vllm/cacheflow/server/llm_server.py
2023-05-28 03:20:05 -07:00

262 lines
10 KiB
Python

import time
from typing import Any, List, Optional
try:
import ray
except ImportError:
ray = None
from cacheflow.config import (CacheConfig, ModelConfig, ParallelConfig,
SchedulerConfig)
from cacheflow.core.scheduler import Scheduler
from cacheflow.logger import init_logger
from cacheflow.outputs import RequestOutput
from cacheflow.sampling_params import SamplingParams
from cacheflow.server.arg_utils import ServerArgs
from cacheflow.server.ray_utils import initialize_cluster
from cacheflow.server.tokenizer_utils import (get_tokenizer,
detokenize_incrementally)
from cacheflow.sequence import Sequence, SequenceGroup, SequenceStatus
from cacheflow.utils import Counter
from cacheflow.worker.worker import Worker
logger = init_logger(__name__)
class LLMServer:
def __init__(
self,
model_config: ModelConfig,
cache_config: CacheConfig,
parallel_config: ParallelConfig,
scheduler_config: SchedulerConfig,
distributed_init_method: str,
stage_devices: List[List[Any]],
log_stats: bool,
) -> None:
logger.info(
"Initializing an LLM server with config: "
f"model={model_config.model!r}, "
f"dtype={model_config.dtype}, "
f"use_dummy_weights={model_config.use_dummy_weights}, "
f"download_dir={model_config.download_dir!r}, "
f"use_np_weights={model_config.use_np_weights}, "
f"tensor_parallel_size={parallel_config.tensor_parallel_size}, "
f"seed={model_config.seed})"
)
# TODO(woosuk): Print more configs in debug mode.
self.model_config = model_config
self.cache_config = cache_config
self.parallel_config = parallel_config
self.scheduler_config = scheduler_config
self.log_stats = log_stats
self._verify_args()
self.tokenizer = get_tokenizer(model_config.model)
self.seq_counter = Counter()
# Create the parallel GPU workers.
self.workers: List[Worker] = []
assert len(stage_devices) == 1, "Only support one stage for now."
for rank, node_resource, _ in stage_devices[0]:
worker_cls = Worker
if self.parallel_config.use_ray:
worker_cls = ray.remote(
num_cpus=0,
num_gpus=1,
resources={node_resource: 1e-5},
)(worker_cls).remote
worker = worker_cls(
model_config,
parallel_config,
scheduler_config,
rank,
distributed_init_method,
)
self.workers.append(worker)
# Profile the memory usage and initialize the cache.
self._init_cache()
# Create the scheduler.
self.scheduler = Scheduler(scheduler_config, cache_config, log_stats)
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)
def _init_cache(self) -> None:
# Get the maximum number of blocks that can be allocated on GPU and CPU.
num_blocks = self._run_workers(
"profile_num_available_blocks",
get_all_outputs=True,
block_size=self.cache_config.block_size,
gpu_memory_utilization=self.cache_config.gpu_memory_utilization,
cpu_swap_space=self.cache_config.swap_space_bytes,
)
# Since we use a shared centralized controller, we take the minimum
# number of blocks across all workers to make sure all the memory
# operators can be applied to all workers.
num_gpu_blocks = min(b[0] for b in num_blocks)
num_cpu_blocks = min(b[1] for b in num_blocks)
# FIXME(woosuk): Change to debug log.
logger.info(f'# GPU blocks: {num_gpu_blocks}, '
f'# CPU blocks: {num_cpu_blocks}')
self.cache_config.num_gpu_blocks = num_gpu_blocks
self.cache_config.num_cpu_blocks = num_cpu_blocks
# Initialize the cache.
self._run_workers("init_cache_engine", cache_config=self.cache_config)
@classmethod
def from_server_args(cls, server_args: ServerArgs) -> "LLMServer":
# Create the server configs.
server_configs = server_args.create_server_configs()
parallel_config = server_configs[2]
# Initialize the cluster.
distributed_init_method, devices = initialize_cluster(parallel_config)
