Files
vllm/vllm/v1/executor/ray_utils.py
Rui Qiao a491d6f535 [V1] TP Ray executor (#11107)
Signed-off-by: Rui Qiao <ruisearch42@gmail.com>
2024-12-23 23:00:12 +00:00

272 lines
11 KiB
Python

import time
from collections import defaultdict
from typing import TYPE_CHECKING, Dict, List, Optional, Tuple
from vllm.config import ParallelConfig
from vllm.logger import init_logger
from vllm.platforms import current_platform
from vllm.utils import get_ip
from vllm.v1.outputs import ModelRunnerOutput
from vllm.worker.worker_base import WorkerWrapperBase
if TYPE_CHECKING:
from vllm.v1.core.scheduler import SchedulerOutput
logger = init_logger(__name__)
PG_WAIT_TIMEOUT = 60
try:
import ray
from ray.util import placement_group_table
from ray.util.placement_group import PlacementGroup
try:
from ray._private.state import available_resources_per_node
except ImportError:
# Ray 2.9.x doesn't expose `available_resources_per_node`
from ray._private.state import state as _state
available_resources_per_node = _state._available_resources_per_node
class RayWorkerWrapper(WorkerWrapperBase):
def __init__(self, *args, **kwargs) -> None:
super().__init__(*args, **kwargs)
# Since the compiled DAG runs a main execution
# in a different thread that calls cuda.set_device.
# The flag indicates is set_device is called on
# that thread. It will be removed soon.
self.compiled_dag_cuda_device_set = False
def get_node_ip(self) -> str:
return get_ip()
def get_node_and_gpu_ids(self) -> Tuple[str, List[int]]:
node_id = ray.get_runtime_context().get_node_id()
gpu_ids = ray.get_gpu_ids()
return node_id, gpu_ids
def setup_device_if_necessary(self):
# TODO(swang): This is needed right now because Ray CG executes
# on a background thread, so we need to reset torch's current
# device.
# We can remove this API after it is fixed in compiled graph.
import torch
assert self.worker is not None, "Worker is not initialized"
if not self.compiled_dag_cuda_device_set:
torch.cuda.set_device(self.worker.device)
self.compiled_dag_cuda_device_set = True
def execute_model(
self,
scheduler_output: "SchedulerOutput",
) -> ModelRunnerOutput:
self.setup_device_if_necessary()
assert self.worker is not None, "Worker is not initialized"
output = self.worker.model_runner.execute_model(scheduler_output)
return output
ray_import_err = None
except ImportError as e:
ray = None # type: ignore
ray_import_err = e
RayWorkerWrapper = None # type: ignore
def ray_is_available() -> bool:
"""Returns True if Ray is available."""
return ray is not None
def assert_ray_available():
"""
Raise an exception if Ray is not available.
"""
if ray is None:
raise ValueError("Failed to import Ray, please install Ray with "
"`pip install ray`.") from ray_import_err
def _verify_bundles(placement_group: "PlacementGroup",
parallel_config: ParallelConfig, device_str: str):
"""
Verify a given placement group has bundles located in the right place.
There are 2 rules.
- Warn if all tensor parallel workers cannot fit in a single node.
- Fail if driver node is not included in a placement group.
Args:
placement_group: The placement group to verify.
parallel_config: The parallel configuration.
device_str: The required device.
"""
assert ray.is_initialized(), (
"Ray is not initialized although distributed-executor-backend is ray.")
pg_data = placement_group_table(placement_group)
# bundle_idx -> node_id
bundle_to_node_ids = pg_data["bundles_to_node_id"]
# bundle_idx -> bundle (e.g., {"GPU": 1})
bundles = pg_data["bundles"]
# node_id -> List of bundle (e.g., {"GPU": 1})
node_id_to_bundle: Dict[str, List[Dict[str, float]]] = defaultdict(list)
for bundle_idx, node_id in bundle_to_node_ids.items():
node_id_to_bundle[node_id].append(bundles[bundle_idx])
driver_node_id = ray.get_runtime_context().get_node_id()
if driver_node_id not in node_id_to_bundle:
raise RuntimeError(
f"driver node id {driver_node_id} is not included in a placement "
f"group {placement_group.id}. Node id -> bundles "
f"{node_id_to_bundle}. "
"You don't have enough GPUs available in a current node. Check "
"`ray status` to see if you have available GPUs in a node "
f"{driver_node_id} before starting an vLLM engine.")
for node_id, bundles in node_id_to_bundle.items():
if len(bundles) < parallel_config.tensor_parallel_size:
logger.warning(
"tensor_parallel_size=%d "
"is bigger than a reserved number of %ss (%d "
"%ss) in a node %s. Tensor parallel workers can be "
"spread out to 2+ nodes which can degrade the performance "
"unless you have fast interconnect across nodes, like "
"Infiniband. To resolve this issue, make sure you have more "
"than %d GPUs available at each node.",
parallel_config.tensor_parallel_size, device_str, len(bundles),
device_str, node_id, parallel_config.tensor_parallel_size)
def _wait_until_pg_ready(current_placement_group: "PlacementGroup"):
"""Wait until a placement group is ready.
