Authors: Tien-Dung Le
Addresses: European Schoolnet, Rue de Trèves 61, 1040 Brussels, Belgium
Abstract: In a large federation of learning resource repositories metadata can become out of date, especially when resources are moved or deleted, frustrating users and making it critical to assure the availability of resources in any learning environment. Regularly checking all of URLs in a federation with thousands of resources negatively impacts content providers causing poor system performance, heavy network traffic and impoliteness. This paper describes a solution that ensures a balance between the number of resources and the number of checking requests performed. It uses a heuristic algorithm to select a group of resources to verify. Depending on the results, the system either stops checking or continues with a new selection of links constructed from URLs that are similar to the broken links in the previous round. To reach the global optimisation, the selection process also randomly picks other resources with a small probability of error.
Keywords: resource availability; broken links; heuristics; learning resources; metadata; URLs; federated environments; broken link checkers; URL similarity.
International Journal of Metadata, Semantics and Ontologies, 2013 Vol.8 No.1, pp.3 - 12
Received: 07 Jun 2012
Accepted: 21 Feb 2013
Published online: 28 May 2013 *