Web Services Interoperability. IBM Global Services Licensed Materials - Property of IBM (C) Copyright IBM Corp. 2005 - 2009 All Rights Reserved This is

Web Services Interoperability


2 IBM Global Services Licensed Materials - Property of IBM (C) Copyright IBM Corp. 2005 - 2009 All Rights Reserved This is an internal IBM asset and contains proprietary information. It is not to be distributed - in whole or in part - external to IBM.

Introduction and Purpose

Introduction Web Services Interoperability – An Overview WS-I Profiles – An Introduction WS-I Profiles and Usage Scenarios WS-I Security Profile WS-I Test Tools References and Summary

The purpose of this lecture is to introduce Web Services Interoperability, a key

consideration for adoption of Web Services and, thereby, SOA.

Licensed Materials - Property of IBM (C) Copyright IBM Corp. 2005 - 2009 All Rights

Reserved.

This is an internal IBM asset and contains proprietary information. It is not to be distributed -

in whole or in part - external to IBM.

Note:



Objectives

After completion of this lecture, you should be able to: Introduce Web Services Interoperability Introduce Web Services Interoperability (WS-I) Organization Discuss the WS-I Profiles Discuss the test tools and the associated architecture Summarize the Web lecture







Web Services Interoperability – An Overview

Web Services interoperability Is about interoperability across platforms, applications, and programming

languages Promotes adoption of Web Services and consistent implementations Reduces the cost, complexity and risk of adopting Web Services Enables and ensures collaboration both within the organization and, externally,

with business partners and vendors Enables IT organizations to deliver business aligned solutions and services with

a focus on business requirements instead of being driven by the underlying

infrastructure and middleware considerations

Interoperability is the ability to exchange information in an eco-system of

multi-vendor platforms.

Web Services Interoperability (WS-I) Organization is chartered with promoting

Web Services interoperability.



Web Services Interoperability – A Context

There is a definite cost to interoperability and hence is an architectural

decision point in crafting Web Services solutions. Interoperability is not always a requirement, Available test tools only verify for compliance with the specification and does

not guarantee interoperability. At this time there is no interoperable way to send attachments. At this time there is no interoperable way to provide reliable messaging. Efforts by WS-I have not always been successful and has many unresolved

issues in many critical areas of Web Services. There are a number of useful "emerging standards" which might be

effectively employed for interoperability, but which are neither approved nor

disapproved by WS-I.



Web Services Interoperability (WS-I) Organization

Is an open industry effort chartered to promote Web Services Interoperability

across platforms, applications, and programming languages Plays the role of a standards integrator to help Web Services advance in a

structured and coherent manner Was founded in 2002 Has 135+ members

– Accenture, BEA, Fujitsu, Hewlett-Packard, IBM, Intel, Microsoft, Oracle, SAP,

Sun, webMethods, Ford, BT, Charles Schwab, Fidelity, AOL, Merrill Lynch, JP

Morgan Chase, IONA, Adobe, CA, DCX, Nokia, OAG, OMG, OASIS, RosettaNet,

AIAG, POSC, Accord, …

Accelerates adoption and promotes interoperability– Deliverables include Profiles,

Testing Tools, and Sample Applications

This will be the next logo that customers will look for on

IT product packaging:



The Role of WS-I

"WS-I will act as a standards integrator therefore bringing some coherence to

the effort carried out concurrently by the W3C, OASIS, OAGi and others . . .”

-- Gartner

Standards Bodies

and Industry

Profiles

Test Suites

SampleApplications

Tools

Deliverables



WS-I Goals

Achieve Web Services interoperability– Integrate specifications– Promote consistent implementations– Provide a visible representation of conformance

Accelerate Web Services deployment– Offer implementation guidance and best practices– Deliver tools and sample applications– Provide a implementer’s forum where developers can collaborate

Encourage Web Services adoption– Build industry consensus to reduce early adopter risks– Provide a forum for end users to communicate requirements







WS-I Profiles – An Introduction

Profiles:– Are a grouping of a defined set of standards or specifications at specific version

levels- Are guidelines and conventions for using the set of standards together in ways

to ensure interoperability- Provide implementation guidelines for how related Web Services specifications

should be used together for best interoperability - Are resources for developers to implement interoperable Web Services and

ensure compliance with WS-I guidelines

Basic Profile comprises of a core set of standards that provide for the

foundation of interoperable Web Services.

