Combining OpenFabrics Software and Simulation Tools for Modeling InfiniBand-Based Interconnection Networks

Abstract

The design of interconnection networks is becoming extremely important for High-Performance Computing (HPC) systems in the Exascale Era. Design decisions like the selection of the network topology, routing algorithm, fault tolerance and/or congestion control are crucial for the network performance. Besides, the interconnection network designers are also focused on creating middleware layers compatible to different network technologies, which make it possible for these technologies to interoperate. One example is the OpenFabrics Software (OFS) used in HPC for breakthrough applications that require high efficiency computing, wire-speed messaging, microsecond latencies and fast I/O for storage and file systems. OFS is compatible with several HPC interconnect technologies, like InfiniBand, iWarp or RoCE. One challenge in the design of new features for improving the interconnection network performance is to model in specific simulation tools the latency introduced by the OFS modules into the network traffic. In this paper, we present a work-in-progress methodology to combine the OFS middleware with OMNeT++-based simulation tools, so that we can use some of the OFS modules, like OpenSM or ibsim, combined with simulation tools. We also propose a set of tools for analyzing the properties of different network topologies. Future work will consist on modeling other OFS modules functionality in network simulators.