llama-stack/llama_stack/providers/inline/inference/vllm/vllm.py

244 lines
8.9 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
import logging
import os
import uuid
from typing import AsyncGenerator, List, Optional
from vllm.engine.arg_utils import AsyncEngineArgs
from vllm.engine.async_llm_engine import AsyncLLMEngine
from vllm.sampling_params import SamplingParams as VLLMSamplingParams
from llama_stack.apis.common.content_types import InterleavedContent
from llama_stack.apis.inference import (
ChatCompletionRequest,
ChatCompletionResponse,
ChatCompletionResponseStreamChunk,
CompletionResponse,
CompletionResponseStreamChunk,
EmbeddingsResponse,
EmbeddingTaskType,
Inference,
InterleavedContentItem,
LogProbConfig,
Message,
ResponseFormat,
SamplingParams,
TextTruncation,
ToolChoice,
ToolConfig,
ToolDefinition,
ToolPromptFormat,
)
from llama_stack.apis.models import Model
from llama_stack.models.llama.llama3.tokenizer import Tokenizer
from llama_stack.models.llama.sku_list import resolve_model
from llama_stack.providers.datatypes import ModelsProtocolPrivate
from llama_stack.providers.utils.inference.openai_compat import (
OpenAICompatCompletionChoice,
OpenAICompatCompletionResponse,
get_sampling_options,
process_chat_completion_response,
process_chat_completion_stream_response,
)
from llama_stack.providers.utils.inference.prompt_adapter import (
chat_completion_request_to_prompt,
)
from .config import VLLMConfig
log = logging.getLogger(__name__)
def _random_uuid() -> str:
return str(uuid.uuid4().hex)
class VLLMInferenceImpl(Inference, ModelsProtocolPrivate):
"""Inference implementation for vLLM."""
def __init__(self, config: VLLMConfig):
self.config = config
self.engine = None
async def initialize(self):
log.info("Initializing vLLM inference provider.")
# Disable usage stats reporting. This would be a surprising thing for most
# people to find out was on by default.
# https://docs.vllm.ai/en/latest/serving/usage_stats.html
if "VLLM_NO_USAGE_STATS" not in os.environ:
os.environ["VLLM_NO_USAGE_STATS"] = "1"
model = resolve_model(self.config.model)
if model is None:
raise ValueError(f"Unknown model {self.config.model}")
if model.huggingface_repo is None:
raise ValueError(f"Model {self.config.model} needs a huggingface repo")
# TODO -- there are a ton of options supported here ...
engine_args = AsyncEngineArgs(
model=model.huggingface_repo,
tokenizer=model.huggingface_repo,
tensor_parallel_size=self.config.tensor_parallel_size,
enforce_eager=self.config.enforce_eager,
gpu_memory_utilization=self.config.gpu_memory_utilization,
guided_decoding_backend="lm-format-enforcer",
)
self.engine = AsyncLLMEngine.from_engine_args(engine_args)
async def shutdown(self):
"""Shut down the vLLM inference adapter."""
log.info("Shutting down vLLM inference provider.")
if self.engine:
self.engine.shutdown_background_loop()
# Note that the return type of the superclass method is WRONG
async def register_model(self, model: Model) -> Model:
"""
Callback that is called when the server associates an inference endpoint
with an inference provider.
:param model: Object that encapsulates parameters necessary for identifying
a specific LLM.
:returns: The input ``Model`` object. It may or may not be permissible
to change fields before returning this object.
"""
log.info(f"Registering model {model.identifier} with vLLM inference provider.")
