Red Hat Teams With Nvidia, Google on llm-d to Scale AI Inference
Ai4
Single-node inference servers fail as agentic workloads drive token demand 20-fold, making Kubernetes-native disaggregation across mixed hardware essential to control enterprise AI costs.
## Background
Published on YouTube by Ai4 on August 19, 2026, this presentation features Rob Greenberg, Principal Product Manager at Red Hat AI, discussing the deployment of open-source LLMs in enterprise production. The session focuses on demystifying core inference mechanics, handling the rising computational costs of agentic workloads, and scaling distributed infrastructure using vLLM and the Kubernetes-native llm-d framework.
## TL;DR
Rob Greenberg explores the mechanics and economics of LLM inference, explaining why inference operational costs now vastly outweigh training as reasoning models demand up to 20x more tokens. He positions vLLM as the standardized open-source engine for hardware-agnostic execution alongside FP8 quantization via the llm-compressor library. To overcome single-node bottlenecks, he presents llm-d—an open-source Kubernetes initiative built with Google, NVIDIA, and Hugging Face that implements disaggregated prefill/decode and LLM-aware request routing. The talk concludes with an overview of agentic trace observability and Red Hat's enterprise packaging for production deployments.
## Atmosphere & style
The presentation is fast-paced, pragmatic, and technically rigorous, delivered with the confident and approachable cadence of an experienced product manager. Greenberg avoids buzzword-heavy hype, instead illustrating the physical realities of memory bandwidth, linear algebra, and cluster scheduling with clear analogies and architectural diagrams. The tone is collaborative and engineering-focused, engaging the audience with quick polls and ending on a grounded, practical Q&A session.
## Key takeaways
- [00:04](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=4s) Red Hat's generative AI strategy centers on open-source infrastructure, championing open models, inference engines, and vendor-agnostic serving over proprietary ecosystems.
- [01:32](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=92s) Transformer inference is split into two distinct mechanical phases: the compute-bound prefill stage that populates the KV cache, and the memory-bandwidth-bound decode stage that autoregressively generates tokens one by one.
- [05:25](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=325s) Reasoning models and agentic workflows drastically increase infrastructure strain, demanding up to 20x more tokens and 150x more compute per request than traditional single forward-pass LLMs.
- [08:09](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=489s) Inference has eclipsed model training as the primary driver of enterprise AI lifecycle costs, driving the need for standardized serving stacks that avoid hardware lock-in across silicon providers.
- [11:14](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=674s) vLLM has emerged as the de facto open-source inference engine, providing multi-vendor hardware optimization across NVIDIA, AMD, Intel, and Google TPUs alongside Day-Zero support for new model releases.
- [14:59](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=899s) Model quantization from BF16 down to FP8 halves memory footprint and reduces token latency while maintaining less than a 1% loss in accuracy.
- [17:00](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1020s) Traditional web load balancing breaks down under LLM workloads due to extreme request size variance, requiring intelligent request routing and disaggregated prefill and decode via distributed frameworks.
- [19:09](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1149s) llm-d is a Kubernetes-native distributed inference project developed jointly by Red Hat, Google, NVIDIA, Hugging Face, and CoreWeave to scale multi-node vLLM clusters.
- [20:16](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1216s) Reliability in multi-turn agentic workloads requires specialized agentic tracing to log tool calls and payloads for failure recovery beyond standard metrics like TTFT and TPOT.
- [21:39](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1299s) Red Hat packages its open-source inference tooling into commercial offerings via the full Red Hat AI Enterprise suite or a dedicated, standalone Red Hat AI Inference SKU.
## Detailed walkthrough
### [00:04](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=4s) Introduction and the Open-Source AI Mission
Rob Greenberg opens the presentation by introducing his background as a Principal Product Manager at Red Hat AI. He joined Red Hat approximately a year and a half prior after working at Neural Magic, a startup focused on large language model (LLM) compression and optimization. Neural Magic originally began by compressing natural language processing and computer vision models for CPUs, but pivoted drastically when ChatGPT launched. Greenberg sets the stage for a fast-paced, twenty-minute session covering inference fundamentals, the reason inference has become a critical focal point, the open-source inference engine vLLM, distributed inference with llm-d, and Red Hat's broader AI stack.
Red Hat operates on the fundamental conviction that "the future of AI is open"—spanning open models, open inference servers, open infrastructure, and open serving. Rather than relying entirely on proprietary ecosystems, Red Hat champions open-source innovation as the true engine driving AI forward. A core part of that mission is bringing open-source LLMs to enterprise production environments using vLLM, an open-source inference server that Red Hat has invested heavily in.
[01:32](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=92s) LLM Inference Fundamentals: Autoregressive Generation, the KV Cache, and Prefill vs. Decode
At its most fundamental level, inference is the process of taking a trained model and supplying a prompt to generate a text response. Whether a user interacts with ChatGPT, Claude, an API endpoint, a local GPU, or a personal laptop, the underlying mechanical flow remains the same: a prompt enters the inference server, the model processes it over hardware, and a response is returned. Mechanically, a large language model based on the transformer architecture is essentially a mathematical function executing linear algebra to "predict the next token in a sequence." While often treated conceptually as a black box where data goes into a pile until the desired outputs appear, the underlying generation operates strictly autoregressively, predicting tokens one at a time that chain together into human-readable sentences.
```
+-----------------------------+
| Input Prompt |
+--------------+--------------+
|
v
[ PREFILL STAGE ] | Ingests entire prompt
Processes full prompt -> +----> Computes Initial KV Pairs
| |
v v
[ DECODE STAGE ] | +---------------+
Autoregressive Loop <--+----> | KV Cache | <---+
Predicts next token +---------------+ |
| | |
+---- Generates 1 token ------+--------------+
| (Appends new KV state to cache)
v
+-------------------------------+
| Output Stream / Final Text |
+-------------------------------+
```
Because processing every prior token repeatedly for each new step would be prohibitively expensive, caching serves as the vital breakthrough for modern LLM performance. The inference lifecycle splits into two distinct operational stages:
- **Prefill Stage:** The initial prompt ingestion phase where the input context (for example, "Where is the capital of Victoria, Australia?") is processed and its key-value representations are stored in the KV cache.
- **Decode Stage:** The autoregressive token generation phase where the model predicts the next token one by one across multiple iterations, leveraging the KV cache to avoid recomputing previous context.
- **The Scheduler:** The foundational traffic controller that orchestrates token scheduling and memory across hardware resources, pods, and Kubernetes architectures at scale.
[05:25](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=325s) Why Inference Matters: The Cost Explosion and Agentic Scaling
Inference represents "AI in production"—it is the real-time execution engine that makes applications feel alive and responsive to end users. However, running inference in production is extraordinarily expensive. Open-source models have grown dramatically from early architectures like LLaMA, MPT, and Falcon (from the 2022–2023 era) to massive, highly capable modern models such as Kimi and Nemotron. This leap in model capability has created acute operational bottlenecks around hardware accelerator availability, with enterprises constantly scrambling to secure cloud or on-premise GPUs.
At the same time, enterprise demand for token throughput is exploding through "token maxing," where leadership demands that engineering teams move faster by generating more code and broader automated outputs. This demand is accelerated further by reasoning models and agentic workflows:
- **Traditional LLMs:** In a standard single forward pass without reasoning, a prompt might consume roughly 439 generated tokens.
- **Reasoning and Agentic LLMs:** Agents that pause to "think"—performing iterative loops, running self-correction checks, executing tool calls, and exploring branching decision trees—can demand up to 20x more tokens and 150x more compute.
- **The Trade-off:** Despite the intense computational cost, reasoning loops deliver a critical breakthrough: the final answers are significantly more accurate and reliable.
[08:09](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=489s) The Enterprise Serving Dilemma and the Economics of Inference
Since the release of ChatGPT in late 2022 and Meta's original LLaMA release in early 2023, the open-weight ecosystem has exploded with top-tier releases from Meta, Qwen, Mistral, and NVIDIA. Today, open models regularly top public leaderboards and compete directly with closed-source frontier providers like Anthropic and OpenAI.
For enterprise environments, adopting these models requires a standardized inference serving stack that bridges "any model, any server, any hardware." Enterprises cannot feasibly maintain twenty disparate inference servers, each with unique configurations and quirks, every time a new architecture appears. Standardizing on an inference layer provides:
- **Speed and Scalability:** Maximizing token throughput and supporting multi-model deployments on shared infrastructure.
- **Routing and Stability:** Enabling intelligent scheduling and distributed execution across clusters without bespoke glue code.
- **Hardware Portability:** Decoupling application logic from specific silicon vendors so enterprises can map models directly to whatever hardware is available.
Greenberg polls the audience on whether training or inference costs more over the long term. While training historically dominated budgets five or six years ago, the audience correctly identifies that inference now accounts for the vast majority of lifecycle costs as generative AI scales into continuous production workloads.
[11:14](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=674s) vLLM: The Standardized Open-Source Inference Engine
To support full-lifecycle AI alongside fine-tuning, training, and observability, Red Hat anchors its enterprise generative AI platform on vLLM. In just two years, vLLM evolved from a UC Berkeley Sky Computing Lab research project into the de facto industry standard for inference serving, leading open-source metrics in GitHub stars and real-world adoption.
vLLM removes hardware lock-in by providing deep, vendor-agnostic optimizations across NVIDIA, AMD, Intel, AWS Trainium, and Google TPUs. To prevent enterprise adoption delays, Red Hat's dedicated inference engineering team works directly with model creators to deliver "Day Zero enablement." When new model families like Gemma, Nemotron, or Kimi drop, they are immediately runnable on vLLM on day one. Red Hat has established itself as the number one corporate contributor to the vLLM project and actively hosts bi-weekly public vLLM community office hours to support users across cloud, on-premise, and regulated environments.
[14:59](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=899s) Model Optimization: Quantization and LLM Compressor
Beyond server-level engineering, Red Hat optimizes models directly through techniques like quantization and speculative decoding, publishing validated models to the public Red Hat AI repository on Hugging Face. When models are released by research labs, they typically arrive in 16-bit brain floating point format (`BFloat16`). Quantization compresses these weights into smaller numerical representations:
- **The Precision Analogy:** Rather than representing the constant $\pi$ with high-precision decimals like $3.141592$, quantization approximates it as simply $3$.
