ProxRouter: Proximity-Weighted LLM Query Routing for Improved Robustness to Outliers

Fuente: arXiv
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Main Authors: Patel, Shivam, Jali, Neharika, Mallick, Ankur, Joshi, Gauri
Format: Preprint
Published: 2025
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author Patel, Shivam
Jali, Neharika
Mallick, Ankur
Joshi, Gauri
author_facet Patel, Shivam
Jali, Neharika
Mallick, Ankur
Joshi, Gauri
contents Large language model (LLM) query routers are critical to modern AI platforms as they seek to improve efficiency by assigning inference queries to accurate, yet low-cost models. Parametric routers typically use trained neural networks for LLM selection but suffer from retraining and maintenance overheads. Nonparametric routers are training-free, instead estimating LLM accuracy and cost via similarity between encodings of the input query and training set queries. However, like their parametric counterparts, nonparametric routers struggle to generalize to outlier queries, an issue exacerbated by limited diversity in training sets which are costly to expand and difficult to keep current with ever-evolving use cases. We propose ProxRouter, which applies an exponentially tilted aggregation mechanism to balance bias and variance in nonparametric routers, improving their robustness to outliers. Experiments show ProxRouter enhances outlier routing while preserving inlier performance with minimal overhead.
format Preprint
id arxiv_https___arxiv_org_abs_2510_09852
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle ProxRouter: Proximity-Weighted LLM Query Routing for Improved Robustness to Outliers
Patel, Shivam
Jali, Neharika
Mallick, Ankur
Joshi, Gauri
Machine Learning
Artificial Intelligence
Large language model (LLM) query routers are critical to modern AI platforms as they seek to improve efficiency by assigning inference queries to accurate, yet low-cost models. Parametric routers typically use trained neural networks for LLM selection but suffer from retraining and maintenance overheads. Nonparametric routers are training-free, instead estimating LLM accuracy and cost via similarity between encodings of the input query and training set queries. However, like their parametric counterparts, nonparametric routers struggle to generalize to outlier queries, an issue exacerbated by limited diversity in training sets which are costly to expand and difficult to keep current with ever-evolving use cases. We propose ProxRouter, which applies an exponentially tilted aggregation mechanism to balance bias and variance in nonparametric routers, improving their robustness to outliers. Experiments show ProxRouter enhances outlier routing while preserving inlier performance with minimal overhead.
title ProxRouter: Proximity-Weighted LLM Query Routing for Improved Robustness to Outliers
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2510.09852