论文标题
使用重型球下降的沟通效率{联合}学习
Communication-Efficient {Federated} Learning Using Censored Heavy Ball Descent
论文作者
论文摘要
分布式机器学习实现可扩展性和计算卸载,但需要大量的通信。因此,分布式学习设置中的沟通效率是一个重要的考虑因素,尤其是当通信是无线且采用电池驱动设备时。在本文中,我们开发了一种基于审查的重球(CHB)方法,用于在服务器工作者体系结构中分布式学习。除非其本地梯度与先前传播的梯度完全不同,否则每个工人的自我审查员。 HB学习问题的重要实践优势是众所周知的,但是尚未解决降低通信的问题。 CHB充分利用HB平滑来消除报告的微小变化,并证明达到了与经典HB方法相当的线性收敛速率,以平滑且强烈地凸出目标函数。 CHB的收敛保证在理论上是合理的,对于凸和非凸病例。此外,我们证明,在某些条件下,至少可以消除所有通信的一半,而不会对收敛率产生任何影响。广泛的数值结果验证了CHB在合成和真实数据集(凸,非凸和非不同情况下)的通信效率。鉴于目标准确性,与现有算法相比,CHB可以显着减少通信数量,从而实现相同的精度而不减慢优化过程。
Distributed machine learning enables scalability and computational offloading, but requires significant levels of communication. Consequently, communication efficiency in distributed learning settings is an important consideration, especially when the communications are wireless and battery-driven devices are employed. In this paper we develop a censoring-based heavy ball (CHB) method for distributed learning in a server-worker architecture. Each worker self-censors unless its local gradient is sufficiently different from the previously transmitted one. The significant practical advantages of the HB method for learning problems are well known, but the question of reducing communications has not been addressed. CHB takes advantage of the HB smoothing to eliminate reporting small changes, and provably achieves a linear convergence rate equivalent to that of the classical HB method for smooth and strongly convex objective functions. The convergence guarantee of CHB is theoretically justified for both convex and nonconvex cases. In addition we prove that, under some conditions, at least half of all communications can be eliminated without any impact on convergence rate. Extensive numerical results validate the communication efficiency of CHB on both synthetic and real datasets, for convex, nonconvex, and nondifferentiable cases. Given a target accuracy, CHB can significantly reduce the number of communications compared to existing algorithms, achieving the same accuracy without slowing down the optimization process.