vllm/vllm/engine/llm_engine.py
Alexander Matveev 7c7714d856
[Core][Bugfix][Perf] Introduce MQLLMEngine to avoid asyncio OH (#8157)
Co-authored-by: Nick Hill <nickhill@us.ibm.com>
Co-authored-by: rshaw@neuralmagic.com <rshaw@neuralmagic.com>
Co-authored-by: Robert Shaw <114415538+robertgshaw2-neuralmagic@users.noreply.github.com>
Co-authored-by: Simon Mo <simon.mo@hey.com>
2024-09-18 13:56:58 +00:00

1724 lines
73 KiB
Python

import time
from collections import deque
from contextlib import contextmanager
from dataclasses import dataclass
from functools import partial
from typing import (TYPE_CHECKING, Any, Callable, ClassVar, Deque, Dict,
Iterable, List, Mapping, NamedTuple, Optional)
from typing import Sequence as GenericSequence
from typing import Set, Type, Union
import torch
from typing_extensions import TypeVar
import vllm.envs as envs
from vllm.config import (CacheConfig, DecodingConfig, DeviceConfig,
EngineConfig, LoadConfig, LoRAConfig, ModelConfig,
ObservabilityConfig, ParallelConfig,
PromptAdapterConfig, SchedulerConfig,
SpeculativeConfig)
from vllm.core.scheduler import (ScheduledSequenceGroup, Scheduler,
SchedulerOutputs)
from vllm.engine.arg_utils import EngineArgs
from vllm.engine.metrics_types import StatLoggerBase, Stats
from vllm.engine.output_processor.interfaces import (
SequenceGroupOutputProcessor)
from vllm.engine.output_processor.stop_checker import StopChecker
from vllm.engine.output_processor.util import create_output_by_sequence_group
from vllm.executor.executor_base import ExecutorBase
from vllm.executor.gpu_executor import GPUExecutor
from vllm.executor.ray_utils import initialize_ray_cluster
from vllm.inputs import (INPUT_REGISTRY, EncoderDecoderLLMInputs,
InputRegistry, LLMInputs, PromptInputs)
from vllm.inputs.preprocess import InputPreprocessor
from vllm.logger import init_logger
from vllm.lora.request import LoRARequest
from vllm.model_executor.layers.sampler import SamplerOutput
from vllm.outputs import (EmbeddingRequestOutput, RequestOutput,
RequestOutputFactory)
from vllm.pooling_params import PoolingParams
from vllm.prompt_adapter.request import PromptAdapterRequest
from vllm.sampling_params import RequestOutputKind, SamplingParams
from vllm.sequence import (EmbeddingSequenceGroupOutput, ExecuteModelRequest,
Sequence, SequenceGroup, SequenceGroupMetadata,
SequenceStatus)
from vllm.tracing import (SpanAttributes, SpanKind, extract_trace_context,
init_tracer)
from vllm.transformers_utils.config import try_get_generation_config
from vllm.transformers_utils.detokenizer import Detokenizer
from vllm.transformers_utils.tokenizer import AnyTokenizer
from vllm.transformers_utils.tokenizer_group import (
BaseTokenizerGroup, init_tokenizer_from_configs)
from vllm.usage.usage_lib import (UsageContext, is_usage_stats_enabled,
usage_message)
from vllm.utils import Counter, Device, weak_bind
from vllm.version import __version__ as VLLM_VERSION
logger = init_logger(__name__)
_LOCAL_LOGGING_INTERVAL_SEC = 5
def _load_generation_config_dict(model_config: ModelConfig) -> Dict[str, Any]:
config = try_get_generation_config(
model_config.model,
trust_remote_code=model_config.trust_remote_code,
revision=model_config.revision,
)
if config is None:
return {}
return config.to_diff_dict()
_G = TypeVar("_G", bound=BaseTokenizerGroup, default=BaseTokenizerGroup)
_O = TypeVar("_O", RequestOutput, EmbeddingRequestOutput)
@dataclass
class SchedulerOutputState:
"""Caches the scheduler outputs for a virtual engine. Used for Multi-Step"""
seq_group_metadata_list: Optional[List[SequenceGroupMetadata]] = None
scheduler_outputs: Optional[SchedulerOutputs] = None
allow_async_output_proc: bool = False
last_output: Optional[SamplerOutput] = None
class OutputData(NamedTuple):
outputs: List[SamplerOutput]
seq_group_metadata_list: List[SequenceGroupMetadata]
scheduler_outputs: SchedulerOutputs
is_async: bool
is_last_step: bool
skip: List[int]
class SchedulerContext:
def __init__(self):
self.output_queue: Deque[OutputData] = deque()
self.request_outputs: List[Union[RequestOutput,
EmbeddingRequestOutput]] = []
self.seq_group_metadata_list: Optional[
List[SequenceGroupMetadata]] = None
self.scheduler_outputs: Optional[SchedulerOutputs] = None
def append_output(self, outputs: List[SamplerOutput],
seq_group_metadata_list: List[SequenceGroupMetadata],
scheduler_outputs: SchedulerOutputs, is_async: bool,
is_last_step: bool):
self.output_queue.append(
OutputData(outputs=outputs,
seq_group_metadata_list=seq_group_metadata_list,
scheduler_outputs=scheduler_outputs,
is_async=is_async,
is_last_step=is_last_step,
skip=[]))
class LLMEngine:
"""An LLM engine that receives requests and generates texts.
This is the main class for the vLLM engine. It receives requests
from clients and generates texts from the LLM. It includes a tokenizer, a
language model (possibly distributed across multiple GPUs), and GPU memory
space allocated for intermediate states (aka KV cache). This class utilizes
iteration-level scheduling and efficient memory management to maximize the
serving throughput.
The :class:`~vllm.LLM` class wraps this class for offline batched inference
and the :class:`AsyncLLMEngine` class wraps this class for online serving.
The config arguments are derived from :class:`~vllm.EngineArgs`. (See
:ref:`engine_args`)
Args:
model_config: The configuration related to the LLM model.
cache_config: The configuration related to the KV cache memory
management.
parallel_config: The configuration related to distributed execution.
scheduler_config: The configuration related to the request scheduler.
device_config: The configuration related to the device.
lora_config (Optional): The configuration related to serving multi-LoRA.
speculative_config (Optional): The configuration related to speculative
decoding.
executor_class: The model executor class for managing distributed
execution.
prompt_adapter_config (Optional): The configuration related to serving
prompt adapters.
log_stats: Whether to log statistics.
usage_context: Specified entry point, used for usage info collection.
"""
DO_VALIDATE_OUTPUT: ClassVar[bool] = False
"""A flag to toggle whether to validate the type of request output."""
