Computer Science and Information Systems 00(0):0000–0000 https://doi.org/10.2298/CSIS123456789X 1 Intelligent query processing in P2P networks: 2 semantic issues and routing algorithms 1 1 1 1 3 AL Nicolini , CM Lorenzetti , AG Maguitman , and CI Chesnevar˜ 4 Institute for Computer Science and Engineering (ICIC) 5 Universidad Nacional del Sur - CONICET, Bah´ıa Blanca, Argentina 6 faln, cml, agm,
[email protected] 7 Abstract. P2P networks have become a commonly used way of disseminating con- 8 tent on the Internet. In this context, constructing efficient and distributed P2P rout- 9 ing algorithms for complex environments that include a huge number of distributed 10 nodes with different computing and network capabilities is a major challenge. In the 11 last years, query routing algorithms have evolved by taking into account different 12 features (provenance, nodes’ history, topic similarity, etc.). Such features are usu- 13 ally stored in auxiliary data structures (tables, matrices, etc.), which provide an extra 14 knowledge engineering layer on top of the network, resulting in an added semantic 15 value for specifying algorithms for efficient query routing. This article examines the 16 main existing algorithms for query routing in unstructured P2P networks in which 17 semantic aspects play a major role. A general comparative analysis is included, as- 18 sociated with a taxonomy of P2P networks based on their degree of decentralization 19 and the different approaches adopted to exploit the available semantic aspects. 20 1. Introduction 21 A peer-to-peer network (or just P2P network) is a computing model present in almost 22 every device, from smartphones to large-scale servers, as a way to leverage large amounts 23 of computing power, storage, and connectivity around the world.