Enhancing fault tolerance capabilities in quorum-based cycle routing

Abstract

In this paper we propose a generalized R redundancy cycle technique that provides optical networks almost fault-tolerant communications. More importantly, when applied using only single cycles rather than the standard paired cycles, the generalized R redundancy technique is shown to almost halve the necessary light-trail resources in the network while maintaining the fault-tolerance and dependability expected from cycle-based routing. For efficiency and distributed control, it is common in distributed systems and algorithms to group nodes into intersecting sets referred to as quorum sets. Optimal communication quorum sets forming optical cycles based on light-trails have been shown to flexibly and efficiently route both point-to-point and multipoint-to-multipoint traffic requests. Commonly cycle routing techniques will use pairs of cycles to achieve both routing and fault-tolerance, which uses substantial resources and creates the potential for underutilization. Instead, we intentionally utilize R redundancy within the quorum cycles for fault-tolerance such that every point-to-point communication pairs occur in at least R cycles. The result is a set of R = 3 redundant cycles with 93.23-99.34% fault coverage even with two simultaneous faults all while using 38.85-42.39% fewer resources.Comment: 7th International Workshop on Reliable Networks Design and Modeling, 5-7 Oct. 2015. arXiv admin note: substantial text overlap with arXiv:1608.05170, arXiv:1608.0516

Unidirectional Quorum-Based Cycle Planning for Efficient Resource Utilization and Fault-Tolerance

“…It was observed in [2] that the quorum-based cycle routing solution had some node pairings occurring together in multiple cycles and it was proposed that these could be used for load balancing. As an alternative to that option, [5] added a requirement that every pair (e i , e j ) would occur together within at least R quorums rather than just one. Exploiting the natural occurrence of redundant pairs is an attempt to eliminate the need for paired cycles, thus moving the redundancy from the paired cycles and putting the redundancy in the quorums.…”

“…In this section we define R redundant cyclic quorums sets as proposed in [5]. Quorum-based cycle routing solutions used cyclic quorums to form a set of communication cycles which were shown to be almost fault tolerant in fiber optic networks [2], [4].…”

“…These can be used to eliminate the paired cycle implementations and use only a single cycle, significantly reducing the required amount of network resources while still maintaining a similar level of fault-tolerance. Our work reported in [5] examined this approach.…”

“…Fault tolerance of optical networks with quorum-based cycle routing has been analyzed [4]. Observing communication pairs were being protected by more than one cycle, R redundancy quorums were used to improve resource efficiency [5]. Resource efficiency can come at a cost and in this research, we propose a heuristic to improve the redundant quorum cycle routing techniques.…”

Efficient computation and communication management for all-pairs interactions

“…When we applied R redundant cyclic quorums to the state of the art paired cycle techniques, it guaranteed all network communication pairs appeared R times within a routed cycle set [Kleinheksel and Somani (2015a)]. The results showed optical networks achieving near faulttolerance with 98.65 -99.91% and 99.04 -99.95% fault coverage rates respectively on the two simultaneous faults simulation.…”