@classmethod
@contextmanager
def enable_output_validation(cls):
cls.DO_VALIDATE_OUTPUT = True
yield
cls.DO_VALIDATE_OUTPUT = False
@classmethod
def validate_output(
cls,
output: object,
output_type: Type[_O],
) -> _O:
do_validate = cls.DO_VALIDATE_OUTPUT
if ((TYPE_CHECKING or do_validate)
and not isinstance(output, output_type)):
raise TypeError(f"Expected output of type {output_type}, "
f"but found type {type(output)}")
return output
@classmethod
def validate_outputs(
cls,
outputs: GenericSequence[object],
output_type: Type[_O],
) -> List[_O]:
do_validate = cls.DO_VALIDATE_OUTPUT
outputs_: List[_O]
if TYPE_CHECKING or do_validate:
outputs_ = []
for output in outputs:
if not isinstance(output, output_type):
raise TypeError(f"Expected output of type {output_type}, "
f"but found type {type(output)}")
outputs_.append(output)
else:
outputs_ = outputs
return outputs_
tokenizer: Optional[BaseTokenizerGroup]
def __init__(
self,
model_config: ModelConfig,
cache_config: CacheConfig,
parallel_config: ParallelConfig,
scheduler_config: SchedulerConfig,
device_config: DeviceConfig,
load_config: LoadConfig,
lora_config: Optional[LoRAConfig],
speculative_config: Optional[SpeculativeConfig],
decoding_config: Optional[DecodingConfig],
observability_config: Optional[ObservabilityConfig],
prompt_adapter_config: Optional[PromptAdapterConfig],
executor_class: Type[ExecutorBase],
log_stats: bool,
usage_context: UsageContext = UsageContext.ENGINE_CONTEXT,
stat_loggers: Optional[Dict[str, StatLoggerBase]] = None,
input_registry: InputRegistry = INPUT_REGISTRY,
) -> None:
logger.info(
"Initializing an LLM engine (v%s) with config: "
"model=%r, speculative_config=%r, tokenizer=%r, "
"skip_tokenizer_init=%s, tokenizer_mode=%s, revision=%s, "
"override_neuron_config=%s, "
"rope_scaling=%r, rope_theta=%r, tokenizer_revision=%s, "
"trust_remote_code=%s, dtype=%s, max_seq_len=%d, "
"download_dir=%r, load_format=%s, tensor_parallel_size=%d, "
"pipeline_parallel_size=%d, "
"disable_custom_all_reduce=%s, quantization=%s, "
"enforce_eager=%s, kv_cache_dtype=%s, "
"quantization_param_path=%s, device_config=%s, "
"decoding_config=%r, observability_config=%r, "
"seed=%d, served_model_name=%s, use_v2_block_manager=%s, "
"num_scheduler_steps=%d, enable_prefix_caching=%s, "
"use_async_output_proc=%s)",
VLLM_VERSION,
model_config.model,
speculative_config,
model_config.tokenizer,
model_config.skip_tokenizer_init,
model_config.tokenizer_mode,
model_config.revision,
model_config.override_neuron_config,
model_config.rope_scaling,
model_config.rope_theta,
model_config.tokenizer_revision,
model_config.trust_remote_code,
model_config.dtype,
model_config.max_model_len,
load_config.download_dir,
load_config.load_format,
parallel_config.tensor_parallel_size,
parallel_config.pipeline_parallel_size,
parallel_config.disable_custom_all_reduce,
model_config.quantization,
model_config.enforce_eager,
cache_config.cache_dtype,
model_config.quantization_param_path,
device_config.device,
decoding_config,
observability_config,
model_config.seed,
model_config.served_model_name,
scheduler_config.use_v2_block_manager,
scheduler_config.num_scheduler_steps,
cache_config.enable_prefix_caching,
model_config.use_async_output_proc,
)
# TODO(woosuk): Print more configs in debug mode.
from vllm.plugins import load_general_plugins
load_general_plugins()
self.model_config = model_config
self.cache_config = cache_config
self.lora_config = lora_config
self.parallel_config = parallel_config
self.scheduler_config = scheduler_config
self.device_config = device_config
self.speculative_config = speculative_config
self.load_config = load_config
self.decoding_config = decoding_config or DecodingConfig()
self.prompt_adapter_config = prompt_adapter_config
self.observability_config = observability_config or ObservabilityConfig(
)
self.log_stats = log_stats
if not self.model_config.skip_tokenizer_init:
self.tokenizer = self._init_tokenizer()
self.detokenizer = Detokenizer(self.tokenizer)
tokenizer_group = self.get_tokenizer_group()
else:
self.tokenizer = None
self.detokenizer = None
tokenizer_group = None
# Ensure that the function doesn't contain a reference to self,
# to avoid engine GC issues
def get_tokenizer_for_seq(sequence: Sequence) -> AnyTokenizer:
assert tokenizer_group, ("tokenizer_group cannot be None, "
"make sure skip_tokenizer_init is False")
return tokenizer_group.get_lora_tokenizer(sequence.lora_request)
self.seq_counter = Counter()
self.generation_config_fields = _load_generation_config_dict(
model_config)
self.input_preprocessor = InputPreprocessor(model_config,
self.tokenizer)
self.input_registry = input_registry
self.input_processor = input_registry.create_input_processor(
model_config)
self.model_executor = executor_class(
model_config=model_config,
cache_config=cache_config,
parallel_config=parallel_config,
scheduler_config=scheduler_config,
device_config=device_config,
lora_config=lora_config,
speculative_config=speculative_config,
load_config=load_config,
prompt_adapter_config=prompt_adapter_config,
observability_config=self.observability_config,
)
if not self.model_config.embedding_mode:
self._initialize_kv_caches()
# If usage stat is enabled, collect relevant info.
if is_usage_stats_enabled():
from vllm.model_executor.model_loader import (
get_architecture_class_name)
usage_message.report_usage(
get_architecture_class_name(model_config),
usage_context,
extra_kvs={
# Common configuration
"dtype":
str(model_config.dtype),
"tensor_parallel_size":
parallel_config.tensor_parallel_size,
"block_size":
cache_config.block_size,
"gpu_memory_utilization":
cache_config.gpu_memory_utilization,
# Quantization
"quantization":
model_config.quantization,
"kv_cache_dtype":
str(cache_config.cache_dtype),
# Feature flags
"enable_lora":
bool(lora_config),
"enable_prompt_adapter":
bool(prompt_adapter_config),
"enable_prefix_caching":
cache_config.enable_prefix_caching,
"enforce_eager":
model_config.enforce_eager,
"disable_custom_all_reduce":
parallel_config.disable_custom_all_reduce,
})
if self.tokenizer:
# Ping the tokenizer to ensure liveness if it runs in a
# different process.
self.tokenizer.ping()
self.cached_scheduler_outputs = [
SchedulerOutputState()
for _ in range(self.parallel_config.pipeline_parallel_size)
]
self.scheduler_contexts = [
SchedulerContext()
for _ in range(self.parallel_config.pipeline_parallel_size)
]
if model_config.use_async_output_proc:
process_model_outputs = weak_bind(self._process_model_outputs)
self.async_callbacks = [
partial(process_model_outputs,
ctx=self.scheduler_contexts[v_id])
for v_id in range(self.parallel_config.pipeline_parallel_size)
]
else:
self.async_callbacks = []
# Currently used by AsyncLLMEngine to ensure quick append
# of request outputs to asyncio queues
self.process_request_outputs_callback: Optional[Callable] = None
# Create the scheduler.
# NOTE: the cache_config here have been updated with the numbers of
# GPU and CPU blocks, which are profiled in the distributed executor.
self.scheduler = [
Scheduler(
scheduler_config, cache_config, lora_config,
parallel_config.pipeline_parallel_size,
self.async_callbacks[v_id]
if model_config.use_async_output_proc else None)
for v_id in range(parallel_config.pipeline_parallel_size)
]
# Metric Logging.
if self.log_stats:
if stat_loggers is not None:
self.stat_loggers = stat_loggers
else:
# Lazy import for prometheus multiprocessing.
# We need to set PROMETHEUS_MULTIPROC_DIR environment variable
# before prometheus_client is imported.
# See https://prometheus.github.io/client_python/multiprocess/
from vllm.engine.metrics import (LoggingStatLogger,
PrometheusStatLogger)
self.stat_loggers = {
"logging":
LoggingStatLogger(
local_interval=_LOCAL_LOGGING_INTERVAL_SEC),
"prometheus":
PrometheusStatLogger(
local_interval=_LOCAL_LOGGING_INTERVAL_SEC,
labels=dict(model_name=model_config.served_model_name),
max_model_len=self.model_config.max_model_len),
}
self.stat_loggers["prometheus"].info("cache_config",
self.cache_config)
self.tracer = None
if self.observability_config.otlp_traces_endpoint:
self.tracer = init_tracer(
"vllm.llm_engine",
self.observability_config.otlp_traces_endpoint)
# Create sequence output processor, e.g. for beam search or
# speculative decoding.
self.output_processor = (
SequenceGroupOutputProcessor.create_output_processor(
self.scheduler_config,
self.detokenizer,
self.scheduler,
self.seq_counter,
get_tokenizer_for_seq,
stop_checker=StopChecker(
self.scheduler_config.max_model_len,
get_tokenizer_for_seq,
),
))
def _initialize_kv_caches(self) -> None:
"""Initialize the KV cache in the worker(s).