# Create the LLM server.
server = cls(*server_configs, distributed_init_method, devices,
log_stats=not server_args.disable_log_stats)
return server
def add_request(
self,
request_id: str,
prompt: str,
sampling_params: SamplingParams,
prompt_token_ids: Optional[List[int]] = None,
arrival_time: Optional[float] = None,
) -> None:
if arrival_time is None:
arrival_time = time.time()
if prompt_token_ids is None:
prompt_token_ids = self.tokenizer.encode(prompt)
# Create the sequences.
block_size = self.cache_config.block_size
seqs: List[Sequence] = []
for _ in range(sampling_params.best_of):
seq_id = next(self.seq_counter)
seq = Sequence(seq_id, prompt, prompt_token_ids, block_size)
seqs.append(seq)
# Create the sequence group.
seq_group = SequenceGroup(request_id, seqs, sampling_params,
arrival_time)
# Add the sequence group to the scheduler.
self.scheduler.add_seq_group(seq_group)
def get_num_unfinished_requests(self) -> int:
return self.scheduler.get_num_unfinished_seq_groups()
def has_unfinished_requests(self) -> bool:
return self.scheduler.has_unfinished_seqs()
def step(self) -> List[RequestOutput]:
seq_group_metadata_list, scheduler_outputs = self.scheduler.schedule()
if (not seq_group_metadata_list) and scheduler_outputs.is_empty():
# Nothing to do.
return []
# Execute the model.
output = self._run_workers(
"execute_model",
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,
)
# Update the scheduler with the model outputs.
seq_groups = self.scheduler.update(output)
# Decode the sequences.
self._decode_sequences(seq_groups)
# Stop the sequences that meet the stopping criteria.
self._stop_sequences(seq_groups)
# Free the finished sequence groups.
self.scheduler.free_finished_seq_groups()
# Create the outputs.
request_outputs: List[RequestOutput] = []
for seq_group in seq_groups:
request_output = RequestOutput.from_seq_group(seq_group)
request_outputs.append(request_output)
return request_outputs
def _decode_sequences(self, seq_groups: List[SequenceGroup]) -> None:
# Decode the sequence outputs.
for seq_group in seq_groups:
for seq in seq_group.get_seqs(status=SequenceStatus.RUNNING):
new_token, new_output_text = detokenize_incrementally(
self.tokenizer,
seq.output_tokens,
seq.get_last_token_id(),
skip_special_tokens=True,
)
seq.output_tokens.append(new_token)
seq.output_text = new_output_text
def _stop_sequences(self, seq_groups: List[SequenceGroup]) -> None:
# Stop the sequences.
for seq_group in seq_groups:
sampling_params = seq_group.sampling_params
for seq in seq_group.get_seqs(status=SequenceStatus.RUNNING):
# Check if the sequence has generated a stop string.
stopped = False
for stop_str in sampling_params.stop:
if seq.output_text.endswith(stop_str):
# Truncate the output text so that the stop string is
# not included in the output.
seq.output_text = seq.output_text[:-len(stop_str)]
self.scheduler.free_seq(seq,
SequenceStatus.FINISHED_STOPPED)
stopped = True
break
if stopped:
continue
# Check if the sequence has reached max_tokens.
if seq.get_output_len() == sampling_params.max_tokens:
self.scheduler.free_seq(
seq, SequenceStatus.FINISHED_LENGTH_CAPPED)
continue
# Check if the sequence has generated the EOS token.
if not sampling_params.ignore_eos:
if seq.get_last_token_id() == self.tokenizer.eos_token_id:
self.scheduler.free_seq(seq,
SequenceStatus.FINISHED_STOPPED)
continue
def _run_workers(
self,
method: str,
get_all_outputs: bool = False,
*args,
**kwargs,
) -> Any:
all_outputs = []
for worker in self.workers:
executor = getattr(worker, method)
if self.parallel_config.use_ray:
executor = executor.remote
output = executor(*args, **kwargs)
all_outputs.append(output)
if self.parallel_config.use_ray:
all_outputs = ray.get(all_outputs)
if get_all_outputs:
return all_outputs
# Make sure all workers have the same results.
output = all_outputs[0]
for other_output in all_outputs[1:]:
assert output == other_output
return output