A Model of a Distributed Information System based on the Z39.50 Protocol

Based on the analysis of typical scenarios of information servers, the tasks that should be solved when organizing an access control system for distributed information resources are formulated. The possibilities of the Z39.50 technologies as the most suitable for building such a system are considered. Within the framework of this technology, three access control models are discussed, which differ in the degree of integration of information server functions with the Z39.50 technologies.The creation and support of distributed information systems and electronic libraries that integrate heterogeneous information resources and operate in various software and hardware environments requires special approaches to managing these systems. If the resources or data themselves can be managed locally, even for distributed information systems, then the task of managing access to distributed resources cannot be solved within the framework of local administration. The justification of the last thesis can be seen when considering typical scenarios of the information server, which we will describe below