FT-RUFT: A Performance and Fault-Tolerant Efficient Indirect Topology

Although performance is a key design issue of interconnection networks, fault-tolerance is becoming more important due to the large amount of components of large machines. In this paper, we focus on designing a simple indirect topology with both good performance and fault-tolerance properties. The idea is to take full advantage of the network resources consumed by the topology. To do that, starting from the RUFT topology, which is a simple UMIN topology that does not tolerate any link fault, we first duplicate injection and ejection links connecting these extra links in a particular way. The resulting topology tolerates 3 network link faults and also slightly increases performance with marginal increase in the network hardware cost. Most important, contrary to most of the available topologies, the topology is able to tolerate also faults in the links that connect to end-nodes. We also propose another topology that also duplicates network links, achieving 2x performance improvements and tolerating up to 7 network link faults. These results are better than the ones obtained by a BMIN with a similar amount of resources.