Thicket: A Protocol for Building and Maintaining Multiple Trees in a P2P Overlay (original) (raw)

Jelly: a dynamic hierarchical P2P overlay network with load balance and locality

24th International Conference on Distributed Computing Systems Workshops, 2004. Proceedings., 2004

P2P systems based on Distributed hash table (DHT) such as CAN, Chord, Pastry, and Tapestry, use uniform hash functions to ensure load balance in each participant nodes. But the evenly distributed behavior in the virtual space destroys the locality between participant nodes. The topology-based hierarchical overlay network like Grapes, exploits the physical distance information among the nodes to construct a two-layered hierarchy, highly improves the locality, but damages the load balance property in original DHTs. In this paper, we propose a dynamic P2P overlay infrastructure, called Jelly. It can achieve both the load balancing and locality properties. Its design is based on the hierarchical overlay and uses the DHT as its routing algorithm. Because the load balancing issue in a hierarchical overlay is originated from whether the virtual hierarchy is balanced or not, Jelly uses a node joining mechanism as a fine-tuning tool and a dynamic checking mechanism as a coarse-tuning tool to balance the hierarchy. We also find that the average routing hops is a practical metric to evaluate the network size, and it is useful for Jelly's dynamic mechanism.

Build One, Get One Free: Leveraging the Coexistence of Multiple P2P Overlay Networks

27th International Conference on Distributed Computing Systems (ICDCS '07), 2007

Many different P2P overlay networks providing various functionalities, targeting specific applications, have been proposed in the past five years. It is now reasonable to consider that multiple overlays may be deployed over a large set of nodes so that the most appropriate overlay might be chosen depending on the application. A physical peer may then host several instances of logical peers belonging to different overlay networks. In this paper, we show that the coexistence of a structured P2P overlay and an unstructured one may be leveraged so that, by building one, the other is automatically constructed as well 1 . More specifically, we show that the randomness provided by an unstructured gossip-based overlay can be used to build the routing table of a structured P2P overlay and the randomness in the numerical proximity links in the structured networks provides the random peer sampling required by gossip-based unstructured overlays. In this paper, we show that maintaining the leaf set of Pastry and the proximity links of an unstructured overlay is enough to build the complete overlays. Simulation results comparing our approach with both a Pastry-like system and a gossip-based unstructured overlay show that we significantly reduce the overlay maintenance overhead without sacrificing the performance.

Performance and Dependability of Structured Peer-to-Peer Overlays

2004

Structured peer-to-peer (p2p) overlay networks provide a useful substrate for building distributed applications. They map object keys to overlay nodes and offer a primitive to send a message to the node responsible for a key. They can implement, for example, distributed hash tables and multicast trees. However, there are concerns about the performance and dependability of these overlays in realistic environments. Several studies have shown that current p2p environments have high churn rates: nodes join and leave the overlay continuously. This paper presents techniques that continuously detect faults and repair the overlay to achieve high dependability and good performance in realistic environments. The techniques are evaluated using large-scale network simulation experiments with fault injection guided by real traces of node arrivals and departures. The results show that previous concerns are unfounded; our techniques can achieve dependable routing in realistic environments with an average delay stretch below two and a maintenance overhead of less than half a message per second per node.

Scaling Unstructured Peer-to-Peer Networks With Multi-Tier Capacity-Aware Overlay Topologies

The peer to peer (P2P) file sharing systems such as Gnutella have been widely acknowledged as the fastest growing Internet applications ever. The P2P model has many potential advantages due to the design flexibility of overlay networks and the serverless management of cooperative sharing of information and resources. However, these systems suffer from the well-known performance mismatch between the randomly constructed overlay network topology and the underlying IP layer topology for packet routing. This paper proposes to structure the P2P overlay topology using a capacity-aware multi-tier topology to better balance load at peers with heterogeneous capacities and to prevent low capacity nodes from downgrading the performance of the system. An analytical model is developed to enable us to construct and maintain capacity-aware overlay topologies with good node connectivity and better load balance. To study the benefits and cost of the multi-tier capacity aware topology with respect to basic and advanced routing protocols, we also develop a probabilistic broadening scheme for efficient routing, which further utilizes capacity-awareness to enhance the P2P routing performance of the system. We evaluate our design through simulations. The results show that our multi-tier topologies alone can provide eight to ten times improvements in the messaging cost, two to three orders of magnitude improvement in terms of load balancing characteristics, and seven to eight times lower topology construction and maintenance costs when compared to Gnutellas random power-law topology.

A Framework for Structured Peer-to-Peer Overlay Networks

Lecture Notes in Computer Science, 2005

Structured peer-to-peer overlay networks have recently emerged as good candidate infrastructure for building novel large-scale and robust Internet applications in which participating peers share computing resources as equals. In the past three year, various structured peer-to-peer overlay networks have been proposed, and probably more are to come. We present a framework for understanding, analyzing and designing structured peer-to-peer overlay networks. The main objective of the paper is to provide practical guidelines for the design of structured overlay networks by identifying a fundamental element in the construction of overlay networks: the embedding of k−ary trees. Then, a number of effective techniques for maintaining these overlay networks are discussed. The proposed framework has been effective in the development of the DKS system, whose preliminary design appears in .

TreeP: A Self-reconfigurable Topology for Unstructured P2P Systems

Lecture Notes in Computer Science

We present an efficient and robust network topology for managing distributed resources in P2P-Grid environments. This topology is called TreeP and exploits both features of P2P and grid computing models. It uses P2P properties in looking for available resources, while using Grid properties for optimizing communications and computations on a distributed computing platform. Here, we study this virtual topology both theoretically and experimentally. We show that this topology is very scalable, robust, load-balanced, and easy to construct and maintain.

Distributed message routing in unstructured P2P network overlays

The IEEE Region 8 EUROCON 2003. Computer as a Tool., 2003

The paper presents an alternative message routing approach in unstructured peer-to-peer overlay networks. Unstructured peer-to-peer systems are loosely coupled, highly autonomous systems without hierarchy. Usually, flooding-based routing mechanisms are used for sending messages through the application layer overlay. Due to the limited scalability and high network load experiences, the paper suggests an improvement to reduce the traffic and overall performance: a peer remembers recently forwarded answers, so that he may route the next query messages with the same contents only to the relevant neighbor, not to all of them. Preliminary network simulations have shown promising results.