# The current version of this provided is hard-coded to serve only
# the model specified in the YAML config file.
configured_model = resolve_model(self.config.model)
registered_model = resolve_model(model.model_id)
if configured_model.core_model_id != registered_model.core_model_id:
raise ValueError(
f"Requested model '{model.identifier}' is different from "
f"model '{self.config.model}' that this provider "
f"is configured to serve"
)
return model
def _sampling_params(self, sampling_params: SamplingParams) -> VLLMSamplingParams:
if sampling_params is None:
return VLLMSamplingParams(max_tokens=self.config.max_tokens)
options = get_sampling_options(sampling_params)
if "repeat_penalty" in options:
options["repetition_penalty"] = options["repeat_penalty"]
del options["repeat_penalty"]
return VLLMSamplingParams(**options)
async def unregister_model(self, model_id: str) -> None:
pass
async def completion(
self,
model_id: str,
content: InterleavedContent,
sampling_params: Optional[SamplingParams] = SamplingParams(),
response_format: Optional[ResponseFormat] = None,
stream: Optional[bool] = False,
logprobs: Optional[LogProbConfig] = None,
) -> CompletionResponse | CompletionResponseStreamChunk:
raise NotImplementedError("Completion not implemented for vLLM")
async def chat_completion(
self,
model_id: str,
messages: List[Message],
sampling_params: Optional[SamplingParams] = SamplingParams(),
tools: Optional[List[ToolDefinition]] = None,
tool_choice: Optional[ToolChoice] = ToolChoice.auto,
tool_prompt_format: Optional[ToolPromptFormat] = None,
response_format: Optional[ResponseFormat] = None,
stream: Optional[bool] = False,
logprobs: Optional[LogProbConfig] = None,
tool_config: Optional[ToolConfig] = None,
) -> ChatCompletionResponse | ChatCompletionResponseStreamChunk:
assert self.engine is not None
request = ChatCompletionRequest(
model=model_id,
messages=messages,
sampling_params=sampling_params,
tools=tools or [],
stream=stream,
logprobs=logprobs,
tool_config=tool_config,
)
log.info("Sampling params: %s", sampling_params)
request_id = _random_uuid()
prompt = await chat_completion_request_to_prompt(request, self.config.model)
vllm_sampling_params = self._sampling_params(request.sampling_params)
results_generator = self.engine.generate(prompt, vllm_sampling_params, request_id)
if stream:
return self._stream_chat_completion(request, results_generator)
else:
return await self._nonstream_chat_completion(request, results_generator)
async def _nonstream_chat_completion(
self, request: ChatCompletionRequest, results_generator: AsyncGenerator
) -> ChatCompletionResponse:
outputs = [o async for o in results_generator]
final_output = outputs[-1]
assert final_output is not None
outputs = final_output.outputs
finish_reason = outputs[-1].stop_reason
choice = OpenAICompatCompletionChoice(
finish_reason=finish_reason,
text="".join([output.text for output in outputs]),
)
response = OpenAICompatCompletionResponse(
choices=[choice],
)
return process_chat_completion_response(response, request)
async def _stream_chat_completion(
self, request: ChatCompletionRequest, results_generator: AsyncGenerator
) -> AsyncGenerator:
tokenizer = Tokenizer.get_instance()
async def _generate_and_convert_to_openai_compat():
cur = []
async for chunk in results_generator:
if not chunk.outputs:
log.warning("Empty chunk received")
continue
output = chunk.outputs[-1]
new_tokens = output.token_ids[len(cur) :]
text = tokenizer.decode(new_tokens)
cur.extend(new_tokens)
choice = OpenAICompatCompletionChoice(
finish_reason=output.finish_reason,
text=text,
)
yield OpenAICompatCompletionResponse(
choices=[choice],
)
stream = _generate_and_convert_to_openai_compat()
async for chunk in process_chat_completion_stream_response(stream, request):
yield chunk
async def embeddings(
self,
model_id: str,
contents: List[str] | List[InterleavedContentItem],
text_truncation: Optional[TextTruncation] = TextTruncation.none,
output_dimension: Optional[int] = None,
task_type: Optional[EmbeddingTaskType] = None,
) -> EmbeddingsResponse:
raise NotImplementedError()