A peer-to-peer indexing service for data grids

We present an index system for locating files or other data objects in a grid environment. The system is constructed using a distributed hash table, and is scalable, fault-tolerant, and self-organizing. The index is dynamically updated to reflect the state of the storage elements, and can hence deal with nomadic data. The system provides extra services to ease integration with other systems: A registrant service integrates existing storage elements into the system, and a query proxy provides an easy way to query the system. A security model, which builds on the existing grid security model is also provided. An implementation has been created and its performance measured. The system is shown to scale as more nodes are added to the system.