CREATING GRID SERVICES TO ENABLE DATA INTEROPERABILITY: AN EXAMPLE FROM THE GEON PROJECT
Our basic architecture follows the common wrapper-mediator model where system components exchange messages in the form of virtual XML documents. Source schemas and capability descriptions are exposed to the mediator in the process of source registration, but the source data sets always reside within the owners domain. Users can pose queries against the integrated view maintained by the mediator from a specially designed mapping interface. The system manages the availability and performance of the data access through staging, caching and replication of the data sets. Each source wrapper exposes a standard interface to the mediator built around WSDL source descriptions. In addition to source wrapping, a variety of data conversion services including type conversion, coordinate conversion, concept resolution and spatial results assembly services are built into the system. All system components and services are built using grid and web services standards, thereby leveraging the common core capabilities and developer tool support. We will present how these grid technologies are being used in the GEON project with specific applications related to state geologic data set integration.