ElasticMoE: An Efficient Auto Scaling Method for Mixture-of-Experts Models

Fuente: arXiv
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Main Authors: Singh, Gursimran, Yu, Timothy, Li, Haley, Chen, Cheng, Sadri, Hanieh, Zhang, Qintao, Zhang, Yu, Xiong, Ying, Zhang, Yong, Fan, Zhenan
Format: Preprint
Published: 2025
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author Singh, Gursimran
Yu, Timothy
Li, Haley
Chen, Cheng
Sadri, Hanieh
Zhang, Qintao
Zhang, Yu
Xiong, Ying
Zhang, Yong
Fan, Zhenan
author_facet Singh, Gursimran
Yu, Timothy
Li, Haley
Chen, Cheng
Sadri, Hanieh
Zhang, Qintao
Zhang, Yu
Xiong, Ying
Zhang, Yong
Fan, Zhenan
contents Mixture-of-Experts (MoE) models promise efficient scaling of large language models (LLMs) by activating only a small subset of experts per token, but their parallelized inference pipelines make elastic serving challenging. Existing strategies fall short: horizontal scaling provisions entire replicas of the current configuration, often tens to hundreds of accelerators, leading to coarse granularity, long provisioning delays, and costly overprovisioning. Vertical scaling offers finer adjustments but typically requires instance restarts, incurring downtime. These limitations make current approaches ill-suited for the bursty, short-lived traffic patterns common in cloud deployments. We present ElasticMoE, an elastic scaling framework for MoE LLMs that achieves fine-grained, low-latency, and zero-downtime scaling. ElasticMoE decouples inference execution from memory operations, enabling scaling steps to proceed concurrently with serving. An HBM Management Module (HMM) reuses weights and KV caches via zero-copy remapping, while high-bandwidth peer-to-peer transfers bring newly added accelerators online without interrupting service. A virtual memory based expert redistribution mechanism migrates MoE experts without costly buffer reallocations, reducing peak memory usage during expert parallelism reconfiguration. Our evaluation on Ascend NPUs with three popular MoE LLMs shows that ElasticMoE achieves up to 9x lower scale-up latency, up to 2x better throughput during scaling, and significantly improves SLO attainment compared to baselines. By enabling fine-grained, concurrent scaling with minimal disruption, ElasticMoE advances the practicality of deploying massive MoE LLMs in dynamic cloud environments.
format Preprint
id arxiv_https___arxiv_org_abs_2510_02613
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle ElasticMoE: An Efficient Auto Scaling Method for Mixture-of-Experts Models
Singh, Gursimran
Yu, Timothy
Li, Haley
Chen, Cheng
Sadri, Hanieh
Zhang, Qintao
Zhang, Yu
Xiong, Ying
Zhang, Yong
Fan, Zhenan
Distributed, Parallel, and Cluster Computing
Mixture-of-Experts (MoE) models promise efficient scaling of large language models (LLMs) by activating only a small subset of experts per token, but their parallelized inference pipelines make elastic serving challenging. Existing strategies fall short: horizontal scaling provisions entire replicas of the current configuration, often tens to hundreds of accelerators, leading to coarse granularity, long provisioning delays, and costly overprovisioning. Vertical scaling offers finer adjustments but typically requires instance restarts, incurring downtime. These limitations make current approaches ill-suited for the bursty, short-lived traffic patterns common in cloud deployments. We present ElasticMoE, an elastic scaling framework for MoE LLMs that achieves fine-grained, low-latency, and zero-downtime scaling. ElasticMoE decouples inference execution from memory operations, enabling scaling steps to proceed concurrently with serving. An HBM Management Module (HMM) reuses weights and KV caches via zero-copy remapping, while high-bandwidth peer-to-peer transfers bring newly added accelerators online without interrupting service. A virtual memory based expert redistribution mechanism migrates MoE experts without costly buffer reallocations, reducing peak memory usage during expert parallelism reconfiguration. Our evaluation on Ascend NPUs with three popular MoE LLMs shows that ElasticMoE achieves up to 9x lower scale-up latency, up to 2x better throughput during scaling, and significantly improves SLO attainment compared to baselines. By enabling fine-grained, concurrent scaling with minimal disruption, ElasticMoE advances the practicality of deploying massive MoE LLMs in dynamic cloud environments.
title ElasticMoE: An Efficient Auto Scaling Method for Mixture-of-Experts Models
topic Distributed, Parallel, and Cluster Computing
url https://arxiv.org/abs/2510.02613