Comet: a scalable coordination space for decentralized distributed environments

The scale, heterogeneity, and dynamism of emerging distributed and decentralized environments make coordination a significant and challenging problem. In this paper we present Comet, a scalable peer-to-peer content-based coordination space. Comet provides a global virtual shared-space that can be associatively accessed by all peer nodes in the system, and access is independent of the physical location of the tuples or identifiers of the host. Dynamically constructed, transient coordination spaces are also supported to enable context locality to be explicitly exploited for improving system performance. The design, implementation, and experimental evaluation of Comet using the PlanetLab platform are presented.