BubbleStorm: Rendezvous Theory in Unstructured Peer-to-Peer Search

This thesis presents BubbleStorm, which attempts to bridge the gap between peer-to-peer and databases. BubbleStorm is a peer-to-peer search system, which solves large-scale rendezvous problems over the unreliable global internet. It provides a concept of user-defined bubble types, loosely corresponding to table schemas. Queries follow the fully general black-box model, allowing powerful queries to be evaluated exhaustively. The system tracks usage statistics with a system-wide measurement service, used to automatically tune search performance. As strong consistency guarantees are impossible, BubbleStorm instead aims for user-controlled probabilistic guarantees. The key contribution of this thesis is to develop rendezvous theory and reformulate the black-box query model within this framework. This reformulation allows us to interpret any black-box system as solving a rendezvous problem, allowing an elegant and tight lower-bound. BubbleStorm leverages rendezvous theory to substantially reduce bandwidth consumption (both practically and asymptotically) while simultaneously improving query latency. The resulting system, which has a full fledged implementation, sports a simple to understand interface, which abstracts away the underlying details, much like the database systems before it

A Peer-to-Peer Approach to Content-Based Publish/Subscribe

Publish/subscribe systems are successfully used to decouple distributed applications. However, their e#ciency is closely tied to the topology of the underlying network, the design of which has been neglected. Peer-to-peer network topologies can o#er inherently bounded delivery depth, load sharing, and self-organisation. In this paper, we present a contentbased publish/subscribe system routed over a peer-to-peer topology graph. The implications of combining these approaches are explored and a particular implementation using elements from Rebeca and Chord is proven correct

BubbleStorm: Rendezvous Theory in Unstructured Peer-to-Peer Search

This thesis presents BubbleStorm, which attempts to bridge the gap between peer-to-peer and databases. BubbleStorm is a peer-to-peer search system, which solves large-scale rendezvous problems over the unreliable global internet. It provides a concept of user-defined bubble types, loosely corresponding to table schemas. Queries follow the fully general black-box model, allowing powerful queries to be evaluated exhaustively. The system tracks usage statistics with a system-wide measurement service, used to automatically tune search performance. As strong consistency guarantees are impossible, BubbleStorm instead aims for user-controlled probabilistic guarantees. The key contribution of this thesis is to develop rendezvous theory and reformulate the black-box query model within this framework. This reformulation allows us to interpret any black-box system as solving a rendezvous problem, allowing an elegant and tight lower-bound. BubbleStorm leverages rendezvous theory to substantially reduce bandwidth consumption (both practically and asymptotically) while simultaneously improving query latency. The resulting system, which has a full fledged implementation, sports a simple to understand interface, which abstracts away the underlying details, much like the database systems before it

Distributed sql queries with bubblestorm

Abstract. Current peer-to-peer (p2p) systems place the burden of application-level query execution on the application developer. Not only do application developers lack the expertise to implement good distributed algorithms, but this approach also limits the ability of overlay architects to apply future optimizations. The analogous problem for data management was solved by the introduction of SQL, a high-level query language for application development and amenable to optimization. This paper attempts to bridge the gap between current access-oriented p2p systems and relational database management systems (DBMS). We outline how to implement every relational operator needed for SQL queries in the BubbleStorm peer-to-peer overlay. The components of BubbleStorm map surprisingly well to components in a traditional DBMS.

Survey on Location Privacy in Pervasive Computing

The goal of ubiquitous computing research is refine devices to the point where their use is transparent. For many applications with mobile devices, transparent operation requires that the device be locationaware

BubbleStorm: Analysis of Probabilistic Exhaustive Search in a Heterogeneous Peer-to-Peer System

Exhaustive search in large-scale peer-to-peer systems is complicated by heterogeneity, crashes, node churn, hotspots, and weakly structured data. While existing approaches solve some of these problems, the BubbleStorm system offers a naturally integrated and simple solution based on random multigraphs. The simplicity of this mathematical structure allows us to rigorously analyze even the heterogeneous case. We present a new communication primitive, named bubblecast, which induces subgraphs (bubbles) of controlled size. It can incrementally enlarge a bubble, but operates in parallel. Further, the underlying topology deals easily with crashes and node churn as maintenance operations are local, atomic, and minimally disruptive. In spite of this, it preserves the global random structure of a simple permutation. When combined into the BubbleStorm system, bubblecast on this topology performs exhaustive search with adjustable probabilistic guarantees and no hotspots. If every query must rendezvous with every datum, this approach has optimal per-node bandwidth complexity. Indeed, rather than suffering from heterogeneity, it is exploited fully

Channel-based Unidirectional Stream Protocol (CUSP)

Abstract—This paper presents a novel transport protocol, CUSP, specifically designed with complex and dynamic network applications in mind. Peer-to-peer applications benefit in particular, as their requirements are met by neither UDP nor TCP. While other modern transports like SCTP or SST have also tried to combine the advantages of TCP and UDP, CUSP overcomes their technical and conceptual shortcomings. CUSP makes it possible to directly express application logic in the message flow. Modern applications need a mixture of request-response, request-multiple-response, publish-subscribe, and message-passing. All of these operations can be conveniently implemented using CUSP’s unidirectional streams. We separate low-level packet management from streams into reusable channels. A channel connects two applications providing negotiation, congestion control, and cryptography. Developers operate on the stream level, sending messages as reliable and ordered byte-streams. Although they may share a common channel, a stall or loss in one stream does not block the others. I