Reference management in a loosely coupled, distributed information system

Abstract

References between objects in loosely coupled distributed information systems pose a problem. On the one hand, one tries to avoid referential inconsistencies like, e.g., dangling links in the WWW. On the other hand, using strict constraints as in databases may restrict the data providers severely. We present the solution to this problem that we developed for the Nexus system. The approach tolerates referential inconsistencies in the data while providing consistent query answers to users. For traversing references, we present a concept based on return references. This concept is especially suitable for infrequent object migrations and provides a good query performance. For scenarios where object migrations are frequent, we developed an alternative concept based on a distributed hash table. © 2008 Springer-Verlag Berlin Heidelberg.