XL peer-to-peer pub/sub systems

Abstract

Increasingly, one of the most prominent ways to disseminate information on the Web is through "notifications" (also known as alerts), and as such they are at the core of many large-scale applications. For instance, users are notified of articles in which they are interested through RSS feeds, of posts from their friends through social networks, or of recommendation generated by various sites. Event notification usually relies on the so-called Publish-Subscribe (PUB/SUB) communication paradigm. In PUB/SUB systems, subscribers sign up for events or classes of events in order to be asynchronously notified afterward by the system. The size of such systems (with respect to events and subscriptions) keeps growing, and providing scalable implementations of PUB/SUB systems is extremely challenging. Although there exist popular examples of centralized PUB/SUB systems that currently support a large number of subscribers, such as online social networks, they periodically face formidable challenges due to peak loads and do not always offer a support for fine-grain subscriptions. In fact, providing scalability along with expressiveness in the subscription patterns calls for distributed implementations of PUB/SUB systems. In parallel, peer-to-peer (P2P) overlay networks have emerged, providing a sound and highly scalable network foundation upon which to build distributed applications including PUB/SUB systems.In this article, we focus on fully decentralized (P2P), highly scalable, PUB/SUB systems. More specifically, we investigate how PUB/SUB and P2P research can be integrated. We define the design space and explore it in a systematic way. We expose an understanding of available design choices; provide a comprehensive classification and understanding of prominent P2P PUB/SUB systems, positioning them against the design dimensions; and highlight correlations between and implications, benefits, and shortcomings of design alternatives.

Filament: A Cohort Construction Service for Decentralized Collaborative Editing Platforms

“…Researchers have been looking into peer-to-peer collaborative editing platforms [4,9,11,12,16,23] for some time. Most of these approaches in decentralized peer-to-peer collaborative editing assume that all users in a system participate in the same edition.…”

Fluidify: Decentralized Overlay Deployment in a Multi-cloud World

“…Overlay networks organize peers in logical topologies on top of an existing network to extend its capabilities, with application to storage [22,25], routing [8,11], recommendation [1,27], and streaming [5,15]. Although overlays were originally proposed in the context of peer-to-peer (P2P) systems, their application today encompasses wireless sensor networks [7] and cloud computing [3,13].…”

“…Overlays are increasingly used as a fundamental building block of modern distributed systems, with numerous applications [5,8,11,13,15,22,25]. Unfortunately, many popular overlay construction protocols [1,10,27] do not usually take into account the underlying network infrastructure on which an overlay is deployed, and those that do tend to be limited to a narrow family of applications or overlays [29,30].…”

VizPub

“…Many of these aspects are known to be at stake with each other [5,10]. Providing a suitable balance in performance is a key design challenge for pub/sub.…”

“…It should be mentioned that despite the significant diversity in system design, the performance metrics of interest are mostly identical for all pub/sub systems (see [5,10] for a detailed discussion). This allows us to define a generic list of performance metrics and a generic reporting interface.…”