The workers will determine the number of blocks in both the GPU cache
and the swap CPU cache.
"""
num_gpu_blocks, num_cpu_blocks = (
self.model_executor.determine_num_available_blocks())
if self.cache_config.num_gpu_blocks_override is not None:
num_gpu_blocks_override = self.cache_config.num_gpu_blocks_override
logger.info(
"Overriding num_gpu_blocks=%d with "
"num_gpu_blocks_override=%d", num_gpu_blocks,
num_gpu_blocks_override)
num_gpu_blocks = num_gpu_blocks_override
self.cache_config.num_gpu_blocks = num_gpu_blocks
self.cache_config.num_cpu_blocks = num_cpu_blocks
self.model_executor.initialize_cache(num_gpu_blocks, num_cpu_blocks)
@classmethod
def _get_executor_cls(cls,
engine_config: EngineConfig) -> Type[ExecutorBase]:
distributed_executor_backend = (
engine_config.parallel_config.distributed_executor_backend)
# Initialize the cluster and specify the executor class.
if isinstance(distributed_executor_backend, type):
if not issubclass(distributed_executor_backend, ExecutorBase):
raise TypeError(
"distributed_executor_backend must be a subclass of "
f"ExecutorBase. Got {distributed_executor_backend}.")
if distributed_executor_backend.uses_ray: # type: ignore
initialize_ray_cluster(engine_config.parallel_config)
executor_class = distributed_executor_backend
elif engine_config.device_config.device_type == "neuron":
from vllm.executor.neuron_executor import NeuronExecutor
executor_class = NeuronExecutor
elif engine_config.device_config.device_type == "tpu":
if distributed_executor_backend == "ray":
initialize_ray_cluster(engine_config.parallel_config)
from vllm.executor.ray_tpu_executor import RayTPUExecutor
executor_class = RayTPUExecutor
else:
assert distributed_executor_backend is None
from vllm.executor.tpu_executor import TPUExecutor
executor_class = TPUExecutor
elif engine_config.device_config.device_type == "cpu":
from vllm.executor.cpu_executor import CPUExecutor
executor_class = CPUExecutor
elif engine_config.device_config.device_type == "openvino":
from vllm.executor.openvino_executor import OpenVINOExecutor
executor_class = OpenVINOExecutor
elif engine_config.device_config.device_type == "xpu":
if distributed_executor_backend == "ray":
initialize_ray_cluster(engine_config.parallel_config)
from vllm.executor.ray_xpu_executor import RayXPUExecutor
executor_class = RayXPUExecutor
elif distributed_executor_backend == "mp":
# FIXME(kunshang):
# spawn needs calling `if __name__ == '__main__':``
# fork is not supported for xpu start new process.
logger.error(
"Both start methods (spawn and fork) have issue "
"on XPU if you use mp backend, Please try ray instead.")
else:
from vllm.executor.xpu_executor import XPUExecutor
executor_class = XPUExecutor
elif distributed_executor_backend == "ray":
initialize_ray_cluster(engine_config.parallel_config)
from vllm.executor.ray_gpu_executor import RayGPUExecutor
executor_class = RayGPUExecutor
elif distributed_executor_backend == "mp":
from vllm.executor.multiproc_gpu_executor import (
MultiprocessingGPUExecutor)
assert not envs.VLLM_USE_RAY_SPMD_WORKER, (
"multiprocessing distributed executor backend does not "
"support VLLM_USE_RAY_SPMD_WORKER=1")
executor_class = MultiprocessingGPUExecutor
else:
from vllm.executor.gpu_executor import GPUExecutor
executor_class = GPUExecutor
return executor_class
@classmethod
def from_engine_args(
cls,
engine_args: EngineArgs,
usage_context: UsageContext = UsageContext.ENGINE_CONTEXT,
stat_loggers: Optional[Dict[str, StatLoggerBase]] = None,
) -> "LLMEngine":
"""Creates an LLM engine from the engine arguments."""
# Create the engine configs.
engine_config = engine_args.create_engine_config()
executor_class = cls._get_executor_cls(engine_config)
# Create the LLM engine.
engine = cls(
**engine_config.to_dict(),
executor_class=executor_class,
log_stats=not engine_args.disable_log_stats,
usage_context=usage_context,
stat_loggers=stat_loggers,
)
return engine
def __reduce__(self):
# This is to ensure that the LLMEngine is not referenced in
# the closure used to initialize Ray worker actors
raise RuntimeError("LLMEngine should not be pickled!")
def __del__(self):
# Shutdown model executor when engine is garbage collected
# Use getattr since __init__ can fail before the field is set
if model_executor := getattr(self, "model_executor", None):
model_executor.shutdown()
def get_tokenizer_group(
self,
group_type: Type[_G] = BaseTokenizerGroup,
) -> _G:
tokenizer_group = self.tokenizer
if tokenizer_group is None:
raise ValueError("Unable to get tokenizer because "
"skip_tokenizer_init is True")
if not isinstance(tokenizer_group, group_type):
raise TypeError("Invalid type of tokenizer group. "
f"Expected type: {group_type}, but "
f"found type: {type(tokenizer_group)}")
return tokenizer_group
def get_tokenizer(
self,
lora_request: Optional[LoRARequest] = None,
) -> AnyTokenizer:
return self.get_tokenizer_group().get_lora_tokenizer(lora_request)
def _init_tokenizer(self) -> BaseTokenizerGroup:
return init_tokenizer_from_configs(
model_config=self.model_config,
scheduler_config=self.scheduler_config,
parallel_config=self.parallel_config,
enable_lora=bool(self.lora_config))
def _verify_args(self) -> None:
self.model_config.verify_with_parallel_config(self.parallel_config)
self.cache_config.verify_with_parallel_config(self.parallel_config)
if self.lora_config:
self.lora_config.verify_with_model_config(self.model_config)
self.lora_config.verify_with_scheduler_config(
self.scheduler_config)
if self.prompt_adapter_config:
self.prompt_adapter_config.verify_with_model_config(
self.model_config)
def _add_processed_request(
self,
request_id: str,
processed_inputs: Union[LLMInputs, EncoderDecoderLLMInputs],
params: Union[SamplingParams, PoolingParams],
arrival_time: float,
lora_request: Optional[LoRARequest],
prompt_adapter_request: Optional[PromptAdapterRequest],
trace_headers: Optional[Mapping[str, str]] = None,
) -> None:
self._validate_model_inputs(processed_inputs)
# Create the sequences.
block_size = self.cache_config.block_size
seq_id = next(self.seq_counter)
eos_token_id = self.input_preprocessor.get_eos_token_id(lora_request)
seq = Sequence(seq_id, processed_inputs, block_size, eos_token_id,
lora_request, prompt_adapter_request)
encoder_seq = None
if 'encoder_prompt_token_ids' in processed_inputs:
encoder_seq = Sequence(seq_id,
processed_inputs,
block_size,
eos_token_id,
lora_request,
prompt_adapter_request,
from_decoder_prompt=False)
# Create a SequenceGroup based on SamplingParams or PoolingParams
if isinstance(params, SamplingParams):
seq_group = self._create_sequence_group_with_sampling(
request_id,
seq,
params,
arrival_time=arrival_time,
lora_request=lora_request,
trace_headers=trace_headers,
prompt_adapter_request=prompt_adapter_request,
encoder_seq=encoder_seq)
elif isinstance(params, PoolingParams):
seq_group = self._create_sequence_group_with_pooling(
request_id,
seq,
params,
arrival_time=arrival_time,
lora_request=lora_request,
prompt_adapter_request=prompt_adapter_request,
encoder_seq=encoder_seq)
else:
raise ValueError(
"Either SamplingParams or PoolingParams must be provided.")
