Sections
IntroductionOrientation01 · Why Inference Servers Exist02 · Where vLLM Sits03 · Anatomy of a vLLM SetupStage 1 — Core Concepts01 · The KV Cache02 · Prefill vs Decode03 · PagedAttention04 · Continuous Batching05 · Sampling ParametersStage 2 — The Engine01 · The Scheduler & Block Manager02 · Lifecycle of a Request03 · Prefix Caching04 · Quantisation05 · Speculative DecodingStage 3 — Running It Locally01 · Installing vLLM02 · Offline Batch Inference03 · The OpenAI-Compatible Server04 · Streaming & Client Patterns05 · The Getting-Started NotebookStage 7 — Case Studies01 · RAG Chatbot at Scale02 · Offline Batch Summarisation03 · Coding Agent on Long Context04 · Multi-Tenant LoRA on One GPU
Stage 3 — Running It Locally
2 min read
You have a server running, you've called it three different ways, and you can read its startup log. · ~3 days
Three stages of theory, and you haven't installed anything. That was deliberate: you now know what
gpu_memory_utilization does before you're asked to choose one, and the startup log you're about to
read is a list of things you can already name.
This stage is short, because the hard part is behind you. It is also the stage where the article's promise gets tested — everything here runs on a free Colab T4.
Pages
| # | Topic | What it covers | Status |
|---|---|---|---|
| 1 | Installing vLLM | uv versus pip; matching CUDA and driver versions; the Docker route; the five install errors everyone hits; getting a Colab T4 ready |
🚧 |
| 2 | Offline Batch Inference | The LLM class end to end; SamplingParams; why batch mode is the honest way to measure throughput |
🚧 |
| 3 | The OpenAI-Compatible Server | vllm serve; completions versus chat completions; chat templates; curl and the openai client |
🚧 |
| 4 | Streaming & Client Patterns | Server-sent events; streaming with the openai client; timeouts, cancellation, and the abandoned request |
🚧 |
| 5 | The Getting-Started Notebook | One Colab-runnable artifact tying Stages 0–3 together: load, generate, serve, stream, measure | 🚧 |
What you'll be able to do by the end
- Install vLLM without breaking an existing environment, and diagnose it when it breaks anyway.
- Read a startup log line by line and say what each number means.
- Generate offline with the
LLMclass, and serve online withvllm serve. - Call the server with
curl, theopenaiclient, and a streaming client — and know what differs. - Measure TTFT and ITL on your own hardware, closing the loop on every experiment in Stages 0–2.
Before you start
One number decides whether any of this works: your GPU's compute capability must be 7.5 or higher. A Colab T4 is exactly 7.5 — at the floor, not above it. Check before installing:
nvidia-smi --query-gpu=name,memory.total,compute_cap --format=csv