The Case for a Hybrid P2P Search Infrastructure

Abstract

Abstract. Popular P2P file-sharing systems like Gnutella and Kazaa use unstructured network designs. These networks typically adopt flooding-based search techniques to locate files. While flooding-based techniques are effective for locating highly replicated items, they are poorly suited for locating rare items. As an alternative, a wide variety of structured P2P networks such as distributed hash tables (DHTs) have been recently proposed. Structured networks can efficiently locate rare items, but they incur significantly higher overheads than unstructured P2P networks for popular files. Through extensive measurements of the Gnutella network from multiple vantage points, we argue for a hybrid search solution, where structured search techniques are used to index and locate rare items, and flooding techniques are used for locating highly replicated content. To illustrate, we present experimental results of a prototype implementation that runs at multiple sites on PlanetLab and participates live on the Gnutella network.

Hybrid Retrieval Mechanisms in Vehicle-Based P2P Networks

“…However, queries for rare objects are also substantial [10]. Both studies correctly reflect different aspects of the Zipfian distributions.…”

Popularity adaptive search in hybrid P2P systems

“…SimpleHybrid combines Gnutella and the DHT-based PIERSearch [10,11]. To improve the search efficiency, GAB [25] makes search decisions based on global statistics of documents' popularity (In this paper, we will use the terms of "item" and "document" interchangeably).…”

“…For example, in [10,11], a query is flooded with a limited depth first, and, if no result is returned, the query goes to the DHT. Such a design is simple and effective but inefficient in that it incurs extra overhead.…”

“…To improve search quality and efficiency for both popular and rare items, hybrid P2P approaches are introduced [10,11]. By combining the unstructured P2Ps with a structured DHT-based global index, queries are handled in a hybrid manner: popular items are found via flooding, while rare items are found via DHT-based algorithm.…”

“…Many efforts have been made for hybrid search, such as the SimpleHybrid [10,11] and GAB [25]. However, they do not successfully deal with the dynamic nature of P2P networks where peers frequently join and leave the systems.…”