- **`llm-compressor` Library:** Red Hat leverages its open-source `llm-compressor` library to productize state-of-the-art compression algorithms.
- **FP8 Efficiency:** Quantizing `BF16` models down to `FP8` halves model memory requirements while maintaining an accuracy loss of less than 1% across all Red Hat AI Hugging Face releases.
- **Latency Gains:** Quantization yields stark reductions in time per output token (TPOT), enabling hardware to serve significantly higher token throughput.
Greenberg concludes the segment by setting up the final and most critical architectural challenge in modern inference serving: scaling beyond single nodes into distributed inference.
[17:00](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1020s) Distributed Inference with llm-d and Why Traditional Microservices Fail
Rob Greenberg introduces **llm-d**, describing it as a "marriage between all the benefits of Kubernetes and all the benefits of vLLM kind of married into one project." While single-node inference engines are sufficient for basic experimentation, scaling up to larger models and high concurrent user traffic requires a distributed inferencing framework. llm-d addresses this by integrating cluster-level workload scheduling and advanced architectural techniques natively out of the box—most notably **disaggregated prefill and decode**—to unlock a new tier of performance as model footprints and inference demands expand.
Greenberg contrasts traditional web microservices with modern LLM serving to explain why conventional load balancing breaks down. In traditional web architectures, modern HTTP requests are relatively uniform, cheap to compute, and characterized by high queries per second (QPS), making standard round-robin or least-connection load balancers effective. In generative AI, however, request sizes and computational costs vary wildly across users. Greenberg highlights this disparity with an everyday workplace example: one request might come from an intern asking a single sentence like `"What's the capital of France?"`, while the next comes from a senior engineer pasting an entire Jupyter notebook into the context window.
LLM Serving with llm-d:
[Intern: Short Query ] \
[Engineer: Full Notebook] ---> [LLM-Aware Router] ---> [Prefill Pods (Compute)]
[Agent: Long Tool Trace ] / [Decode Pods (Memory) ]
```
To prevent cluster instability and memory exhaustion from such volatile inputs, llm-d uses an LLM-aware router. This router inspects the incoming request characteristics and intelligently schedules workloads to the optimal compute pods, matching the request's computational profile to maximize throughput, lower token processing costs, and maintain strict latency targets.
- Traditional HTTP requests are lightweight and uniform, whereas LLM requests exhibit extreme variance in prompt length and compute intensity.
- llm-d pairs Kubernetes orchestration with vLLM's optimized execution engine to manage distributed multi-pod inference clusters.
- Native disaggregated prefill and decode allows separating compute-bound prompt ingestion from memory-bandwidth-bound token generation.
---
[19:09](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1149s) The Open-Source Ecosystem Behind llm-d and the Red Hat AI Platform
Turning to the broader ecosystem, Greenberg stresses that llm-d is not an isolated Red Hat project, but an open-source industry collaboration alongside partners including **Google, NVIDIA, Hugging Face, and CoreWeave**. The collective goal is to push the boundaries of inference optimization beyond what a single inference engine can do on an isolated server by establishing a cloud-native standard for distributed scale across edge, private data centers, and public clouds.
While the presentation focuses primarily on the inference runtime, Greenberg notes that Red Hat integrates these capabilities across its broader Red Hat AI portfolio. In addition to inference serving, enterprise deployments require end-to-end tooling spanning model training, fine-tuning, guardrails, governance, and cluster security. As he wraps up the formal presentation to applause, he opens the floor for a brief Q&A before directing attendees to the Red Hat booth in the main exhibition hall.
- **Key llm-d Contributors:** Red Hat, Google, NVIDIA, Hugging Face, CoreWeave.
- The project focuses on three operational pillars: performance, operationalization, and hardware flexibility across diverse accelerator architectures.
- llm-d serves as the inference engine component within Red Hat's broader AI platform architecture.
---
[20:16](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1216s) Q&A: Handling Fault Tolerance, Agent Resumes, and Agentic Traces
An audience member asks about fault tolerance in multi-step agentic workflows: if an autonomous agent fails midway or veers off course, how does the load balancer handle failure recovery, and are there tools to rewind and resume execution?
Greenberg explains that at the baseline infrastructure tier, vLLM ships with out-of-the-box telemetry exported via Prometheus. This provides visibility into standard serving metrics such as Time to First Token (TTFT), Time Per Output Token (TPOT), end-to-end latency, and token throughput. However, to handle complex agents, Red Hat and the open-source community are actively investing in **agentic traces**. When models execute multi-turn tool calling, these tracing mechanisms capture exactly which tool was invoked, inspect the specific input and output payloads, pinpoint where an execution step failed, and determine how the system can reason through recovery and route subsequent resolution compute to the appropriate pods.
- **Standard LLM Observability:** Exported via Prometheus to monitor TTFT, TPOT, throughput, and queue latency.
- **Agentic Tracing:** Emerging tooling designed to log tool-calling parameters, validate structured inputs/outputs, and manage failure recovery states.
- Active research and evaluation benchmarks are underway across both the vLLM and llm-d communities to standardize agentic routing and tool-use resilience.
---
[21:39](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1299s) Q&A: FP8 Quantization Trade-offs, Open-Source Licensing, and OpenShift AI SKUs
Another attendee asks about model quantization, noting that they currently run Qwen FP8 checkpoints on vLLM and wondering what advantage Red Hat's hosted models on Hugging Face provide. Greenberg breaks down the technical nuances between quantization formats, noting that FP8 comes primarily in **FP8 block** and **FP8 dynamic** schemes. If an upstream model and a Red Hat model are both quantized using identical FP8 dynamic methods, they will yield identical performance on vLLM. However, Red Hat occasionally tunes specific weight or activation quantization strategies to extract additional execution speedups on particular hardware targets, such as NVIDIA GPUs.
When asked to clarify the project's licensing and product packaging, Greenberg confirms that **llm-d is 100% open source**. He then maps out how these open-source tools fit into Red Hat's commercial offerings:
```
+-----------------------------------------------------------------------+
| Red Hat AI Enterprise |
| +------------------------+ +------------------+ +------------------+ |
| | OpenShift AI Platform | | OpenShift (OCP) | | AI Accelerator | |
| | (Train, Tune, Govern) | | Container Base | | Entitlement | |
| +------------------------+ +------------------+ +------------------+ |
+-----------------------------------------------------------------------+
OR
+-----------------------------------------------------------------------+
| Red Hat AI Inference |
| +-----------------------+ +--------------------+ +-----------------+ |
| | Optimized Model Hub | | vLLM Engine Core | | llm-d Scheduler | |
| +-----------------------+ +--------------------+ +-----------------+ |
+-----------------------------------------------------------------------+
```
1. **Red Hat AI Enterprise:** A comprehensive bundle combining OpenShift AI, the core OpenShift Container Platform (OCP), and an AI accelerator entitlement. This covers the entire lifecycle, including training, fine-tuning, observability, governance, and distributed inference.
2. **Red Hat AI Inference:** A targeted, more affordable standalone SKU built specifically for organizations that only need the inference serving stack—bundling the validated/quantized model catalog, vLLM, and llm-d without the full training and fine-tuning suite.
- **FP8 Quantization Differences:** Dynamic vs. block quantization applied across weights versus activations can yield distinct performance profiles depending on GPU hardware.
- **llm-d Licensing:** Fully open-source and developed collaboratively in the public domain.
- **Product Packaging:** Customers can deploy the full lifecycle stack via **Red Hat AI Enterprise** or select the dedicated **Red Hat AI Inference** SKU for a cost-effective, inference-only footprint.
## Notable quotes
> [00:04](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=4s) the future of AI is open — Rob Greenberg
> [01:32](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=92s) predict the next token in a sequence — Rob Greenberg
> [01:32](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=92s) Where is the capital of Victoria, Australia? — Rob Greenberg
> [05:25](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=325s) AI in production — Rob Greenberg
> [05:25](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=325s) token maxing — Rob Greenberg
> [08:09](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=489s) any model, any server, any hardware — Rob Greenberg
> [11:14](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=674s) Day Zero enablement — Rob Greenberg
> [17:00](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1020s) marriage between all the benefits of Kubernetes and all the benefits of vLLM kind of married into one project — Rob Greenberg
> [17:00](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1020s) What's the capital of France? — Rob Greenberg
> [20:16](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1216s) agentic traces — Rob Greenberg
> [21:39](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1299s) llm-d is 100% open source — Rob Greenberg
## Mentioned
Rob Greenberg, Red Hat, Neural Magic, ChatGPT, vLLM, llm-d, Claude, LLaMA, MPT, Falcon, Kimi, Nemotron, Meta, Qwen, Mistral, NVIDIA, Anthropic, OpenAI, UC Berkeley Sky Computing Lab, AMD, Intel, AWS Trainium, Google TPU, Gemma, Hugging Face, llm-compressor, Kubernetes, CoreWeave, Prometheus, OpenShift AI, OpenShift Container Platform (OCP), Red Hat AI Enterprise, Red Hat AI Inference
## Video description
Rob Greenberg - Principal Product Manager, Red Hat
Training gets the headlines, but inference is where generative AI meets production — and where the costs, latency, and scaling challenges actually live. This session demystifies LLM inference from the ground up: how models generate tokens, why the KV cache and the prefill/decode split matter, and what an inference server actually does to make GPUs go "brrrr." From there we turn to the hard part — running inference at scale. As reasoning and agentic workloads drive token demand 20x higher (and compute 150x higher), single-node serving stops being enough.
We'll show how Red Hat approaches distributed inference with llm-d, a Kubernetes-native, open-source initiative built jointly with Google, NVIDIA, Hugging Face, and others. You'll see how disaggregated prefill and decode, intelligent request scheduling, KV-cache-aware routing, and hardware-agnostic serving across NVIDIA, AMD, Intel, and Google TPUs come together to maximize GPU utilization and hit demanding SLOs — across edge, private, and public cloud.
We'll connect the dots from vLLM as the de facto inference engine to llm-d as the scaling layer, rounding out the picture with validated and quantized models that stretch more tokens out of fixed hardware.
Attendees will leave understanding not just what inference is, but how to deploy it efficiently and reliably at enterprise scale.
