aphrodite-engine

Breathing Life into Language

[!IMPORTANT]
Aphrodite is being actively developed on the dev branch. The main branch is treated as "stable".

Aphrodite is the official backend engine for PygmalionAI. It is designed to serve as the inference endpoint for the PygmalionAI website, and to allow serving the Pygmalion models to a large number of users with blazing fast speeds (thanks to FasterTransformer and vLLM).

Aphrodite builds upon and integrates the exceptional work from various projects.

Features

• Continuous Batching
• Efficient K/V management with PagedAttention
• Optimized CUDA kernels for improved inference
• Quantization support via AWQ and GPTQ
• Distributed inference
• Variety of sampling methods (Mirostat, Locally Typical Sampling, Tail-Free Sampling, etc)

Quickstart

pip install git+https://github.com/PygmalionAI/aphrodite-engine@dev

python -m aphrodite.endpoints.openai.api_server --model PygmalionAI/pygmalion-2-7b

This will create a OpenAI-compatible API server that can be accessed at port 2242 of the localhost. You can plug in the API into a UI that supports Kobold, such as SillyTavern.

Performance

Speeds vary with different GPUs, model sizes, quantization schemes, batch sizes, etc. Here are some baseline benchmarks conducted by requesting as many completions as possible from the API server. Keep in mind that these are the theoritical peak throughput with parallel decoding, with as high a batch size as possible. Per-request generation speed is a fraction of this, at 30-40 t/s.

[!NOTE]
16bit models can achieve much higher throughput if they have access to more VRAM, either by using larger GPUs, or tensor parallelism over many GPUs.

Model	Quantization	GPU	Throughput (output t/s)
Llama-2 7B	None	RTX 4090	2576.2
	AWQ	RTX 4090	3551.3
	GPTQ	RTX 4090	2919.1
	SqueezeLLM	RTX 4090	580.3
Mistral 7B	None	RTX 4090	5489.3
	AWQ	RTX 4090	4078.8
	GPTQ	RTX 4090	4516.2
	SqueezeLLM	RTX 4090	549.5

Requirements

• Operating System: Linux (or WSL for Windows)
• Python: at least 3.8

Build Requirements:

• CUDA 11.8 (recommended, supports 11.0-11.8)

Supported GPUs

Any NVIDIA GPU with a compute capability of 6.0 or higher. Refer to this page for a full list of CUDA GPUs:

https://developer.nvidia.com/cuda-gpus.

Or, you can manually find out your GPU's Compute Capability by opening a Python interpreter and running:

>>> import torch    # if you don't have `torch` installed, run `pip install torch` first
>>> print(torch.cuda.get_device_capability())

This should print something like this: (7, 5), which would indicate a CC of 7.5

If you do not meet the minimum CC, you will not be able to run Aphrodite. At the moment, compute capability of 7.5 or higher is required for AWQ quantization scheme; you can use GPTQ if your GPU does not support it.

Setting up the environment

If you run into any problems, please refer to the common Common Issues section, or open an Issue if you can't find the answer there.

Normally, all you need is NVIDIA device drivers. You can then simply run pip install aphrodite-engine to install the package. If you wish to build from source, however, then follow along with the instructions below.

Aphrodite will require a slightly specialized environment to build, as the latest CUDA versions are currently not supported. You can use Conda to easily configure your environment. If you're on windows, make sure you have WSL2 installed. You can do this by opening Windows PowerShell and running:

wsl --install

Aphrodite provides an easy-to-use install script, which helps with both setting up a suitable environment for installing via the pip package and/or building from source.

The requirements is git, wget, bzip2, and tar - all of which are available on the majority of Linux distributions. You may need to install them for WSL (apt update && apt install git etc).

git clone https://github.com/PygmalionAI/aphrodite-engine && cd aphrodite-engine

Then you can simply run:

./runtime.sh python -m aphrodite.endpoints.openai.api_server --help

The ./runtime.sh prefix will need to be appended to every command you run that involves Aphrodite, as it launches your commands within the created environment. If you prefer not doing that, you can run ./runtime.sh by itself to enter the environment and execute commands as normal.

For updating the engine, run git pull and then ./update-runtime.sh to update the environment.

Alternatively, you can install via pip:

pip install git+https://github.com/PygmalionAI/aphrodite-engine

Make sure you have a proper environment (with CUDA <12.0) set up.