# Add the sequence group to the scheduler with least unfinished seqs.
costs = [
scheduler.get_num_unfinished_seq_groups()
for scheduler in self.scheduler
]
min_cost_scheduler = self.scheduler[costs.index(min(costs))]
min_cost_scheduler.add_seq_group(seq_group)
def stop_remote_worker_execution_loop(self) -> None:
self.model_executor.stop_remote_worker_execution_loop()
def add_request(
self,
request_id: str,
inputs: PromptInputs,
params: Union[SamplingParams, PoolingParams],
arrival_time: Optional[float] = None,
lora_request: Optional[LoRARequest] = None,
trace_headers: Optional[Mapping[str, str]] = None,
prompt_adapter_request: Optional[PromptAdapterRequest] = None,
) -> None:
"""Add a request to the engine's request pool.
The request is added to the request pool and will be processed by the
scheduler as `engine.step()` is called. The exact scheduling policy is
determined by the scheduler.
Args:
request_id: The unique ID of the request.
inputs: The inputs to the LLM. See
:class:`~vllm.inputs.PromptInputs`
for more details about the format of each input.
params: Parameters for sampling or pooling.
:class:`~vllm.SamplingParams` for text generation.
:class:`~vllm.PoolingParams` for pooling.
arrival_time: The arrival time of the request. If None, we use
the current monotonic time.
trace_headers: OpenTelemetry trace headers.
Details:
- Set arrival_time to the current time if it is None.
- Set prompt_token_ids to the encoded prompt if it is None.
- Create `best_of` number of :class:`~vllm.Sequence` objects.
- Create a :class:`~vllm.SequenceGroup` object
from the list of :class:`~vllm.Sequence`.
- Add the :class:`~vllm.SequenceGroup` object to the scheduler.
Example:
>>> # initialize engine
>>> engine = LLMEngine.from_engine_args(engine_args)
>>> # set request arguments
>>> example_prompt = "Who is the president of the United States?"
>>> sampling_params = SamplingParams(temperature=0.0)
>>> request_id = 0
>>>
>>> # add the request to the engine
>>> engine.add_request(
>>> str(request_id),
>>> example_prompt,
>>> SamplingParams(temperature=0.0))
>>> # continue the request processing
>>> ...
"""
if lora_request is not None and not self.lora_config:
raise ValueError(f"Got lora_request {lora_request} but LoRA is "
"not enabled!")
if arrival_time is None:
arrival_time = time.time()
preprocessed_inputs = self.input_preprocessor.preprocess(
inputs,
request_id=request_id,
lora_request=lora_request,
prompt_adapter_request=prompt_adapter_request,
)
processed_inputs = self.input_processor(preprocessed_inputs)
self._add_processed_request(
request_id=request_id,
processed_inputs=processed_inputs,
params=params,
arrival_time=arrival_time,
lora_request=lora_request,
prompt_adapter_request=prompt_adapter_request,
trace_headers=trace_headers,
)
def _create_sequence_group_with_sampling(
self,
request_id: str,
seq: Sequence,
sampling_params: SamplingParams,
arrival_time: float,
lora_request: Optional[LoRARequest],
trace_headers: Optional[Mapping[str, str]] = None,
prompt_adapter_request: Optional[PromptAdapterRequest] = None,
encoder_seq: Optional[Sequence] = None,
) -> SequenceGroup:
"""Creates a SequenceGroup with SamplingParams."""
max_logprobs = self.get_model_config().max_logprobs
if (sampling_params.logprobs
and sampling_params.logprobs > max_logprobs) or (
sampling_params.prompt_logprobs
and sampling_params.prompt_logprobs > max_logprobs):
raise ValueError(f"Cannot request more than "
f"{max_logprobs} logprobs.")
# Defensive copy of SamplingParams, which are used by the sampler,
# this doesn't deep-copy LogitsProcessor objects
sampling_params = sampling_params.clone()
sampling_params.update_from_generation_config(
self.generation_config_fields, seq.eos_token_id)
# Create the sequence group.
seq_group = SequenceGroup(
request_id=request_id,
seqs=[seq],
arrival_time=arrival_time,
sampling_params=sampling_params,
lora_request=lora_request,
trace_headers=trace_headers,
prompt_adapter_request=prompt_adapter_request,
encoder_seq=encoder_seq)
return seq_group
def _create_sequence_group_with_pooling(
self,
request_id: str,
seq: Sequence,
pooling_params: PoolingParams,
arrival_time: float,
lora_request: Optional[LoRARequest],
prompt_adapter_request: Optional[PromptAdapterRequest],
encoder_seq: Optional[Sequence] = None,
) -> SequenceGroup:
"""Creates a SequenceGroup with PoolingParams."""
# Defensive copy of PoolingParams, which are used by the pooler
pooling_params = pooling_params.clone()
# Create the sequence group.
seq_group = SequenceGroup(
request_id=request_id,
seqs=[seq],
arrival_time=arrival_time,
lora_request=lora_request,
pooling_params=pooling_params,
prompt_adapter_request=prompt_adapter_request,
encoder_seq=encoder_seq)
return seq_group
def abort_request(self, request_id: Union[str, Iterable[str]]) -> None:
"""Aborts a request(s) with the given ID.
Args:
request_id: The ID(s) of the request to abort.
Details:
- Refer to the
:meth:`~vllm.core.scheduler.Scheduler.abort_seq_group`
from class :class:`~vllm.core.scheduler.Scheduler`.
Example:
>>> # initialize engine and add a request with request_id
>>> request_id = str(0)
>>> # abort the request
>>> engine.abort_request(request_id)
"""
for scheduler in self.scheduler:
scheduler.abort_seq_group(request_id)
def get_model_config(self) -> ModelConfig:
"""Gets the model configuration."""
return self.model_config
def get_parallel_config(self) -> ParallelConfig:
"""Gets the parallel configuration."""
return self.parallel_config
def get_decoding_config(self) -> DecodingConfig:
"""Gets the decoding configuration."""
return self.decoding_config
def get_scheduler_config(self) -> SchedulerConfig:
"""Gets the scheduler configuration."""
return self.scheduler_config
def get_lora_config(self) -> LoRAConfig:
"""Gets the LoRA configuration."""
return self.lora_config
def get_num_unfinished_requests(self) -> int:
"""Gets the number of unfinished requests."""
return sum(scheduler.get_num_unfinished_seq_groups()
for scheduler in self.scheduler)
def has_unfinished_requests(self) -> bool:
"""Returns True if there are unfinished requests."""
return any(scheduler.has_unfinished_seqs()
for scheduler in self.scheduler)
def has_unfinished_requests_for_virtual_engine(
self, virtual_engine: int) -> bool:
"""
Returns True if there are unfinished requests for the virtual engine.
