A peer-to-peer system for on-demand sharing of capacity across network applications Georgios Exarchakos & Nick Antonopoulos Received: 14 March 2009 / Accepted: 24 August 2011 / Published online: 6 September 2011 # Springer Science+Business Media, LLC 2011 Abstract As a plethora of various distributed applications emerge, new computing platforms are necessary to support their extra and sometimes evolving requirements. This research derives its motive from deficiencies of real networked applications deployed on platforms unable to fully support their characteristics and proposes a network architecture to address that issue. Hoverlay is a system that enables logical movement of nodes from one network to another aiming to relieve requesting nodes, which experi- ence high workload. Node migration and dynamic server overlay differentiate Hoverlay from Condor-based architec- tures, which exhibit more static links between managers and nodes. In this paper, we present a number of important extensions to the basic Hoverlay architecture, which collectively enhance the degree of control owners have over their nodes and the overall level of cooperation among servers. Furthermore, we carried out extensive simulations, which proved that Hoverlay outperforms Condor and Flock of Condors in both success rate and average successful query path length at a negligible increase in messages. Keywords Peer-to-peer . Computational resource sharing . Resource migration . Keyword-based control 1 Introduction Heterogeneous distributed applications deployed on differ- ent networks may have quite variable network throughput performance requirements during their lifetime. We define the Network Capacity as the number of user queries a node can process within a time unit. The Network Capacity depends on the combined communication and computation throughput of that node. In case the application’ s workload overcomes the available network capacity (overloaded situation), new nodes are required to join the network to serve the demand. On the contrary, when the application produces traffic that fewer nodes could efficiently serve (underloaded situation) the network application may free some of them and increase the remaining nodes’ utilization. Hoverlay is a P2P management system that enables the sharing of reusable resources and specifically network capacity. Network capacity is a non-replicable, reusable, stochastically available resource and only one instance of it may exist within a network and no more than one user may use it each time [1]. This architecture facilitates the cooperation of heterogeneous networks for improving the utilization of the spare (currently not used) capacity in the whole system. The overlay consists of a set of interconnected servers each of which represents the nodes of an underlying network. In this paper we extend the CSOA model presented in [2] with a detailed presentation of the resource matching functionality of servers and with a mechanism for an improved server collaboration based on keyword-driven description of underlying applications. Moreover, this paper builds on top of [2] with an extensive evaluation section comparing Hoverlay with competitive systems. That model, CSOA, was named after the initials of a phrase describing G. Exarchakos : N. Antonopoulos University of Surrey, Surrey GU2 7XH, Guildford, UK N. Antonopoulos e-mail: n.antonopoulos@surrey.ac.uk G. Exarchakos (*) Electrical Engineering, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands e-mail: g.exarchakos@tue.nl Peer-to-Peer Netw. Appl. (2012) 5:58–73 DOI 10.1007/s12083-011-0108-4