Basic Security Profile addresses security considerations of Web Services.

Vendor implementations that support the profiles form the baseline for

interoperable Web Services.



Web Services Basic Profile

The Web Services Interoperability Organization (http://www.ws-i.org) has

defined a basic profile called the Basic Profile version 1.1 that: Addresses and resolves more than 200 interoperability issues within the

Web Services space with defined conventions around messaging,

service description, and dynamic discovery Reduces the cost, complexity, and risk of Web Services implementation

by enhancing the interoperability of products delivered by vendors who

adhere to the guidelines of the profile Is a set of non-proprietary Web Services specifications that promote

interoperability Provides a set of common implementation guidelines



WS-I Basic Profile 1.1

The Web Services specifications that form the core technology

components covered by the Basic Profile include:– SOAP version 1.1– Web Services Description Language version 1.1 (WSDL v1.1)– eXtensible Markup Language version 1.0 (XML v1.0)– XML Schema– Hypertext Transfer Protocol version 1.1 (HTTP v1.1)

This is an enhancement to Basic Profile 1.0

Finalized in August 2004

UDDI V2 is mechanism the Profile has adopted to describe Web

Services providers and the Web Services they provide

Includes a set of security specifications:– Addresses the security requirements for Web Services implementation



Additional WS-I Profiles

Attachments Profile 1.0– The Attachment Profile 1.0 complements the Basic Profile 1.1 to add support for

interoperable SOAP Messages with attachments-based Web Services.

Simple SOAP Binding Profile 1.0– The Simple SOAP Binding Profile consists of those Basic Profile 1.0 requirements related

to the serialization of the SOAP message envelope and its representation in the message, incorporating any errata to date.

Basic Security Profile– The Basic Security Profile provides guidance on the use of WS-Security, the User Name

and X.509 security token formats.

Security Assertion Markup Language (SAML) Token Profile– This is the interoperability profile for the SAML security token that is used with WS-

Security.

Test Tools – The Testing Tools Working Group develops the documentation and processes for WS-I

test tools development, and develops or supervises the development of materials that test Web Services implementations for conformance to WS-I profiles.







Design Considerations: WS-I Usage Scenarios

Common patterns of usage of a profile’s specifications Derived from examining Web Services Use Cases Intended for Web Services architects and developers Describe

– Runtime flow of a pattern using activities that occur within and among the

layers of the Web Services stack– Constraints applied to the pattern by the profile– Descriptive (WSDL) aspects of the pattern– Advertisement (UDDI) aspects of the pattern– Error handling considerations – Security threats associated with the pattern

Use these because:– Partners want this added assurance of adherence to the WS-I profiles– These subset WS-I profiles are more manageable chunks, based on what the

Web Services user is trying to do with each profile– Covers all of the various aspects of using the pattern



Usage Scenarios for the Basic Profile

Common Message Exchange Patterns represented– Synchronous request/response– One way (fire and forget)– Basic Callback (basic asynchronous)

Synchronous request/response– Most common of the patterns– Two messages for each wsdl:operation: request and response– With WebSphere, implemented using plain java objects or EJBs

One Way (Fire and Forget)– One request message for each operation– No SOAP fault generated because there is no response– With WebSphere, implemented using plain java objects or EJBs



Basic Callback Usage Scenario

SOAP Request is sent and acknowledgement response received, representing the

initial Request. Asynchronous Response is delivered to the originator as another SOAP request,

with an expected acknowledge response. Both requests contain application defined correlation information. Initial request contains callback information to be used as the endpoint for the

Asynchronous Response. Separate wsdl:portType and wsdl:binding elements for the Initial Request and the

Asynchronous Response message pair, each containing a wsdl:operation that

references the request and response message. Additional operations can be added to the Asynchronous Response wsdl:portType

and wsdl:binding to address error conditions encountered asynchronously. Basic advertisement pattern applies only to the wsdl:binding and uddi:endpoint

representing the Initial Request; Asynch Response is a private exchange. With WebSphere, implemented using a Message Driven Bean.



