model-serving

Benchmarks and tunes deployed LLM inference servers for latency, throughput, and capacity.

22|Updated Sep 10, 2026
One-click install
npx skills add https://github.com/Lynricsy/HyperSkills --skill model-serving-lynricsy
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: model-serving
Source: https://github.com/Lynricsy/HyperSkills/tree/main/skills/model-serving
Command: npx skills add https://github.com/Lynricsy/HyperSkills --skill model-serving-lynricsy

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve? Serving benchmarks and scaling decisions for LLM inference are routinely invalidated by saturation-ceiling runs, missing warmups, GPU-utilization autoscaling, and unrepresentative synthetic load, producing capacity numbers that collapse in production. ## Core Features & Use Cases - Benchmark design and review: Builds rate-sweep benchmarks with goodput SLOs, explicit readiness gates, warmup, noise floors, and load that matches production in length distribution, arrival shape, and prefix reuse. - Regression diagnosis: Attributes TTFT, TPOT, and throughput regressions to concrete causes such as prefix-cache collapse, KV cache pressure, preemption, or chunked-prefill budget misconfiguration. - Capacity and scaling: Derives per-replica capacity from goodput collapse points, sizes cold-start budgets, and selects queue-depth or latency-based autoscaling signals instead of GPU utilization. - Configuration evaluation: Assesses changes like speculative decoding, memory utilization, parallelism strategy, and LoRA adapters with acceptance and withdrawal rules measured at production concurrency. - Use Case: Given a benchmark report claiming 7x H100 capacity for 30 req/s, the skill identifies that --request-rate inf measured only the saturation ceiling, warmup was skipped, and the synthetic 512/512 load misrepresents production, then prescribes the correct rate-sweep methodology. ## Quick Start Review this vLLM serving benchmark report and tell me whether the capacity conclusion is safe to plan against.

Frequently Asked Questions about model-serving

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I benchmark a vLLM serving deployment correctly?

Sweep finite --request-rate values with a --goodput SLO attached and find where goodput collapses; that rate is the capacity number. Gate on readiness explicitly, warm up with hundreds of requests, discard the first run, and match synthetic load to production length distributions and prefix reuse.

Why is GPU utilization a bad autoscaling signal for LLM serving?

Decode is memory-bandwidth-bound, so GPU utilization reads near-full at three requests in flight and at three hundred, making it nearly constant. Scale on queue depth (vllm:num_requests_waiting), KV cache occupancy, or latency against the SLO instead.

When does speculative decoding actually help inference latency?

Speculative decoding shortens decode only at low concurrency, roughly 2 requests or below; at production concurrency, continuous batching already saturates the GPU and speculation competes with it. Justify draft-token counts with a measured acceptance rate above roughly 0.6.

Why did TTFT regress after my model deploy?

Check the prefix cache hit rate first, computed as rate(vllm:prefix_cache_hits_total) / rate(vllm:prefix_cache_queries_total); a hit-rate collapse explains more TTFT regressions than any kernel change. Then check prompt length distribution and the batched-token budget.

What does vLLM preemption mean and how do I fix it?

A rising vllm:num_preemptions_total means the KV cache cannot hold the working set; it is a capacity signal, not a bug. Fix in order: reduce max-model-len to the real requirement, reduce max-num-seqs, raise gpu-memory-utilization only with genuine headroom, then add tensor parallelism.

Does this skill cover training or managed inference platforms?

No. Training, fine-tuning, and quantization format selection belong to a separate training skill, and managed control planes like SageMaker, Vertex, and Azure ML belong to the cloud provider skills. This skill covers only models already being served.