vllm/vllm/v1/engine/core.py
Robert Shaw 9597a095f2
[V1][Core][1/n] Logging and Metrics (#11962)
Signed-off-by: rshaw@neuralmagic.com <rshaw@neuralmagic.com>
2025-01-12 21:02:02 +00:00

287 lines
11 KiB
Python

import pickle
import queue
import signal
import threading
import time
from multiprocessing.connection import Connection
from typing import List, Tuple, Type
import psutil
import zmq
import zmq.asyncio
from msgspec import msgpack
from vllm.config import CacheConfig, VllmConfig
from vllm.logger import init_logger
from vllm.transformers_utils.config import (
maybe_register_config_serialize_by_value)
from vllm.utils import get_exception_traceback, zmq_socket_ctx
from vllm.v1.core.scheduler import Scheduler
from vllm.v1.engine import (EngineCoreOutputs, EngineCoreProfile,
EngineCoreRequest, EngineCoreRequestType,
EngineCoreRequestUnion)
from vllm.v1.engine.mm_input_mapper import MMInputMapperServer
from vllm.v1.executor.abstract import Executor
from vllm.v1.request import Request, RequestStatus
from vllm.v1.serial_utils import PickleEncoder
from vllm.version import __version__ as VLLM_VERSION
logger = init_logger(__name__)
POLLING_TIMEOUT_S = 2.5
class EngineCore:
"""Inner loop of vLLM's Engine."""
def __init__(
self,
vllm_config: VllmConfig,
executor_class: Type[Executor],
):
assert vllm_config.model_config.runner_type != "pooling"
logger.info("Initializing an LLM engine (v%s) with config: %s",
VLLM_VERSION, vllm_config)
# Setup Model.
self.model_executor = executor_class(vllm_config)
# Setup KV Caches and update CacheConfig after profiling.
num_gpu_blocks, num_cpu_blocks = self._initialize_kv_caches(
vllm_config.cache_config)
vllm_config.cache_config.num_gpu_blocks = num_gpu_blocks
vllm_config.cache_config.num_cpu_blocks = num_cpu_blocks
# Setup scheduler.
self.scheduler = Scheduler(vllm_config.scheduler_config,
vllm_config.cache_config,
vllm_config.lora_config)
self.mm_input_mapper_server = MMInputMapperServer(
vllm_config.model_config)
def _initialize_kv_caches(self,
cache_config: CacheConfig) -> Tuple[int, int]:
start = time.time()
num_gpu_blocks, _ = self.model_executor.determine_num_available_blocks(
)
if cache_config.num_gpu_blocks_override is not None:
num_gpu_blocks_override = 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
num_cpu_blocks = 0
self.model_executor.initialize(num_gpu_blocks)
elapsed = time.time() - start
logger.info(("init engine (profile, create kv cache, "
"warmup model) took %.2f seconds"), elapsed)
return num_gpu_blocks, num_cpu_blocks
def add_request(self, request: EngineCoreRequest):
"""Add request to the scheduler."""
if request.mm_hashes is not None:
# Here, if hash exists for an image, then it will be fetched
# from the cache, else it will be added to the cache.
# Note that the cache here is mirrored with the client side of the
# MM mapper, so anything that has a hash must have a HIT cache
# entry here as well.
assert request.mm_inputs is not None
request.mm_inputs = self.mm_input_mapper_server.process_inputs(
request.mm_inputs, request.mm_hashes)
req = Request.from_engine_core_request(request)
self.scheduler.add_request(req)
def abort_requests(self, request_ids: List[str]):
"""Abort requests from the scheduler."""
# TODO: The scheduler doesn't really need to know the
# specific finish reason, TBD whether we propagate that
# (i.e. client-aborted vs stop criteria met).
self.scheduler.finish_requests(request_ids,
RequestStatus.FINISHED_ABORTED)
def step(self) -> EngineCoreOutputs:
"""Schedule, execute, and make output."""
if not self.scheduler.has_unfinished_requests():
return EngineCoreOutputs(
outputs=[], scheduler_stats=self.scheduler.make_stats())
scheduler_output = self.scheduler.schedule()
output = self.model_executor.execute_model(scheduler_output)
engine_core_outputs = self.scheduler.update_from_output(
scheduler_output, output)
return engine_core_outputs
def shutdown(self):
self.model_executor.shutdown()
def profile(self, is_start: bool = True):
self.model_executor.profile(is_start)
class EngineCoreProc(EngineCore):
"""ZMQ-wrapper for running EngineCore in background process."""