"""
return self.scheduler[virtual_engine].has_unfinished_seqs()
@staticmethod
def _process_sequence_group_outputs(
seq_group: SequenceGroup,
outputs: List[EmbeddingSequenceGroupOutput],
) -> None:
seq_group.embeddings = outputs[0].embeddings
for seq in seq_group.get_seqs():
seq.status = SequenceStatus.FINISHED_STOPPED
return
def _process_model_outputs(self,
ctx: SchedulerContext,
request_id: Optional[str] = None) -> None:
"""Apply the model output to the sequences in the scheduled seq groups
and return responses.
ctx: The virtual engine context to work on
request_id: If provided, then only this request is going to be processed
"""
now = time.time()
if len(ctx.output_queue) == 0:
return None
# Get pending async postprocessor
if request_id:
# When we process only one request, no pop is required
# (since later we will process all of the rest)
(outputs, seq_group_metadata_list, scheduler_outputs, is_async,
is_last_step, skip) = ctx.output_queue[0]
else:
(outputs, seq_group_metadata_list, scheduler_outputs, is_async,
is_last_step, skip) = ctx.output_queue.popleft()
# Sanity check
assert len(seq_group_metadata_list) == len(
scheduler_outputs.scheduled_seq_groups)
# Organize outputs by [step][sequence group] instead of
# [sequence group][step].
if len(outputs) > 1:
outputs_by_sequence_group = create_output_by_sequence_group(
outputs, num_seq_groups=len(seq_group_metadata_list))
else:
outputs_by_sequence_group = outputs
# Determine the requests we need to operate on
if request_id:
indices = []
for i, seq_group_meta in enumerate(seq_group_metadata_list):
if seq_group_meta.request_id == request_id:
assert i not in skip # Cannot be called twice
indices.append(i)
break
# If the request_id was not found, then it means that
# this is a new request that has no pending async
# postprocessor
if not indices:
return
else:
indices = range(len(seq_group_metadata_list)) # type: ignore
finished_before: List[int] = []
finished_now: List[int] = []
for i in indices:
if i in skip:
continue
seq_group_meta = seq_group_metadata_list[i]
scheduled_seq_group = scheduler_outputs.scheduled_seq_groups[i]
seq_group = scheduled_seq_group.seq_group
if seq_group.is_finished():
finished_before.append(i)
continue
if len(outputs) > 1:
output = outputs_by_sequence_group[i]
else:
output = [outputs_by_sequence_group[0][i]]
if not is_async:
seq_group.update_num_computed_tokens(
scheduled_seq_group.token_chunk_size)
if outputs:
for o in outputs:
if (isinstance(o, SamplerOutput)
and seq_group.metrics is not None):
if seq_group.metrics.model_forward_time is not None:
seq_group.metrics.model_forward_time += (
o.model_forward_time)
else:
seq_group.metrics.model_forward_time = (
o.model_forward_time)
if seq_group.metrics.model_execute_time is not None:
seq_group.metrics.model_execute_time += (
o.model_execute_time)
else:
seq_group.metrics.model_execute_time = (
o.model_execute_time)
if self.model_config.embedding_mode:
self._process_sequence_group_outputs(seq_group, output)
else:
self.output_processor.process_prompt_logprob(seq_group, output)
if seq_group_meta.do_sample:
self.output_processor.process_outputs(
seq_group, output, is_async)
if seq_group.is_finished():
finished_now.append(i)
# Generate outputs for the requests that finished this iteration
for i in finished_now:
scheduled_seq_group = scheduler_outputs.scheduled_seq_groups[i]
seq_group = scheduled_seq_group.seq_group
seq_group.maybe_set_first_token_time(now)
request_output = RequestOutputFactory.create(seq_group)
if request_output:
ctx.request_outputs.append(request_output)
# When we process a single request, we skip it for the next time,
# and invoke the request output callback (if there was final output)
if request_id:
assert len(indices) == 1
skip.append(indices[0])
if (finished_now
and self.process_request_outputs_callback is not None):
self.process_request_outputs_callback(ctx.request_outputs)
ctx.request_outputs.clear()
return
# Free currently finished requests
if finished_now:
for scheduler in self.scheduler:
scheduler.free_finished_seq_groups()
# For multi-step, do not create outputs each iteration
if not is_last_step:
# Immediately process request outputs here (if callback is given)
if (finished_now
and self.process_request_outputs_callback is not None):
self.process_request_outputs_callback(ctx.request_outputs)
ctx.request_outputs.clear()
return
# Create the outputs
for i in indices:
if i in skip or i in finished_before or i in finished_now:
continue # Avoids double processing
scheduled_seq_group = scheduler_outputs.scheduled_seq_groups[i]
seq_group = scheduled_seq_group.seq_group
seq_group.maybe_set_first_token_time(now)
request_output = RequestOutputFactory.create(seq_group)
if request_output:
ctx.request_outputs.append(request_output)
for seq_group in scheduler_outputs.ignored_seq_groups:
params = seq_group.sampling_params
if params is not None and params.output_kind == (
RequestOutputKind.DELTA) and not seq_group.is_finished():
continue
request_output = RequestOutputFactory.create(seq_group)
if request_output:
ctx.request_outputs.append(request_output)
# Immediately process request outputs here (if callback is given)
if (ctx.request_outputs
and self.process_request_outputs_callback is not None):
self.process_request_outputs_callback(ctx.request_outputs)
ctx.request_outputs.clear()
# For async case, we need to record the stats here.
# For non-async case, the stats are done in the
# LLMEngine/AsyncLLMEngine directly
if is_async:
# Log stats.
self.do_log_stats(scheduler_outputs, outputs, finished_before,
skip)
# Tracing
self.do_tracing(scheduler_outputs)
return None
def _advance_to_next_step(
self, output: List[SamplerOutput],
seq_group_metadata_list: List[SequenceGroupMetadata],
scheduled_seq_groups: List[ScheduledSequenceGroup]) -> None:
"""Given model output from a single run, append the tokens to the
sequences. This is normally done inside output processor, but it is
required if the worker is to perform async forward pass to next step.
"""
for seq_group_metadata, sequence_group_outputs, scheduled_seq_group in \
zip(seq_group_metadata_list, output, scheduled_seq_groups):
seq_group = scheduled_seq_group.seq_group
if seq_group.is_finished():
continue
seq_group.update_num_computed_tokens(
seq_group_metadata.token_chunk_size)
if seq_group_metadata.do_sample:
assert len(sequence_group_outputs.samples) == 1, (
"Async output processor expects a single sample"
" (i.e sampling_params.n == 1 and no "
"sampling_params.best_of > 1)")
sample = sequence_group_outputs.samples[0]
assert len(seq_group.seqs) == 1
seq = seq_group.seqs[0]
seq.append_token_id(sample.output_token, sample.logprobs)
def step(self) -> List[Union[RequestOutput, EmbeddingRequestOutput]]:
"""Performs one decoding iteration and returns newly generated results.
.. figure:: https://i.imgur.com/sv2HssD.png
:alt: Overview of the step function
:align: center
Overview of the step function.
Details:
- Step 1: Schedules the sequences to be executed in the next
iteration and the token blocks to be swapped in/out/copy.
- Depending on the scheduling policy,
sequences may be `preempted/reordered`.
- A Sequence Group (SG) refer to a group of sequences
that are generated from the same prompt.
- Step 2: Calls the distributed executor to execute the model.
- Step 3: Processes the model output. This mainly includes:
- Decodes the relevant outputs.
- Updates the scheduled sequence groups with model outputs
based on its `sampling parameters` (`use_beam_search` or not).
- Frees the finished sequence groups.
