# SGLang Router

SGLang router is a standalone module implemented in Rust to achieve data parallelism across SGLang instances.

### Installation

1. Install Rust
```bash
# Install rustup (Rust installer and version manager)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Follow the installation prompts, then reload your shell
source $HOME/.cargo/env

# Verify installation
rustc --version
cargo --version
```

2. Build the router
```bash
# Navigate to the rust directory
cd ./rust

# Build the project
cargo build

# Verify the binary works correctly
./target/debug/router --help
```

The help command will show available options:
```
Usage: router [OPTIONS]

Options:
      --host <HOST>                [default: 127.0.0.1]
      --port <PORT>                [default: 3001]
      --worker-urls <WORKER_URLS>
      --policy <POLICY>            [default: round_robin] [possible values: round_robin, random]
  -h, --help                       Print help
  -V, --version                    Print version
```

### Setting Up Workers

1. Launch worker instances
```bash
# Launch first worker on GPU 0
export CUDA_VISIBLE_DEVICES=0
python -m sglang.launch_server \
    --model-path meta-llama/Meta-Llama-3.1-8B-Instruct \
    --host 127.0.0.1 \
    --port 30000

# Launch second worker on GPU 1
export CUDA_VISIBLE_DEVICES=1
python -m sglang.launch_server \
    --model-path meta-llama/Meta-Llama-3.1-8B-Instruct \
    --host 127.0.0.1 \
    --port 30002
```

2. Launch router and connect to workers
```bash
./target/debug/router --worker-urls http://127.0.0.1:30000,http://127.0.0.1:30002
```

**Note**: This module is still experimental. Please expect active changes and updates.

### Python bindings

```bash
$ cargo build --release
$ maturin build -i /usr/bin/python
$ pip install <path to wheel>
```


### Development

1. Run test

```
$ cargo test
```

2. Run lint

```
$ cargo fmt
```
