Synapse: A Scalable Protocol for Interconnecting Heterogeneous Overlay Networks

Abstract

Abstract. This paper presents Synapse, a scalable protocol for information retrieval over the inter-connection of heterogeneous overlay networks. Applications on top of Synapse see those intra-overlay networks as a unique inter-overlay network. Scalability in Synapse is achieved via co-located nodes, i.e. nodes that are part of multiple overlay networks at the same time. Co-located nodes, playing the role of neural synapses and connected to several overlay networks, allow a larger search area and provide alternative routing. Synapse can either work with "open" overlays adapting their protocol to synapse interconnection requirements, or with "closed" overlays that will not accept any change to their protocol. Results from simulation and experiments show that Synapse is scalable, with a communication and state overhead scaling similarly as the networks interconnected. Thanks to alternate routing paths, Synapse also gives a practical solution to network partitions. We precisely capture the behavior of traditional metrics of overlay networks within Synapse and present results from simulations as well as some actual experiments of a client prototype on the Grid'5000 platform. The prototype developed implements the Synapse protocol in the particular case of the interconnection of many Chord overlay networks.

Analyzing the exhaustiveness of the Synapse protocol

“…As the Synapse protocol is not fully exhaustive [5] and its underlying structure depends on the protocols of all overlay networks participating in the system, in this section we restrict ourselves to extending [9] by presenting only a specification of the Synapse protocol in ASM.…”

“…Where the settings of the experiment and simulation corresponds the setting of a theorem we will use the results of obtained in [5].…”

“…One of the possible solutions for the inter-connection of heterogeneous overlay networks is the Synapse protocol, introduced in [2], [5] and [8]. It is a generic and flexible metaprotocol that provides simple mechanisms and algorithms for easy interconnection of overlay networks.…”

Interconnection of Large Scale Unstructured P2P Networks: Modeling and Analysis

“…In this paper, we consider the interconnection of large-scale unstructured P2P networks by means of special nodes called Synapses [1], which are co-located in more than one network, and act as connectors by sending or forwarding a query to some or all the P2P networks they belong to. Modeling and analysis of the resulting interconnected system is crucial to design e cient and e↵ective search algorithms and to control the cost of network interconnection.…”

An Extension and Cooperation Mechanism for Heterogeneous Overlay Networks

“…In [12], we have introduced a protocol, which we have named Synapse, capable of interconnecting heterogeneous overlays through utilization of co-located nodes as distributed gateways. This protocol was further explored and improved in [17], resulting in the Synapse Framework, which consists of the related Synapse protocol, software architecture, libraries in the OverSim simulator [3], and a peer client written in Java.…”