Structure Management for Scalable Overlay Service Construction

This paper explores the model of providing a common overlay structure management layer to assist the construction of large-scale wide-area Internet services. To this end, we propose Saxons, a distributed software layer that dynamically maintains a selected set of overlay links for a group of nodes. Saxons maintains high-quality overlay structures with three performance objectives: low path latency, low hop-count distance, and high path bandwidth. Additionally, it provides partition repair support for the overlay structure. Saxons targets large self-organizing services with high scalability and stability requirements. Services can directly utilize the Saxons structure for overlay communication. Saxons can also benefit unicast or multicast overlay path selection services by providing them a small link selection base without hurting their performance potential. Our simulations and experiments on 55 PlanetLab sites demonstrate Saxons’s structure quality and the performance of Saxons-based service construction. In particular, a simple overlay multicast service built on Saxons provides nearloss-free data delivery to 4 times more multicast receivers compared with the same multicast service running on random overlay structures. Our experiments also show that this performance is close to that of direct Internet unicast without simultaneous traffic.