ICLR 2025poster0 citations

Local Steps Speed Up Local GD for Heterogeneous Distributed Logistic Regression

Michael Crawshaw, Blake Woodworth, Mingrui Liu

Abstract

We analyze two variants of Local Gradient Descent applied to distributed logistic regression with heterogeneous, separable data and show convergence at the rate $O(1/KR)$ for $K$ local steps and sufficiently large $R$ communication rounds. In contrast, all existing convergence guarantees for Local GD applied to any problem are at least $\Omega(1/R)$, meaning they fail to show the benefit of local updates. The key to our improved guarantee is showing progress on the logistic regression objective when using a large stepsize $\eta \gg 1/K$, whereas prior analysis depends on $\eta \leq 1/K$.

optimizationconvex optimizationdistributed optimizationfederated learninglogistic regression
BibTeX
@inproceedings{
crawshaw2025local,
title={Local Steps Speed Up Local {GD} for Heterogeneous Distributed Logistic Regression},
author={Michael Crawshaw and Blake Woodworth and Mingrui Liu},
booktitle={The Thirteenth International Conference on Learning Representations},
year={2025},
url={https://openreview.net/forum?id=lydPkW4lfz}
}
Local Steps Speed Up Local GD for Heterogeneous Distributed Logistic Regression · ICLR 2025