titleDISCO: Distributed Long Context Scaling with Grounding-Reasoning Disaggregation
authorsGuanzheng Chen, Viet Dac Lai, Subhojyoti Mukherjee, Branislav Kveton, Seunghyun Yoon, Franck Dernoncourt, Qizhe Xie, Trung Bui
date2026-09-27
venuearXiv (preprint, not peer reviewed)
idarXiv:2609.33485
upvotes3 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractWhile Large Language Models (LLMs) advertise million-token context windows, reasoning quality often collapses as inputs grow -- a phenomenon termed context rot. This failure stems from a structural entanglement in monolithic architectures, where the massive search burden of contextual grounding exhausts the representational capacity needed for complex reasoning. To resolve this, we propose Grounding-Reasoning Disaggregation via DIStributed long COntext scaling (DISCO). Inspired by distributed computing frameworks like Apache Spark, DISCO partitions long context across a fleet of Worker LLMs dedicated exclusively to parallel, localized grounding. A central Driver LLM, trained via Reinforcement Learning (GRPO) to optimize planning, orchestrates execution by dynamically mapping queries into atomic extraction tasks and reducing the gathered evidence to synthesize a final answer. By isolating reasoning from raw context noise, DISCO effectively eliminates context rot. On RULER-QA (1M tokens), it maintains 78.4% accuracy where standard baselines collapse. Furthermore, it outperforms full-context models by up to 9.8 points on LongBench v2 and matches frontier models like Gemini-3-Pro-Preview while reducing inference costs by over 80%, establishing a highly efficient paradigm for robust long-context inference.

cite

@misc{chen2026disco,
  title={DISCO: Distributed Long Context Scaling with Grounding-Reasoning Disaggregation},
  author={Guanzheng Chen and Viet Dac Lai and Subhojyoti Mukherjee and Branislav Kveton and Seunghyun Yoon and Franck Dernoncourt and Qizhe Xie and Trung Bui},
  year={2026},
  eprint={2609.33485},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2609.33485}
}