def __init__(
self,
input_path: str,
output_path: str,
ready_pipe: Connection,
vllm_config: VllmConfig,
executor_class: Type[Executor],
log_stats: bool = False,
):
super().__init__(vllm_config, executor_class)
self.log_stats = log_stats
# Background Threads and Queues for IO. These enable us to
# overlap ZMQ socket IO with GPU since they release the GIL,
# and to overlap some serialization/deserialization with the
# model forward pass.
# Threads handle Socket <-> Queues and core_busy_loop uses Queue.
self.input_queue: queue.Queue[EngineCoreRequestUnion] = queue.Queue()
self.output_queue: queue.Queue[EngineCoreOutputs] = queue.Queue()
threading.Thread(target=self.process_input_socket,
args=(input_path, ),
daemon=True).start()
threading.Thread(target=self.process_output_socket,
args=(output_path, ),
daemon=True).start()
# Send Readiness signal to EngineClient.
ready_pipe.send({"status": "READY"})
@staticmethod
def run_engine_core(*args, **kwargs):
"""Launch EngineCore busy loop in background process."""
# Signal handler used for graceful termination.
# SystemExit exception is only raised once to allow this and worker
# processes to terminate without error
shutdown_requested = False
# Ensure we can serialize transformer config after spawning
maybe_register_config_serialize_by_value()
def signal_handler(signum, frame):
nonlocal shutdown_requested
if not shutdown_requested:
shutdown_requested = True
raise SystemExit()
# Either SIGTERM or SIGINT will terminate the engine_core
signal.signal(signal.SIGTERM, signal_handler)
signal.signal(signal.SIGINT, signal_handler)
parent_process = psutil.Process().parent()
engine_core = None
try:
engine_core = EngineCoreProc(*args, **kwargs)
engine_core.run_busy_loop()
except SystemExit:
logger.debug("EngineCore interrupted.")
except Exception:
traceback = get_exception_traceback()
logger.error("EngineCore hit an exception: %s", traceback)
parent_process.send_signal(signal.SIGUSR1)
finally:
if engine_core is not None:
engine_core.shutdown()
def run_busy_loop(self):
"""Core busy loop of the EngineCore."""
# Loop until process is sent a SIGINT or SIGTERM
while True:
# 1) Poll the input queue until there is work to do.
if not self.scheduler.has_unfinished_requests():
while True:
try:
req = self.input_queue.get(timeout=POLLING_TIMEOUT_S)
self._handle_client_request(req)
break
except queue.Empty:
logger.debug("EngineCore busy loop waiting.")
# Break out the loop so we can log_stats in step().
if self.log_stats:
break
except BaseException:
raise
# 2) Handle any new client requests (Abort or Add).
while not self.input_queue.empty():
req = self.input_queue.get_nowait()
self._handle_client_request(req)
# 3) Step the engine core.
outputs = self.step()
# 5) Put EngineCoreOutputs into the output queue.
self.output_queue.put_nowait(outputs)
def _handle_client_request(self, request: EngineCoreRequestUnion) -> None:
"""Handle EngineCoreRequest or EngineCoreABORT from Client."""
if isinstance(request, EngineCoreRequest):
self.add_request(request)
elif isinstance(request, EngineCoreProfile):
self.model_executor.profile(request.is_start)
else:
# TODO: make an EngineCoreAbort wrapper
assert isinstance(request, list)
self.abort_requests(request)
def process_input_socket(self, input_path: str):
"""Input socket IO thread."""
# Msgpack serialization decoding.
decoder_add_req = PickleEncoder()
decoder_abort_req = PickleEncoder()
with zmq_socket_ctx(input_path, zmq.constants.PULL) as socket:
while True:
# (RequestType, RequestData)
type_frame, data_frame = socket.recv_multipart(copy=False)
request_type = type_frame.buffer
request_data = data_frame.buffer
# Deserialize the request data.
if request_type == EngineCoreRequestType.ADD.value:
request = decoder_add_req.decode(request_data)
elif request_type == EngineCoreRequestType.ABORT.value:
request = decoder_abort_req.decode(request_data)
elif request_type == EngineCoreRequestType.PROFILE.value:
request = pickle.loads(request_data)
else:
raise ValueError(f"Unknown RequestType: {request_type}")
# Push to input queue for core busy loop.
self.input_queue.put_nowait(request)
def process_output_socket(self, output_path: str):
"""Output socket IO thread."""
# Msgpack serialization encoding.
encoder = msgpack.Encoder()
# Reuse send buffer.
buffer = bytearray()
with zmq_socket_ctx(output_path, zmq.constants.PUSH) as socket:
while True:
outputs = self.output_queue.get()
encoder.encode_into(outputs, buffer)
socket.send_multipart((buffer, ), copy=False)