Mitigating Inter-Job Interference Using Adaptive Flow-Aware Routing
Staci A. Smith, Clara E. Cromey, David K. Lowenthal, Jens Domke, Nikhil Jain, Jayaraman J. Thiagarajan, Abhinav Bhatelé · 2018
On most high performance computing platforms, concurrently executing jobs share network resources. This sharing can lead to inter-job network interference, which can have a significant impact on the performance of communication-intensive applications. No satisfactory solutions yet exist for mitigating such performance degradation on systems that allow jobs to share the network for the sake of higher utilization. In this paper, we analyze network congestion caused by multi-job workloads on two production systems that use popular network topologies-fat-tree and dragonfly. For each system, we establish a regression model to relate network hotspots to application performance degradation. The models show that current routing strategies are ineffective at balancing network traffic and mitigating interference on production systems. We propose an alternative routing strategy, which we call adaptive flow-aware routing. We implement our strategy on a fat-tree system, and tests on the system show up to a 46% improvement in job run time when compared to the default routing.