Brief announcement: Constructing fault-tolerant overlay networks for topic-based publish/subscribe

We incorporate fault tolerance in designing reliable and scalable overlay networks to support topic-based pub/sub communication. We propose the M in Avg-kTCO problem parameterized by k: use the minimum number of edges to create a k-topic-connected overlay (kTCO) for pub/sub systems, i.e., for each topic the sub-overlay induced by nodes interested in the topic is k-connected. We prove the NP-completeness of M in Avg-kTCO and show a lower-bound for the hardness of its approximation. With regard to M in Avg-2TCO, we present GM2, the first polynomial time algorithm with an approximation ratio. With regards to M in Avg-kTCO, where k ≥ 2, we propose a simple and efficient heuristic algorithm, namely HararyPT, that aligns nodes across different sub-overlays. We experimentally demonstrate the scalability of GM 2 and HararyPT under representative pub/sub workloads.