- Finally, it creates and returns the newly generated results.
Example:
>>> # Please see the example/ folder for more detailed examples.
>>>
>>> # initialize engine and request arguments
>>> engine = LLMEngine.from_engine_args(engine_args)
>>> example_inputs = [(0, "What is LLM?",
>>> SamplingParams(temperature=0.0))]
>>>
>>> # Start the engine with an event loop
>>> while True:
>>> if example_inputs:
>>> req_id, prompt, sampling_params = example_inputs.pop(0)
>>> engine.add_request(str(req_id),prompt,sampling_params)
>>>
>>> # continue the request processing
>>> request_outputs = engine.step()
>>> for request_output in request_outputs:
>>> if request_output.finished:
>>> # return or show the request output
>>>
>>> if not (engine.has_unfinished_requests() or example_inputs):
>>> break
"""
if self.parallel_config.pipeline_parallel_size > 1:
raise NotImplementedError(
"Pipeline parallelism is only supported through AsyncLLMEngine "
"as performance will be severely degraded otherwise.")
# For llm_engine, there is no pipeline parallel support, so the engine
# used is always 0.
virtual_engine = 0
# These are cached outputs from previous iterations. None if on first
# iteration
cached_outputs = self.cached_scheduler_outputs[virtual_engine]
seq_group_metadata_list = cached_outputs.seq_group_metadata_list
scheduler_outputs = cached_outputs.scheduler_outputs
allow_async_output_proc = cached_outputs.allow_async_output_proc
ctx = self.scheduler_contexts[virtual_engine]
# Clear outputs for each new scheduler iteration
ctx.request_outputs.clear()
# Skip the scheduler if there are any remaining steps in the seq groups.
# This ensures that the scheduler is only called again when the current
# batch has completed.
if not self._has_remaining_steps(seq_group_metadata_list):
# Schedule iteration
(seq_group_metadata_list, scheduler_outputs,
allow_async_output_proc
) = self.scheduler[virtual_engine].schedule()
ctx.seq_group_metadata_list = seq_group_metadata_list
ctx.scheduler_outputs = scheduler_outputs
# Maybe switch from async mode to sync mode
if not allow_async_output_proc and len(ctx.output_queue) > 0:
self._process_model_outputs(ctx=ctx)
if (self.scheduler_config.is_multi_step
and scheduler_outputs.num_lookahead_slots > 0):
# cache the scheduler outputs for the next iteration if we have
# lookahead slots
self._cache_scheduler_outputs_for_multi_step(
virtual_engine, seq_group_metadata_list, scheduler_outputs,
allow_async_output_proc)
assert seq_group_metadata_list is not None
assert scheduler_outputs is not None
if not scheduler_outputs.is_empty():
finished_requests_ids = self.scheduler[
virtual_engine].get_and_reset_finished_requests_ids()
# Check if we have a cached last_output from the previous iteration.
# For supporting PP this is probably the best way to pass the
# sampled_token_ids, as a separate broadcast over all the PP stages
# will cause one virtual engine's microbatch to block the pipeline.
last_sampled_token_ids = \
self._get_last_sampled_token_ids(virtual_engine)
execute_model_req = ExecuteModelRequest(
seq_group_metadata_list=seq_group_metadata_list,
blocks_to_swap_in=scheduler_outputs.blocks_to_swap_in,
blocks_to_swap_out=scheduler_outputs.blocks_to_swap_out,
blocks_to_copy=scheduler_outputs.blocks_to_copy,
num_lookahead_slots=scheduler_outputs.num_lookahead_slots,
running_queue_size=scheduler_outputs.running_queue_size,
finished_requests_ids=finished_requests_ids,
# We use ExecuteModelRequest to pass the last sampled_token_ids
# to each of the non-last PP stages for in-place prepare_input.
last_sampled_token_ids=last_sampled_token_ids)
if allow_async_output_proc:
execute_model_req.async_callback = self.async_callbacks[
virtual_engine]
outputs = self.model_executor.execute_model(
execute_model_req=execute_model_req)
# We need to do this here so that last step's sampled_token_ids can
# be passed to the next iteration for PP.
if self.scheduler_config.is_multi_step:
self._update_cached_scheduler_output(virtual_engine, outputs)
else:
# Nothing scheduled => If there is pending async postprocessor,
# then finish it here.
if len(ctx.output_queue) > 0:
self._process_model_outputs(ctx=ctx)
# No outputs in this case
outputs = []
# Finish the current step for all the sequence groups.
if self.scheduler_config.is_multi_step:
for seq_group in seq_group_metadata_list:
seq_group.finish_step()
if not self._has_remaining_steps(seq_group_metadata_list):
# clear the cache if we have finished all the steps.
if self.scheduler_config.is_multi_step:
self.cached_scheduler_outputs[0] = SchedulerOutputState()
# Add results to the output_queue
ctx.append_output(outputs=outputs,
seq_group_metadata_list=seq_group_metadata_list,
scheduler_outputs=scheduler_outputs,
is_async=allow_async_output_proc,
is_last_step=True)
if outputs and allow_async_output_proc:
assert len(outputs) == 1, (
"Async postprocessor expects only a single output set")
self._advance_to_next_step(
outputs[0], seq_group_metadata_list,
scheduler_outputs.scheduled_seq_groups)
# Check if need to run the usual non-async path
if not allow_async_output_proc:
self._process_model_outputs(ctx=ctx)
# Log stats.
self.do_log_stats(scheduler_outputs, outputs)
# Tracing
self.do_tracing(scheduler_outputs)
else:
# Multi-step case
return ctx.request_outputs
if not self.has_unfinished_requests():
# Drain async postprocessor (if exists)
if len(ctx.output_queue) > 0:
self._process_model_outputs(ctx=ctx)
assert len(ctx.output_queue) == 0
# Stop the execute model loop in parallel workers until there are
# more requests to process. This avoids waiting indefinitely in
# torch.distributed ops which may otherwise timeout, and unblocks
# the RPC thread in the workers so that they can process any other
# queued control plane messages, such as add/remove lora adapters.
logger.debug("Stopping remote worker execution loop.")
self.model_executor.stop_remote_worker_execution_loop()
return ctx.request_outputs
def _has_remaining_steps(
self, seq_group_metadata_list: Optional[List[SequenceGroupMetadata]]
) -> bool:
if (not self.scheduler_config.is_multi_step
or not seq_group_metadata_list):
return False
# TODO(will) this is a sanity check for nowto make sure that all the
# seqs are on the same steps. Eventually we will want to do some sort of
# dynamic scheduling when doing multi-step decoding.
ref_remaining_steps = seq_group_metadata_list[0].state.remaining_steps
if any([
seq_group.state.remaining_steps != ref_remaining_steps
for seq_group in seq_group_metadata_list[1:]
]):
raise AssertionError(("All running sequence groups should "
"have the same remaining steps."))