Red Hat 联手英伟达和谷歌推进 llm-d 以扩展 AI 推理
随着智能体工作负载推动 Token 需求增长 20 倍,单节点推理服务器逐渐失效,使跨混合硬件的 Kubernetes 原生解耦成为控制企业 AI 成本的关键。
Rob Greenberg 深入探讨了 LLM 推理的技术机制与经济学,阐明了在推理模型需要多达 20 倍 Token 的背景下,推理运营成本如今为何远超训练成本。他将 vLLM 视为支持与硬件解耦执行的标准化开源引擎,并结合了通过 llm-compressor 库实现的 FP8 量化技术。为克服单节点瓶颈,他介绍了 llm-d——这是一个与 Google、NVIDIA 和 Hugging Face 共同打造的开源 Kubernetes 倡议,实现了预填充与解码解耦以及具备 LLM 感知能力的请求路由。演讲最后概述了智能体调用链的可观测性,以及 Red Hat 针对生产环境部署的企业级封装方案。
Transformer 模型推理分为计算密集的 Prefill(填充 KV cache)与内存带宽受限的 Decode(自回归逐 token 生成)两个阶段;随着生成式 AI 规模化生产落地,推理已取代训练成为企业生命周期成本的主要开销。 (1:32)
推理模型与 Agent 智能体工作流显著加剧了算力压力,相比传统单次前向传递的 LLM,这类迭代任务每个请求的 token 消耗提升高达 20 倍,计算需求增加 150 倍。 (5:25)
vLLM 已成为支持 NVIDIA、AMD、Intel 和 Google TPU 等多硬件供应商的事实开源推理标准;结合 llm-compressor 将模型从 BF16 量化至 FP8 可将显存占用减半,同时精度损失控制在 1% 以内。 (11:14)
传统 Web 负载均衡无法应对输入长度波动极大的 LLM 请求,Red Hat 联合 Google、NVIDIA 等开源了 Kubernetes 原生分布式推理项目 llm-d,通过智能路由与 Prefill/Decode 物理分离解耦实现多节点集群扩展。 (17:00)
Reading summary
Rob Greenberg of Red Hat AI argues that inference has overtaken training as the primary generative AI operational cost, necessitating vendor-neutral serving architectures like vLLM and distributed orchestration frameworks like llm-d to handle volatile enterprise workloads and agentic scaling.
The Economic Shift Toward Production Inference (5:25)
Greenberg emphasizes that enterprise generative AI spending has shifted from initial model training to continuous production inference. This change is driven by the growing scale of open-weight models—advancing from early architectures like LLaMA and Falcon to massive models like Kimi and Nemotron—which intensifies hardware accelerator shortages. Compounding this is enterprise demand for high token throughput, termed 'token maxing.'
This compute demand increases substantially with reasoning models and agentic workflows. While a standard forward pass without reasoning might generate approximately 439 tokens, agents that pause to iterate, call tools, and evaluate decision trees can consume up to 20 times more tokens and 150 times more compute. Greenberg notes that despite the severe cost increase, organizations accept this computational burden because reasoning loops yield substantially more accurate results.
Unified Engine Architecture and Hardware Portability (11:14)
Transformer inference operates in two core mechanical stages: a compute-bound prefill stage that processes the input prompt into a key-value (KV) cache, and an autoregressive decode stage that generates subsequent tokens one by one using the cache. To prevent enterprises from maintaining fragmented serving stacks across varying architectures, Red Hat centers its inference platform on vLLM, an open-source engine originating from UC Berkeley's Sky Computing Lab.
vLLM provides techniques like PagedAttention and continuous batching while abstracting hardware across NVIDIA, AMD ROCm, Intel, AWS Trainium, and Google TPUs. Greenberg highlights that Red Hat is the leading corporate contributor to vLLM, coordinating with model creators to provide day-zero runtime enablement whenever new open models are released.
Memory Compression Through FP8 Quantization (14:59)
To mitigate accelerator scarcity, Red Hat utilizes model optimization techniques like quantization via its open-source library, llm-compressor. Models released in 16-bit brain floating point format (BFloat16) are compressed into smaller numerical representations, such as FP8, effectively halving memory requirements while keeping accuracy degradation below 1% across Red Hat's validated Hugging Face releases.
This footprint reduction lowers time per output token (TPOT) and improves overall cluster throughput. In response to audience questions, Greenberg clarifies that FP8 performance nuances depend on whether dynamic or block quantization is applied across weights versus activations, with specific tuning strategies applied to maximize speedups on particular hardware targets like NVIDIA GPUs.
Distributed Workload Scheduling with llm-d (17:00)
Traditional microservice load balancers fail in LLM serving because conventional HTTP requests are lightweight and uniform, whereas generative AI inputs exhibit radical variance in context length and computational cost—ranging from a single short question to an entire ingested Jupyter notebook. To manage this volatility, Red Hat co-developed llm-d alongside Google, NVIDIA, Hugging Face, and CoreWeave.
Described as combining Kubernetes orchestration with vLLM execution, llm-d uses an LLM-aware router to schedule requests to appropriate compute pods based on their computational profile. The architecture natively implements disaggregated prefill and decode, separating compute-bound prompt ingestion from memory-bandwidth-bound token generation across distinct pod configurations to prevent cluster memory exhaustion.
Failure Recovery and Enterprise Packaging (20:16)
While baseline infrastructure metrics like Time to First Token (TTFT) and TPOT are monitored via Prometheus, Greenberg points out that autonomous agents require deeper observability. To address multi-step agent failures, the open-source community is building agentic tracing tools that capture tool parameters, track structured inputs and outputs, identify where an execution derailed, and facilitate recovery routing.
Greenberg confirms that llm-d remains completely open source, fitting into two enterprise packaging options: the comprehensive Red Hat AI Enterprise bundle, which integrates OpenShift AI for training, tuning, and governance, and the dedicated Red Hat AI Inference SKU, designed specifically for organizations seeking only the vLLM and llm-d serving stack.
While open serving stacks like vLLM and llm-d address hardware lock-in and multi-node throughput, operationalizing resilient production systems remains an ongoing industry effort, particularly around standardizing agentic failure recovery and fine-tuning quantization formats across diverse accelerator architectures.
精炼阅读摘要
Red Hat 人工智能首席产品经理 Rob Greenberg 认为,随着推理取代模型训练成为企业生命周期的主要支出,开源技术栈已成为降低服务成本与消除硬件绑定的核心支柱;通过结合 vLLM 推理引擎与基于 Kubernetes 的分布式编排框架 llm-d,企业能够在异构硬件集群上实现高吞吐、解耦化的生产级推理。
推理成本结构转变与智能体算力激增 (5:25)
自 2022 年底 ChatGPT 及开源大语言模型兴起以来,企业人工智能的成本重心发生了根本性逆转。Greenberg 指出,早年模型训练曾占据大部分预算,但如今推理作为“生产环境中的 AI”已占据全生命周期成本的绝大部分。由于 Transformer 架构采用自回归机制逐个生成 Token,计算流程被严格划分为处理输入上下文的 Prefill(预填充)阶段和依赖 KV 缓存逐步预测的 Decode(解码)阶段,上下文长度与并发量的增加对底层硬件加速器形成了持续的供给压力。
在企业追求 Token 吞吐最大化的背景下,推理模型与自主智能体(Agent)工作流进一步加剧了算力消耗。普通的单次前向传递可能仅消耗约 439 个生成 Token,但具备自主思考、多轮工具调用、自纠错与分支决策的智能体系统,其消耗的 Token 数量可达普通模型的 20 倍,计算需求更激增高达 150 倍。尽管这种反复迭代的推理循环显著提升了最终输出的准确度与可靠性,但也给企业带来了严峻的算力成本与硬件短缺挑战。
vLLM 标准化引擎与 FP8 模型量化 (11:14)
面对快速迭代的开源模型架构(如 Qwen、Mistral、Nemotron 等),企业无法为每类模型单独维护互不兼容的推理服务,亟需在“任意模型、任意服务器、任意硬件”间建立统一的标准服务层。Red Hat 将其企业级生成式 AI 平台锚定在开源推理引擎 vLLM 上,借助其 PagedAttention 与连续批处理(Continuous Batching)技术消除厂商锁定,全面适配 NVIDIA、AMD、Intel 及 Google TPU 等多款加速芯片,并在新模型发布首日提供零延迟兼容支持。
为了在单节点层面压榨硬件性能,Red Hat 通过开源库 llm-compressor 对模型实施量化压缩。针对主流的 16 位浮点(BF16)格式,Red Hat 验证并发布了 FP8 格式的模型权重。Greenberg 表示,将模型压缩至 FP8 能够直接降低一半显存占用,在所有 Red Hat AI 发布的模型中将准确率损失控制在 1% 以内,并大幅缩短每输出 Token 所需时间(TPOT),从而成倍提升单机吞吐上限。
llm-d 分布式架构与解耦调度机制 (17:00)
