B-Tracker: Improving load balancing and efficiency in distributed P2P trackers

Abstract

Trackers are used in peer-to-peer (P2P) networks for provider discovery, that is, mapping resources to potential providers. Centralized trackers, e.g., as in the original BitTorrent protocol, do not benefit from P2P properties, such as no single point of failure, scalability, and load balancing. Decentralized mechanisms have thus been proposed, based on distributed hash tables (DHTs) and gossiping, such as BitTorrent's Peer Exchange (PEX). While DHT-based trackers suffer from load balancing problems, gossip-based ones cannot deliver new mappings quickly. This paper presents B-Tracker, a fullydistributed, pull-based tracker. B-Tracker extends DHT functionality by distributing the tracker load among all providers in a swarm. Bloom filters are used to avoid redundant mappings to be transmitted. This results in the important properties of load balancing and scalability, while adding the ability for peers to fetch new mappings instantly. B-Tracker shows, through simulations, improved load balancing and better efficiency when compared to pure DHTs and PEX.

Survey of Network Coding Based P2P File Sharing in Large Scale Networks

“…M. Guanjun et al [56] proposed a sparse network coding scheme based on stochastic formulas; the probability of the number of pieces that will be encoded by the seeder, which has all the pieces (n) is set as in (7). For a non-source peer which has k pieces, the encoding probability is set as in (8).…”

“…Chord overlay network [1] is used as a network topology and the encoding interval, which is a window to limit selecting pieces for encoding according to their expected innovation, is used to minimize the likelihood of transmitting dependent pieces. The authors argue that using the aforementioned formulas, (7) and (8), for encoding probability ensures that all of the encoded pieces generated by the same peer are linear independent with high probability (99.991%), taking into account that the used finite field is GF(2 8 ) . Moreover, a dependency test at the receiver nodes is conducted to prevent receiving more dependent pieces which works as follow: let H and G be two connected peers via a link, if no less than 3% of the pieces from H to G are dependent, H will stop requesting G for pieces for 30 seconds.…”

“…BitTorrent-like systems work in two phases, the first phase utilizes a discovery protocol, in which peers discover and establish connections to each other. Detailed discussions on the discovery protocol can be found in [5][6][7][8][9], and [10]. The second phase utilizes file dissemination protocol, in which peers start to download and upload the chunks of a file until they get the complete file.…”

Enhancing Scalability in On-Demand Video Streaming Services for P2P Systems

“…Distributed P2P network is more advantageous in the setup of VOD system [17,40]. Each peer node is equipped to handle a factor of the overall load from the server by serving with its buffered content.…”

“…The tracker acts as message transmitter across the peers and services media streams that the peers have requested to and from the media server. The management of the peers, like the peer request scheduling, managing entry and exit of each peers, Look-Up- Table (LUT) management using Ant-Based optimized routing for the peer groups are handled at the tracker rather than by the server [16,17]. The combination of the QPMVM at server and the tracker enhances the system as a whole and hence reduces the latency during scalability.…”