318 lines
11 KiB
Python
318 lines
11 KiB
Python
# SPDX-License-Identifier: Apache-2.0
|
||
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
|
||
import json
|
||
import time
|
||
from collections.abc import Awaitable, Mapping
|
||
from dataclasses import dataclass, field
|
||
from http import HTTPStatus
|
||
from typing import ClassVar, Generic, TypeVar
|
||
|
||
from fastapi import Request
|
||
from pydantic import ConfigDict
|
||
from starlette.datastructures import Headers
|
||
|
||
from vllm.engine.protocol import EngineClient
|
||
from vllm.entrypoints.generate.beam_search.online import BeamSearchOnlineMixin
|
||
from vllm.entrypoints.openai.chat_completion.protocol import ChatCompletionRequest
|
||
from vllm.entrypoints.openai.completion.protocol import CompletionRequest
|
||
from vllm.entrypoints.openai.engine.protocol import (
|
||
ErrorResponse,
|
||
GenerationError,
|
||
PerRequestTimingMetrics,
|
||
)
|
||
from vllm.entrypoints.openai.models.serving import OpenAIServingModels
|
||
from vllm.entrypoints.openai.responses.protocol import ResponsesRequest
|
||
from vllm.entrypoints.serve.engine.serving import BaseServing
|
||
from vllm.entrypoints.serve.engine.typing import AnyRequest
|
||
from vllm.entrypoints.serve.utils.request_logger import RequestLogger
|
||
from vllm.inputs import EngineInput
|
||
from vllm.logger import init_logger
|
||
from vllm.logprobs import Logprob, PromptLogprobs
|
||
from vllm.lora.request import LoRARequest
|
||
from vllm.tokenizers import TokenizerLike
|
||
from vllm.tracing import (
|
||
contains_trace_headers,
|
||
extract_trace_headers,
|
||
log_tracing_disabled_warning,
|
||
)
|
||
from vllm.v1.metrics.stats import RequestStateStats
|
||
|
||
logger = init_logger(__name__)
|
||
|
||
RequestT = TypeVar("RequestT", bound=AnyRequest)
|
||
_T = TypeVar("_T")
|
||
|
||
|
||
def build_per_request_timing_metrics(
|
||
metrics: RequestStateStats | None,
|
||
num_generation_tokens: int,
|
||
) -> PerRequestTimingMetrics:
|
||
"""Build per-request timing metrics from ``RequestStateStats``.
|
||
|
||
``generation_time_ms`` is the decode interval only (first output token to
|
||
last output token); it excludes both queue wait and prefill/TTFT.
|
||
``tokens_per_second`` is overall output throughput: all generated tokens
|
||
over the inference interval (scheduling to last output token), so it counts
|
||
the prefill/TTFT phase and is not simply the reciprocal of ``mean_itl_ms``.
|
||
Each field is left ``None`` when the timestamps it depends on are
|
||
unavailable.
|
||
"""
|
||
if metrics is None:
|
||
return PerRequestTimingMetrics()
|
||
|
||
queued_ts = metrics.queued_ts
|
||
scheduled_ts = metrics.scheduled_ts
|
||
first_token_ts = metrics.first_token_ts
|
||
last_token_ts = metrics.last_token_ts
|
||
|
||
time_to_first_token_ms: float | None = None
|
||
generation_time_ms: float | None = None
|
||
queue_time_ms: float | None = None
|
||
mean_itl_ms: float | None = None
|
||
tokens_per_second: float | None = None
|
||
|
||
if scheduled_ts > 0 and first_token_ts > 0:
|
||
time_to_first_token_ms = (first_token_ts - scheduled_ts) * 1000
|
||
|
||
if first_token_ts > 0 and last_token_ts > 0:
|
||
generation_time_ms = (last_token_ts - first_token_ts) * 1000
|
||
|
||
if queued_ts > 0 and scheduled_ts > 0:
|
||
queue_time_ms = (scheduled_ts - queued_ts) * 1000
|
||
|
||
if first_token_ts > 0 and last_token_ts > 0 and num_generation_tokens > 1:
|
||
decode_time = last_token_ts - first_token_ts
|
||
mean_itl_ms = decode_time / (num_generation_tokens - 1) * 1000
|
||
|
||
if scheduled_ts > 0 and last_token_ts > 0:
|
||
inference_time_ms = (last_token_ts - scheduled_ts) * 1000
|
||
if inference_time_ms > 0:
|
||
tokens_per_second = num_generation_tokens / inference_time_ms * 1000
|
||
|
||
return PerRequestTimingMetrics(
|
||
time_to_first_token_ms=time_to_first_token_ms,
|
||
generation_time_ms=generation_time_ms,
|
||
queue_time_ms=queue_time_ms,
|
||
mean_itl_ms=mean_itl_ms,
|
||
tokens_per_second=tokens_per_second,
|
||
)
|
||
|
||
|
||
@dataclass(kw_only=True)
|
||
class ServeContext(Generic[RequestT]):
|
||
request: RequestT
|
||
raw_request: Request | None = None
|
||
model_name: str
|
||
request_id: str
|
||
created_time: int = field(default_factory=lambda: int(time.time()))
|
||
lora_request: LoRARequest | None = None
|
||
engine_inputs: list[EngineInput] | None = None
|
||
model_config = ConfigDict(arbitrary_types_allowed=True)
|
||
|
||
|
||
class GenerateBaseServing(BaseServing, BeamSearchOnlineMixin):
|
||
request_id_prefix: ClassVar[str] = """
|
||
A short string prepended to every request’s ID.
