Evaluation of Topology-Aware Broadcast Algorithms for Dragonfly Networks
Two-tiered direct network topologies such as Dragonflies have been proposed for future post-petascale and exascale machines, since they provide a high-radix, low-diameter, fast interconnection network. Such topologies call for redesigning MPI collective communication algorithms in order to attain the best performance. Yet as increasingly more applications share a machine, it is not clear how these topology-aware algorithms will react to interference with concurrent jobs accessing the same network. In this paper, we study three topology-aware broadcast algorithms, including one designed by ourselves. We evaluate their performance through event-driven simulation for small- and large-sized broadcasts (in terms of both data size and number of processes). We study the effect of different routing mechanisms on the topology-aware collective algorithms, as well as their sensitivity to network contention with other jobs. Our results show that while topology-aware algorithms dramatically reduce link utilization, their advantage in terms of latency is more limited.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science - Office of Advanced Scientific Computing Research
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1366302
- Resource Relation:
- Conference: 2016 Institute of Electrical and Electronics Engineers Cluster, 09/12/16 - 09/16/16, Taipei, TW
- Country of Publication:
- United States
- Language:
- English
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