임베딩 모델

임베딩 모델 (Pooling: Embed)

임베딩(pooling) 모델을 vLLM으로 생성하는 다양한 예제입니다. llm.embed()로 텍스트 임베딩을 얻고, OpenAI 호환 /v1/embeddings 클라이언트, base64/bytes 인코딩 형식까지 다룹니다.

출처: 문서

본문

runner="pooling"으로 LLM을 만들면 llm.embed()EmbeddingRequestOutputs를 얻습니다. 온라인 예제는 encoding_format을 base64·bytes로 지정해 서버와 효율적으로 주고받는 방법을 보여줍니다.

openai_embedding_client.py

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Example Python client for embedding API using vLLM API server
NOTE:
    start a supported embeddings model server with `vllm serve`, e.g.
    vllm serve intfloat/e5-small
"""

from openai import OpenAI

# Modify OpenAI's API key and API base to use vLLM's API server.
openai_api_key = "EMPTY"
openai_api_base = "http://localhost:8000/v1"


def main():
    client = OpenAI(
        # defaults to os.environ.get("OPENAI_API_KEY")
        api_key=openai_api_key,
        base_url=openai_api_base,
    )

    models = client.models.list()
    model = models.data[0].id

    responses = client.embeddings.create(
        # ruff: noqa: E501
        input=[
            "Hello my name is",
            "The best thing about vLLM is that it supports many different models",
        ],
        model=model,
    )

    for data in responses.data:
        print(data.embedding)  # List of float of len 4096


if __name__ == "__main__":
    main()

embedding_requests_base64_online.py

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Example Python client for embedding API using vLLM API server
NOTE:
    start a supported embeddings model server with `vllm serve`, e.g.
    vllm serve intfloat/e5-small
"""

import argparse

import pybase64 as base64
import requests
import torch

from vllm.utils.serial_utils import EMBED_DTYPES, ENDIANNESS, binary2tensor


def post_http_request(prompt: dict, api_url: str) -> requests.Response:
    headers = {"User-Agent": "Test Client"}
    response = requests.post(api_url, headers=headers, json=prompt)
    return response


def parse_args():
    parse = argparse.ArgumentParser()
    parse.add_argument("--host", type=str, default="localhost")
    parse.add_argument("--port", type=int, default=8000)
    return parse.parse_args()


def main(args):
    base_url = f"http://{args.host}:{args.port}"
    models_url = base_url + "/v1/models"
    embeddings_url = base_url + "/v1/embeddings"

    response = requests.get(models_url)
    model = response.json()["data"][0]["id"]

    input_texts = [
        "The best thing about vLLM is that it supports many different models",
    ] * 2

    # The OpenAI client does not support the embed_dtype and endianness parameters.
    for embed_dtype in EMBED_DTYPES:
        for endianness in ENDIANNESS:
            prompt = {
                "model": model,
                "input": input_texts,
                "encoding_format": "base64",
                "embed_dtype": embed_dtype,
                "endianness": endianness,
            }
            response = post_http_request(prompt=prompt, api_url=embeddings_url)

            embedding = []
            for data in response.json()["data"]:
                binary = base64.b64decode(data["embedding"])
                tensor = binary2tensor(binary, (-1,), embed_dtype, endianness)
                embedding.append(tensor.to(torch.float32))
            embedding = torch.stack(embedding)
            print(embed_dtype, endianness, embedding.shape)


if __name__ == "__main__":
    args = parse_args()
    main(args)

embedding_requests_bytes_online.py

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Example Python client for embedding API using vLLM API server
NOTE:
    start a supported embeddings model server with `vllm serve`, e.g.
    vllm serve intfloat/e5-small
"""

import argparse
import json

import requests
import torch

from vllm.entrypoints.pooling.utils import (
    MetadataItem,
    build_metadata_items,
    decode_pooling_output,
)
from vllm.utils.serial_utils import EMBED_DTYPES, ENDIANNESS


def post_http_request(prompt: dict, api_url: str) -> requests.Response:
    headers = {"User-Agent": "Test Client"}
    response = requests.post(api_url, headers=headers, json=prompt)
    return response


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("--host", type=str, default="localhost")
    parser.add_argument("--port", type=int, default=8000)

    return parser.parse_args()


def main(args):
    base_url = f"http://{args.host}:{args.port}"
    models_url = base_url + "/v1/models"
    embeddings_url = base_url + "/v1/embeddings"

    response = requests.get(models_url)
    model = response.json()["data"][0]["id"]

    embedding_size = 0

    input_texts = [
        "The best thing about vLLM is that it supports many different models",
    ] * 2

    # The OpenAI client does not support the bytes encoding_format.
    # The OpenAI client does not support the embed_dtype and endianness parameters.
    for embed_dtype in EMBED_DTYPES:
        for endianness in ENDIANNESS:
            prompt = {
                "model": model,
                "input": input_texts,
                "encoding_format": "bytes",
                "embed_dtype": embed_dtype,
                "endianness": endianness,
            }
            response = post_http_request(prompt=prompt, api_url=embeddings_url)
            metadata = json.loads(response.headers["metadata"])
            body = response.content
            items = [MetadataItem(**x) for x in metadata["data"]]

            embedding = decode_pooling_output(items=items, body=body)
            embedding = [x.to(torch.float32) for x in embedding]
            embedding = torch.stack(embedding)
            embedding_size = embedding.shape[-1]
            print(embed_dtype, endianness, embedding.shape)

    # The vllm server always sorts the returned embeddings in the order of input. So
    # returning metadata is not necessary. You can set encoding_format to bytes_only
    # to let the server not return metadata.
    for embed_dtype in EMBED_DTYPES:
        for endianness in ENDIANNESS:
            prompt = {
                "model": model,
                "input": input_texts,
                "encoding_format": "bytes_only",
                "embed_dtype": embed_dtype,
                "endianness": endianness,
            }
            response = post_http_request(prompt=prompt, api_url=embeddings_url)
            body = response.content

            items = build_metadata_items(
                embed_dtype=embed_dtype,
                endianness=endianness,
                shape=(embedding_size,),
                n_request=len(input_texts),
            )
            embedding = decode_pooling_output(items=items, body=body)
            embedding = [x.to(torch.float32) for x in embedding]
            embedding = torch.stack(embedding)
            print(embed_dtype, endianness, embedding.shape)


if __name__ == "__main__":
    args = parse_args()
    main(args)

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