Mitigating Inter-Job Interference via Process-Level Quality-of-Service

Jobs on most high-performance computing (HPC) systems share the network with other concurrently executing jobs. This sharing creates contention that can severely degrade performance. We investigate the use of Quality of Service (QoS) mechanisms to reduce the negative impacts of network contention. Our results show that careful use of QoS reduces the impact of contention for specific jobs, resulting in up to a 27% performance improvement. In some cases the impact of contention is completely eliminated. These improvements are achieved with limited negative impact to other jobs; any job that experiences performance loss typically degrades less than 5%, often much less. Our approach can help ensure that HPC machines maintain high throughput as per-node compute power continues to increase faster than network bandwidth.