Click here to close now.

Welcome!

SOA & WOA Authors: Plutora Blog, Carmen Gonzalez, Leo Reiter, Elizabeth White, John M. Hawkins

Related Topics: SOA & WOA

SOA & WOA: Article

WS-I Basic Profile - Not just another Web service specification

WS-I Basic Profile - Not just another Web service specification

On August 12, 2003, the Web Services Interoperability Organization (WS-I), released the Final Material version of the WS-I Basic Profile 1.0 specification. This publication represents an important milestone for WS-I and the Web services community as a whole. It specifies the standards and technologies required for interoperability between Web services implementations running on different software and operating system platforms.

The Promise of Interoperability
The promise of interoperability is possibly the most important aspect of Web services technologies. That promise stems from the fact that Web services has its foundations in XML, which itself is interoperable across all platforms and programming languages. However, because Web services leverages heavily on the extensible nature of XML, the interoperability aspect of Web services is significantly challenged.

While most, if not all, vendors provide support for the established Web services standards, they are still motivated to provide added value to their customers in the form of advanced feature support for things such as security, reliability, transactions, and business process orchestration. Because many of the advanced Web services features are still in the early stages of development and adoption, developers and IT managers need more than just a checklist of (emerging) standards when making project implementation or product purchasing decisions. They need help in being able to determine when they are "coloring outside the lines" so that they can weigh the merits of incorporating these advanced features against the importance of ensuring broad interoperability of the deployed solution.

WS-I was founded with a mission to provide users of Web services technology with the guidance and tools that help them better understand where the boundary lies between the interoperable and not-necessarily-interoperable solution spaces so that they can make well-informed decisions.

About WS-I
The Web Services Interoperability Organization is an open industry effort chartered to promote Web services interoperability across platforms, applications, and programming languages. The organization brings together a diverse community of Web services leaders to respond to customer needs by providing guidance, recommended practices, and supporting resources, such as testing tools and sample applications, that enable the development of interoperable Web services.

WS-I Deliverables
The Basic Profile 1.0 is the first of a set of deliverables being produced by WS-I related to the Basic Profile. When complete, the package of deliverables produced in conjunction with all WS-I Profiles will be as follows:

  • Use cases and usage scenarios: Use cases and usage scenarios capture (respectively) business and technical requirements for the use of Web services. These requirements reflect the classes of real-world requirements supporting Web services solutions, and provide a framework to demonstrate the guidelines described in WS-I Profiles.
  • Profiles: A set of named Web services specifications at specific revision levels, together with a set of implementation and interoperability guidelines recommending how the specifications may be used to develop interoperable Web services.
  • Sample applications: Demonstrate the implementation of applications that are built from Web services usage scenarios and use cases, and that conform to a given set of profiles. Implementations of the same sample application on multiple platforms, languages, and development tools demonstrate interoperability in action, and provide readily usable resources for the Web services practitioner.
  • Testing tools: Used to monitor and analyze interactions with a Web service to determine whether or not the Web service instance or its artifacts (such as messages, WSDL, and UDDI registration components) conform to WS-I Profile guidelines.
At the time of this writing, each of the WS-I deliverables related to the Basic Profile 1.0 has been either formally approved as Final Material, or has been made public in the form of a Working Group Approval Draft.

Philosophy of the Profile
The WS-I Basic Profile was developed by the Basic Profile Working Group with a set of guiding principles that have been outlined in the Profile. These guiding principles form the "philosophy of the Profile."

Possibly the most important of these guiding principles is that there can be no guarantee of interoperability. The best that we could hope to achieve would be to improve the potential for interoperability since we were only dealing with the very basics of Web services technologies and we did not intend to address application-level semantics. Another key guiding principle is that the Profile never relaxes requirements of an underlying specification. That is to say that the Profile never changes a MUST to a SHOULD. However, the Profile often seeks to improve interoperability by reducing the optional features of an underlying specification by changing SHOULDs and SHOULD NOTs to MUSTs and MUST NOTs.

