Recursive Dragonfly: A Massive Interconnection Network with Low Hardware Costs
Yaodong Wang, Yamin Li · 2023
The dragonfly topology has been widely utilized in large-scale interconnection networks due to its scalability and low diameter. However, a large dragonfly system requires a large number of high-radix routers, resulting in high hardware costs. This paper introduces Recursive Dragonfly (RDF) as a solution to overcome this problem. RDF uses a new parameter, n, which represents the number of recurrences in the network. The RDF is constructed based on a recursive approach. For n = 1, RDF acts the same as a traditional dragonfly. For n = 2, each traditional dragonfly network forms a group within the RDF network. In general, for RDF with n ≥ 2, each group can be viewed as an RDF network with n − 1. The new parameter n allows RDF to construct an interconnection network with various diameters and radices. Our evaluation results show that RDF achieves lower hardware costs while maintaining shorter packet latencies compared to the traditional dragonfly network. RDF topology is more suitable for constructing large-scale interconnection networks.