Thought Leadership

Web Services – An Overview
By Sreedhar Kajeepeta
Chief Technology Officer & Vice President
Covansys Corporation (a CSC company)
As Published In: C-Level Business Review

If you have been wondering what the fuss over Web Services is all about, when and how this technology can be useful for your company, what methodologies to use, what risks to watch out for, and what to anticipate in the future, here are some pointers.

Background

C-level management teams are examining Web Services with a growing sense of interest and optimism. This is a strong reflection of how the evolving technology is already redefining the architecture of business integration.

On the strategic side, revenue generation and improved service are the primary benefits enterprises are realizing by deploying Web Services. Real-time accessibility to customers, business partners, and employees is becoming a reality and proving to be a lot simpler to implement.

On the tactical side, one couldn’t have asked for a better convergence of technological forces (open standards, sponsorship and support of all the leading and competing vendors of the software development market such as IBM, Microsoft and Sun) that can provide a cost-effective platform for connectivity both within and across firewalls.

Business Value

Business value for the enterprises is what is keeping this momentum alive. That value is coming from the ability to create a service-oriented infrastructure that enables sharing of critical data in a consistent, self-descriptive, and secure manner. And such an infrastructure doesn.t have to be created all anew; instead it is made up of a combination of old and new systems that leverage each other.s strengths in the form of services. All of a sudden the varied platforms that years of investments have been running on (be it packages like ERP or CRM on Unix or Windows platforms, or legacy custom applications on the mainframe) are not islands any more. They can now be transformed into complementary components of a distributed architecture that provides appropriate balance between system performance and business integration. There are compelling advantages:

• No new code has to be written.
  
• The underlying standards based XML data formats enable a seamless and collaborative workflow that cuts across organizational boundaries providing comprehensive end user services.
  
• Use of industry-specific data format standards further enhance the value of these solutions with the unprecedented ease of integration they offer, to bring multiple partners on board almost immediately, to participate in a business opportunity.

By eliminating manual and batch-mode of integration between mission-critical systems, web sites and enterprise portals, Web Services have now become an important aspect of building real-time enterprises. To meet the needs of many self-service applications, the transactional backend systems can now be harnessed to avoid having to settle for dayold data.

Growing Adoption

The growing adoption of Web Services is benefiting businesses in industries such as public sector, manufacturing, financial services, and travel. They take the shape of enterprise integration solutions within the C-Level organizations or data exchanges between trusted partners. Public Web Services, both free and fee-based, are also springing up.

Government agencies are able to provide faster citizen services such as licensing, titling, and registration through the deployment of Web Services to integrate websites and point of service/sale (POS) systems with backend legacy applications.

In the manufacturing industry OEMs are integrating their backend applications with dealer and customer facing websites to facilitate faster processing of such critical transactions as credit applications, part orders and warranty claims. Prior to Web Services, these transactions involved a lot of manual handling, duplicate data sources, file transfers and paper documents.

In the travel industry, Web Services make it possible to look at the multiple segments of a travel request (the airline ticket, the car rental, the hotel reservation) as one single transaction that can seamlessly interact with the various backend applications of the organizations involved (for example Northwest Airlines, Enterprise Car Rental, Westin Hotel) to provide the customer with a unified experience of buying that service from a single website. Thanks to Web Services, the customer can even be alerted of any changes to the schedule on a mobile device such as Sprint PCS phone.

Incorporation of open standards for messaging protocols, support for neutrality of programming languages used by different companies, and use of industry standard XML schemas (such as STAR for the automotive industry) make these solutions highly extendable to a whole community of business partners and .competitors. to explore joint business opportunities. It is easier for another government agency, OEM, airliner, car rental company, hotel and mobile service provider to join in and benefit from the infrastructure and be able to offer their unique portion or flavor of service to the end customer.

What, How and When?

What is Web Services? Is it a collection of standards, or is it a new technology? How does it work with current application development technologies such as J2EE, .Net, EAI etc?

Web Services are a set of messaging protocols and tools that help in looking at information systems in terms of reusable software components, which embody a discrete functionality; and provide the ability to loosely tie these components together, over the web to offer internal and external business services.

