The Ohio Society of CPAs
Large scale InfiniBand clusters are becoming increasingly popular, as reflected by the TOP 500 supercomputer rankings. At the same time, fat tree has become a popular interconnection topology for these clusters, since it allows multiple paths to be available in between a pair of nodes. However, even with fat tree, hot-spots may occur in the network depending upon the route configuration between end nodes and communication patterns in the application. To make matters worse, the deterministic routing natures of InfiniBand limits the application from effective use of multiple paths transparently and avoid the hot-spots in the network.