A Comparative Study of Topology Design Approaches for HPC Interconnects
A Comparative Study of Topology Design Approaches for HPC Interconnects
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HPC 互连拓扑设计方法的比较研究
DOI：
10.1109/ccgrid.2018.00066
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Lang
中科院分区：
文献类型：
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作者：
Md Atiqul Mollah;Peyman Faizian;Md. Shafayat Rahman;Xin Yuan;S. Pakin;M. Lang
目前高性能计算系统的互连拓扑设计主要有两个方向，一个是低直径互连，另一个是高路径分集互连。低直径设计侧重于构建具有小直径的大型网络，确保每对节点之间有一条短路径。例子包括Slim Fly和Dragonfly。高路径多样性设计不仅考虑了其他拓扑度量，如直径，而且还考虑了节点对之间的路径多样性。例子包括胖树，随机正则图（RRG）和广义德布鲁因图（GDBG）。从这两种方法设计的拓扑结构具有不同的功能，需要非常不同的路由方案，以利用网络容量。在这项工作中，我们研究了两种设计方法，包括超薄飞，蜻蜓，RRG，和GDBG的代表性拓扑结构的性能相关的拓扑特征，并比较HPC应用程序的性能在这些拓扑结构与一组路由方案。这项研究揭示了新的知识，这两种方法设计的拓扑结构。研究结果包括：（1）为低直径拓扑设计的负载平衡路由技术，称为通用全局自适应负载平衡路由（UGAL），可以有效地适应高路径分集拓扑，以及（2）对于由类似数量的相同类型的交换机构建的网络，高路径分集拓扑通常比低直径拓扑实现更高的性能。
The recent interconnect topology designs for High Performance Computing (HPC) systems have followed two directions, one characterized by low diameter and the other by high path diversity. The low diameter design focuses on building large networks with small diameters, guaranteeing one short path between each pair of nodes. Examples include Slim Fly and Dragonfly. The high path diversity design takes into account not only other topological metrics such as diameter but also path diversity between pairs of nodes. Examples include fat-tree, Random Regular Graph (RRG) and Generalized De Bruin Graph (GDBG). Topologies designed from these two approaches have distinct features and require very different routing schemes to exploit the network capacity. In this work, we study the performance-related topological features of representative topologies of the two design approaches, including Slim Fly, Dragonfly, RRG, and GDBG, and compare HPC application performance on these topologies with a set of routing schemes. The study uncovers new knowledge about the topologies designed by these two approaches. Findings of the study include (1) the load balance routing technique designed for low diameter topologies, known as the Universal Globally Adaptive Load-balanced routing (UGAL), can be effectively adapted for the high path diversity topologies, and (2) high path diversity topologies in general achieve higher performance than low diameter topologies for networks built by a similar number of the same type of switches.