Implementation and evaluation of a distributed RDF storage and retrieval system

It is widely agreed that the semantic Web will be build on RDF. Therefore the success of the semantic Web also depends on the availability of a scalable and reliable infrastructure for storing and accessing RDF data. A number of storage and retrieval systems have been developed recently, but despite the inherently distributed nature of the semantic Web most of these systems do not support distributed storage and retrieval of data. In this paper we report our experiences with implementing a distributed storage and query infrastructure on top of an existing RDF infrastructure. We present the system architecture and discuss performance issues based on a set of experiments with the infrastructure. We conclude with an identification of remaining performance bottlenecks and point to further improvements.