Usage

Aphrodite Engine provides 3 API endpoint types:

OpenAI

  python -m aphrodite.endpoints.openai.api_server --model PygmalionAI/pygmalion-2-7b --api-keys sk-example-key

Completions example:

curl http://localhost:2242/v1/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer sk-example-key" \
-d '{
  "model": "PygmalionAI/pygmalion-2-7b",
  "prompt": "Every age it seems is tainted by the greed of men. Rubbish to one such as I,",
  "stream": false,
  "mirostat_mode": 2,
  "mirostat_tau": 6.5,
  "mirostat_eta": 0.2
}'

Chat Completions example:

curl -X POST -H 'Authorization: Bearer sk-example-key' -H "Content-type: application/json" -d '{
  "model": "PygmalionAI/pygmalion-2-7b",
  "messages": [
    {
      "role": "system",
      "content": "<|system|>Enter assistant mode."
    },
    {
      "role": "user",
      "content": "Who won the world series in 2020?"
    },
    {
      "role": "assistant",
      "content": "The Los Angeles Dodgers won the World Series in 2020."
    },
    {
      "role": "user",
      "content": "Where was it played?"
    }
  ]
}' 'http://localhost:2242/v1/chat/completions'

For authorization, both the Authorization: Bearer KEY and x-api-key: KEY headers will work.

#### KoboldAI:

python -m aphrodite.endpoints.kobold.api_server --model PygmalionAI/pygmalion-2-7b

cURL example:

curl -X 'POST' \
  'http://localhost:5000/api/v1/generate' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "prompt": "Niko the kobold stalked carefully down the alley, his small scaly figure obscured by a dusky cloak that fluttered lightly in the cold winter breeze.",
  "max_context_length": 4096,
  "max_length": 512,
  "stream": false,
  "mirostat_mode": 2,
  "mirostat_tau": 6.5,
  "mirostat_eta": 0.2
}' 

To run a quantized model, use the --quantization flag with either gptq, awq, or squeezellm and the --dtype float16 flags. Make sure your model is in the appropriate format (i.e. not GGUF or exl2). Run with only the --help flag for a full list of arguments.

For the full list of Sampling parameters, please refer to SamplingParams:

https://github.com/PygmalionAI/aphrodite-engine/blob/9a47d6fc1a8ad53d6272f1ec04f848068c5c261b/aphrodite/common/sampling_params.py#L25-L104

Common Issues

`The detected CUDA version (12.1) mismatches the version that was used to compile

  PyTorch (11.8). Please make sure to use the same CUDA versions.`

This is normally due to your environment referring to the global installation of CUDA and not the one in your current env. Run which nvcc and note down the output. For example, if your output is /home/anon/miniconda3/envs/aphrodite/bin/nvcc, run this command:

export CUDA_HOME=/home/anon/miniconda3/envs/aphrodite

Then run the installation command again.

---

Aborted due to the lack of CPU swap space. Please increase the swap space to avoid this error.

You've run out of swap space! Please pass the --swap-space followed by the amount of swap (in GBs) to allocate. Make sure you leave enough RAM for the model loading process.

---

ncclInternalError: Internal check failed.
Last error:
No NVML device handle. Skipping nvlink detection.

This happens if you're doing tensor parallelism (multi-GPU) on NVLinked NVIDIA GPUs and they don't support P2P. Please run this command before running the server:

export NCCL_P2P_DISABLE=1

Alternatively, you can prepend NCCL_P2P_DISABLE=1 to your server launch command.

Notes

1. By design, Aphrodite takes up 90% of your GPU's VRAM. If you're not serving an LLM at scale, you may want to limit the amount of memory it takes up. You can do this in the API example by launching the server with the --gpu-memory-utilization 0.6 (0.6 means 60%).

2. You can view the full list of commands by running python -m aphrodite.endpoints.ooba.api_server --help.

3. Context Length extension via the RoPE method is supported for most models. Use the command-line flag --max-model-len to specify a desired context length and the engine will adjust the RoPE scaling accordingly.

Acknowledgements

Aphrodite Engine would have not been possible without the phenomenal work of other open-source projects. Credits go to:

• vLLM (CacheFlow)
• FasterTransformer
• xFormers
• AutoAWQ
• AutoGPTQ
• SqueezeLLM
• ExLlama
• Exllamav2
• KoboldAI
• Text Generation WebUI
• Megatron-LM
• FastChat
• Ray
• SkyPilot
• OpenAI Python Library

Contributing

Everyone is welcome to contribute. You can support the project by opening Pull Requests for new features, fixes, or general UX improvements.