TNG: Long Prompts Block LLM Requests - Sequential Prefill Bottleneck

AI Impact Summary

Long prompts within TNG's LLM infrastructure cause significant performance bottlenecks due to the sequential nature of prefill processing. When a request with a lengthy prompt is scheduled, subsequent requests are forced to wait, leading to increased latency and a degraded user experience. This issue stems from the inherent parallelization limitations of vLLM's chunked-prefill strategy, where prefill chunks are processed sequentially for each request, regardless of prompt length.