A web service is any useful task executed at the request of a client. The
Web Service Definition Language (WSDL) is an XML language designed to
abstract the interface between clients and services in a way that is
independent of programming language. Two of the PIs (Yuen, Erlebacher)
have been exploring the means of interfacing WEB-IS, a collection of
interfaces being designed to analyze and visualize Earth science data, to
NB to allow inter-laboratory work. Currently WEB-IS connects a single user
to a single computational resource. We have created client and service
proxies to intercept SOAP messages, attach them to a topic, and route them
through NB to publish command messages for controlling data retrieval,
computation, and visualization that result in images delivered back to
multiple clients. Although this approach enables support for existing Web
service tools like Apache Axis and gSOAP, the client and service pieces
lie outside the broker framework and so do not inherently benefit from
intrinsic broker capabilities like reliable messaging and security. To
avoid this drawback, we will pull the message translation within NB.