单节点推理无法支撑高并发的大规模生产场景,而传统针对 HTTP 统一请求的微服务负载均衡机制在大模型场景下会彻底失效。Greenberg 说明,传统微服务的网络请求相对轻量且计算负载均衡,但大模型请求的提示词长度与计算开销极度分化——从单句简单查询到长达数万字的完整 Jupyter 笔记本代码分析,计算强度差异极大。若沿用轮询或最少连接等传统算法,极易导致局部节点显存耗尽和集群崩溃。
为此,Red Hat 联合 Google、NVIDIA、Hugging Face 和 CoreWeave 等产业伙伴共同发起了完全开源的 llm-d 项目。该项目将 Kubernetes 的容器编排与 vLLM 引擎结合,配备感知大模型负载特征的智能路由调度器,并原生支持 Prefill 与 Decode 阶段解耦(Disaggregated Prefill and Decode)。该架构将计算密集型的预填充任务与显存带宽受限的解码任务分配至不同 Pod 执行,显著提升了集群吞吐效率并保障了响应延迟目标。
智能体追踪可观测性与企业交付路径 (20:16)
在复杂智能体多步执行的容错场景中,基础架构面临着新的运维挑战。针对智能体中间步骤崩溃或执行偏差问题,Greenberg 指出,除 Prometheus 导出的首字生成时间(TTFT)、每 Token 生成时间(TPOT)等基础吞吐指标外,开源社区正重点推进“智能体追踪”(Agentic Traces)能力建设。该技术专门记录多轮工具调用的具体参数与输入输出数据,协助系统在执行故障后定位断点,进而规划恢复推理并将任务重定向至合适计算节点。
在商业落地方面,Greenberg 阐明了开源组件向商业化产品线(SKU)的转化结构。针对需要覆盖模型训练、微调、治理与分布式推理全生命周期的客户,Red Hat 提供基于 OpenShift 的 Red Hat AI Enterprise 套件;而对于仅需部署生产推理的企业,则提供轻量级且成本更低的 Red Hat AI Inference 独立产品线,仅打包预优化模型库、vLLM 与 llm-d 调度器以满足特定推理需求。
Greenberg 总结表明,开放协作是支撑企业级 AI 推理规模化落地的关键路径;然而,随着智能体长链路调用的普及,如何在复杂断点状态下实现健壮的自动恢复与动态资源调度,仍是 vLLM 与 llm-d 社区当前持续探索与基准测试的核心课题。
Detailed notes — zh
## Background
该视频由 Ai4 频道于 2026 年 8 月 19 日发布在 YouTube 平台上。内容记录了 Red Hat 首席产品经理 Rob Greenberg 的主题演讲,主要探讨大语言模型(LLM)在生产环境中的推理挑战,并系统介绍如何结合开源推理引擎 vLLM 与 Kubernetes 原生分布式平台 llm-d 实现企业级的大规模高效部署。
## TL;DR
演讲指出随着 Agentic 思考与工具调用普及,推理阶段的算力与 Token 消耗呈爆发式增长,推理已成为企业 AI 生命周期的核心成本重心。Red Hat 倡导全栈开源,依托事实标准的 vLLM 推理引擎实现跨 NVIDIA、AMD、Intel、TPU 等异构硬件的统一抽象,并结合 FP8 量化大幅降低延迟与显存开销。面对单节点瓶颈,开源分布式项目 llm-d 结合 Kubernetes 提供了 LLM 感知智能路由以及 Prefill 与 Decode 的阶段解耦,有效化解了长短负载不均的流量调度难题。整套推理方案已整合进 OpenShift AI 商业套件,为企业提供从全生命周期到纯推理部署的高可用解决方案。
## Atmosphere & style
演讲整体呈现出务实、严谨且充满技术洞见的工程布道风格,讲者在底层矩阵计算原理与顶层云原生架构设计之间深入浅出地自如切换。通过现场问答与即兴调研,讲者以轻松诙谐的方式直观揭示了行业从“重训练”向“重推理”的认知剧变,极大地调动了现场听众的共鸣。问答环节针对 Agent 容错与 FP8 硬件调优的讨论直接切中生产痛点,交流氛围浓厚且极具开源极客色彩。
## Key takeaways
- [00:04](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=4s) Red Hat 倡导全栈开源的 AI 战略,涵盖模型、推理引擎、基础设施与部署架构,并以开源生态作为推动生成式 AI 发展的核心基石。
- [01:32](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=92s) LLM 的自回归生成机制在架构上分为 Prefill(并行写入 KV Cache)和 Decode(自回归单步生成)两个阶段,KV Cache 是避免重复计算并实现长文本生成的关键技术突破。
- [05:23](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=323s) 随着 Agent 智能体和深度思考链(CoT)工作流的普及,推理阶段的 Token 消耗量暴增 20 倍,算力需求提升 150 倍,使推理成为模型生命周期中成本和算力消耗的核心来源。
- [08:10](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=490s) 面对多模型共存的业务现实,企业亟需解耦硬件与模型的统一标准化推理服务栈,避免为每个新模型维护专属推理架构所带来的高昂运维开销。
- [11:12](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=672s) vLLM 已经成为行业事实上的开源推理引擎标准,支持跨 NVIDIA、AMD、Intel、AWS Trainium 及 Google TPU 等异构算力部署,并提供首日即用的 Day-0 模型兼容能力。
- [14:59](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=899s) 通过 LLM Compressor 工具对模型进行 FP8 动态量化,可将模型体积减半并显著降低单 Token 延迟,同时在主流基准测试中将精度损失严格控制在 1% 以内。
- [16:44](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1004s) 由 Red Hat 联合 Google、NVIDIA 等共同发起的开源项目 llm-d,将 Kubernetes 的调度能力与 vLLM 深度结合,提供 LLM 感知路由和 Prefill 与 Decode 解耦架构,有效突破单机推理瓶颈。
- [20:02](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1202s) 针对 Agent 智能体及工具调用(Tool Calling)场景,推理栈正进一步整合 Prometheus 原生可观测性指标,并探索多步推理的状态追踪、容错重试及断点续传机制。
- [22:51](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1371s) Red Hat 通过 OpenShift AI 将整套大规模推理架构产品化,并提供覆盖全生命周期的 Red Hat AI Enterprise 以及专注高并发生产推理的 Red Hat AI Inference 两种商业化订阅方案。
## Detailed walkthrough
### [00:04](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=4s) 开场介绍:Red Hat 的开源 AI 愿景与 vLLM
Red Hat AI 的首席产品经理 Rob Greenberg 向与会观众作开场介绍。他回顾了自己约一年半前加入 Red Hat 的经历——当时他所在的 Neural Magic 专注于大语言模型(LLM)的压缩与优化,起初主要针对 CPU 上的 NLP 和计算机视觉模型进行压缩,而在 ChatGPT 问世后团队迅速完成业务转型。Greenberg 明确了本场 20 分钟演讲的核心目标:梳理从推理基本原理到 vLLM 与 llm-d 在生产环境中的部署实践,并介绍 Red Hat 的开源推理技术栈。
Red Hat 坚信“AI 的未来是开放的”(The future of AI is open),这种开放性必须贯穿整个技术栈:开放模型(Open Models)、开源推理服务引擎(Open Inference Servers)、开放基础设施(Open Infrastructure)以及开放部署架构(Open Serving)。Red Hat 坚信开源生态是推动 AI 持续向前发展的核心动力,并通过主导和支持开源推理引擎 vLLM,践行将开源 LLM 普惠全球的使命。
- **演讲者背景**:Rob Greenberg,Red Hat AI 首席产品经理,前 Neural Magic 团队成员。
- **核心主张**:全栈开源(Open Stack),覆盖模型、推理引擎、调度与底层硬件适配。
- **关键引擎**:vLLM 作为事实上的开源推理服务标准引擎,是 Red Hat 推理战略的核心支柱。
---
### [01:32](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=92s) 大语言模型推理的基本机制:自回归、KV Cache 与两阶段拆分
从底层逻辑来看,推理(Inference)即使用已训练完成的模型根据输入的 Prompt 生成文本的过程。在硬件层面上,输入提示词进入部署在 API 端点、本地 GPU 或笔记本上的推理服务器,模型进行矩阵运算后返回响应。本质上,基于 Transformer 架构的 LLM 并非传统的线性回归或随机森林等预测型 AI,而是一个通过大量线性代数运算来预测序列中下一个 Token 的“黑盒函数”(Black Box)。
LLM 文本生成的核心机制是**自回归(Auto-regressive)**,即模型必须单步逐个预测下一个 Token,再将它们依次拼接为人类可读的连续句子。为了避免生成每个新 Token 时重复处理所有历史 Token 所带来的巨大算力浪费,**KV Cache(键值缓存)** 应运而生。它是大模型推理中最重要的突破之一。
整个 LLM 推理流程在架构上被清晰地拆分为两个截然不同的阶段:
1. **Prefill(预填充阶段/Prompt 阶段)**:一次性接收并并行计算输入 Prompt 的所有 Token,并将其 Key/Value 状态写入 KV Cache。
2. **Decode(解码阶段/生成阶段)**:进入自回归循环,结合已有的 KV Cache,每次只迭代计算并生成一个新 Token,直到命中终止符。
```mermaid
flowchart LR
accTitle: LLM Inference Lifecycle with KV Cache
subgraph S1["1. Prefill 阶段"]
A["输入 Prompt"] --> B["并行计算上下文"]
B --> C["写入 KV Cache"]
end
subgraph S2["2. Decode 阶段"]
C --> D["单步自回归迭代"]
D --> E["预测下一个 Token"]
E --> F{"是否结束?"}
F -- 否 --> D
F -- 是 --> G["生成最终文本"]
end
H["调度器 (Scheduler) / Kubernetes Pods"] -.-> S1
H -.-> S2
```
- **黑盒本质**:Transformer 依赖庞大的数据与参数堆叠,核心运算目标高度聚焦于“预测序列中的下一个 Token”。
- **KV Cache 价值**:消除历史上下文的重复计算,使长时间对话与长文本生成在算力上可行。
- **调度器(Scheduler)角色**:在 Kubernetes 等容器化架构中充当“流量交警”,智能管控 Token 与请求的流向,是大规模扩展的核心前提。
---
### [05:23](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=323s) 生产落地挑战:算力瓶颈、Token 需求爆发与 Agent 推理扩展
推理是生成式 AI 在生产环境中的生命线,也是系统真正产生成本、面对延迟和吞吐考验的地方。当前企业面临着严峻的现实制约:模型参数规模持续攀升(从早期的 LLaMA、MPT、Falcon,演进至如今架构更庞大的顶尖开源模型),专用硬件加速器(GPU)供应极度紧张。与此相伴的是企业对“Token 极致利用(Token Maxing)”的狂热追求——管理层普遍期望借助 AI 生成更多代码、更多产出,推动业务极速创新。
更关键的技术转折点在于**智能体与推理模型(Agentic Reasoning)**的崛起。传统 LLM 往往只需单次前向传播(例如输入一个 Prompt 生成 439 个 Token);而具备思考链(CoT)与工具调用能力的 Agent 模型(如 Claude 思考模式、DeepSeek-R1、OpenAI o1 等)会进行多轮自我校验、分支路径探索与循环调用。这种推理扩展机制带来了显著的代价与回报:
- **Token 消耗量**:相比传统单次调用暴增高达 **20 倍**。
- **算力需求**:推理阶段消耗的算力可激增达 **150 倍**。
- **产出收益**:换取了最终答案准确率与复杂任务解决能力的质的飞跃。
---
### [08:10](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=490s) 企业级推理诉求:多模型生态与统一推理服务栈的价值
回顾开源模型的演进历程,自 2022 年底 ChatGPT 爆发后,Meta、Mistral、阿里巴巴(Qwen)、NVIDIA 等机构持续开源了一系列强大的权重模型。如今开源社区每周都会涌现刷新排行榜的顶尖模型,在逻辑推理和 Agent 工作流中已能与顶级闭源提供商(如 OpenAI、Anthropic)正面抗衡。
面对开源模型的爆发式增长,企业不可能依赖“单模型通吃”的策略,而是必然采用多模型协同体系。这就对底层的推理服务栈提出了严苛要求:
| 核心维度 | 自建/碎片化推理栈的痛点 | 现代化统一推理栈 (vLLM / llm-d) 的优势 |
|:--- |:--- |:--- |
| **硬件与模型解耦** | 为每种模型或专用硬件开发适配逻辑,维护负担极重 | 实现 **Any Model, Any Server, Any Hardware** 的全通用抽象 |
| **扩展性 (Scalability)** | 单节点吞吐受限,难以应对超大并发与长文本 | 原生支持分布式推理、智能请求路由与多模型协同并发 |
| **稳定性与维护成本** | 团队无法针对企业内 20 种不同的推理服务逐一维护和排错 | 标准化推理服务端,降低企业拥抱新开源模型的集成与运维门槛 |
正如 Greenberg 所强调的,企业无法承受每引入一个新模型就要重新学习一套全新推理架构的代价;建立跨硬件、跨云环境的标准化开源推理层,是企业将 AI 真正规模化落地的必由之路。
### [09:58](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=598s) 成本重心转移与红帽的企业级 GenAI 推理架构
在现场进行的一个快速举手问卷中,讲者向观众抛出了一个经典问题:从长远来看,模型的训练(Training)和推理(Inference)究竟哪个成本更高?台下观众几乎一致选择了推理。讲者笑着指出,如果倒退五六年前问同样的问题,答案会完全不同;这种认知的颠倒清晰地展示了整个 AI 生命周期的演进速度——随着模型走向实际生产应用,推理已经成为成本和资源占用的绝对大头。
红帽(Red Hat)致力于提供一套完整的企业级 GenAI 推理平台。虽然红帽在模型训练、微调(Fine-tuning)和可观测性(Observability)等全流程均有布局,但本次分享的核心重点在于推理层。对于企业而言,底层存在各种异构算力,上层有层出不穷的新模型与新架构,而推理服务层正是连接所有新模型能力与底层物理硬件的关键枢纽。
```mermaid
flowchart TD
accTitle: LLM Inference Ecosystem
accDescription: Architectural connection from models through the inference engine to heterogeneous hardware.