Usage Scenarios for the Attachments Profile

Referenced attachments are used when:– Attachment is logically part of some other structure.– Attachment repeats an indeterminate number of times.– Attachment is optional.

The SOAP message contains an element contained in soap:body or

soap:header that contains a URL reference to a MIME:part within the

same message.

The WSDL binding contains multipartRelated, but the attachment is not

explicitly bound to a mime part.

With WebSphere, implemented with a DataHandler.



Interoperability Development Considerations

Contract is most important: WSDL for now; WS-Policy later

Use top-down development of WSDL when interoperability is of primary

importance

Follow WS-I Basic Profile WSDL guidelines carefully

Use a WSDL validation tool – WS-I Test Tools– IBM WSAD 5.1 or later

Ensure the wsdl:portType references ALL parts of a message

Describe explicit faults and include contextual information

Group related operations in the same wsdl:portType and wsdl:binding– Separate optional operations– Separate operations that use different WS-Security capabilities




Introduction Web Services Interoperability – An Overview WS-I Profiles – An Introduction WS-I Profile and Usage Scenarios WS-I Security Profile WS-I Test Tools References and Summary



Web Services Basic Security Profile V1.0 – An Overview

Basic Security Profile v1.0: Is an interoperability profile dealing with transport security, SOAP messaging

security, and other Basic Profile related Web Services security considerations Includes a set of usage scenarios and their component message exchange

patterns Leverages the WS-I Security Plan Framework, particularly its collection of usage

scenarios and use cases, and the WS-I Work Plan for Web Services Security

Interoperability as input Currently is a draft and is not final Is an extension to the Web Services Basic Profile Focuses on interoperability

Intent of the Profile is not to define security best practices; but, maybe, the

intent is to leverage the Profile to explore security weaknesses as a means

of reducing choice and thus enhancing interoperability.







WS-I Test Tools Overview

Objective– Provide an easy way to determine if a Web Service conforms to the

requirements of WS-I Profile – Is not intended for interoperability testing

Two tools: – Monitor

Logs Web Services messages using a man-in-the-middle approach– Analyzer

Determine if Web Services and other artifacts conform to WS-I Profile

Two implementations– C#– Java

WS-I Test Tools download site:– http://ws-i.org/implementation.aspx



WS-I Test Tools Architecture

RequestorWeb

Service

SOAPMessages

Normal Message Flow

Monitor

Analyzer

Interceptor

Logger

MessageLog

ConformanceReport

MonitorConfig File

MonitorAnalyzer

AnalyzerConfig File

TestAssertionDocument

WSDL

XML Schema

UDDI

SOAPMessages







References

Web Services Interoperability Organizationhttp://www.ws-i.org/Default.aspx

Web Services Interoperability Organization - Deliverableshttp://www.ws-i.org/deliverables/Default.aspx

XML.org http://www.xml.org/

SOAP 1.1 http://www.w3.org/TR/2000/NOTE-SOAP-20000508/

HTTP 1.1 http://www.ietf.org/rfc/rfc2616

WSDL 1.1http://www.w3.org/TR/wsdl.html

UDDI V2http://www.oasis-open.org/committees/uddi-spec/doc/tcspecs.htm#uddiv2



References

Web Services Interoperability Arcticles and White Papers

http://www-130.ibm.com/developerworks/webservices

Search for “Web Services Interoperability”

Microsoft Book: Building Interoperable Web Serviceshttp://download.microsoft.com/download/8/d/8/8d828b77-2ab2-4c8e-b389-e23684f12035/WSI-BP.pdf

Microsoft WS-I Sample Application implementation sourcehttp://ws-i.org/implementation.aspx



Summary

Achieving interoperability is still hard.– Matching compatible versions of tools and

runtime platforms– Watching out for different implementations

WS-I provides a number of deliverables.– Profiles– Usage Scenarios– Sample Applications– Test Tools

Test Tools address requirements of

conformance testing only. Charter of WS-I is to accelerate the adoption

and implementation of Web Services.

Documents

Web Services Interoperability. IBM Global Services Licensed Materials - Property of IBM (C) Copyright IBM Corp. 2005 - 2009 All Rights Reserved This is