The Profile also focuses on interoperability, not functionality. While the underlying specifications may contain design flaws and inconsistencies, the Profile focuses only on those that directly affect interoperability. WS-I leaves the work of addressing any inadequacies of a specification to the standards body that is assigned stewardship of the standard.

Scope of the Profile
Each Profile has a scope that is defined by the set of referenced specifications. A Profile attempts to improve interoperability within its own scope by placing constraints on optional features of the referenced specifications, clarifications of ambiguities in the referenced specifications, and guidelines for use of the referenced specifications. A Profile does not impose constraints on that which is out of the scope of the Profile.

A key aspect of Web services is the composable nature of the specifications. WS-I Profiles are also intended to exhibit this same composable nature. They do so by defining the set of extensibility points, the extension mechanisms and parameters defined in the underlying specifications that may require out-of-band negotiation and/or agreement explicitly outside the scope of a Profile. While their use may impair interoperability, it is not subject to claims of conformance.

A Profile may place constraints on the use of extensibility points without constraining their range, so that specific uses of extensibility points may be further constrained by other Profiles to improve their interoperability when used in conjunction with the Profile.

The WS-I Basic Profile specification defines conformance of a Web service instance and its artifacts such as the messages it sends, its WSDL description and UDDI registration. The profile consists of the following set of nonproprietary Web services specifications:

  • SOAP 1.1
  • WSDL 1.1
  • UDDI 2.0
  • XML 1.0 (Second Edition)
  • XML Schema Part 1: Structures
  • XML Schema Part 2: Datatypes
  • RFC2246: The Transport Layer Security Protocol version 1.0
  • RFC2459: Internet X.509 Public Key Infrastructure Certificate and CRL Profile
  • RFC2616: HyperText Transfer Protocol 1.1
  • RFC2818: HTTP over TLS
  • RFC2965: HTTP State Management Mechanism
  • The Secure Sockets Layer Protocol version 3.0
The Profile adds constraints and clarifications to those base specifications with the intent to promote interoperability. Where the Profile is silent (i.e., imposes no clarification or constraint), the base specifications are normative. If the Profile prescribes a requirement in the form of a clarification or constraint, the Profile supersedes the underlying base specification. Some of the constraints imposed by the Profile are intended to restrict, or require, optional behavior and functionality so as to reduce the potential for interoperability problems resulting from impedance mismatch between implementations that have made different choices with regard to implementation of the optional functionality. Other Profile requirements are intended to clarify language in the base specifications that have been the source of frequent misinterpretation, resulting in interoperability problems. Where possible, the Basic Profile WG has tried to ensure that the Profile clarifications are aligned with the thinking and direction of the Working Group responsible for the stewardship of the underlying specification to which the clarification applies. For example, clarifications to the SOAP1.1 specification were often aligned with issue resolutions made by the W3C XML Protocol WG responsible for the development of the SOAP1.2 specification.

Profile Highlights
The following list highlights some of the key constraints imposed by the Profile:

  • Precludes the use of SOAP encoding
  • Requires the use of HTTP binding for SOAP
  • Requires the use of HTTP 500 status response for SOAP Fault messages
  • Requires the use of HTTP POST method
  • Requires the use of WSDL1.1 to describe the interface of a Web service
  • Requires the use of RPC-literal or document-literal forms of WSDL
  • Precludes the use of RPC-encoded–style WSDL
  • Precludes the use of solicit-response and notification style operations
  • Requires the use of WSDL SOAP binding extension with HTTP as the required transport
  • Requires the use of WSDL1.1 descriptions for UDDI tModel elements representing a Web service
What's Relevant to the Developer?
The WS-I Basic Profile 1.0 specification is a rather complex document. A majority of the specification is targeted at the audience of runtime platform and development tool vendors working on vendor-specific implementations of SOAP processors, WSDL parsers, code generators, and the like. You could reasonably consider the Profile to be a concerted effort by those tools and platform vendors to ensure that their respective products will either generate or host interoperable Web services instances.