subgraph Models["上层模型生态 (Models)"]
M1["开源/专有模型<br/>(Gemma, Nemotron, Kimi 等)"]
M2["量化/压缩模型<br/>(FP8, Speculative Decoding)"]
end
subgraph Serving["核心推理层 (Inference Layer)"]
VLLM["vLLM 推理引擎<br/>(性能优化 / 统一抽象)"]
LLMD["llm-d 分布式调度<br/>(K8s 原生 / 智能路由 / 解耦 Prefill-Decode)"]
end
subgraph Hardware["底层异构算力 (Hardware)"]
H1["NVIDIA / AMD / Intel GPU"]
H2["Google TPU / AWS Trainium / IBM"]
end
Models --> Serving
Serving --> Hardware
```
---
### [11:12](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=672s) vLLM:连接任意模型与异构硬件的标准引擎
在整个推理平台的中枢,正是扮演核心角色的 vLLM。如果市场上每一个模型都需要自己专属的推理服务器,那么支撑各种模型和架构所带来的运维管理开销将变得不可承受。vLLM 仅用了大约两年时间,就从加州大学伯克利分校 Sky Computing Lab 的一个学术研究项目,跃升为整个行业的事实标准,在 GitHub 标星数和实际使用量上均处于领先地位。vLLM 不仅解决了模型落地的兼容性问题,更在性能优化层面带来了质的飞跃。
vLLM 实现了"任意模型运行在任意硬件上"(Any Model to Any Hardware)的愿景,打破了单一硬件厂商的锁定。它不仅深度适配 NVIDIA 架构,还全面支持 AMD、Intel、AWS Trainium 以及 Google TPU。红帽拥有全职的推理工程团队,与 Gemma、Nemotron 以及 Kimi 等前沿大模型提供方直接合作,实现所谓的"Day-0 兼容支持"(Day-zero Enablement)。这意味着开源社区发布新模型的第一天,用户就能直接在 vLLM 上将其跑起来并用于构建实际应用。红帽是 vLLM 社区的第一大贡献者(Number One Contributor),并定期举办双周 vLLM Office Hours 进行技术交流与优化探讨。
- **多硬件解耦**:企业可自由选用 NVIDIA、AMD、Intel、IBM 或公有云定制芯片(如 AWS Trainium、Google TPU),底层无需重写推理逻辑。
- **混合部署自由**:支持公有云与本地私有化(On-prem)部署,特别契合金融、电信等强监管行业对数据控制、成本与延迟的严苛要求。
- **生态驱动力**:作为去年增长最快的开源 AI 项目之一,vLLM 正在驱动新一轮开源 AI 创新的爆发。
---
### [14:59](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=899s) 模型层压缩优化:FP8 量化与精度无损压缩
除了推理引擎本身的算力调度,模型本身的轻量化也是降本增效的核心抓手。红帽在 Hugging Face 上维护了公开的 Red Hat AI 仓库,团队不仅专注于 vLLM 引擎工程,也是模型优化与压缩领域的专家。通过量化(Quantization)与投机采样(Speculative Decoding)等技术,模型可以在各类硬件上以更高的吞吐量和更低的延迟运行。
传统模型从实验室发布时通常采用 BF16(BFloat16)格式,权重以全精度表示。量化本质上是一种模型压缩技术,讲者打了一个生动的比方:就像把原本精确记录的圆周率 $\pi$(3.141592...)直接简化表示为 3。借助红帽开源的 `LLM Compressor` 工具库,团队能够对模型进行 FP8 等低精度量化。FP8 格式的模型体积仅有 BF16 的一半,但红帽发布的每一个 FP8 模型在主流基准测试中的精度损失均被严格控制在 1% 以内,以极微小的精度代价换取了单 Token 输出时间(Time Per Output Token)的显著缩短和硬件利用效率的大幅提升。
---
### [16:44](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1004s) llm-d:Kubernetes 与 vLLM 结合的分布式推理平台
当面对更大规模的模型以及极高的并发请求时,单节点推理引擎逐渐暴露出瓶颈,这正是分布式推理项目 `llm-d` 应运而生的背景。讲者将 llm-d 形容为"Kubernetes 的全部优势与 vLLM 的全部优势的完美联姻"(A marriage between all the benefits of Kubernetes and all the benefits of vLLM)。llm-d 是红帽与 Google、NVIDIA、Hugging Face、CoreWeave 等生态伙伴共同发起的开源项目,旨在突破单机推理的极限。
传统微服务架构中基于统一 HTTP 请求的负载均衡在 LLM 场景下彻底失效。传统的 Web 请求成本低廉、尺寸均匀、QPS 极高;而 LLM 请求的计算负载差异极其悬殊——可能一个实习生只发来一句话问"法国的首都在哪里?",而一位资深工程师则直接粘贴进整篇几十页的 Jupyter Notebook 代码。针对输入负载高度不均的特性,llm-d 引入了具备 LLM 感知能力的智能路由器(LLM-aware Router),能够根据输入特征将请求精准调度至最合适的 Pod,并原生支持 Prefill(预填充)与 Decode(解码)的解耦分离(Disaggregated Prefill and Decode),大幅提升并发承载能力并满足严苛的 SLO。
```mermaid
flowchart LR
accTitle: llm-d Architecture and Intelligent Routing
accDescription: LLM-aware router dispatches heterogeneous requests into specialized pods or disaggregated stages.
subgraph Ingress["客户端请求接入"]
R1["短文本请求<br/>(例如: 简单问答)"]
R2["超长文本请求<br/>(例如: 完整 Notebook)"]
end
subgraph Router["llm-d 分布式调度层"]
LMR["LLM 感知智能路由器<br/>(LLM-Aware Router)"]
end
subgraph Execution["解耦与异构执行集群"]
P_Prefill["Prefill 计算密集节点<br/>(加速处理长 Prompt)"]
P_Decode["Decode 显存带宽密集节点<br/>(自回归生成 Token)"]
end
R1 --> LMR
R2 --> LMR
LMR -->|"按负载/阶段拆分"| P_Prefill
P_Prefill -.->|"传递 KV Cache"| P_Decode
```
---
### [20:02](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1202s) 现场互动:智能体容错机制与可观测性度量
在演讲最后的问答环节,现场观众提问关注分布式环境下 Agent(智能体)工作流的容错与恢复能力:当 Agent 在执行多步推理任务中途失败或走偏时,负载均衡器和推理集群如何处理容错,是否支持从失败状态回滚或恢复。
讲者对此作出了积极回应:
- **原生可观测性指标**:vLLM 开箱即集成了基于 Prometheus 的遥测与指标采集系统,能够实时监控诸如首字延迟(Time to First Token, TTFT)、每个输出 Token 耗时(Time Per Output Token, TPOT)、整体延迟和吞吐量等核心指标。
- **Agent 追踪与容错探索**:针对多轮交互与 Agent 状态的失败重试与轨迹回放(Agentic Traces),团队目前正在进一步深入探索与研发,以帮助开发者在复杂工作流发生异常时实现更智能的断点续传与调度容错。
### [20:58](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1258s) Agent 与工具调用(Tool Calling)的推理与路由优化
随着大语言模型逐步拓展到工具调用(Tool Calling)和智能体(Agent)工作流,推理系统的核心诉求发生了显著变化。在复杂的 Agent 交互中,开发者需要清晰洞察模型究竟调用了哪项工具、输入与输出参数是什么、执行在哪个环节出现了偏差,以及系统如何更高效地对推理路径进行逻辑推导与错误定位。当涉及实际的计算工作负载时,推理架构必须确保每一个解析任务(Resolution)都能被精准路由到最合适、最高效的计算节点上。
针对这些前沿挑战,Red Hat 正依托 llm-d 和 vLLM 开展大量活跃的研究与落地工作。团队一方面致力于保障主流前沿模型在工具调用场景下具备高效的执行力,另一方面积极与开源社区紧密协作,持续投入并完善针对 Agent 与工具调用能力的标准化评测体系,以便向行业公开发布更多可量化的基准测试数据。
```mermaid
flowchart TD
accTitle: Tool Calling and Routing Flow
subgraph AGENT ["Agent 推理与工具调用"]
direction TB
A["用户请求 / 任务输入"] --> B["LLM 推理与决策"]
B --> C{"是否需要工具调用?"}
C -- 是 --> D["调用外部 Tool / API"]
D --> E["捕获输入/输出与可观测性追踪"]
E --> B
C -- 否 --> F["生成最终响应"]
end
subgraph ROUTING ["llm-d & vLLM 智能调度层"]
direction TB
G["请求分析与上下文评估"] --> H["KV Cache 感知路由"]
H --> I["分发至最佳计算节点 (GPU/TPU)"]
end
B -. 动态分发.-> G
```
---
### [21:40](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1300s) FP8 模型量化差异与 Red Hat 模型版本解析
在现场问答环节中,一位与会者提出了具体的技术疑问:用户在 Hugging Face 上既看到了 Qwen 官方发布的 `Qwen-36-27B-FP8` 模型,也看到了 Red Hat 发布的同规格版本,两者之间到底存在什么技术差异,使用 Red Hat 维护的版本是否有额外优势?
