DHT over NICE

Home Up CASS IBN ATP DHT over NICE ABR Multicast HFR

 

[With Bobby Bhattacharjee, Assistant Professor, Dept of Computer Science, University of Maryland, USA]

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Generic peer-to-peer overlay networks like Chord, CAN, Pastry, and Tapestry provide efficient and fault-tolerant-routing, object-location, and load balancing within a self-organizing overlay network. One important aspect of these systems is how they exploit network proximity in the underlying Internet. Adapting their structures to exploit this valuable tool come at the expense of more expensive overlay maintenance protocol.

NICE is a cooperative framework for scalably implementing distributed applications over the Internet. Applications in NICE are cooperative: they devote a part of their own resources to be used by any member of a cooperative group. NICE scheme is based upon a hierarchical clustering of peers depending on their relative physical locations. The hierarchy enjoys topology aware characteristics that enhance its stress and stretch properties over the above overlays.

In this project, we leverage the good locality properties of NICE to provide an efficient object lookup service for NICE group members. We separate the multicast (which was the main functionality of NICE topology construction) from the hierarchy maintenance and only use the latter to provide the new service. The distributed object lookup over NICE supports two extra basic operations: key-value pair insertion, and value retrieval. Each key in the system has two IDs, a global key ID that will map the key to a certain cluster in the NICE lowest layer and a local key ID to map the key to a certain node in that cluster. The hierarchal topology of the NICE overlay can be used to efficiently locate objects in O(log N) overlay hops using links between physically-nearby peers.