Improving the performance of Federated Digital Library services

The number of Digital Libraries (DLs) accessible over the Open Archives Initiative - Protocol for Metadata Harvesting (OAI-PMH) has been constantly increasing in the past years. Earlier efforts in the DL area have concentrated on metadata harvesting and provisioning of value-added Federated Digital Library (FDL) services to the users. FDL services, however, have to meet significant performance and scalability requirements, which is difficult to achieve in centralized metadata harvesting systems. The goal of the present study was to evaluate the benefits of using Web Services Resource Framework (WSRF) compliant grid middleware infrastructure for providing efficient and reliable FDL services. The presented FDL application allows for parallel harvesting of OAI-PMH compliant DLs. The results show that this approach efficiently solves the performance related problems, while it also contributes to greater flexibility of the system. The quality of service is improved as metaclata can be updated frequently, and the system does not exhibit a single point of failure. (c) 2008 Elsevier B.V. All rights reserved.