vllm/cacheflow/server/ray_utils.py
2023-05-20 13:06:59 -07:00

91 lines
3.4 KiB
Python

import random
from typing import List, Optional, Tuple
try:
import ray
except ImportError:
ray = None
from cacheflow.config import ParallelConfig
DeviceID = Tuple[int, str, int] # rank, node resource (node IP), device id
def initialize_cluster(
parallel_config: ParallelConfig,
address: Optional[str] = None,
) -> Tuple[str, List[List[DeviceID]]]:
if not parallel_config.use_ray:
# Initialize cluster locally.
port = random.randint(10000, 20000)
# We need to setup the distributed init method to make sure
# the distributed megatron code (e.g., get world size) works correctly.
distributed_init_method = f"tcp://localhost:{port}"
all_stage_devices = [[(0, None, 0)]]
return distributed_init_method, all_stage_devices
if ray is None:
raise ImportError(
"Ray is not installed. Please install Ray to use distributed "
"serving.")
# Connect to a ray cluster.
ray.init(address=address)
# Assume we have a uniform cluster that each node has the same number of
# GPUs for now.
valid_node_resources = []
num_devices_per_node = None
for node in ray.nodes():
if (not node['Alive']) or node['Resources']['GPU'] <= 0:
continue
if num_devices_per_node is None:
num_devices_per_node = node['Resources']['GPU']
else:
assert num_devices_per_node == node['Resources']['GPU'], (
"The number of GPUs per node is not uniform.")
for key in node['Resources']:
if key.startswith('node:'):
valid_node_resources.append(key)
# Verify the parallel config.
num_nodes = len(valid_node_resources)
if parallel_config.world_size > num_nodes * num_devices_per_node:
raise ValueError(
"The number of required GPUs exceeds the total number of "
"available GPUs.")
if parallel_config.tensor_parallel_size >= num_devices_per_node:
if parallel_config.tensor_parallel_size % num_devices_per_node != 0:
raise ValueError(
"The number of tensor parallelism is not divisible by the "
"number of GPUs per node.")
else:
if num_devices_per_node % parallel_config.tensor_parallel_size != 0:
raise ValueError(
"The number of GPUs per node is not divisible by the number "
"of tensor parallelism.")
# Assign GPUs to pipeline stages.
rank = 0
current_node_id = 0
current_device_id = 0
distributed_init_method = None
all_stage_devices = []
for _ in range(parallel_config.pipeline_parallel_size):
stage_devices = []
for _ in range(parallel_config.tensor_parallel_size):
node_resource = valid_node_resources[current_node_id]
stage_devices.append((rank, node_resource, current_device_id))
if distributed_init_method is None:
ip = node_resource.split("node:")[-1]
port = random.randint(10000, 20000)
distributed_init_method = f"tcp://{ip}:{port}"
rank += 1
current_device_id += 1
if current_device_id >= num_devices_per_node:
current_node_id += 1
current_device_id = 0
all_stage_devices.append(stage_devices)
return distributed_init_method, all_stage_devices