arXiv AI

Context Is Not Free: Carbon-Aware LLM Routing for Multi-Turn LLM Web Services across Geo-Distributed Data Centers

The paper introduces CarbonRouter, an online framework that jointly selects the model, GPU type, and region for each query in multi‑turn LLM web services to minimize carbon emissions. It incorporates a cache‑aware carbon cost model that accounts for the history recomputation cost when a conversation is routed to a different deployment, and a lightweight gate that keeps a session on its cached deployment when a move back is likely. Experiments on two real‑world conversation datasets show that CarbonRouter achieves the lowest carbon footprint among evaluated policies, reducing CO₂ emissions by 16.1 % on average and up to 23.1 % for longer sessions, while also improving predicted answer quality and estimated latency.

arXiv Computation and Language
3d ago

Multi-Turn Semantic Caching for Low-Cost LLM Serving

The paper introduces two algorithms—CUCB‑SC‑MT and CLCB‑LS‑MT—for multi‑turn semantic caching in large language model serving. These methods learn a "reuse risk" metric from judge feedback to decide which conversation states to cache, balancing avoided generation cost against the risk of unacceptable reuse. Experiments on math‑tutoring and movie‑ticketing dialogues show that the online CLCB‑LS‑MT algorithm reduces generation cost by 35–41% and estimated latency by 19–35% compared to prior caching approaches.

By Baran Atalar, Selly Beyene, Xutong Liu, Carlee Joe-Wong
arXiv Computation and Language
Oct 26

Cluster, Route, Escalate: Cascaded Framework for Cost-Aware LLM Serving

arXiv:2606.27457v2 Announce Type: replace-cross Abstract: Serving open-weight language models on premises forces a trade-off between accuracy and computational cost. Hosting models of different sizes...

By Yasmin Moslem, Magdalena Kacmajor, Vasudevan Nedumpozhimana, Ammar Abbas, Solmaz Panahi, David Lynch, Zhuangzhuang Nie, Alexandros Agapitos, Aleksandar Milenovic, Hongmeng Song, Yucheng Shi, Yue Pan, Patricia Buffini, John D. Kelleher
arXiv AI
Sep 15

Carbon-Aware Routing for Function Calling in Edge-Cloud LLM Systems

The paper presents a carbon‑aware routing framework for function‑calling in large language models that distributes queries across a three‑tier edge‑cloud architecture. A lightweight k‑NN predictor estimates accuracy, delay, and power for each edge tier, and real‑time grid carbon intensity is used to route queries to the lowest‑emission tier that can execute them. Experiments on state‑of‑the‑art benchmarks show the framework matches cloud‑level accuracy while cutting operational carbon emissions by an average of four times.

By Aikaterini Maria Panteleaki, Varatheepan Paramanayakam, Spyros Tragoudas, Iraklis Anagnostopoulos
arXiv AI
Oct 16

Mind the Delay: Latency-aware Query Routing for Heterogeneous LLM pools

The paper introduces BEA, a fine‑grained estimator that predicts the time‑to‑first‑token (TTFT) for language model queries by replaying token‑batch formation based on current workload snapshots. BEA achieves about 5% error with 0.1 ms prediction time, enabling the latency‑aware router BEAR to balance accuracy, cost, and latency across heterogeneous LLM pools. BEAR outperforms seven baselines, improving utility of on‑target responses by 63% on average and by 30.5% at each arrival rate.

By Shivam Patel, Akaash R. Parthasarathy, Akash Dhasade, Ankur Mallick, Gauri Joshi
arXiv AI
Aug 11

KGCache: Amortized Subgraph Retrieval for KG Reasoning with LLMs

arXiv:2608. 07954v1 Announce Type: new Abstract: Large language models can answer knowledge-intensive questions more reliably when they are grounded with knowledge graphs, but systems such as Think-on-Graph and Reasoning-on-Graph repeatedly query the same graph neighborhoods across different questions.

By Uros Stanic, Changcheng Yuan, Sabuj Laskar, Ariful Azad
arXiv AI
Aug 18

From LLM Inference to Agentic Workloads: Characterization and Implications for Serving Systems

arXiv:2608. 15127v1 Announce Type: cross Abstract: Agentic applications are shifting AI serving from isolated model inference to long-running workloads in which LLMs coordinate tools, environments, and persistent state.

By Chaokun Chang, Yukun Zhou, Kaihua Fu, Dakai An, Tianyu Feng, Hanfeng Lu, Sheng Yao, Pu Guo, Yinghao Yu, Yizhou Shan, Bo Li, Binhang Yuan, Wei Wang