Web Services are self-contained, self-describing, modular applications that
can be published, located, and invoked across the Web. QoS of a Web
Service is its ability to have some level of assurance that its service and
traffic requirements are satisfied in a timely fashion. That means that all
the components of a Web Service need to be considered when evaluating its
QoS: backbone, core, access, and applications.
So, what are the criteria (Quality Indicators) of a usable and reliable Web
Service? When dealing with QoS, it is critical to have an end-to-end view
of Web Services because they represent a paradigm shift in the way
applications are developed. Modules are no longer modules by one party. Some
of the functionality a user will get by calling Web services. But then, that
user will need to be very careful which services are useful and which are
not. Some sites are doing a great service by providing acceptance tests and
expected results, but they still provide a granular view of QoS since they
only validate only one component. This presentation addresses the
end-to-end challenges of Web Services QoS.