Live Access Server (LAS) For Web Services

Roland Schweitzer
Climate Diagnostics Center, OAR

The Live Access Server is a general purpose Web-server for geo-science data sets. Data providers can use the three tiered LAS architecture to build custom Web interfaces to their scientific data. Users can then access the LAS site to search the provider’s on-line data holdings, make plots of data, create sub-sets in a variety of formats, compare data sets and perform analysis on the data.

An important new technology for delivering information on the Web is that of a Web service. The W3C Web Services Architecture Working Group defines a Web service as “a software application identified by a URI, whose interfaces and bindings are capable of being defined, described, and discovered as XML artifacts. A Web service supports direct interactions with other software agents using XML-based messages exchanged via Internet-based protocols.” Many Web developers extend this definition to require that the services be defined and described using the Web Services Description Language (WSDL) standard and that Simple Object Access Protocol (SOAP) be used as the communication protocol.

With the substantial number of LAS installations in place around the world, it seems natural to look for technical connections between LAS and the Web at large. The LAS development team recognized the value of having LAS servers be able operate as a Web service as defined by the Web Services Architecture Working Group.

This paper will explore the process of adapting LAS servers to operate as formal a Web service. It will give a complete technical description of the techniques used to have LAS operate as Web service in the strictest definition as well as describe the enhancements needed to satisfy the more broadly accepted definition of a Web service using the WSDL standard and the SOAP protocol.