FeedTree: Sharing Web micronews with peer-to-peer event notification

Syndication of micronews, frequently-updated content on the Web, is currently accomplished with RSS feeds and client applications that poll those feeds. However, providers of RSS content have recently become concerned about the escalating bandwidth demand of RSS readers. Current efforts to address this problem by optimizing the polling behavior of clients sacrifice timeliness without fundamentally improving the scalability of the system. In this paper, we argue for a micronews distribution system called FeedTree, which uses a peer-to-peer overlay network to distribute RSS feed data to subscribers promptly and efficiently. Peers in the network share the bandwidth costs, which reduces the load on the provider, and updated content is delivered to clients as soon as it is available

Strata: A simple lightweight ad hoc communications infrastructure

This thesis presents Strata, a lightweight scalable implementation of the Safari architecture. Safari is an ad hoc network architecture, providing scalability to tens of thousands of nodes, integration of existing infrastructure, and self-organizing, decentralized network services. The Safari architecture is based on a self-organizing hierarchy that recursively partitions the network and assigns coordinates to nodes. Strata leverages the Safari structure to efficiently provide routing between two network hosts. As part of Strata's development, we developed a scalable, extensible network simulation environment that enables simulation of very large networks. The simulator's extensibility allowed us to explore the design space, revisiting many of the design decisions in the original Safari prototype. Early simulation results indicate that Strata can scale to several thousand fully mobile nodes with acceptable overhead

[Software]: General—Peer-to-peer systems

Peer-to-peer (p2p) technology can potentially be used to build highly reliable applications without a single point of failure. However, most of the existing applications, such as file sharing or web caching, have only moderate reliability demands. Without a challenging proving ground, it remains unclear whether the full potential of p2p systems can be realized. To provide such a proving ground, we have designed, deployed and operated a p2p-based email system. We chose email because users depend on it for their daily work and therefore place high demands on the availability and reliability of the service, as well as the durability, integrity, authenticity and privacy of their email. Our system, ePOST, has been actively used by a small group of participants for over two years. In this paper, we report the problems and pitfalls we encountered in this process. We were able to address some of them by applying known principles of system design, while others turned out to be novel and fundamental, requiring us to devise new solutions. Our findings can be used to guide the design of future reliable p2p systems and provide interesting new directions for future research

Fallacies in evaluating decentralized systems

Research on decentralized systems such as peer-to-peer overlays and ad hoc networks has been hampered by the fact that few systems of this type are in production use, and the space of possible applications is still poorly understood. As a consequence, new ideas have mostly been evaluated using common synthetic workloads, traces from a few existing systems, testbeds like PlanetLab, and simulators like ns-2. Some of these methods have, in fact, become the “gold standard ” for evaluating new systems, and are often a prerequisite for getting papers accepted at top conferences in the field. In this paper, we examine the current practice of evaluating decentralized systems under these specific sets of conditions and point out pitfalls associated with this practice. In particular, we argue that (i) despite authors ’ best intentions, results from such evaluations often end up being inappropriately generalized; (ii) there is an incentive not to deviate from the accepted standard of evaluation, even if that is technically appropriate; (iii) research may gravitate towards systems that are feasible and perform well when evaluated in the accepted environments; and, (iv) in the worst-case, research may become ossified as a result. We close with a call to action for the community to develop tools, data, and best practices that allow systems to be evaluated across a space of workloads and environments. 1