|
||
"""
|
||
|
||
def __init__(
|
||
self,
|
||
engine_client: EngineClient,
|
||
models: OpenAIServingModels,
|
||
*,
|
||
request_logger: RequestLogger | None,
|
||
return_tokens_as_token_ids: bool = False,
|
||
):
|
||
super().__init__(
|
||
models=models,
|
||
model_config=engine_client.model_config,
|
||
request_logger=request_logger,
|
||
)
|
||
|
||
self.engine_client = engine_client
|
||
self.return_tokens_as_token_ids = return_tokens_as_token_ids
|
||
self.renderer = engine_client.renderer
|
||
self.input_processor = engine_client.input_processor
|
||
vllm_config = getattr(engine_client, "vllm_config", None)
|
||
kv_transfer_config = getattr(vllm_config, "kv_transfer_config", None)
|
||
self.has_kv_connector = kv_transfer_config is not None
|
||
|
||
# Computed once at startup (cached by ``vllm_config`` identity) and
|
||
# stamped on non-streaming responses. Streaming chunks deliberately
|
||
# omit it to avoid per-chunk overhead.
|
||
from vllm.entrypoints.serve.utils.fingerprint import get_system_fingerprint
|
||
|
||
try:
|
||
self.system_fingerprint: str | None = get_system_fingerprint(
|
||
engine_client.vllm_config
|
||
)
|
||
except Exception:
|
||
# Never fail server startup over the fingerprint.
|
||
self.system_fingerprint = None
|
||
|
||
def create_streaming_error_response(
|
||
self,
|
||
message: str | Exception,
|
||
err_type: str = "BadRequestError",
|
||
status_code: HTTPStatus = HTTPStatus.BAD_REQUEST,
|
||
param: str | None = None,
|
||
) -> str:
|
||
json_str = json.dumps(
|
||
self.create_error_response(
|
||
message=message,
|
||
err_type=err_type,
|
||
status_code=status_code,
|
||
param=param,
|
||
).model_dump()
|
||
)
|
||
return json_str
|
||
|
||
def _raise_if_error(self, finish_reason: str | None, request_id: str) -> None:
|
||
"""Raise GenerationError if finish_reason indicates an error."""
|
||
if finish_reason == "error":
|
||
logger.error(
|
||
"Request %s failed with an internal error during generation",
|
||
request_id,
|
||
)
|
||
raise GenerationError("Internal server error")
|
||
|
||
def _convert_generation_error_to_streaming_response(
|
||
self, e: GenerationError
|
||
) -> str:
|
||
"""Convert GenerationError to streaming error response."""