What HTTP protocol does to textual documents, Web Services do to enterprise applications. Using the paradigm of publish, find and bind, they help in creating an infrastructure that supports data integration across a wide range of business applications. In addition they provide a more open and scalable infrastructure than previously offered by distributed object standards such as CORBA and DCOM. This infrastructure includes:

Basic Infrastructure:

• eXtensible Markup Language (XML) is a platform-independent data definition standard for describing data and creating other markup languages. XML is at the very core of Web Services, serving as a tool for defining other components.

• Simple Object Access Protocol (SOAP) is a messaging protocol, built using XML, to describe communication between applications. It provides the necessary platform and programming language independence to integrate applications and business processes. SOAP supports the bind aspect of Web Services.

• Web Services Description Language (WSDL) is an XML-based language for describing Web Services and for exposing them for URL-like ease of access. WSDL supports the publish aspect of Web Services.

• Universal Description, Discovery and Integration (UDDI) provides a common repository through which Web Services can be advertised to internal and external service requestors. UDDI supports the find aspect of Web Services.

• XML Schemas
  • XML provides an enabling technology for companies to collaborate and standardize on data formats to be used in business processes among organizations and across industries. The full benefits of Web Services can only be realized when efforts to develop common XML standards succeed on a global basis. Electronic Business XML (ebXML) is one such framework that is widely popular with support from many companies, and industry consortia such as RosettaNet, with representation from Electronics, Semiconductor and IT industries.

Development Environments for Web Services:

Fine, Web Services are platform and language independent, but developers do need a platform (such as J2EE or .Net), and language specific (such as Java or Visual Basic) tools for building, deploying and accessing Web Services. The following is a list some of the technologies and vendors that support these activities.

Java/J2EE

Open Source code: The Apache Software foundation offers a SOAP tool kit, called Apache SOAP, and a Web Services Java development framework called Axis. To use these tools a developer needs to install an application server such as Apache Tomcat and XML parser such as Xerces.

IBM: IBM has included Web Services technologies in its flagship WebSphere family of products, WebSphere Studio Application Developer, (WSAD) and WebSphere Application Server and WebSphere Business Integration; and also in DB2, Lotus andTivoli.

BEA: BEA WebLogic Workshop and the WebLogic family of application server and integration server products provide an integrated environment to develop and deploy Web Services.

Sun: Sun.s Web Services strategy is based on its Open Net Environment (Sun ONE, formerly iPlanet). The platform includes development studio, application server, directory server and portal server. Sun also coordinates the efforts for introducing several popular Java APIs to support the development of Web Services. Some of these APIs include:

• Java API for XML Messaging (JAXM)
• Java API for XML processing (JAXP)
• Java API for XML registries (JAXR)
• Java API for XML-based RPC (JAX-RPC)
• SOAP with Attachments API for Java (SAAJ)

Net

- Microsoft.s .Net platform offers an integrated platform through Visual Studio .Net, a variety of languages including C, C++ and Visual Basic. Net technologies provide a very cost-effective platform to create and deploy Web Services.

EAI

- Traditional EAI vendors are building support for Web Services into their software solutions. This promotes a synergy between their proprietary data transformation/messaging/workflow/adapter features, and the open find/bind/publish features of Web Services, thereby extending the capability of the resulting solutions beyond corporate firewalls. Some of these vendors include SeeBeyond, Tibco, Vitria, and webMethods.

Work Flow

- When multiple Web Services are combined to support a complex business process, we need tools to manage the interaction of the various services and the corresponding workflow. Web Services Workflow Language (WSFL) from IBM and XLANG from Microsoft support the need to define the workflows. Other workflow vendors such as Avinon, Savvion and Versata provide tools to define and manage Web Services, to implement business processes.

3rd Party

- GLUE from The Mind Electric (now part of webMethods) is a widely used, small, Java based platform for creating and deploying Web Services. GAIA from the same company is a more mature platform for launching high performance Web Services systems with support for load balancing and failover.

So how does it all work and what developmental efforts are involved?

The mechanism of how Web Service work involves a series of interactions in which the basic infrastructure elements come together to find and bind, a published service, to a client in need of that service. These interactions include:

• Publishing the contract and bindings details of the identified Web Services into an internal or external registry (UDDI) using WSDL
  
• Finding and invoking of the service by the client
  
• Binding the request into a SOAP XML message
  
• SOAP calls made by the client over HTTP to the web server to be forwarded to the SOAP engine
  
• SOAP calls can be either asynchronous messages or RPC-calls depending on the type of communication needed between the client application and the service it is requesting.
  
