Abstract

The success of a P2P file-sharing network highly depends on the scalability and versatility of its search mechanism. Two particularly desirable search features are scope (ability to find infrequent items) and support for partial-match queries (queries that contain typos or include a subset of keywords). While centralized-index architectures (such as Napster) can support both these features, existing decentralized architectures seem to support at most one: prevailing protocols (such as Gnutella and FastTrack) support partial-match queries, but since search is unrelated to the query, they have limited scope. Distributed Hash Tables (such as CAN and CHORD) constitute another class of P2P architectures promoted by the research community. DHTs couple index location with the item's hash value and are able to provide scope but can not effectively support partialmatch queries; another hurdle in DHT deployment is their tight control the overlay structure and data placement which makes them more sensitive to failures.

Citations