vLLM Router

vLLM Router is a centralized API gateway that provides a single entry point for routing requests to various vLLM services. vLLM Router simplifies the process of managing and accessing multiple vLLM models by abstracting away the complexities of individual service endpoints. It is built using FastAPI and Uvicorn, ensuring high performance and scalability.

Motivation

vLLM can be deployed as a server that implements the OpenAI API protocol, allowing it to be used as a drop-in replacement for applications using the OpenAI API. However, the current vLLM server hosts only one model at a time. This limitation can be challenging when deploying multiple vLLM models, as it requires managing separate API endpoints for each model.

vLLM Router addresses this challenge by providing a unified interface for accessing all the vLLM services. It acts as a proxy, routing requests to the appropriate vLLM service based on the specified model.

By using vLLM Router, developers can easily integrate various vLLM models into their applications without worrying about the underlying infrastructure. They can make API requests to the vLLM Router, specifying the desired model, and the router will handle the routing to the appropriate vLLM service.

Features

Single entry point for accessing multiple vLLM services
Dynamic routing based on model name
Seamless integration with Kubernetes using Helm for easy deployment and scaling
Built using FastAPI and Uvicorn for high performance and scalability
Simplifies the management and usage of vLLM models in applications

Architecture

The vLLM Router consists of the following components:

FastAPI Application: The core of the vLLM Router is a FastAPI application that exposes API endpoints for handling incoming requests. It receives requests from clients and routes them to the appropriate vLLM service based on the specified model.
Kubernetes Integration: vLLM Router is designed to work seamlessly with Kubernetes. It leverages Kubernetes' service discovery mechanism to route requests to the vLLM services running within the cluster.
Configuration: The vLLM Router reads the model configuration from environment variables, which are set based on the values defined in the Helm chart's values.yaml file. This allows for easy configuration and updates without modifying the router's code.

Installation

Prerequisites

Kubernetes cluster
Helm (version 3+)
Docker

Deployment

Clone the vLLM Router repository:

git clone https://github.com/yourusername/vllm-router.git

Build the vLLM Router Docker image:
```
cd vllm-router
docker build -t quay.io/llm_router/vllm-router:latest .
docker push
```
If you want to push the image to a different registry, update the router.image value in the values.yaml file.
Deploy the vLLM Router using Helm:
```
cd vllm-chart
```
Update the values.yaml file with the desired configuration for your vLLM models and the vLLM Router.

Install the Helm chart:
```
helm install vllm-router .
```
This command will deploy the vLLM Router and the configured vLLM models in your Kubernetes cluster.
Access the vLLM Router:
```
kubectl port-forward service/vllm-router 8000:8000
```
The vLLM Router will be accessible at http://localhost:8000.

Usage

To use the vLLM Router, make API requests to the following endpoint:

http://localhost:8000/v1/completions

Include the desired model in the request payload, and the vLLM Router will route the request to the appropriate vLLM service based on the model name.

Example requests:

curl http://localhost:8000/v1/completions -H "Content-Type: application/json" -d '{ "prompt": "San Francisco is a", 
"model": "TheBloke/Llama-2-13B-chat-GPTQ", "max_tokens": 30, "temperature": 1}'

curl http://localhost:8000/v1/completions -H "Content-Type: application/json" -d '{ "prompt": "San Francisco is a", 
"model": "meta-llama/Llama-2-7B-chat-hf", "max_tokens": 30, "temperature": 1}'

Configuration

The vLLM Router and the vLLM models can be configured using the values.yaml file in the Helm chart. Update the file to specify the desired models, their resources, and other configuration options.

Refer to the values.yaml file for more information on the available configuration options.

Contributing

Contributions to the vLLM Router project are welcome! If you find any issues or have suggestions for improvements, please open an issue or submit a pull request on the GitHub repository.

License

This project is licensed under the Apache-2.0 license.

wangchen615/vllm-router