讲师对此进行了详细澄清:Red Hat 所采用的 vLLM 内核与开源社区上游(Upstream)保持完全同步,而在模型权重方面,如果原始模型提供方已经发布了标准的 FP8 动态量化版本,Red Hat 通常不会重复制作。FP8 量化主要细分为两种常见实现方式:**FP8 Block 量化**与 **FP8 Dynamic 量化**。两者的主要区别在于针对底层硬件架构所做的微调与取舍:
- **权重与激活值处理**:Red Hat 在制作特定模型的 FP8 量化版本时,可能会针对模型权重(Weights)或激活值(Activations)采用针对性的量化策略,以期在 NVIDIA 等特定硬件加速卡上榨取更高的执行速度与吞吐量。
- **性能等价性**:如果原始厂商发布的模型与 Red Hat 发布的模型均基于完全相同的 FP8 Dynamic 方案且未做特殊硬件调优,那么两者在 vLLM 引擎上的运行性能是完全一致的。
---
### [22:51](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1371s) llm-d 开源属性与 Red Hat AI 产品商业化布局(OpenShift AI)
针对现场关于开源许可与企业级产品集成的提问,讲师明确指出 **llm-d 是一项完全彻底的开源项目**。随后,讲师梳理了演讲中介绍的各项技术组件在 Red Hat 整体企业级 AI 产品矩阵中的落地形式:
演讲中展示的整套大规模推理架构目前已全面整合进 OpenShift AI 体系,并以 **Red Hat AI Enterprise** 这一商业套件形式对外交付。该套件打包了完整的端到端 AI 生命周期能力,为企业提供从模型训练、微调(Tuning)、可观测性监控到底层高性能分布式推理(包含 vLLM 与 llm-d)的一站式支持。
为了满足不同企业的差异化诉求,Red Hat 提供了两种灵活的产品形态(SKU):
| 产品方案 (SKU) | 包含的核心组件 | 适用场景与定位 |
|:--- |:--- |:--- |
| **Red Hat AI Enterprise** | OpenShift AI + OpenShift Container Platform (OCP) + AI 加速器授权 | 覆盖模型全生命周期的完整平台,涵盖训练、微调、全链路可观测性以及完整推理技术栈。 |
| **Red Hat AI Inference** | 经优化与量化的官方模型目录 + vLLM 引擎 + llm-d 分布式扩展层及核心推理组件 | 专为生产级纯推理场景设计的轻量级订阅方案,成本更低、性价比更高,适合专注于模型高并发部署的企业。 |
演讲最后,讲师向全场观众致谢,并邀请感兴趣的开发者移步展台(Booth)进行更深入的一对一技术交流。
## Notable quotes
> [00:04](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=4s) The future of AI is open — Rob Greenberg
> Training gets the headlines, but inference is where generative AI meets production — and where the costs, latency, and scaling challenges actually live. — Rob Greenberg
> [08:10](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=490s) Any Model, Any Server, Any Hardware — Rob Greenberg
> [11:12](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=672s) Any Model to Any Hardware — Rob Greenberg
> [16:44](https://www.youtube.com/watch?v=cDTxNxzDIvM&t=1004s) A marriage between all the benefits of Kubernetes and all the benefits of vLLM — Rob Greenberg
## Mentioned
Rob Greenberg, Red Hat, Neural Magic, vLLM, llm-d, Kubernetes, Google, NVIDIA, Hugging Face, AMD, Intel, Google TPU, AWS Trainium, IBM, CoreWeave, Meta, Mistral, Alibaba, Qwen, Gemma, Nemotron, Kimi, Claude, DeepSeek-R1, OpenAI o1, LLM Compressor, Prometheus, OpenShift AI, Red Hat AI Enterprise, Red Hat AI Inference
## Video description
Rob Greenberg - Principal Product Manager, Red Hat
Training gets the headlines, but inference is where generative AI meets production — and where the costs, latency, and scaling challenges actually live. This session demystifies LLM inference from the ground up: how models generate tokens, why the KV cache and the prefill/decode split matter, and what an inference server actually does to make GPUs go "brrrr." From there we turn to the hard part — running inference at scale. As reasoning and agentic workloads drive token demand 20x higher (and compute 150x higher), single-node serving stops being enough.
We'll show how Red Hat approaches distributed inference with llm-d, a Kubernetes-native, open-source initiative built jointly with Google, NVIDIA, Hugging Face, and others. You'll see how disaggregated prefill and decode, intelligent request scheduling, KV-cache-aware routing, and hardware-agnostic serving across NVIDIA, AMD, Intel, and Google TPUs come together to maximize GPU utilization and hit demanding SLOs — across edge, private, and public cloud.
We'll connect the dots from vLLM as the de facto inference engine to llm-d as the scaling layer, rounding out the picture with validated and quantized models that stretch more tokens out of fixed hardware.
Attendees will leave understanding not just what inference is, but how to deploy it efficiently and reliably at enterprise scale.
[Source](https://www.youtube.com/watch?v=cDTxNxzDIvM)
Source quotes
[0:04] Rob Greenberg: The future of AI is open
Rob Greenberg: Training gets the headlines, but inference is where generative AI meets production — and where the costs, latency, and scaling challenges actually live.
[8:10] Rob Greenberg: Any Model, Any Server, Any Hardware
[11:12] Rob Greenberg: Any Model to Any Hardware
[16:44] Rob Greenberg: A marriage between all the benefits of Kubernetes and all the benefits of vLLM
Source quotes
[0:04] Rob Greenberg: the future of AI is open
[1:32] Rob Greenberg: predict the next token in a sequence
[1:32] Rob Greenberg: Where is the capital of Victoria, Australia?
[5:25] Rob Greenberg: AI in production
[5:25] Rob Greenberg: token maxing
[8:09] Rob Greenberg: any model, any server, any hardware
[11:14] Rob Greenberg: Day Zero enablement
[17:00] Rob Greenberg: marriage between all the benefits of Kubernetes and all the benefits of vLLM kind of married into one project
[17:00] Rob Greenberg: What's the capital of France?
[20:16] Rob Greenberg: agentic traces
[21:39] Rob Greenberg: llm-d is 100% open source
Original transcript
[0:04] Well, good afternoon, um, everybody. Um,
so yeah, my name is Rob Greenberg. I'm a
[0:08] principal product manager at Red Hat AI. Um,
I joined Red Hat about a year and a half ago,
[0:14] um, from a company called Neural Magic, where
we did, um, LLM compression and optimization.
[0:20] Um, we started as a company that compressed models
for CPUs, so think NLP and computer vision models,
[0:25] and then um, chat GPT came about, and
we really pivoted. Um, and now, yeah,
[0:30] I'm here to talk to you all today about vLLM
and LMD, um, and inference, uh, in production.
[0:36] So, an intro So, this this talk will be kind of,
you know, we have 20 minutes, so it'll be pretty
[0:39] quick, but I wanted to cover a few different, um,
topics to just set the baseline with everyone. Uh,
[0:44] so the first one will be inference fundamentals,
so understanding, you know, what inference is,
[0:48] why it's important, um, why inference matters, and
then we'll very briefly at the end touch upon Red
[0:53] Hat's AI stack, um, and our inference stack. So,
at Red Hat, we believe the future of AI is open,
[1:00] right? That means the entire stack, open models,
open inference servers, open infrastructure,
[1:06] um, open serving, right? We want, you know, at
Red Hat, we really believe that the open source
[1:10] ecosystem is what's going to drive AI forward,
um, and we're big proponents of that message.
[1:15] Um, we are also in a, um, our mission is to bring
open source LLMs, um, to the world via vLLM. So,
[1:23] vLLM is an open source inference server, um, that
we're really, really excited about, and we've been
[1:27] working on for many years, and we'll kind of get
into, uh, talking a little bit more about that.
[1:32] Okay, so I'm sure we have different levels
of understanding of inference, so very,
[1:36] very basically, um, inference is kind of this
this diagram sums it up really nicely, right?
[1:41] Inference is the process of using a trained model,
uh, to generate text in response to a prompt,
[1:46] right? So, prompt goes in, everyone here has used
chat GPT, we've all probably used Claude as well,
[1:51] um, but really the process of inference is prompt
goes in, it gets processed, um, by a model, right?
[1:57] Um, which is served somewhere. You have
a model, you have an inference server,
[2:00] you have hardware, whether it's any an API
endpoint or you're doing yourself on your own
[2:04] GPU or on your own laptop. We can kind of get into
those details. And then the model will then go in
[2:09] and kind of give you a response back. So that's
what inference is at a high level. What is a
[2:13] model, right? The next question is, okay, I
understand what inference is. Prompts go in,
[2:17] responses go out. How does a model work? All
a model really is, it's a function to predict
[2:22] the next token in a sequence, right? I mean,
I say model, I mean LLM, large language model,
[2:27] generally based off the transformers architecture.
But really all it is, right, is words are going
[2:32] in, it's a bunch of linear algebra, really
to just predict the next token in a sequence.
[2:39] Here's just a little meme, right? So this
is your machine learning and it's the idea
[2:44] that data goes in and it's just a pile. You
don't really know what's going in and out.
[2:48] And this just kind of highlights, yeah,
just keep doing it again until, you know,
[2:52] it's doing the right things. And this really
just kind of goes to show that like these models
[2:56] are traditionally known as black boxes, right?
