Making The Network Scalable: Inter-Subnet Routing In Infiniband

As InfiniBand clusters grow in size and complexity, the need arises to segment the network into manageable sections. Up until now, InfiniBand routers have not been used extensively and little research has been done to accommodate them. However, the limits imposed on local addressing space, inability to logically segment fabrics, long reconfiguration times for large fabrics in case of faults, and, finally, performance issues when interconnecting large clusters, have rekindled the industry's interest into IB-IB routers. In this paper, we examine the routing problems that exist in the current implementation of OpenSM and we introduce two new routing algorithms for inter-subnet IB routing. We evaluate the performance of our routing algorithms against the current solution and we show an improvement of up to 100 times that of OpenSM.