Profile will begin to address interoperability among higher-level security specs, including WS-Security, SAML and proposals for directory and identity from the Liberty Alliance.

  • A WS-I logo program for Basic Profile 1.0 tools, products and components, to assure users that components comply with the Basic Profile. While WS-I spokespersons have said the group does not want to be a "certification authority" for the program, it will offer a WS-I logo for components that pass a self-certification test.

What the Vendor Players Say
For devs concerned that vendor disagreements over core web services may disrupt their development plans, here is a sampling of comments from leading vendors on the public release of the Basic Profile 1.0.

For now, the evident unity should present some relief to devs with concerns about vendors splintering off from WS-I's interop efforts. IDN will continue to watch to see if the current state of vendor unity can survive next WS-I releases of tools and tests for Java and C# code, as well as higher-level profiles that seek to assure interoperability between competing standards.

BEA Systems --"Completion of the WS-I Basic Profile 1.0 is a significant milestone for WS-I and the industry. We believe the WS-I Basic Profile 1.0 will significantly reduce the risk and complexity of Web services adoption, and enable customers to more effectively leverage Web services and service-oriented architecture for greater business responsiveness and adaptability." -- Ed Cobb, VP, Architecture and Standards.

IBM --"IBM is delighted with the broad industry support for WS-I's first profile, WS-I Basic Profile 1.0. Interoperability is a "must have" characteristic/attribute for the viability and growth of our industry and to the emerging technical infrastructures of Grid and IBM's e-business on demand computing initiatives. With the availability of the Basic Profile 1.0, IBM continues its commitment to the development of open standards for web services and their incorporation into products, thus ensuring the interoperability and viability of solutions for our customers. " -- Rod Smith, VP, Emerging Internet Technology -- Software Group.

Microsoft --"Microsoft applauds the ratification of the Basic Profile 1.0, and sees it as a significant milestone, taking the industry a step closer to ensuring web services are able to interoperate across heterogeneous systems. With companies across the industry providing support for the Basic Profile 1.0, such as Microsoft's support in technologies such as Visual Studio .NET and the .NET Framework, we expect the momentum to continue toward the industry's goal of interoperability." -- Steven Van Roekel, Director of Web Services.

Oracle --"Oracle is committed to promoting interoperability based on open industry standards. As a founder, a member of its Executive Board, and a major contributor to WS-I, Oracle applauds the efforts of the Basic Profile working group and encourages the industry to continue working collaboratively toward a common, open vision for web services. Oracle will be fully supporting the WS-I Basic Profile 1.0 across all of its products, including the application server, database, development tools and Oracle E-Business Suite." -- Donald Deutsch, VP of Standards Strategy and Architecture.

SAP --"SAP is pleased to see the release of the WS-I Basic Profile 1.0. By delivering the Basic Profile 1.0 on time, participating companies like SAP have taken a great step toward promoting web services interoperability across platforms. The Basic Profile has the strong potential to become the industry's common denominator for application interoperability through web services. SAP NetWeaver, the leading platform for business applications and collaboration, will support Basic Profile 1.0 in its next release. SAP expects its customers to see immediate benefits which go beyond the boundaries traditional integration can provide." -- Sinisa Zimek, Director of Technology Strategy and Standards.

Sun Microsystems --" Delivery of the WS-I Basic Profile 1.0 is an important development in the evolution of interoperable web services. Sun's support of Basic Profile 1.0 in the Javaâ„¢ 2, Enterprise Edition 1.4 specification, the Java Web Services Developer Pack and Sun ONE products will help ensure Web services interoperability across the J2EE [TM] compatible market and heterogeneous IT environments." -- Mark Hapner, Chief Web Services Strategist.

webMethods --"WebMethods is very excited by the release of the WS-I Basic Profile 1.0. This specification, along with the testing tools and sample applications that will follow shortly, provide the industry's first pragmatic guidance for developing truly interoperable web services. Without the work of the WS-I, web services standards would be interpreted differently across the technology industry, and the promise of interoperability would be compromised." -- Andy Astor, VP, Enterprise Web Services.