It prints the informative log messages if the placement group is
not created within time.
"""
# Wait until PG is ready - this will block until all
# requested resources are available, and will timeout
# if they cannot be provisioned.
placement_group_specs = current_placement_group.bundle_specs
s = time.time()
pg_ready_ref = current_placement_group.ready()
wait_interval = 10
while time.time() - s < PG_WAIT_TIMEOUT:
ready, _ = ray.wait([pg_ready_ref], timeout=wait_interval)
if len(ready) > 0:
break
# Exponential backoff for warning print.
wait_interval *= 2
logger.info(
"Waiting for creating a placement group of specs for "
"%d seconds. specs=%s. Check "
"`ray status` to see if you have enough resources.",
int(time.time() - s), placement_group_specs)
try:
ray.get(pg_ready_ref, timeout=0)
except ray.exceptions.GetTimeoutError:
raise ValueError(
"Cannot provide a placement group of "
f"{placement_group_specs=} within {PG_WAIT_TIMEOUT} seconds. See "
"`ray status` to make sure the cluster has enough resources."
) from None
def initialize_ray_cluster(
parallel_config: ParallelConfig,
ray_address: Optional[str] = None,
):
"""Initialize the distributed cluster with Ray.
it will connect to the Ray cluster and create a placement group
for the workers, which includes the specification of the resources
for each distributed worker.
Args:
parallel_config: The configurations for parallel execution.
ray_address: The address of the Ray cluster. If None, uses
the default Ray cluster address.
"""
assert_ray_available()
# Connect to a ray cluster.
if current_platform.is_rocm() or current_platform.is_xpu():
# Try to connect existing ray instance and create a new one if not found
try:
ray.init("auto")
except ConnectionError:
logger.warning(
"No existing RAY instance detected. "
"A new instance will be launched with current node resources.")
ray.init(address=ray_address,
ignore_reinit_error=True,
num_gpus=parallel_config.world_size)
else:
ray.init(address=ray_address, ignore_reinit_error=True)
if parallel_config.placement_group:
# Placement group is already set.
return
device_str = "GPU" if not current_platform.is_tpu() else "TPU"
# Create placement group for worker processes
current_placement_group = ray.util.get_current_placement_group()
if current_placement_group:
# We are in a placement group
bundles = current_placement_group.bundle_specs
# Verify that we can use the placement group.
device_bundles = 0
for bundle in bundles:
bundle_devices = bundle.get(device_str, 0)
if bundle_devices > 1:
raise ValueError(
"Placement group bundle cannot have more than 1 "
f"{device_str}.")
if bundle_devices:
device_bundles += 1
if parallel_config.world_size > device_bundles:
raise ValueError(
f"The number of required {device_str}s exceeds the total "
f"number of available {device_str}s in the placement group."
f"Required number of devices: {parallel_config.world_size}. "
f"Total number of devices: {device_bundles}.")
else:
num_devices_in_cluster = ray.cluster_resources().get(device_str, 0)
if parallel_config.world_size > num_devices_in_cluster:
raise ValueError(
f"The number of required {device_str}s exceeds the total "
f"number of available {device_str}s in the placement group.")
# Create a new placement group
placement_group_specs: List[Dict[str, float]] = ([{
device_str: 1.0
} for _ in range(parallel_config.world_size)])
# vLLM engine is also a worker to execute model with an accelerator,
# so it requires to have the device in a current node. Check if
# the current node has at least one device.
current_ip = get_ip()
current_node_id = ray.get_runtime_context().get_node_id()
current_node_resource = available_resources_per_node()[current_node_id]
if current_node_resource.get(device_str, 0) < 1:
raise ValueError(
f"Current node has no {device_str} available. "
f"{current_node_resource=}. vLLM engine cannot start without "
f"{device_str}. Make sure you have at least 1 {device_str} "
f"available in a node {current_node_id=} {current_ip=}.")
# This way, at least bundle is required to be created in a current
# node.
placement_group_specs[0][f"node:{current_ip}"] = 0.001
# By default, Ray packs resources as much as possible.
current_placement_group = ray.util.placement_group(
placement_group_specs, strategy="PACK")
_wait_until_pg_ready(current_placement_group)
assert current_placement_group is not None
_verify_bundles(current_placement_group, parallel_config, device_str)
# Set the placement group in the parallel config
parallel_config.placement_group = current_placement_group