However, it isn't enough that each of the major vendors adopt the Profile for their product offerings since each will likely retain support for certain features that the Profile does not sanction (such as RPC-encoded Web services) and most will offer support for features that are outside the scope of the Profile. A Web services developer or IT manager should be familiar with all of the profile specification's contents. However, certain sections of the Profile are specifically relevant to the implementation of interoperable Web services.

The following lists each substantive section of the profile specification and its relevance to a Web service practitioner.

  • Section 4: Relates to SOAP and the use of HTTP binding for SOAP. As such, it is mostly of interest to those developers writing SOAP processor implementations rather than Web services developers.
  • Section 5: Pertains to conformant use of WSDL, and as such should be of interest to Web services practitioners, especially those who handcraft their WSDL descriptions.
  • Section 6: Pertains to Web service discovery using UDDI. This, too, should be of interest to Web services practitioners. It describes conformant approaches to registration and categorization of a Web service in a UDDI registry.
  • Section 7: Relates to security of Web services using HTTP/S and should also be of interest to Web services practitioners who require security for the Web services they develop.
Many of the Profile requirements are often accompanied by examples of SOAP messages or WSDL descriptions that demonstrate both conformant and nonconformant adherence to the constraints and clarifications provided. The requirements associated with examples are likely to be of specific interest to Web services practitioners. However, the other WS-I deliverables related to the Profile may be more appropriate and relevant to the IT manager and Web service developer.

Scenarios, Sample Applications, and Testing Tools
The WS-I Sample Applications Working Group has developed deliverables based on the Basic Profile that a Web services practitioner will find useful.

  • A mock supply-chain sample application that demonstrates most of the key features of the WS-I Basic Profile
  • A Usage Scenarios specification that defines the most common design patterns for Web services and maps those scenarios to the Profile requirements that apply
The sample application serves a dual purpose. For vendors, it provides a means by which they can demonstrate and test their product's support for the requirements set forth by the Profile. To date, 10 vendors have produced independently developed implementations of the sample application, typically based on their respective runtime platform and/or development tooling. Each vendor has provided the source of their implementation so that Web services developers can better understand what they need to do to develop their own interoperable Web services.

The Testing Tools Working Group has delivered approval drafts of their reference testing tools for each of the major runtime platforms (Java and C#). They have also translated the constraints and requirements defined in WS-I Basic Profile 1.0 into formal test assertions that are used to configure the WS-I Testing Tools.

Web services practitioners can use the published reference testing tools to test their Web service instances, WSDL descriptions, and UDDI registrations for conformance to the Profile's requirements. IT managers can use the reports produced by the WS-I Testing Tools as a means of determining whether the Web services their developers have developed conform to the requirements of the Profile.

Future versions of the WS-I Testing Tools reports will be augmented to identify the extensibility points that are used in a Web service instance so that IT managers (and developers) can make informed decisions as to whether the solutions they develop and deploy meet the specific interoperability requirements of a given situation. If a Web service requires broad interoperability, such as might be the case with an Internet deployment of a service, they might wish to constrain the use of extensibility points to those covered by a WS-I Profile(s). Conversely, if a Web service is being deployed for use within an intranet, interoperability may not be considered as high a priority as the advanced features provided through the use of an extensibility point. IT managers can leverage the information provided by the testing tools to make an appropriate, well-informed decision based on the requirements of the given situation.

Looking Beyond WS-I Basic Profile 1.0
The WS-I Basic Profile 1.0 is, of course, just the tip of the iceberg. WS-I has already begun work on a number of follow-on profiles for Web services, including Attachments and Basic Security. Work will begin on future profiles, tackling some of the more advanced Web services features as the various specifications upon which they are based mature and stabilize and as the interoperability requirements associated with these advanced features are better understood by the community.

