MOSAIC: Declarative platform for dynamic overlay composition

Overlay networks create new networking services using nodes that communicate using pre-existing networks. They are often optimized for specific applications and targeted at niche vertical domains, but lack interoperability with which their functionalities can be shared. Mosaic is a declarative platform for constructing new overlay networks from multiple existing overlays, each possessing a subset of the desired new network’s characteristics.This paper focuses on the design and implementation of Mosaic: composition and deployment of control and/or data plane functions of different overlay networks, dynamic compositions of overlay networks to meet changing application needs and network conditions, and seamless support for legacy applications. Mosaic overlays are specified using Mozlog, a new declarative language for expressing overlay properties independently from their particular implementation or underlying network.Mosaic is validated experimentally using compositions specified in Mozlog in order to create new overlay networks with compositions of their functions: the i3 indirection overlay that supports mobility, the resilient overlay network (RON) overlay for robust routing, and the Chord distributed hash table for scalable lookups. Mosaic uses runtime composition to simultaneously deliver application-aware mobility, NAT traversal and reliability. We further demonstrate Mosaic’s dynamic composition capabilities by Chord switching its underlay from IP to RON at runtime.Mosaic’s benefits are obtained at a low performance cost, as demonstrated by measurements on both a local cluster environment and the PlanetLab global testbed.