return ref_remaining_steps > 0
def _cache_scheduler_outputs_for_multi_step(
self, virtual_engine: int,
seq_group_metadata_list: Optional[List[SequenceGroupMetadata]],
scheduler_outputs: SchedulerOutputs,
allow_async_output_proc: bool) -> None:
co = self.cached_scheduler_outputs[virtual_engine]
co.seq_group_metadata_list = seq_group_metadata_list
co.scheduler_outputs = scheduler_outputs
co.allow_async_output_proc = allow_async_output_proc
co.last_output = None
def _update_cached_scheduler_output(
self, virtual_engine: int,
output: List[Optional[SamplerOutput]]) -> None:
if (self.parallel_config.pipeline_parallel_size > 1 and len(output) > 0
and output[0] is not None):
last_output = output[-1]
assert last_output is not None
assert last_output.sampled_token_ids_cpu is not None
assert last_output.sampled_token_ids is None
assert last_output.sampled_token_probs is None
self.cached_scheduler_outputs[
virtual_engine].last_output = last_output
def _get_last_sampled_token_ids(
self, virtual_engine: int) -> Optional[torch.Tensor]:
cached_last_output = self.cached_scheduler_outputs[
virtual_engine].last_output
if (self.scheduler_config.is_multi_step
and self.parallel_config.pipeline_parallel_size > 1
and cached_last_output is not None
and cached_last_output.sampled_token_ids_cpu is not None):
return cached_last_output.sampled_token_ids_cpu
return None
def add_logger(self, logger_name: str, logger: StatLoggerBase) -> None:
if not self.log_stats:
raise RuntimeError(
"Stat logging is disabled. Set `disable_log_stats=False` "
"argument to enable.")
if logger_name in self.stat_loggers:
raise KeyError(f"Logger with name {logger_name} already exists.")
self.stat_loggers[logger_name] = logger
def remove_logger(self, logger_name: str) -> None:
if not self.log_stats:
raise RuntimeError(
"Stat logging is disabled. Set `disable_log_stats=False` "
"argument to enable.")
if logger_name not in self.stat_loggers:
raise KeyError(f"Logger with name {logger_name} does not exist.")
del self.stat_loggers[logger_name]
def do_log_stats(self,
scheduler_outputs: Optional[SchedulerOutputs] = None,
model_output: Optional[List[SamplerOutput]] = None,
finished_before: Optional[List[int]] = None,
skip: Optional[List[int]] = None) -> None:
"""Forced log when no requests active."""
if self.log_stats:
stats = self._get_stats(scheduler_outputs, model_output,
finished_before, skip)
for logger in self.stat_loggers.values():
logger.log(stats)
def _get_stats(self,
scheduler_outputs: Optional[SchedulerOutputs],
model_output: Optional[List[SamplerOutput]] = None,
finished_before: Optional[List[int]] = None,
skip: Optional[List[int]] = None) -> Stats:
"""Get Stats to be Logged to Prometheus.
Args:
scheduler_outputs: Optional, used to populate metrics related to
the scheduled batch,
model_output: Optional, used to emit speculative decoding metrics
which are created by the workers.
finished_before: Optional, indices of sequences that were finished
before. These sequences will be ignored.
skip: Optional, indices of sequences that were preempted. These
sequences will be ignored.
"""
now = time.time()
# System State
# Scheduler State
num_running_sys = sum(
len(scheduler.running) for scheduler in self.scheduler)
num_swapped_sys = sum(
len(scheduler.swapped) for scheduler in self.scheduler)
num_waiting_sys = sum(
len(scheduler.waiting) for scheduler in self.scheduler)
# KV Cache Usage in %
num_total_gpu = self.cache_config.num_gpu_blocks
gpu_cache_usage_sys = 0.
if num_total_gpu is not None:
num_free_gpu = sum(
scheduler.block_manager.get_num_free_gpu_blocks()
for scheduler in self.scheduler)
gpu_cache_usage_sys = 1.0 - (num_free_gpu / num_total_gpu)
num_total_cpu = self.cache_config.num_cpu_blocks
cpu_cache_usage_sys = 0.
if num_total_cpu is not None and num_total_cpu > 0:
num_free_cpu = sum(
scheduler.block_manager.get_num_free_cpu_blocks()
for scheduler in self.scheduler)
cpu_cache_usage_sys = 1.0 - (num_free_cpu / num_total_cpu)
# Prefix Cache Hit Rate. Note that we always use
# the cache hit rate of the first virtual engine.
cpu_prefix_cache_hit_rate = self.scheduler[
0].get_prefix_cache_hit_rate(Device.CPU)
gpu_prefix_cache_hit_rate = self.scheduler[
0].get_prefix_cache_hit_rate(Device.GPU)
# Iteration stats
num_prompt_tokens_iter = 0
num_generation_tokens_iter = 0
time_to_first_tokens_iter: List[float] = []
time_per_output_tokens_iter: List[float] = []
num_preemption_iter = (0 if scheduler_outputs is None else
scheduler_outputs.preempted)
# Request stats
# Latency
time_e2e_requests: List[float] = []
# Metadata
num_prompt_tokens_requests: List[int] = []
num_generation_tokens_requests: List[int] = []
best_of_requests: List[int] = []
n_requests: List[int] = []
finished_reason_requests: List[str] = []
# NOTE: This loop assumes prefill seq_groups are before
# decode seq_groups in scheduled_seq_groups.
if scheduler_outputs is not None:
# For async postprocessor, already finished sequences need to be
# not counted (to avoid double counting)
actual_num_batched_tokens = scheduler_outputs.num_batched_tokens # type: ignore
num_generation_tokens_from_prefill_groups = 0.
# NOTE: if scheduler_outputs.num_prefill_groups > 0 and
# the len of scheduler_outputs.scheduled_seq_groups is !=
# scheduler_outputs.num_prefill_groups, this means that
# chunked prefills have been detected.
for idx, scheduled_seq_group in enumerate(
scheduler_outputs.scheduled_seq_groups):
# Skip double logging when using async output proc
if finished_before and idx in finished_before:
actual_num_batched_tokens -= 1
continue
# Currently, skip == preempted sequences, so we need to skip
# their log stats
if skip and idx in skip:
continue
group_was_prefill = idx < scheduler_outputs.num_prefill_groups
seq_group = scheduled_seq_group.seq_group
# NOTE: a seq_group that completed all of its prefill tokens
# in the last iteration will have seq_group.is_prefill() = False
# with group_was_prefill = True
if group_was_prefill:
# Number of prompt tokens.
num_prompt_tokens_iter += (
scheduled_seq_group.token_chunk_size)
# If the seq_group just finished the prefill state
# get TTFT.
if not seq_group.is_prefill():
latency = seq_group.get_last_latency(now)
time_to_first_tokens_iter.append(latency)
# One generation token per finished prefill.
num_generation_tokens_from_prefill_groups += (
seq_group.num_seqs())
else:
# TPOTs.
latency = seq_group.get_last_latency(now)
time_per_output_tokens_iter.append(latency)
# Because of chunked prefill, we can have a single sequence
# group that does multiple prompt_runs. To prevent logging
# the same metadata more than once per request, we standardize
# on logging request level information for finished requests,
# which can only happen once.
if seq_group.is_finished():
# Latency timings
time_e2e_requests.append(now -
seq_group.metrics.arrival_time)
# Metadata
num_prompt_tokens_requests.append(
len(seq_group.prompt_token_ids))
num_generation_tokens_requests.extend([
seq.get_output_len()
for seq in seq_group.get_finished_seqs()
])
if seq_group.sampling_params is not None:
best_of_requests.append(
seq_group.sampling_params.best_of)
n_requests.append(seq_group.sampling_params.n)
finished_reason_requests.extend([
SequenceStatus.get_finished_reason(seq.status)
for seq in seq_group.get_finished_seqs()
])
