AReaL: A Large-Scale Asynchronous Reinforcement Learning System for Language Reasoning

Fuente: arXiv
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Main Authors: Fu, Wei, Gao, Jiaxuan, Shen, Xujie, Zhu, Chen, Mei, Zhiyu, He, Chuyi, Xu, Shusheng, Wei, Guo, Mei, Jun, Wang, Jiashu, Yang, Tongkai, Yuan, Binhang, Wu, Yi
Format: Preprint
Published: 2025
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author Fu, Wei
Gao, Jiaxuan
Shen, Xujie
Zhu, Chen
Mei, Zhiyu
He, Chuyi
Xu, Shusheng
Wei, Guo
Mei, Jun
Wang, Jiashu
Yang, Tongkai
Yuan, Binhang
Wu, Yi
author_facet Fu, Wei
Gao, Jiaxuan
Shen, Xujie
Zhu, Chen
Mei, Zhiyu
He, Chuyi
Xu, Shusheng
Wei, Guo
Mei, Jun
Wang, Jiashu
Yang, Tongkai
Yuan, Binhang
Wu, Yi
contents Reinforcement learning (RL) has become a dominant paradigm for training large language models (LLMs), particularly for reasoning tasks. Effective RL for LLMs requires massive parallelization and poses an urgent need for efficient training systems. Most existing large-scale RL systems for LLMs are synchronous, alternating generation and training in a batch setting where rollouts in each training batch are generated by the same model. This approach stabilizes RL training but suffers from severe system-level inefficiency: generation must wait until the longest output in the batch is completed before model updates, resulting in GPU underutilization. We present AReaL, a fully asynchronous RL system that completely decouples generation from training. Rollout workers in AReaL continuously generate new outputs without waiting, while training workers update the model whenever a batch of data is collected. AReaL also incorporates a collection of system-level optimizations, leading to substantially higher GPU utilization. To stabilize RL training, AReaL balances the workload of rollout and training workers to control data staleness, and adopts a staleness-enhanced PPO variant to better handle outdated training samples. Extensive experiments on math and code reasoning benchmarks show that AReaL achieves up to 2.77$\times$ training speedup compared to synchronous systems with the same number of GPUs and matched or improved final performance. The code of AReaL is available at https://github.com/inclusionAI/AReaL/.
format Preprint
id arxiv_https___arxiv_org_abs_2505_24298
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle AReaL: A Large-Scale Asynchronous Reinforcement Learning System for Language Reasoning
Fu, Wei
Gao, Jiaxuan
Shen, Xujie
Zhu, Chen
Mei, Zhiyu
He, Chuyi
Xu, Shusheng
Wei, Guo
Mei, Jun
Wang, Jiashu
Yang, Tongkai
Yuan, Binhang
Wu, Yi
Machine Learning
Artificial Intelligence
Reinforcement learning (RL) has become a dominant paradigm for training large language models (LLMs), particularly for reasoning tasks. Effective RL for LLMs requires massive parallelization and poses an urgent need for efficient training systems. Most existing large-scale RL systems for LLMs are synchronous, alternating generation and training in a batch setting where rollouts in each training batch are generated by the same model. This approach stabilizes RL training but suffers from severe system-level inefficiency: generation must wait until the longest output in the batch is completed before model updates, resulting in GPU underutilization. We present AReaL, a fully asynchronous RL system that completely decouples generation from training. Rollout workers in AReaL continuously generate new outputs without waiting, while training workers update the model whenever a batch of data is collected. AReaL also incorporates a collection of system-level optimizations, leading to substantially higher GPU utilization. To stabilize RL training, AReaL balances the workload of rollout and training workers to control data staleness, and adopts a staleness-enhanced PPO variant to better handle outdated training samples. Extensive experiments on math and code reasoning benchmarks show that AReaL achieves up to 2.77$\times$ training speedup compared to synchronous systems with the same number of GPUs and matched or improved final performance. The code of AReaL is available at https://github.com/inclusionAI/AReaL/.
title AReaL: A Large-Scale Asynchronous Reinforcement Learning System for Language Reasoning
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2505.24298