Comparing Global Link Arrangements for Dragonfly Networks
Comparing Global Link Arrangements for Dragonfly Networks
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DOI：
10.1109/cluster.2015.57
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
Emily M. Hastings;David Rincon-Cruz;Marc Spehlmann;S. Meyers;Anda Xu;David P. Bunde;V. Leung
中科院分区：
文献类型：
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作者：
Emily M. Hastings;David Rincon-Cruz;Marc Spehlmann;S. Meyers;Anda Xu;David P. Bunde;V. Leung
高性能计算系统正在从传统的互连拓扑转移到利用新技术并降低互连功耗。Dragonfly拓扑是新系统的一个有前途的候选者，已经有几个变体在生产中。它是分层的，本地链接组成组，全局链接加入组。在每一级，互连是一个集团，在组中的每对交换机之间有一条链路，在每对组之间有一条链路。本文表明，群体间的联系可以有意义的不同方式。我们评估三个以前提出的方法链接组织（称为全球链接安排）在两个方面。首先，我们使用二等分带宽，这是一种重要且常用的通信瓶颈潜在度量。我们发现，全球链路的安排往往给平分带宽不同的百分之十，与特定的分离不同的基础上的相对带宽的本地和全球的链接。对于当前Dragonfly实现中使用的链路带宽，它是33%。其次，我们表明，全球链接安排的选择可以极大地影响最近邻模板通信模式，在科学应用中的一个重要模式的任务映射的规律性。
High-performance computing systems are shifting away from traditional interconnect topologies to exploit new technologies and to reduce interconnect power consumption. The Dragonfly topology is one promising candidate for new systems, with several variations already in production. It is hierarchical, with local links forming groups and global links joining the groups. At each level, the interconnect is a clique, with a link between each pair of switches in a group and a link between each pair of groups. This paper shows that the intergroup links can be made in meaningfully different ways. We evaluate three previously-proposed approaches for link organization (called global link arrangements) in two ways. First, we use bisection bandwidth, an important and commonly-used measure of the potential for communication bottlenecks. We show that the global link arrangements often give bisection bandwidths differing by 10s of percent, with the specific separation varying based on the relative bandwidths of local and global links. For the link bandwidths used in a current Dragonfly implementation, it is 33%. Second, we show that the choice of global link arrangement can greatly impact the regularity of task mappings for nearest neighbor stencil communication patterns, an important pattern in scientific applications.