iServe: An Intent-based Serving System for LLMs

Abstract

Large Language Models (LLMs) are becoming ubiquitous across industries, where applications demand they fulfill diverse user intents. However, developers currently face the challenge of manually exploring numerous deployment configurations - combinations of parallelism and compression techniques that impact resource usage, latency, cost, and accuracy - to meet these intents. Assessing the impact of these configurations on user metrics requires extensive, costly profiling for each model. Existing approaches avoid this expense by using fixed, static configurations, but this often leads to sub-optimal performance and higher costs. Moreover, none of these solutions dynamically adapt to changing user intents to balance latency and cost, effectively. We present iServe, an automated, intent-based system for distributed LLM inference. Instead of manually selecting deployment configurations, developers simply specify their intent - such as minimizing latency, reducing cost, or meeting specific targets for either. iServe introduces fingerprints, lightweight representations of LLMs, to efficiently estimate how different configurations impact latency and memory usage. Based on these insights and GPU availability, iServe dynamically selects the optimal configuration to align with the user's intent. For various LLMs and query arrival rates, iServe best meets user intents compared to state-of-the-art systems by reducing latency by 77.62% and SLO violations by 7.09x while improving GPU throughput by 4.72x. Moreover, iServe's fingerprint-based profiling reduces profiling cost by 6.05x (GPU-hours) compared to baselines.