The Web services horizon

The Web Services Toolkit from IBM alphaWorks shows off advances and innovations at a price anyone can afford

MAINTAINING A GRASP on Web services development platforms and environments can be a challenge. To help developers remain familiar with these innovations, IBM has released the next iteration of its alphaWorks tools, WSTK (Web Services Toolkit) 3.01, available free from the alphaWorks Web site ( www.alphaworks.ibm.com ).

This Web Services Toolkit includes run-time platforms and utilities for services-based development, delivery, and consumption, including: the WebSphere Application Server (MicroEdition); a private UDDI (Universal Description, Discovery, and Integration) registry for local test publishing and lookup of services; and several demos and tutorials to highlight the plentiful new capabilities.

We found the most interesting features in this release to be the technology previews, which are the next wave of products and standards maturing to address many of the deficiencies in services-oriented architectures. Among them is Axis, an alpha version of the new Apache SOAP (Simple Object Access Protocol) 3 implementation; HTTPr, the next-generation protocol for HTTP-based messaging; security functions for digital signatures and encrypted payloads in SOAP; and a new class of pluggable utilities for, among other possibilities, metering and billing for services usage.

What this product lacks is a comprehensive Web services deployment platform or graphical development IDE (integrated development environment). In fact, IBM has removed tools, such as the Web Services Tooling for EJBs (Enterprise JavaBeans), that came with previous versions of the kit. Now tools are included in commercial products such as IBM's WebSphere Studio Application Developer. But that level of support is not the intention of this toolkit. The alphaWorks tools are delivered as-is, free of charge, to provide an advance look at new functionality.

The wizard-driven installation shield deployed easily and the configuration utility made the process of readying our Web services environment uncomplicated.

The toolkit's Web services stack includes a lightweight version of the WebSphere 4.0 application server, and XML processing support brought by Apache XML utilities such as Xerces and Xalan. But for any additional capabilities -- such as support for EJB 1.1, transaction management, connection pooling, or performance monitoring -- you will need to look elsewhere.

Furthermore, the UDDI (Universal Description, Discovery, and Integration) implementation is a lightweight rendition that cannot be used with any application servers outside this Web services stack.

However, the configuration wizard helped to set dependencies in the runtime stack environment and can configure use with the full-blown WebSphere application server as well as Jakarta Tomcat 4.

Although setup was easy, we felt the kit could benefit from some additional shortcuts for quick access to tasks such as starting of the Web services stack and UDDI registry, for example.

In addition to server-side components, the kit contains a number of client-side APIs for accessing the UDDI registry and WSDL (Web Services Description Language) documents. WSTK also implements the relatively new WSIL (Web Services Inspection Language) that allows Web services to be discovered straight from a Web server URL, bypassing the need for a UDDI lookup.

Windows developers may be put off by the lack of graphical tools. But the supplied APIs, demos, and documentation, as well as the browser-based application server administration, will give developers an opportunity to look at several new innovations occurring in Web services.

Crystal ball

The WSTK offers a preview of several innovations taking place in Web services, including Apache Axis Alpha Release 3, which represents the rearchitecting of the original SOAP implementation code base. We found Axis to be fast, and it offers additional benefits such as transport independence, better WSDL (Web Services Description Language) abstraction from SOAP, a new XML-based deployment descriptor format, and closer alignment with the Microsoft SOAP implementation, all of which should help promote trouble-free development.

IBM has also fashioned an impressive first look at some pluggable utilities called Utility Services. The utilities offer the beginnings of Web services tracking and usage metering, billing, publish and subscribe event messaging, and the beginnings of an XML-based identity service.

Although far from comprehensive, Utility Services represent a step in the right direction for addressing some of the challenges still facing real world deployment of Web services.

Developers should avoid comparing WSTK 3.01 and the Early Access release of Sun's Web Services Developer Pack. Unlike the community process-driven development at Sun, WSTK components are primarily aligned with open-source efforts, many of which have been sponsored by IBM.

Furthermore, whereas Sun is laying the groundwork for the future of Java, the intent of the WSTK is to use that groundwork as a launchpad for future Web services advances. Sun's approach is structured, includes support for Solaris OS, and provides comprehensive documentation and tutorials. IBM's WSTK is still primarily experimental, and cannot be considered for a production environment.

But the price is right, and this type of advance look keeps your developers ahead of the curve in such a rapidly advancing paradigm. To that end, IBM's Web Services Toolkit succeeds wholly.

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