Designing and Evaluating MPI-2 Dynamic Process Management Support for InfiniBand

Dynamic process management is a feature of MPI-2 that allows an MPI process to create new processes and manage communication with these processes. The dynamic creation of processes allows application writers to develop multiscale applications or master/worker based programs. Although several MPI implementations support this feature we are not aware of any studies on the issues in designing the dynamic process management interface and benchmarking of dynamic process framework. In this paper we design a MPI-2 dynamic process management interface over InfiniBand. We consider two alternative designs using Unreliable Datagram (UD) and Reliable Connection (RC) transport modes of InfiniBand with two job startup models. In our evaluations we found that having an UD based-design allows for much higher spawns rates with existing job launch frameworks. We also design a set of micro-benchmarks to evaluate the performance of our design and other MPI libraries. Finally, we provide an evaluation of the dynamic process framework using a re-designed ray-tracing application.