Randomization Boosts KV Caching, Learning Balances Query Load: A Joint Perspective

Fuente: arXiv
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Main Authors: Wu, Fangzhou, Silwal, Sandeep, Qiuyi, Zhang
Format: Preprint
Published: 2026
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author Wu, Fangzhou
Silwal, Sandeep
Qiuyi
Zhang
author_facet Wu, Fangzhou
Silwal, Sandeep
Qiuyi
Zhang
contents KV caching is a fundamental technique for accelerating Large Language Model (LLM) inference by reusing key-value (KV) pairs from previous queries, but its effectiveness under limited memory is highly sensitive to the eviction policy. The default Least Recently Used (LRU) eviction algorithm struggles with dynamic online query arrivals, especially in multi-LLM serving scenarios, where balancing query load across workers and maximizing cache hit rate of each worker are inherently conflicting objectives. We give the first unified mathematical model that captures the core trade-offs between KV cache eviction and query routing. Our analysis reveals the theoretical limitations of existing methods and leads to principled algorithms that integrate provably competitive randomized KV cache eviction with learning-based methods to adaptively route queries with evolving patterns, thus balancing query load and cache hit rate. Our theoretical results are validated by extensive experiments across 4 benchmarks and 3 prefix-sharing settings, demonstrating improvements of up to 6.92$\times$ in cache hit rate, 11.96$\times$ reduction in latency, 14.06$\times$ reduction in time-to-first-token (TTFT), and 77.4% increase in throughput over the state-of-the-art methods. Our code is available at https://github.com/fzwark/KVRouting.
format Preprint
id arxiv_https___arxiv_org_abs_2601_18999
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Randomization Boosts KV Caching, Learning Balances Query Load: A Joint Perspective
Wu, Fangzhou
Silwal, Sandeep
Qiuyi
Zhang
Machine Learning
Artificial Intelligence
KV caching is a fundamental technique for accelerating Large Language Model (LLM) inference by reusing key-value (KV) pairs from previous queries, but its effectiveness under limited memory is highly sensitive to the eviction policy. The default Least Recently Used (LRU) eviction algorithm struggles with dynamic online query arrivals, especially in multi-LLM serving scenarios, where balancing query load across workers and maximizing cache hit rate of each worker are inherently conflicting objectives. We give the first unified mathematical model that captures the core trade-offs between KV cache eviction and query routing. Our analysis reveals the theoretical limitations of existing methods and leads to principled algorithms that integrate provably competitive randomized KV cache eviction with learning-based methods to adaptively route queries with evolving patterns, thus balancing query load and cache hit rate. Our theoretical results are validated by extensive experiments across 4 benchmarks and 3 prefix-sharing settings, demonstrating improvements of up to 6.92$\times$ in cache hit rate, 11.96$\times$ reduction in latency, 14.06$\times$ reduction in time-to-first-token (TTFT), and 77.4% increase in throughput over the state-of-the-art methods. Our code is available at https://github.com/fzwark/KVRouting.
title Randomization Boosts KV Caching, Learning Balances Query Load: A Joint Perspective
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2601.18999