• Even though HTTP is the most common protocol, based on infrastructure, content and individual requirements, other protocols such as SMTP and WebSphere MQ may be considered.
  
• Processing of the request by SOAP Engine and getting the data from the addressed Web Service using a Request Handler Business Review
  
• SOAP Engine parses the SOAP envelope and passes the XML document to the Request Handler
  
• Request Handlers parses the XML message and invokes the required backend service
  
• Passing the results back to the client
  
• Involves the reverse activities of creating XML messages, SOAP envelops and responses over desired protocols

Most of the developmental work can be grouped into the following areas:

Given the evolving nature of the technology and the related standards, when is it the right fit for your needs?

If you are looking on the business side, the possible areas where you might want to consider deploying Web Services are:

• Opportunities for lowering operational costs
  
  • Phasing out existing data exchange solutions, such as EDI (in manufacturing and retail industries) and SWIFT (in financial services industry).
  • You can consider building new B2E, B2C and B2B Interfaces and Portals, by integrating a collection of systems. These efforts will not require making significant alterations to the participating systems.
    
• Opportunities for expanding revenue
  
  • Customer and/or partner facing exchanges to create new services or to expand the channels for existing products/services

On the technical side, it is important to realize that Web Services are but one part of your overall integration tool set, and they should be used in conjunction with any existing EAI Integration Servers and Message Brokers. Even when implementing integration solutions for use behind the firewall, it is advantageous to deploy elements of Web Services to promote and to facilitate reusability through a service-oriented architecture. Internal UDDI registries should be used to act like repositories of reusable components across enterprise.

Methodology

The methodologies used to build solutions involving Web Services vary in their approach based on the scope and objectives of the underlying initiative. If the effort is a pilot, it is a typical approach to use a highly tactical and bottom-up style that is focused on immediate results.
The steps in such an approach would involve:

- Creating the technical infrastructure
- Identifying the applications that constitute the list of service providers
- Describing those services using WSDL
- Publishing those services using UDDI
- Developing client applications using the WSDL descriptions
- Developing the dispatchers to invoke the service provider components
- Functional testing (including security), Integration Testing and Performance Testing

For larger efforts, it is more common to use principles of a Service-Oriented-Architecture and to look across the enterprise to identify a broader list of reusable components. The components should be grouped by workflows, their functionality, and their technical environments. This list will serve as specification for developing the detailed constructs of an enterprise architecture where Web Services would address the total needs of interconnectivity, security, and transactional support together with Integration Servers, Message Brokers and Access Control packages. Individual integration solutions are then developed conforming to the details of this architecture.

Risks

SOAP is not designed to handle security. Even though XML packets can be encrypted and digitally signed to improve confidentiality and authenticity of the messages, many companies are hesitant to deploy Web Services outside of corporate firewalls until more standardized and cost-effective mechanisms are in place.

Guaranteeing Quality of Service (QoS) is another challenge for faster adoption of Web Services. Response times and scalability are some of the concerns related to QoS. Network latency and availability can fluctuate widely, based on the Internet infrastructure and may not be suitable for high performance requirements.

Additionally, there is no standard way to implement commits and rollbacks on a business transaction that is made up of multiple physical transactions.

What To Look Forward To

This technology is still in its early stages as an enabler of universal interconnectivity between applications. As the underlying infrastructure becomes more robust, Web Services will be used for broader, more complex and high performance transactional systems that can reach out to different types of corporate and mobile devices. Internet (including the wireless infrastructure) is still a stronger medium for connecting people, not computer systems. In parallel with the improvements to this medium, the feature-function set of Web Services will also improve with major advances in J2EE, .Net, EAI and Workflow technologies to provide better support for:

- Business integration and work flow
- Security
- Web Services management
- Transactional support
- Increased developer productivity

Sreedhar Kajeepeta is vice president and chief technology officer of Covansys Corporation (a CSC company), a global consulting and technology services company specializing in industry-specific solutions, strategic outsourcing and integration services through its unique on-site, offsite, offshore delivery capability.