484 research outputs found
Optimally Efficient Prefix Search and Multicast in Structured P2P Networks
Searching in P2P networks is fundamental to all overlay networks.
P2P networks based on Distributed Hash Tables (DHT) are optimized for single
key lookups, whereas unstructured networks offer more complex queries at the
cost of increased traffic and uncertain success rates. Our Distributed Tree
Construction (DTC) approach enables structured P2P networks to perform prefix
search, range queries, and multicast in an optimal way. It achieves this by
creating a spanning tree over the peers in the search area, using only
information available locally on each peer. Because DTC creates a spanning
tree, it can query all the peers in the search area with a minimal number of
messages. Furthermore, we show that the tree depth has the same upper bound as
a regular DHT lookup which in turn guarantees fast and responsive runtime
behavior. By placing objects with a region quadtree, we can perform a prefix
search or a range query in a freely selectable area of the DHT. Our DTC
algorithm is DHT-agnostic and works with most existing DHTs. We evaluate the
performance of DTC over several DHTs by comparing the performance to existing
application-level multicast solutions, we show that DTC sends 30-250% fewer
messages than common solutions
Exploiting the Synergy Between Gossiping and Structured Overlays
In this position paper we argue for exploiting the synergy between gossip-based algorithms and structured overlay networks (SON). These two strands of research have both aimed at building fault-tolerant, dynamic, self-managing, and large-scale distributed systems. Despite the common goals, the two areas have, however, been relatively isolated. We focus on three problem domains where there is an untapped potential of using gossiping combined with SONs. We argue for applying gossip-based membership for ring-based SONs---such as Chord and Bamboo---to make them handle partition mergers and loopy networks. We argue that small world SONs---such as Accordion and Mercury---are specifically well-suited for gossip-based membership management. The benefits would be better graph-theoretic properties. Finally, we argue that gossip-based algorithms could use the overlay constructed by SONs. For example, many unreliable broadcast algorithms for SONs could be augmented with anti-entropy protocols. Similarly, gossip-based aggregation could be used in SONs for network size estimation and load-balancing purposes
Socially-Aware Distributed Hash Tables for Decentralized Online Social Networks
Many decentralized online social networks (DOSNs) have been proposed due to
an increase in awareness related to privacy and scalability issues in
centralized social networks. Such decentralized networks transfer processing
and storage functionalities from the service providers towards the end users.
DOSNs require individualistic implementation for services, (i.e., search,
information dissemination, storage, and publish/subscribe). However, many of
these services mostly perform social queries, where OSN users are interested in
accessing information of their friends. In our work, we design a socially-aware
distributed hash table (DHTs) for efficient implementation of DOSNs. In
particular, we propose a gossip-based algorithm to place users in a DHT, while
maximizing the social awareness among them. Through a set of experiments, we
show that our approach reduces the lookup latency by almost 30% and improves
the reliability of the communication by nearly 10% via trusted contacts.Comment: 10 pages, p2p 2015 conferenc
Structured P2P Technologies for Distributed Command and Control
The utility of Peer-to-Peer (P2P) systems extends far beyond traditional file sharing. This paper provides an overview of how P2P systems are capable of providing robust command and control for Distributed Multi-Agent Systems (DMASs). Specifically, this article presents the evolution of P2P architectures to date by discussing supporting technologies and applicability of each generation of P2P systems. It provides a detailed survey of fundamental design approaches found in modern large-scale P2P systems highlighting design considerations for building and deploying scalable P2P applications. The survey includes unstructured P2P systems, content retrieval systems, communications structured P2P systems, flat structured P2P systems and finally Hierarchical Peer-to-Peer (HP2P) overlays. It concludes with a presentation of design tradeoffs and opportunities for future research into P2P overlay systems
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