The Essence of P2P: A Reference Architecture for Overlay Networks

2004

In a peer-to-peer (P2P) system, nodes typically connect to a small set of random nodes (their neighbors), and queries are propagated along these connections. Such query flooding tends to be very expensive. We propose that node connections be influenced by content, so that for example, nodes having many "Jazz" files will connect to other similar nodes. Thus, semantically related nodes form a Semantic Overlay Network (SON). Queries are routed to the appropriate SONs, increasing the chances that matching files will be found quickly, and reducing the search load on nodes that have unrelated content. We have evaluated SONs by using an actual snapshot of musicsharing clients. Our results show that SONs can significantly improve query performance while at the same time allowing users to decide what content to put in their computers and to whom to connect.

Peer-to-Peer Networking …, 2010

While Peer-to-Peer (P2P) model gains significant attention in distributed computing, it is also expected to be a powerful model for information sharing. P2P systems are expected to provide exhaustive reliable computational resources and scalable accessibility. The data management and distribution in such systems requires storage, replication, data modeling, indexing, querying, retrieval, streaming, and topology management. While a lot of data management strategies have been proposed through the last years, these strategies have not been investigated with respect to a common model for P2P systems. However, since the services provided by the P2P systems are so diverse, it is very challenging to come up with a common layer-based model for all P2P systems. In this paper, we firstly propose a conceptual model for P2P systems, and then provide a classification and summary of data management and distribution strategies by referring to this model. The horizontal layers of the model correspond to modules of a P2P system whereas the columns are related to the services provided. The modules include base P2P service, storage, indexing, logical, service, and application modules. The services include security, querying, publish, join/leave, collaboration, and streaming. The paper concludes by providing a comprehensive list of data management and distribution strategies used in the existing P2P systems.

2006

2003

In the P2P community a fundamental distinction is made among unstructured and structured P2P systems for resource location. In unstructured P2P systems in principle peers are unaware of the resources that neighboring peers in the overlay networks maintain. Typically they resolve search requests by flooding techniques. Gnutella [9] is the most prominent example of this class. In contrast, in structured P2P systems peers maintain information about what resources neighboring peers offer.

2005

Research in overlay and P2P networking has been tightly focused on fundamentals in the last few years, leading to developments on a range of important issues. The time has come to integrate these insights into existing and new systems. We see this as a vital part of the effort to influence the development of Internet services and arrive at a generalized architecture within which to design and construct overlay and P2P systems. This paper analyzes deployed P2P systems in the public and research arenas providing a taxonomy of issues and research. The paper then discusses the roles of overlays, P2P applications and network infrastructure and argues for a multi-dimensional view of systems development to describe the inter-relationships between these components. The parametric space in which one defines the role of a P2P application depends on the level of complexity we expect in that application, in comparison to the richness of the services provided by overlays and the network core.

Proceedings. Second International Conference on Peer-to-Peer Computing,, 2002

The Peer-To-Peer (P2P) computing paradigm is an emerging paradigm that aims to overcome most of the main limitations of the traditional client/server architecture. In the P2P setting, individual computers communicate directly with each other in order to share information and resources without relying on any kind of centralized server. To achieve this full decentralization, an application-level (or overlay) network is constructed using, for example, TCP connections.

Computer Communications, 2008

Modeling peer-to-peer (P2P) networks is a challenge for P2P researchers. In this paper, we provide a detailed analysis of large-scale hybrid P2P overlay network topology, using Gnutella as a case study. First, we re-examine the power-law distributions of the Gnutella network discovered by previous researchers. Our results show that the current Gnutella network deviates from the earlier power-laws, suggesting that the Gnutella network topology may have evolved a lot over time. Second, we identify important trends with regard to the evolution of the Gnutella network between September 2005 and February 2006. Upon analyzing the limitations of the power-laws, we provide a novel two-layered approach to study the topology of the Gnutella network. We divide the Gnutella network into two layers, namely the mesh and the forest, to model the hybrid and highly dynamic architecture of the current Gnutella network. We give a detailed analysis of the two-layered overlay and present six power-laws and one empirical law to characterize the topology. Using the two-layered approach and laws proposed, realistic topologies can be generated and the realism of artificial topologies can be validated.

Lecture Notes in Computer Science, 2009

Structured peer-to-peer (P2P) overlay are scalable, robust and selforganizing in nature, and provide a promising platform for a range of largescale distributed applications. Applications proposed to date utilize a similar key-based routing service but "re-invent the wheel" by deploying their own dedicated structured P2P overlay network. This is highly inefficient and results in a significant duplication of work in terms of development, deployment and maintenance of the overlays. To address this problem, we propose a PROgrammable STructured P2P infrastructure (PROST), which allows the dynamic and incremental deployment of multiple applications over a single structured P2P overlay. In this paper, we outline the PROST architecture and discuss the implementation of our prototype.

ACM SIGCOMM Computer Communication Review, 2003

The success of a P2P file-sharing network highly depends on the scalability and versatility of its search mechanism. Two particularly desirable search features are scope (ability to find infrequent items) and support for partial-match queries (queries that contain typos or include a subset of keywords). While centralized-index architectures (such as Napster) can support both these features, existing decentralized architectures seem to support at most one: prevailing protocols (such as Gnutella and FastTrack) support partial-match queries, but since search is unrelated to the query, they have limited scope. Distributed Hash Tables (such as CAN and CHORD) constitute another class of P2P architectures promoted by the research community. DHTs couple index location with the item's hash value and are able to provide scope but can not effectively support partialmatch queries; another hurdle in DHT deployment is their tight control the overlay structure and data placement which makes them more sensitive to failures.

The Journal of Supercomputing, 2009

Traditional Peer-to-Peer (P2P) systems were restricted to sharing of files on the Internet. Although some of the more recent P2P distributed systems have tried to support transparent sharing of other types of resources, like computer processing power, but none allow and support sharing of all types of resources available on the Internet. This is mainly because the resource management part of P2P systems are custom designed in support of specific features of only one type of resource, making simultaneous access to all types of resources impractical. Another shortcoming of existing P2P systems is that they follow a client/server model of resource sharing that makes them structurally constrained and dependent on dedicated servers (resource managers). Clients must get permission from a limited number of servers to share or access resources, and resource management mechanisms run on these servers. Because resource management by servers is not dynamically reconfigurable, such P2P systems are not scalable to the ever growing extent of Internet. We present an integrated framework for sharing of all types of resources in P2P systems by using a dynamic structure for managing four basic types of resources, namely process, file, memory, and I/O, in the same way they are routinely managed by operating systems. The proposed framework allows P2P systems to use dynamically reconfigurable resource management mechanisms where each machine in the P2P system can at the same time serve both as a server and as a client. The pattern of requests for shared resources at a given time identifies which machines are currently servers and which ones are currently clients. The client server pattern changes with changes in the pattern of requests for distributed resources. Scalable P2P systems with dynamically M. Sharifi ( ) • S.