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Title: LESS: A Matrix Split and Balance Algorithm for Parallel Circuit (Optical) or Hybrid Data Center Switching and More
The research problem of how to use a high-speed circuit switch, typically an optical switch, to most effectively boost the switching capacity of a datacenter network, has been extensively studied. In this work, we focus on a different but related research problem that arises when multiple (say $s$) parallel circuit switches are used: How to best split a switching workload $D$ into sub-workloads $D_1, D_2, ..., D_s$, and give them to the $s$ switches as their respective workloads, so that the overall makespan of the parallel switching system is minimized? Computing such an optimal split is unfortunately NP-hard, since the circuit/optical switch incurs a nontrivial reconfiguration delay when the switch configuration has to change. In this work, we formulate a weaker form of this problem: How to minimize the total number of nonzero entries in $D_1, D_2, ..., D_s$ (so that the overall reconfiguration cost can be kept low), under the constraint that every row or column sum of $D$ (which corresponds to the workload imposed on a sending or receiving rack respectively) is evenly split? Although this weaker problem is still NP-hard, we are able to design LESS, an approximation algorithm that has a low approximation ratio of only $1+\epsilon$ more » in practice and a low computational complexity of only $O(m^2)$, where $m = \|D\|_0$ is the number of nonzero entries in $D$. Our simulation studies show that LESS results in excellent overall makespan performances under realistic datacenter traffic workloads and parameter settings. « less
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Award ID(s):
1909048 1717947
Publication Date:
Journal Name:
IEEE/ACM 12th International Conference on Utility and Cloud Computing (UCC'19), December 2--5, 2019, Auckland, New Zealand
Page Range or eLocation-ID:
187 to 197
Sponsoring Org:
National Science Foundation
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