# Number of generation tokens.
# num_batched_tokens equals the number of prompt_tokens plus the
# number of decode_tokens in a single iteration. So,
# num_generation_tokens = num_batched_tokens - num_prompt_tokens
# + num_generation_tokens_from_prefill_groups (since we generate
# one token on prefills on iters where the prefill finishes).
num_generation_tokens_iter = (
actual_num_batched_tokens - num_prompt_tokens_iter +
num_generation_tokens_from_prefill_groups)
# Spec decode, if enabled, emits specialized metrics from the worker in
# sampler output.
if model_output and (model_output[0].spec_decode_worker_metrics
is not None):
spec_decode_metrics = model_output[0].spec_decode_worker_metrics
else:
spec_decode_metrics = None
return Stats(
now=now,
# System stats
# Scheduler State
num_running_sys=num_running_sys,
num_swapped_sys=num_swapped_sys,
num_waiting_sys=num_waiting_sys,
# KV Cache Usage in %
gpu_cache_usage_sys=gpu_cache_usage_sys,
cpu_cache_usage_sys=cpu_cache_usage_sys,
# Prefix Cache Hit Rate
cpu_prefix_cache_hit_rate=cpu_prefix_cache_hit_rate,
gpu_prefix_cache_hit_rate=gpu_prefix_cache_hit_rate,
# Iteration stats
num_prompt_tokens_iter=num_prompt_tokens_iter,
num_generation_tokens_iter=num_generation_tokens_iter,
time_to_first_tokens_iter=time_to_first_tokens_iter,
time_per_output_tokens_iter=time_per_output_tokens_iter,
spec_decode_metrics=spec_decode_metrics,
num_preemption_iter=num_preemption_iter,
# Request stats
# Latency
time_e2e_requests=time_e2e_requests,
# Metadata
num_prompt_tokens_requests=num_prompt_tokens_requests,
num_generation_tokens_requests=num_generation_tokens_requests,
best_of_requests=best_of_requests,
n_requests=n_requests,
finished_reason_requests=finished_reason_requests,
)
def add_lora(self, lora_request: LoRARequest) -> bool:
return self.model_executor.add_lora(lora_request)
def remove_lora(self, lora_id: int) -> bool:
return self.model_executor.remove_lora(lora_id)
def list_loras(self) -> Set[int]:
return self.model_executor.list_loras()
def pin_lora(self, lora_id: int) -> bool:
return self.model_executor.pin_lora(lora_id)
def add_prompt_adapter(
self, prompt_adapter_request: PromptAdapterRequest) -> bool:
return self.model_executor.add_prompt_adapter(prompt_adapter_request)
def remove_prompt_adapter(self, prompt_adapter_id: int) -> bool:
return self.model_executor.remove_prompt_adapter(prompt_adapter_id)
def list_prompt_adapters(self) -> List[int]:
return self.model_executor.list_prompt_adapters()
def check_health(self) -> None:
if self.tokenizer:
self.tokenizer.check_health()
self.model_executor.check_health()
def start_profile(self) -> None:
# using type instead of isinstance to check to avoid capturing
# inherited classes (MultiprocessingGPUExecutor)
if type(self.model_executor) == GPUExecutor: # noqa: E721
self.model_executor.start_profile()
else:
self.model_executor._run_workers("start_profile")
def stop_profile(self) -> None:
# using type instead of isinstance to check to avoid capturing
# inherited classes (MultiprocessingGPUExecutor)
if type(self.model_executor) == GPUExecutor: # noqa: E721
self.model_executor.stop_profile()
else:
self.model_executor._run_workers("stop_profile")
def is_tracing_enabled(self) -> bool:
return self.tracer is not None
def do_tracing(self, scheduler_outputs: SchedulerOutputs) -> None:
if self.tracer is None:
return
for scheduled_seq_group in scheduler_outputs.scheduled_seq_groups:
seq_group = scheduled_seq_group.seq_group
if seq_group.is_finished():
self.create_trace_span(seq_group)
def create_trace_span(self, seq_group: SequenceGroup) -> None:
if self.tracer is None or seq_group.sampling_params is None:
return
arrival_time_nano_seconds = int(seq_group.metrics.arrival_time * 1e9)
trace_context = extract_trace_context(seq_group.trace_headers)
with self.tracer.start_as_current_span(
"llm_request",
kind=SpanKind.SERVER,
context=trace_context,
start_time=arrival_time_nano_seconds) as seq_span:
metrics = seq_group.metrics
ttft = metrics.first_token_time - metrics.arrival_time
e2e_time = metrics.finished_time - metrics.arrival_time
# attribute names are based on
# https://github.com/open-telemetry/semantic-conventions/blob/main/docs/gen-ai/llm-spans.md
seq_span.set_attribute(SpanAttributes.LLM_RESPONSE_MODEL,
self.model_config.model)
seq_span.set_attribute(SpanAttributes.LLM_REQUEST_ID,
seq_group.request_id)
seq_span.set_attribute(SpanAttributes.LLM_REQUEST_TEMPERATURE,
seq_group.sampling_params.temperature)
seq_span.set_attribute(SpanAttributes.LLM_REQUEST_TOP_P,
seq_group.sampling_params.top_p)
seq_span.set_attribute(SpanAttributes.LLM_REQUEST_MAX_TOKENS,
seq_group.sampling_params.max_tokens)
seq_span.set_attribute(SpanAttributes.LLM_REQUEST_BEST_OF,
seq_group.sampling_params.best_of)
seq_span.set_attribute(SpanAttributes.LLM_REQUEST_N,
seq_group.sampling_params.n)
seq_span.set_attribute(SpanAttributes.LLM_USAGE_NUM_SEQUENCES,
seq_group.num_seqs())
seq_span.set_attribute(SpanAttributes.LLM_USAGE_PROMPT_TOKENS,
len(seq_group.prompt_token_ids))
seq_span.set_attribute(
SpanAttributes.LLM_USAGE_COMPLETION_TOKENS,
sum([
seq.get_output_len()
for seq in seq_group.get_finished_seqs()
]))
seq_span.set_attribute(SpanAttributes.LLM_LATENCY_TIME_IN_QUEUE,
metrics.time_in_queue)
seq_span.set_attribute(
SpanAttributes.LLM_LATENCY_TIME_TO_FIRST_TOKEN, ttft)
seq_span.set_attribute(SpanAttributes.LLM_LATENCY_E2E, e2e_time)
if metrics.scheduler_time is not None:
seq_span.set_attribute(
SpanAttributes.LLM_LATENCY_TIME_IN_SCHEDULER,
metrics.scheduler_time)
if metrics.model_forward_time is not None:
seq_span.set_attribute(
SpanAttributes.LLM_LATENCY_TIME_IN_MODEL_FORWARD,
metrics.model_forward_time / 1000.0)
if metrics.model_execute_time is not None:
seq_span.set_attribute(
SpanAttributes.LLM_LATENCY_TIME_IN_MODEL_EXECUTE,
metrics.model_execute_time)
def is_encoder_decoder_model(self):
return self.input_preprocessor.is_encoder_decoder_model()
def is_embedding_model(self):
return self.model_config.is_embedding_model
def _validate_model_inputs(self, inputs: Union[LLMInputs,
EncoderDecoderLLMInputs]):
if self.is_encoder_decoder_model():
prompt_ids = inputs.get("encoder_prompt_token_ids")
else:
prompt_ids = inputs.get("prompt_token_ids")
if prompt_ids is None or len(prompt_ids) == 0:
raise ValueError("Prompt cannot be empty")
if self.model_config.is_multimodal_model:
max_prompt_len = self.model_config.max_model_len
if len(prompt_ids) > max_prompt_len:
raise ValueError(
f"The prompt (total length {len(prompt_ids)}) is too long "
f"to fit into the model (context length {max_prompt_len}). "
"Make sure that `max_model_len` is no smaller than the "
"number of text tokens plus multimodal tokens. For image "
"inputs, the number of image tokens depends on the number "
"of images, and possibly their aspect ratios as well.")
# TODO: Find out how many placeholder tokens are there so we can
# check that chunked prefill does not truncate them
# max_batch_len = self.scheduler_config.max_num_batched_tokens