These aren't predictive AI models like linear
[3:01] regression models or random forest models. These
are black box transformer models. So what goes in,
[3:07] we don't know what's going to come out. All we
know is the model's predicting the next token.
[3:11] In terms of generating text with the model itself,
right? The model functions The model functions
[3:16] auto-aggressively. So what auto-aggressively means
is basically one at a time the next token will be
[3:22] generated. And what you see on the right is a
visual representation of what's called the KB
[3:27] cache, right? A lot of us know what caching is
because of the internet, because of browsers,
[3:31] right? You have cache, you have cookies.
It's the same kind of idea. So as you go in
[3:36] and you prompt the model and get a response back,
the model's then predicting sequential tokens.
[3:41] Right? And And these then get chained together
and these form human-readable sentences. And
[3:46] this is how we understand how text is how models
generate text. Um, talked about this a second ago,
[3:52] but key optimization is caching, right? So,
pro- uh processing all previous tokens is really
[3:58] expensive, right? You can imagine if you have to
keep loading in the context for a short sentence,
[4:03] um it just keeps getting longer and you're
throwing away all the previous computation. So,
[4:08] caching was really a um a really big breakthrough
in terms of how these LLMs actually generate text.
[4:14] Um, this is just a really high-level
view of the architecture, right? So,
[4:18] there are two stages of inference as well that
we can talk about. So, there's the prefill stage,
[4:22] which is that prompt stage, right? So, a
prompt goes in, goes into the inference server,
[4:27] um that then gets uh cached, right? So,
where is the capital of Victoria, Australia?
[4:31] Um, and then you can see um the decode stage,
decode you can think of as the generation stage,
[4:38] where the model's actually generating text
back to you. Um, this is the auto-regressive um
[4:43] nature of multiple iterations predicting the next
token. With caching in play, this is how you get
[4:48] uh better performance. Right? And none of this
is possible without what's called the scheduler,
[4:53] and the scheduler will go in and basically like
controlling the traffic, um right? Of like what
[4:57] tokens are being sent where, um as you start
thinking about like a Kubernetes architecture
[5:02] with different pods, um and kind of how to
actually do this thing at scale. So, we we kind of
[5:07] covered a basic overview of of what inference is,
right? It's the process of feeding in a prompt,
[5:13] um and then getting a uh generated token, um
which is then read as text by us humans back, um
[5:18] and these two different stages of prefill, right?
Which is that prompt stage, and then decode. Um,
[5:23] so, we we talked a little bit about that. Why
does inference really matter though, right?
[5:26] Under the hood. Um, and really inference is AI in
production. Right? At its at its absolute core,
[5:33] this is what is powering the applications.
This is what makes AI feel alive. Um,
[5:38] this is what's actually running when you get that
prediction, right? And then this has been the way
[5:43] that AI's worked since it was, you know, started
many, many years ago, um over a decade ago,
[5:49] uh even with predictive AI. Um but inference is
really the the real-live action of AI happening.
[5:55] Now, while inference is super important, right? Um
it's also really expensive. Um so, models are only
[6:01] getting bigger. Um I'm sure all of you have, you
know, many of you have been keeping up with what's
[6:05] going on in the open source um with models, you
know, we started out with Llama models, MPT model,
[6:11] Falcon. These are models from 2022, 2023 uh time
frame. And now, you know, Kimmy K3, NeMo-1 Ultra,
[6:19] a lot of these models are just keep getting bigger
and they're advancing in capability, but this
[6:23] creates constraints, right? And and cost is one
of them. Um specialized hardware accelerators, I'm
[6:28] sure everyone in this room has felt the pain of
trying to get a GPU, whether it's on the cloud or,
[6:34] you know, at your company, to figure out how do we
actually take advantage of the latest and greatest
[6:39] models? And we can talk a little bit about some
different methods on how to do that in just a
[6:43] little bit. Um but then the demand for tokens,
right? Everyone's heard about this concept of
[6:47] token maxing. Um every company wants to you move
fast. Every company wants to innovate with AI.
[6:53] Um and to do that, right? It's every every CEO
is saying, "Use more tokens, generate more code,
[6:59] generate more output. How do we move faster?" Um
agents and agentic reasoning, um which is kind
[7:05] of a newer um group of LLMs that has come out and
have really evolved over the last few years, um is
[7:12] actually driving inference scaling significantly.
Right? So, what, you know, here's just a sample
[7:17] input to a traditional LLM to a traditional
LLM. And what you can see is without reasoning,
[7:22] right? The model may just be going through once,
just a singular forward pass auto regressively.
[7:27] Um and you might get 439 tokens that the model
is kind of using to generate, right? So, the
[7:32] model's getting this prompt in, then generating
439 tokens. That has a cost. For age for agents,
[7:39] that cost could be up to 20x more, right? We've
all seen Claude think, {quote} and {unquote},
[7:44] where basically it will go in and do these
kind of iterative loops of checking itself,
[7:48] whether that be doing tool calls, whether that be
assessing different pathways, right? It's going
[7:54] down different trees. This is really expensive.
So, more tokens, 150x more compute potentially,
[8:01] but the the big breakthrough here is
that the answer is correct, right? So,
[8:05] we've all seen this kind of happen in real time.
These models getting better. [sighs and gasps] So,
[8:10] now we'll talk about a little bit why
this really matters to the enterprise,
[8:13] right? So, we talked a little bit about open
models, the explosion of open weight models
[8:18] back in March of 2022 three, we were kind of
at the very early days. You know, we had Llama
[8:24] in 2022 in November. I'm sure we all remember when
ChatGPT came out from OpenAI, and that really kind
[8:30] of proliferated a long tail of releases from a lot
of key model providers, right? So, Meta, we have
[8:36] Quan, we have Mistral, Nvidia, all these different
companies kept putting out open source models. And
[8:42] today, you know, in the news, it feels like you
can go and check every single week there's a new
[8:46] model at the top of the leaderboard, right? That
is now crushing in agentic workflows, in reasoning
[8:53] that can compete with a lot of the closed model
providers like an Anthropic, like a an OpenAI.
[8:59] So, what a well-optimized inference serving
stack really enables you to do is, we talked
[9:05] about before, right? Any model, any server,
any hardware. The inference server layer is
[9:10] really what allows you to do this, right? So,
this is what gives you the speed. It gives you
[9:15] the scalability, right? How do I actually, you
know, serve multiple models potentially at once?
[9:20] We'll talk a little bit about the end like
distributed inferencing. So, as these models get
[9:23] bigger and the workloads get larger, how do you
actually route and do intelligent scheduling and
[9:28] things like that? Stability, right? So, a lot of
companies will kind of build their own hardware,
[9:34] build their own inference server on top,
but what happens as a as an enterprise when
[9:38] you want to now use a new model, right? You
can't learn 20 different inference servers
[9:44] and each of their kind of ins and outs as a
large company that wants to actually scale AI,
[9:50] right? We don't think there's going to be a
one model solution at Red Hat. We see kind of
[9:54] a combination of multiple models as the way this
is going to evolve and standardizing the inference
[9:58] server layer is really what can help connect all
those new models, all those new capabilities,
[10:03] all those advancements in architecture down
to your actual hardware that's available.
[10:08] Um this is a quick poll. I'm sure we all
know the answer. What do we think costs
[10:13] more to run in the long term, training or
inference? Who thinks Who thinks training?
[10:20] Okay, good. No one was asleep. Who thinks
inference? [snorts] Okay, that's correct.
[10:25] The answer is inference. Um but yeah, this is
basically this turned the world on its head if
[10:30] you look back five or six years. If you had asked
this question five or six years ago in this room,
[10:35] the answer would be very different, right?
So, I think this just this goes to show
[10:39] the speed and the evolution of where
we are in kind of this AI life cycle.
[10:44] Um very quickly, I'll just kind of give
an overview of Red Hat's inference stack
[10:49] and then I'll I'll save a few minutes at the end
for some some questions as well. So, what Red Hat
[10:55] does is basically we deliver an enterprise GenAI
inference platform as part of our inference piece
[11:03] as a as part of the entire story. So, we also do
training, we do fine-tuning, we do observability,
[11:09] but today we're talking about inference and this
is kind of a high-level view of our inference
[11:12] stack. So, um at the middle level, we talked a
lot about inference already. Let's talk about the
[11:17] inference server that makes this all happen and
that's vLLM, right? So, this is what the key is to
[11:24] unlock that picture of all models to all hardware,
right? If every single model had its own inference
[11:31] server, the amount of overhead you would have to
deal with to serve all these different models,
[11:36] all these architectures, would be too much to deal
with. And this is what vLLM critically solves,
[11:41] and it doesn't just solve it from a enablement
perspective, but from an optimization perspective.
[11:46] So, vLLM, for those of you that don't know,
in about 2 years went from a research project
[11:51] to an industry uh standard. Um and basically,
this came out of the Berkeley Sky Computing Lab,
[11:56] um very quickly gained steam as one of the
leading inference servers in the market,
[12:01] um and now is kind of at the lead in terms
of stars and GitHub usage over the last um
[12:08] probably last year at least or so. Um and really
the benefit here is, you know, what we've been
[12:13] talking about already, high performance. Right?
So, vLLM kind of is highly optimized for you know,
[12:20] specifically the Nvidia stack as well as AMD, um
Intel, um as well as uh Trainium. We we have we've
[12:27] done worked with um AWS. We've also worked with
Google on TPU enablement, which we talked about
[12:32] um at a Google summit um about a year or so back.
Um and really the benefits here are that you're
[12:37] not kind of locked in to any one specific hardware
vendor, whether you want to buy from Nvidia or you
[12:42] want to buy from Intel or you want to buy from
IBM, you can do that, and vLLM can still serve as
[12:46] that core inference server for your platform.
Um it's also really easy to use, right? So,
[12:51] at Red Hat, we have a full inference engineering
team that actually partners with a lot of the
[12:56] model providers themselves to ensure what's
called day zero enablement. So, when a new model
[13:02] comes out of a lab, call it, you know, Gemma 4,
call it NeMo Tron, call it Kimmy K2 or Kimmy K3,
[13:08] we work with those original providers to ensure
that on day zero, that model will run on vLLM.
