Coordinated Replay Sample Selection for Continual Federated Learning
Jack Good, Jimit Majmudar, Christophe Dupuy, Jixuan Wang, Charith Peris, Clement Chung, Richard Zemel, Rahul Gupta
Abstract
Continual Federated Learning (CFL) combines Federated Learning (FL), the decentralized learning of a central model on a number of client devices that may not communicate their data, and Continual Learning (CL), the learning of a model from a continual stream of data without keeping the entire history. In CL, the main challenge is forgetting what was learned from past data. While replay-based algorithms that keep a small pool of past training data are effective to reduce forgetting, only simple replay sample selection strategies have been applied to CFL in prior work, and no previous work has explored coordination among clients for better sample selection. To bridge this gap, we adapt a replay sample selection objective based on loss gradient diversity to CFL and propose a new relaxation-based selection of samples to optimize the objective. Next, we propose a practical algorithm to coordinate gradient-based replay sample selection across clients without communicating private data. We benchmark our coordinated and uncoordinated replay sample selection algorithms against random sampling-based baselines with language models trained on a large scale de-identified real-world text dataset. We show that gradient-based sample selection methods both boost performance and reduce forgetting compared to random sampling methods, with our coordination method showing gains early in the low replay size regime (when the budget for storing past data is small).- Anthology ID:
- 2023.emnlp-industry.32
- Volume:
- Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing: Industry Track
- Month:
- December
- Year:
- 2023
- Address:
- Singapore
- Editors:
- Mingxuan Wang, Imed Zitouni
- Venue:
- EMNLP
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 331–342
- Language:
- URL:
- https://aclanthology.org/2023.emnlp-industry.32
- DOI:
- 10.18653/v1/2023.emnlp-industry.32
- Cite (ACL):
- Jack Good, Jimit Majmudar, Christophe Dupuy, Jixuan Wang, Charith Peris, Clement Chung, Richard Zemel, and Rahul Gupta. 2023. Coordinated Replay Sample Selection for Continual Federated Learning. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 331–342, Singapore. Association for Computational Linguistics.
- Cite (Informal):
- Coordinated Replay Sample Selection for Continual Federated Learning (Good et al., EMNLP 2023)
- PDF:
- https://preview.aclanthology.org/emnlp22-frontmatter/2023.emnlp-industry.32.pdf