vllm/examples/others/lmcache/cpu_offload_lmcache.py

154 lines
4.6 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
This file demonstrates the example usage of cpu offloading
with LMCache in vLLM v1 or v0.
Usage:
Specify vLLM version
-v v0 : Use LMCacheConnector
model = mistralai/Mistral-7B-Instruct-v0.2
(Includes enable_chunked_prefill = True)
-v v1 : Use LMCacheConnectorV1 (default)
model = meta-llama/Meta-Llama-3.1-8B-Instruct
(Without enable_chunked_prefill)
Note that `lmcache` is needed to run this example.
Requirements:
https://docs.lmcache.ai/getting_started/installation.html#prerequisites
Learn more about LMCache environment setup, please refer to:
https://docs.lmcache.ai/getting_started/installation.html
"""
import argparse
import contextlib
import os
import time
from dataclasses import asdict
from lmcache.integration.vllm.utils import ENGINE_NAME
from lmcache.v1.cache_engine import LMCacheEngineBuilder
from vllm import LLM, SamplingParams
from vllm.config import KVTransferConfig
from vllm.engine.arg_utils import EngineArgs
def setup_environment_variables(vllm_version: str):
# LMCache-related environment variables
# Use experimental features in LMCache
os.environ["LMCACHE_USE_EXPERIMENTAL"] = "True"
# LMCache is set to use 256 tokens per chunk
os.environ["LMCACHE_CHUNK_SIZE"] = "256"
# Enable local CPU backend in LMCache
os.environ["LMCACHE_LOCAL_CPU"] = "True"
# Set local CPU memory limit to 5.0 GB
os.environ["LMCACHE_MAX_LOCAL_CPU_SIZE"] = "5.0"
if vllm_version == "v0":
os.environ["VLLM_USE_V1"] = "0"
@contextlib.contextmanager
def build_llm_with_lmcache(lmcache_connector: str, model: str, vllm_version: str):
ktc = KVTransferConfig(
kv_connector=lmcache_connector,
kv_role="kv_both",
)
# Set GPU memory utilization to 0.8 for an A40 GPU with 40GB
# memory. Reduce the value if your GPU has less memory.
# Note: LMCache supports chunked prefill (see vLLM#14505, LMCache#392).
if vllm_version == "v0":
llm_args = EngineArgs(
model=model,
kv_transfer_config=ktc,
max_model_len=8000,
gpu_memory_utilization=0.8,
enable_chunked_prefill=True, # Only in v0
)
else:
llm_args = EngineArgs(
model=model,
kv_transfer_config=ktc,
max_model_len=8000,
gpu_memory_utilization=0.8,
)
llm = LLM(**asdict(llm_args))
try:
yield llm
finally:
# Clean up lmcache backend
LMCacheEngineBuilder.destroy(ENGINE_NAME)
def print_output(
llm: LLM,
prompt: list[str],
sampling_params: SamplingParams,
req_str: str,
):
# Should be able to see logs like the following:
# `LMCache INFO: Storing KV cache for 6006 out of 6006 tokens for request 0`
# This indicates that the KV cache has been stored in LMCache.
start = time.time()
outputs = llm.generate(prompt, sampling_params)
print("-" * 50)
for output in outputs:
generated_text = output.outputs[0].text
print(f"Generated text: {generated_text!r}")
print(f"Generation took {time.time() - start:.2f} seconds, {req_str} request done.")
print("-" * 50)
def parse_args():
parser = argparse.ArgumentParser()
parser.add_argument(
"-v",
"--version",
choices=["v0", "v1"],
default="v1",
help="Specify vLLM version (default: v1)",
)
return parser.parse_args()
def main():
args = parse_args()
if args.version == "v0":
lmcache_connector = "LMCacheConnector"
model = "mistralai/Mistral-7B-Instruct-v0.2"
else:
lmcache_connector = "LMCacheConnectorV1"
model = "meta-llama/Meta-Llama-3.1-8B-Instruct"
setup_environment_variables(args.version)
with build_llm_with_lmcache(lmcache_connector, model, args.version) as llm:
# This example script runs two requests with a shared prefix.
# Define the shared prompt and specific prompts
shared_prompt = "Hello, how are you?" * 1000
first_prompt = [
shared_prompt + "Hello, my name is",
]
second_prompt = [
shared_prompt + "Tell me a very long story",
]
sampling_params = SamplingParams(temperature=0, top_p=0.95, max_tokens=10)
# Print the first output
print_output(llm, first_prompt, sampling_params, "first")
time.sleep(1)
# print the second output
print_output(llm, second_prompt, sampling_params, "second")
if __name__ == "__main__":
main()