[13:14] Right? A model on itself coming to the market in
the open source ultimately doesn't mean much if
[13:20] no one can run it. And vLLM kind of and our team
at Red Hat, along with the core contributors to
[13:25] vLLM across many companies, help make that reality
possible of like how do we get this thing live?
[13:30] How do I test this in my cloud code setup? How
do I run this with open code? How do I start
[13:34] doing the reasoning? How do I start building
applications? This is what vLLM enables,
[13:38] right? So that work in the community really pays
dividends throughout the whole ecosystem. Um I
[13:43] talked about all the companies that contribute to
vLLM and there are many. Um Red Hat notoriously is
[13:48] is the number one contributor um to vLLM. Uh we
also do a lot of work within the vLLM community.
[13:54] So we offer a bi-weekly LLM uh vLLM office hours
where we talk about all sorts of different topics
[14:00] um related to vLLM and inference and optimization.
So definitely stay tuned for those. Um
[14:08] And yeah, kind of you know, it's nice to
see different shout-outs and different kind
[14:11] of highlights. This is a a really nice one
that came out from the vLLM project team of
[14:15] one of the fastest-growing open-source AI projects
of the year last year. Right? So this isn't small
[14:21] small pennies. Um vLLM is really powering a
whole new wave of open-source AI innovation.
[14:28] Um this is just a really nice summary picture. So
if you've been taking photos, this is a good one
[14:32] to take pictures of, but really just anchors
home that vLLM is that middle connector layer
[14:37] of any model to any hardware, right? Wherever you
want. So you can run these things in the cloud,
[14:42] you can run these models on prem, right? Red
Hat, we do a lot of work with regulated customers
[14:48] who like to run AI models on prem and have
full control over cost, over performance,
[14:52] right? And these are things that vLLM can enable
you to do with this open-source model ecosystem.
[14:59] Um the next layer we talk very briefly
about is the model layer. Um so Red Hat AI
[15:06] is a uh public-facing repo on Hugging Face. So our
team at Red Hat, along with becoming vLLM experts,
[15:14] we are also model optimization experts. So we
do quantization, um we do other optimization
[15:20] techniques such as speculative decoding as well
to models to basically make them more performant
[15:26] on VLLM on whatever hardware that
you have of your choice. Right? So,
[15:30] when models come out from labs, traditionally
they come out in what's called BFloat16,
[15:35] um which is just full representation of each of
the weights. Um with techniques like quantization,
[15:40] it's really just model compression. Right?
So, instead of representing pi like 3.141592,
[15:46] you can just say three. And it turns out that
with a lot of these cutting-edge algo- rithms
[15:50] that we've been able to productize in the open
source um through a library called LLM Compressor,
[15:55] we're able to emulate the same baseline
performance as a full precision model. Right?
[16:00] And this was a really big breakthrough that you
can have a model that's represented say as FP8,
[16:05] um so half the size of the BF16 model. However,
the accuracy hit is less than 1% for every single
[16:12] FP8 model that Red Hat puts out on the Red Hat AI
Hugging Face. So, the trade-off of performance for
[16:18] accuracy is you you know, it's it's quite light.
And this is a kind of a really big benefit of
[16:23] what VLLM enables you to speed up and what Red Hat
does in terms of model compression and research.
[16:29] Here's just a graph um showing kind of
the impact of quantization. Right? So,
[16:34] you can just kind of see on the left it looks
like we're looking at uh time per output token.
[16:38] And you can just kind of see the performance of
the baseline model compared to the FP8 model.
[16:44] Um the last piece we'll talk about is kind of
the uh the biggest one. And this is the one I
[16:48] I would say I'm most excited about as we think
about the future of open models, open source,
[16:54] um as well as kind of inference serving.
And that's distributed inference. Um
[17:00] so, LLMD is a distributed LLM inference platform.
The way I like to explain it is a marriage between
[17:07] all the benefits of Kubernetes and all the
benefits of VLLM kind of married into one project,
[17:12] right? And it's really, you know, the goal
of LLMD is to enable this wide scale and this
[17:19] distributed inferencing framework so that you can
run larger models, serve more users concurrently,
[17:25] properly schedule where your workloads are
actually running, and it comes with some really,
[17:31] really awesome techniques out of the box
such as disaggregated pre-fill and decode
[17:37] that are really kind of unlocked a new tier
performance that you can unlock as these
[17:42] models continue to get bigger and we start
thinking about serve inference more widely.
[17:47] So, why distributed inference, right? On the left,
you can kind of see up here modern HTTP requests.
[17:54] So, the traditional like microservice model
is kind of dead when it comes to LLMs and AI
[18:00] inference serving mostly because HTTP requests
generally more uniform, they're load balanced
[18:07] because they're cheap, and you have like a high
QPS, right? Like there's not a lot of cost that
[18:13] you're paying to process workloads in that sense.
LLM requests are really different, right? Requests
[18:18] come in at very different sizes. You might have
an intern ask a sentence, "What's the capital of
[18:23] France?" You might have a senior engineer copy and
paste an entire Jupiter notebook in, right? So,
[18:29] you're having variable inputs, and really what
what LMD can help do is it has an LLM-based
[18:36] aware router that will help you load balance
and route the right requests to the right pods
[18:42] so that you're able to more cheaply process and
generate these inputs to get stronger outputs.
[18:51] This is just another view of kind of
some of the big benefits of LMD around um
[18:58] operatization Sorry, operation I can't even read
that word from here. Flexibility, performance,
[19:06] and how to operationalize your AI.
[19:09] This is like summary slide, but really so Red Hat
is not the only one that works on um LLMD. We work
[19:16] with a ton of different ecosystem partners as
well, such as Google, Nvidia, Hugging Face,
[19:21] CoreWeave um are all kind of part of this LLMD
initiative. Um, and really it's all about kind
[19:26] of the future of how do you optimize inference
even further beyond a single inference server,
[19:30] marry the benefits of ELM with Kubernetes to
achieve this kind of new scale. Um, so yeah, that
[19:36] was a quick overview. Um, all of this is kind of
do POCs at Red Hat uh for the Red Hat AI platform.
[19:43] Today we just covered the inference piece. There's
a lot more around training, tuning, security,
[19:48] governance, um tons of different layers that we
can kind of get into. Um, but yeah, hopefully
[19:53] this was educational and informative for you all
and thank you very much. Um, thanks. [applause]
[20:02] So I'm at the clock, but if there's like one
or two questions, I can try to do them fairly
[20:06] quickly. Otherwise, I'm at the Red Hat booth. Um,
we're right in the main exhibition hall, so feel
[20:11] free to find me today, tomorrow. Um, I'm here
until Thursday. So yeah, question in the front.
[20:17] Are you guys also have mechanical tools
for fault tolerance and if the agent goes
[20:24] in the wrong direction or fails, then
can we rewind that using the 40 spots?
[20:29] And how would the load balancer handle like
fault tolerance and uh you know, issues such as
[20:35] agent failed and now it has to resume from
where it failed, like the Yeah, so I mean,
[20:41] so traditionally VLM out of the box ships with
telemetry uh via Prometheus. Um, so there are
[20:47] logs that look at traditional LLM metrics like
time per output token, time to first token,
[20:52] latency, throughput. Um, we are investigating now
more into like what's called like agentic traces,
[20:58] right? So as you get into different capabilities
like tool calling, right? You want to see
[21:01] what tool did this model call, um what was
the input and output, where did it go wrong,
[21:07] and how do you more efficiently like reason
through that? And then when you get to like the
[21:11] compute workload, how do you make sure that like
the resolution is routing to the right place? Um
[21:16] so we're we're doing a lot of active research with
LLMD and tool calling as well as just with VLLM
[21:21] and making sure that the top models are able to do
that effectively and working within the community
[21:27] um to also like invest in more evaluations there
so that we can kind of publish more of those
[21:31] results. But that's like an active area that we're
invested in. Yeah. It's a quick question. Yeah.
[21:40] Go ahead, go ahead. Okay, I'm sorry, quick
question. Uh also you're using VLLM with uh
[21:44] Qwen-36-27B-FP8. Yeah. Wanted to know is there
any advantage to running your version cuz I just
[21:52] you know Yeah. So our ver So and yeah, that you
guys have a version. So our our version of VLLM
[21:58] is the same version that's upstream. However,
the model. I mean, I'm talking about the model
[22:03] on Hugging Face. Right now I'm literally using the
Qwen version of three uh uh 36-27B-FP8, but I just
[22:10] noticed that you guys also have a Qwen-36-27B-FP8.
I mean, what's the difference between So Qwen's
[22:16] version and your version. So there's two types of
FP8. There's FP8 block and FP8 dynamic. Um there's
[22:22] minor tradeoffs that are being had depending
on the hardware that you're running it on so we
[22:25] could look at that. Uh but no, like if it's an FP8
dynamic model that Red Hat puts out versus I mean,
[22:30] we try not to make them if the original provider
puts it out. The only difference would be um if
[22:34] it's a different type of FP8 quantization,
maybe to the weights or the activations,
[22:38] we might do something slightly different uh to
try to get some speed up on Nvidia hardware or
[22:42] something like that. But otherwise, no, if it if
they're both FP8 dynamic, you would get the same
[22:46] performance on VLLM. Okay. Uh real quick, LLMD,
[clears throat] is that also open source? LLMD is
[22:51] fully open source. Yep. How does OpenShift AI fit
into this landscape that you just uh All of what
[22:59] I just shared is part of OpenShift AI. It's now
delivered as what's called Red Hat AI Enterprise,
[23:05] um which is really just it's a bundle of
OpenShift AI, um OpenShift Container Platform,
[23:10] and and an AI accelerator entitlement. So, really
you get the entire platform. So, we just went into
[23:14] the inference stack. However, OpenShift AI comes
with everything. So, we get everything, training,
[23:19] tuning, observability, plus everything I just
covered, LLMD, and the whole inference side. Um
[23:24] we also have an inference skew called Red Hat AI
Inference. So, if you just wanted the bits I spoke
[23:29] about, just, you know, the model catalog with
our quantized optimized models, VLAM and LLMD,
[23:35] um and a few other components, you could get
that just with a Red Hat AI Inference, which
[23:40] is another skew, a little bit more affordable,
um focused just at going after the inference.
[23:45] So, those are your like kind of the two options.
Yeah. All right, we're probably at time, um but
[23:51] thank you all very much. And again, I'll be at the
booth if you have any further questions. Thanks.