As WS-I releases these future profiles and their associated testing tools and sample applications deliverables, the Web services community benefits by reducing the tension induced by having to choose between the need for broad interoperability and the need for advanced functionality that is not yet broadly adopted.

References

  • WS-I: http://ws-i.org
  • WS-I Basic Profile 1.0: http://ws-i.org/Profiles/Basic/2003-08/BasicProfile-1.0a.htm
  • WS-I Testing Tools: http://ws-i.org/implementation.aspx
  • More Stories By Christopher Ferris

    Chris Ferris is an IBM Distinguished Engineer and CTO of Industry Standards in the Software Group Standards Strategy organization. He has been actively engaged in open standards development for XML and Web services since 1999. Ferris is former chair of the WS-I Basic Profile Working Group. He co-chairs the W3C Web Services Policy Working Group and serves as chair of the W3C XML Protocols Working Group. He represents IBM on the OASIS WS-RX Technical Committee. He is a former elected member of the OASIS Technical Advisory Board (TAB).

    Comments (0)

    Share your thoughts on this story.

    Add your comment
    You must be signed in to add a comment. Sign-in | Register

    In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


    @ThingsExpo Stories
    Every innovation or invention was originally a daydream. You like to imagine a “what-if” scenario. And with all the attention being paid to the so-called Internet of Things (IoT) you don’t have to stretch the imagination too much to see how this may impact commercial and homeowners insurance. We’re beyond the point of accepting this as a leap of faith. The groundwork is laid. Now it’s just a matter of time. We can thank the inventors of smart thermostats for developing a practical business application that everyone can relate to. Gone are the salad days of smart home apps, the early chalkb...
    Cloud data governance was previously an avoided function when cloud deployments were relatively small. With the rapid adoption in public cloud – both rogue and sanctioned, it’s not uncommon to find regulated data dumped into public cloud and unprotected. This is why enterprises and cloud providers alike need to embrace a cloud data governance function and map policies, processes and technology controls accordingly. In her session at 15th Cloud Expo, Evelyn de Souza, Data Privacy and Compliance Strategy Leader at Cisco Systems, will focus on how to set up a cloud data governance program and s...
    Roberto Medrano, Executive Vice President at SOA Software, had reached 30,000 page views on his home page - http://RobertoMedrano.SYS-CON.com/ - on the SYS-CON family of online magazines, which includes Cloud Computing Journal, Internet of Things Journal, Big Data Journal, and SOA World Magazine. He is a recognized executive in the information technology fields of SOA, internet security, governance, and compliance. He has extensive experience with both start-ups and large companies, having been involved at the beginning of four IT industries: EDA, Open Systems, Computer Security and now SOA.
    The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focused on understanding how industrial data can create intelligence for industrial operations. Imagine ...
    We certainly live in interesting technological times. And no more interesting than the current competing IoT standards for connectivity. Various standards bodies, approaches, and ecosystems are vying for mindshare and positioning for a competitive edge. It is clear that when the dust settles, we will have new protocols, evolved protocols, that will change the way we interact with devices and infrastructure. We will also have evolved web protocols, like HTTP/2, that will be changing the very core of our infrastructures. At the same time, we have old approaches made new again like micro-services...
    Operational Hadoop and the Lambda Architecture for Streaming Data Apache Hadoop is emerging as a distributed platform for handling large and fast incoming streams of data. Predictive maintenance, supply chain optimization, and Internet-of-Things analysis are examples where Hadoop provides the scalable storage, processing, and analytics platform to gain meaningful insights from granular data that is typically only valuable from a large-scale, aggregate view. One architecture useful for capturing and analyzing streaming data is the Lambda Architecture, representing a model of how to analyze rea...
    SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes for use cases across the industrial, enterprise, and consumer segments.
    Today’s enterprise is being driven by disruptive competitive and human capital requirements to provide enterprise application access through not only desktops, but also mobile devices. To retrofit existing programs across all these devices using traditional programming methods is very costly and time consuming – often prohibitively so. In his session at @ThingsExpo, Jesse Shiah, CEO, President, and Co-Founder of AgilePoint Inc., discussed how you can create applications that run on all mobile devices as well as laptops and desktops using a visual drag-and-drop application – and eForms-buildi...
    Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
    SYS-CON Events announced today that Dyn, the worldwide leader in Internet Performance, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Dyn is a cloud-based Internet Performance company. Dyn helps companies monitor, control, and optimize online infrastructure for an exceptional end-user experience. Through a world-class network and unrivaled, objective intelligence into Internet conditions, Dyn ensures traffic gets delivered faster, safer, and more reliably than ever.
    CommVault has announced that top industry technology visionaries have joined its leadership team. The addition of leaders from companies such as Oracle, SAP, Microsoft, Cisco, PwC and EMC signals the continuation of CommVault Next, the company's business transformation for sales, go-to-market strategies, pricing and packaging and technology innovation. The company also announced that it had realigned its structure to create business units to more directly match how customers evaluate, deploy, operate, and purchase technology.
    In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect at GE, and Ibrahim Gokcen, who leads GE's advanced IoT analytics, focused on the Internet of Things / Industrial Internet and how to make it operational for business end-users. Learn about the challenges posed by machine and sensor data and how to marry it with enterprise data. They also discussed the tips and tricks to provide the Industrial Internet as an end-user consumable service using Big Data Analytics and Industrial Cloud.
    The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
    Performance is the intersection of power, agility, control, and choice. If you value performance, and more specifically consistent performance, you need to look beyond simple virtualized compute. Many factors need to be considered to create a truly performant environment. In his General Session at 15th Cloud Expo, Harold Hannon, Sr. Software Architect at SoftLayer, discussed how to take advantage of a multitude of compute options and platform features to make cloud the cornerstone of your online presence.
    Almost everyone sees the potential of Internet of Things but how can businesses truly unlock that potential. The key will be in the ability to discover business insight in the midst of an ocean of Big Data generated from billions of embedded devices via Systems of Discover. Businesses will also need to ensure that they can sustain that insight by leveraging the cloud for global reach, scale and elasticity.
    IoT is still a vague buzzword for many people. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed the business value of IoT that goes far beyond the general public's perception that IoT is all about wearables and home consumer services. He also discussed how IoT is perceived by investors and how venture capitalist access this space. Other topics discussed were barriers to success, what is new, what is old, and what the future may hold. Mike Kavis is Vice President & Principal Cloud Architect at Cloud Technology Pa...
    Even as cloud and managed services grow increasingly central to business strategy and performance, challenges remain. The biggest sticking point for companies seeking to capitalize on the cloud is data security. Keeping data safe is an issue in any computing environment, and it has been a focus since the earliest days of the cloud revolution. Understandably so: a lot can go wrong when you allow valuable information to live outside the firewall. Recent revelations about government snooping, along with a steady stream of well-publicized data breaches, only add to the uncertainty
    The explosion of connected devices / sensors is creating an ever-expanding set of new and valuable data. In parallel the emerging capability of Big Data technologies to store, access, analyze, and react to this data is producing changes in business models under the umbrella of the Internet of Things (IoT). In particular within the Insurance industry, IoT appears positioned to enable deep changes by altering relationships between insurers, distributors, and the insured. In his session at @ThingsExpo, Michael Sick, a Senior Manager and Big Data Architect within Ernst and Young's Financial Servi...
    PubNub on Monday has announced that it is partnering with IBM to bring its sophisticated real-time data streaming and messaging capabilities to Bluemix, IBM’s cloud development platform. “Today’s app and connected devices require an always-on connection, but building a secure, scalable solution from the ground up is time consuming, resource intensive, and error-prone,” said Todd Greene, CEO of PubNub. “PubNub enables web, mobile and IoT developers building apps on IBM Bluemix to quickly add scalable realtime functionality with minimal effort and cost.”
    Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...