Decentralized consensus-based optimization is a general computational framework where a network of nodes cooperatively minimizes a sum of locally available cost functions via only local computation and communication. In this article, we survey recent advances on this topic, particularly focusing on decentralized, consensus-based, first-order gradient methods for large-scale stochastic optimization. The class of consensus-based stochastic optimization algorithms is communication-efficient, able to exploit data parallelism, robust in random and adversarial environments, and simple to implement, thus providing scalable solutions to a wide range of large-scale machine learning problems. We review different state-of-the-art decentralized stochastic optimization formulations, different variants of consensus-based procedures, and demonstrate how to obtain decentralized counterparts of centralized stochastic first-order methods. We provide several intuitive illustrations of the main technical ideas as well as applications of the algorithms in the context of decentralized training of machine learning models.

本文综述了基于梯度追踪和方差减少的去中心化随机一阶优化方法，介绍了这些算法在去中心化机器学习模型训练中的应用。

分散随机优化与梯度追踪简介