A new routing scheme for jellyfish and its performance with HPC workloads

The jellyfish topology where switches are connected using a random graph has recently been proposed for large scale data-center networks. It has been shown to offer higher bisection bandwidth and better permutation throughput than the corresponding fat-tree topology with a similar cost. In this work, we propose a new routing scheme for jellyfish that out-performs existing schemes by more effectively exploiting the path diversity, and comprehensively compare the performance of jellyfish and fat-tree topologies with HPC workloads. The results indicate that both jellyfish and fat-tree topologies offer comparable high performance for HPC workloads on systems that can be realized by 3-level fat-trees using the current technology and the corresponding jellyfish topologies with similar costs. Fat-trees are more effective for smaller systems while jellyfish is more scalable.