JISC Information Environment Architecture

Notes on the JIE Architecture and Web Services

This set of notes outlines the relationship between the JISC IE technical architecture and Web services.

As outlined in An introduction to Web Services, the Web services architecture comprises three component roles - service provider, service requestor and service registry. These three roles map quite cleanly onto the JISC IE architecture components, as shown below:

JISC IE architecture and Web services

All JISC IE components that offer services are service providers - this includes content providers, aggregators, brokers and all the JISC IE shared services.

All JISC IE components that connect to those services are service requestors - this includes portals, aggregators and brokers.

The JISC IE collection description service and service description service can jointly be thought of as providing a JISC IE directory. This combined service is the JISC IE service registry.

The key Web service technologies are the Simple Object Access Protocol (SOAP), the Web Service Description Language (WSDL) and the Universal Description, Discovery and Integration of Web Services (UDDI):

SOAP does not curently feature in the JISC IE architecture protocols - Z39.50, OAI and RSS. However, there is work underway to develop a SOAP-based implementation of Z39.50 known as Search/Retrieve Web service (SRW). Similarly there has been some discussion on the OAI technical implementation lists about the desirability of implementing OAI in SOAP. It is reasonable to assume that if these developments go ahead, they will form part of a future JISC IE architecture.
WSDL, the XML application for describing Web services, covers the description of four main entities - businessEntity, businessService, bindingTemplate and tModel. The businessService and bindingTemplate entities map quite closely onto the current JISC IE architecture 'collection' and 'service' terminology. We currently have a small pilot underway to evaluate the possibilities for describing JISC IE collections and services using WSDL. This work acknowledges that WSDL descriptions are not as rich as other collection descriptions, e.g. descriptions based on the RSLP or EAD schemas. Therefore, it may be necessary to incorporate these richer schemas into WSDL descriptions in some way.
UDDI provides the Web services registry function. As well as being a 'directory' technology, it is also the name of a global, public Web services registry. Depending on the progress of the WSDL pilot, it will be necessary to consider the benefits of developing a 'private' JISC IE UDDI registry vs. registering all JISC IE services in the global UDDI registry.