PromisQoS: an architecture for delivering QoS to high-performance applications on Myrinet clusters

Clusters of workstations are being extensively used for solving computationally intensive scientific problems. However, there is limited support for quality of service (QoS) based distributed computing on commercial off- the-shelf (COTS) clusters. This limitation has restricted successful deployment of distributed real-time high-performance computing applications to customized and dedicated embedded multi-processor systems. This paper describes research work that attempts to provide a cluster platform that can guarantee access to computational and communication resources to distributed applications. The authors have developed PromisQoS, an architecture that supports execution of hard real-time distributed applications on a Linux cluster while providing high-throughput and low-latency communication using Myrinet. PromisQoS consists of the following major components - Hare, BDM-RT and Turtle. Hare is a prototype implementation of time-based QoS channels specified by the real-time message passing interface (MPI/RT 1.1) standard. BDM-RT is a low-level messaging library on Myrinet that provides deterministic communication latency and bandwidth on Myrinet. Turtle, a variant of RT-Linux, is the real-time operating system that provides guaranteed computation time. This work demonstrates that it is possible to deploy hard real-time distributed applications on COTS clusters and underlines the significance of the MPI/RT API in the realm of distributed high-performance computing applications that require QoS.