Download Web Services Aggregation Frame Work

Web Services Aggregation Frame Work
Version: 0.2
Christian Martinez
Web Services Aggregation Frame Work ............................................................................ 1
1 Introduction ................................................................................................................. 3
2 WSA Frame Work ...................................................................................................... 4
2.1
XML Schema for UDDI and WSDL descriptions .............................................. 4
1 Introduction
Web services are becoming an integrated part of business operations. As developing
businesses look to compete in international markets, the internet is becoming the main
pipe line for the trade of goods and/or delivery of services. With the use of technology,
smaller business can level the playing field by lowering the cost of production and or the
cost of delivering services and goods. This research paper has as its goal to aid smaller
organizations take advantage of web services by automating the discovery and
simplifying the interaction with Web Services. Although there are many ways to
accomplish this, we will focus on the definition of what I call Web Services Aggregations
(WSA).
Considering the time and effort involved in taking on such a task, I will attempt to
integrate other technologies into my research. This will allow me to focus on the
definition of a WSA. By using a semantic rich language such as RDF, I can describe the
capabilities, relationships and dependencies amongst the various services in a WSA. I
hope to portray individual web services as methods encapsulated in an object that provide
and define that object’s goals. By defining a semantic rich markup for each service, an
application will be able to identify what the end-to-end goal of a particular WSA is. As a
result, an application can use the services by instantiating the object and calling its
methods, this can be accomplished using XML Data Binding technology. For the
purpose of this research, we can think of individual web services as attributes and
capabilities of an end-to-end service, also know as a WSA.
Before going into defining a markup that aggregates a series of Web Services, there is a
need to identify the set of constraints or the frame work under which such a markup will
operate. Once the frame work is introduced, I will demonstrate how RDF provides the
necessary tools for creating a WSA description file.
In general, the idea is to provide applications the ability of implementing the use of web
services with out the need to edit code. The WSA file contains all the knowledge needed
by a client of a service to empower the client and make it self sustaining. Although an
ambitious approach, I believe it pushes us one step closer to the realization of a Semantic
Web.
2 WSA Frame Work
The frame work consists of the following components:



Schema representation of UDDI and WSDL descriptions.
RDF document pointing to the required schemas for each required web service.
Services compiler that can aggregate all the necessary services by interpreting the
RDF document. This compiler needs to return an object structure of the WSA.
2.1 XML Schema for UDDI and WSDL descriptions
The object of defining such a schema is to create ontology’s of web services markup that
facilitate the sharing of knowledge across applications [1]. My research has a similar
goal as [1], the main difference is that I plan on building a layer on top of UDDI and
WSDL enabling the WSA to identify the different capabilities required of any service to
accomplish an aggregated end-to-end task. The details on this schema will be discussed
later on in this document. In addition to this difference, I also differ from the mentioned
research project in that I am not trying to automate the composition of web services. The
different components of this frame work will require a human to create them.
Complexities of Discovering Web Services
References
[1]
Semantic Web Services, Sheila A. McIlraith, Tran Cao Son, and Honglei
Zeng, Stanford University, 2001