|
||
return self.create_streaming_error_response(
|
||
str(e),
|
||
err_type="InternalServerError",
|
||
status_code=e.status_code,
|
||
)
|
||
|
||
async def _get_trace_headers(
|
||
self,
|
||
headers: Headers,
|
||
) -> Mapping[str, str] | None:
|
||
is_tracing_enabled = await self.engine_client.is_tracing_enabled()
|
||
|
||
if is_tracing_enabled:
|
||
return extract_trace_headers(headers)
|
||
|
||
if contains_trace_headers(headers):
|
||
log_tracing_disabled_warning()
|
||
|
||
return None
|
||
|
||
@staticmethod
|
||
def _get_data_parallel_rank(raw_request: Request | None) -> int | None:
|
||
"""Pulls the data parallel rank from a header, if provided"""
|
||
if raw_request is None:
|
||
return None
|
||
|
||
rank_str = raw_request.headers.get("X-data-parallel-rank")
|
||
if rank_str is None:
|
||
return None
|
||
|
||
try:
|
||
return int(rank_str)
|
||
except ValueError:
|
||
return None
|
||
|
||
async def _with_kv_transfer_rejection_cleanup(
|
||
self,
|
||
awaitable: Awaitable[_T],
|
||
request: ChatCompletionRequest | CompletionRequest | ResponsesRequest,
|
||
raw_request: Request | None,
|
||
) -> _T:
|
||
"""Wrap a `create_*` coroutine so that, if it raises or returns an
|
||
ErrorResponse (i.e. the request never reached the engine), the KV
|
||
connector is notified to free any pinned remote-prefill blocks."""
|
||
kv_transfer_params = self.has_kv_connector and request.kv_transfer_params
|
||
if not kv_transfer_params or not kv_transfer_params.get("do_remote_prefill"):
|
||
return await awaitable
|
||
|
||
notify = True
|
||
try:
|
||
result = await awaitable
|
||
if not isinstance(result, ErrorResponse):
|
||
notify = False
|
||
return result
|
||
finally:
|
||
if notify:
|
||
try:
|
||
await self.engine_client.notify_kv_transfer_request_rejected(
|
||
request.request_id,
|
||
kv_transfer_params,
|
||
data_parallel_rank=self._get_data_parallel_rank(raw_request),
|
||
)
|
||
except Exception:
|
||
logger.warning(
|
||
"Failed to notify KV connector about rejected request %s",
|
||
request.request_id,
|
||
exc_info=True,
|
||
)
|
||
|
||
@staticmethod
|
||
def _get_decoded_token(
|
||
logprob: Logprob,
|
||
token_id: int,
|
||
tokenizer: TokenizerLike | None,
|
||
return_as_token_id: bool = False,
|
||
) -> str:
|
||
if return_as_token_id:
|
||
return format_token_id_placeholder(token_id)
|
||
|
||
if logprob.decoded_token is not None:
|
||
return logprob.decoded_token
|
||
|
||
if tokenizer is None:
|
||
raise ValueError(
|
||
"Unable to get tokenizer because `skip_tokenizer_init=True`"
|
||
)
|
||
|
||
return tokenizer.decode([token_id])
|
||
|
||
|
||
def format_token_id_placeholder(token_id: int) -> str:
|
||
return f"token_id:{token_id}"
|
||
|
||
|
||
def resolve_token_id_placeholder(
|
||
token: str, tokenizer: TokenizerLike
|
||
) -> tuple[str, list[int] | None]:
|
||
"""Decode a 'token_id:N' placeholder back to a token string and UTF-8 bytes.
|
||
|
||
Returns (token, None) unchanged if token is not a placeholder.
|
||
This is the inverse of format_token_id_placeholder / _get_decoded_token
|
||
when return_as_token_id=True.
|
||
"""
|
||
suffix = token.removeprefix("token_id:")
|
||
if suffix == token:
|
||
return token, None
|
||
try:
|
||
token_id = int(suffix)
|
||
except ValueError:
|
||
return token, None
|
||
token_repr = tokenizer.convert_ids_to_tokens([token_id])[0]
|
||
if token_repr is None:
|
||
logger.warning_once(
|
||
"resolve_token_id_placeholder: token_id %d has no vocab entry; "
|
||
"substituting empty string",
|
||
token_id,
|
||
)
|
||
return "", None
|
||
token_str = tokenizer.convert_tokens_to_string([token_repr])
|
||
return token_str, list(token_str.encode("utf-8", errors="replace"))
|
||
|
||
|
||
def clamp_prompt_logprobs(
|
||
prompt_logprobs: PromptLogprobs | None,
|
||
) -> PromptLogprobs | None:
|
||
if prompt_logprobs is None:
|
||
return prompt_logprobs
|
||
|
||
for logprob_dict in prompt_logprobs:
|
||
if logprob_dict is None:
|
||
continue
|
||
for logprob_values in logprob_dict.values():
|
||
if logprob_values.logprob == float("-inf"):
|
||
logprob_values.logprob = -9999.0
|
||
return prompt_logprobs
|