Abstract
We study distributed optimization methods based on the local training (LT) paradigm: achieving communication efficiency by performing richer local gradient-based training on the clients before parameter averaging. Looking back at the progress of the field, we identify 5 generations of LT methods: 1) heuristic, 2) homogeneous, 3) sublinear, 4) linear, and 5) accelerated. The 5th generation, initiated by the ProxSkip method of Mishchenko et al. [2022] and its analysis, is characterized by the first theoretical confirmation that LT is a communication acceleration mechanism. Inspired by this recent progress, we contribute to the 5th generation of LT methods by showing that it is possible to enhance them further using variance reduction. While all previous theoretical results for LT methods ignore the cost of local work altogether, and are framed purely in terms of the number of communication rounds, we show that our methods can be substantially faster in terms of the total training cost than the state-of-the-art method ProxSkip in theory and practice in the regime when local computation is sufficiently expensive. We characterize this threshold theoretically, and confirm our theoretical predictions with empirical results.
Original language | English (US) |
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Title of host publication | Advances in Neural Information Processing Systems 35 - 36th Conference on Neural Information Processing Systems, NeurIPS 2022 |
Editors | S. Koyejo, S. Mohamed, A. Agarwal, D. Belgrave, K. Cho, A. Oh |
Publisher | Neural information processing systems foundation |
ISBN (Electronic) | 9781713871088 |
State | Published - 2022 |
Event | 36th Conference on Neural Information Processing Systems, NeurIPS 2022 - New Orleans, United States Duration: Nov 28 2022 → Dec 9 2022 |
Publication series
Name | Advances in Neural Information Processing Systems |
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Volume | 35 |
ISSN (Print) | 1049-5258 |
Conference
Conference | 36th Conference on Neural Information Processing Systems, NeurIPS 2022 |
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Country/Territory | United States |
City | New Orleans |
Period | 11/28/22 → 12/9/22 |
Bibliographical note
Funding Information:We would like to thank Eduard Gorbunov for useful discussions related to some aspects of the theory.
Publisher Copyright:
© 2022 Neural information processing systems foundation. All rights reserved.
ASJC Scopus subject areas
- Computer Networks and Communications
- Information Systems
- Signal Processing