The interconnect is one of the most critical components in large scale
computing systems, and its impact on the performance of applications is going
to increase with the system size. In this paper, we will describe Slingshot, an
interconnection network for large scale computing systems. Slingshot is based
on high-radix switches, which allow building exascale and hyperscale
datacenters networks with at most three switch-to-switch hops. Moreover,
Slingshot provides efficient adaptive routing and congestion control
algorithms, and highly tunable traffic classes. Slingshot uses an optimized
Ethernet protocol, which allows it to be interoperable with standard Ethernet
devices while providing high performance to HPC applications. We analyze the
extent to which Slingshot provides these features, evaluating it on
microbenchmarks and on several applications from the datacenter and AI worlds,
as well as on HPC applications. We find that applications running on Slingshot
are less affected by congestion compared to previous generation networks.Comment: To be published in Proceedings of The International Conference for
High Performance Computing Networking, Storage, and Analysis (SC '20) (2020
