AReaL/arealite/experimental/sglang_engine.py

377 lines
14 KiB
Python

import asyncio
import threading
import time
import traceback
from concurrent.futures import ThreadPoolExecutor
from queue import Empty, Full, Queue
from typing import TYPE_CHECKING, Any, Callable, Dict, List, Optional
import sglang as sgl
import torch.distributed as dist
from tensordict import TensorDict
from arealite.api.cli_args import InferenceEngineConfig
from arealite.api.engine_api import InferenceEngine
from arealite.api.io_struct import (
LLMRequest,
LLMResponse,
RolloutStat,
WeightUpdateMeta,
)
from realhf.base import logging, name_resolve, names, pkg_version
if TYPE_CHECKING:
from arealite.api.workflow_api import RolloutWorkflow
logger = logging.getLogger(__name__)
if pkg_version.is_available("sglang"):
if pkg_version.is_version_greater_or_equal("sglang", "0.4.4"):
SGLANG_TOKEN_OUTPUT_IDENTIFIER = "output_ids"
else:
SGLANG_TOKEN_OUTPUT_IDENTIFIER = "token_ids"
ROLLOUT_POLL_WAIT_TIME = 0.4
RID_CACHE_SIZE = 128
"""
Local SGLang Inference Engine
SGLangEngine currently only supports single-controller. Cannot be used in SPMD
"""
class SGLangEngine(InferenceEngine):
def __init__(
self,
config: InferenceEngineConfig,
engine_args: Optional[Dict[str, Any]] = None,
):
config.max_concurrent_rollouts = (
config.max_concurrent_rollouts or config.consumer_batch_size
)
self.config = config
self.engine_args = engine_args or {}
qsize = config.queue_size or config.max_concurrent_rollouts * 10
self.input_queue = Queue(maxsize=qsize)
self.output_queue = Queue(maxsize=qsize)
self.result_cache = []
self.exiting = threading.Event()
self.lock = threading.Lock()
self.rollout_stat = RolloutStat()
self._version = 0
def initialize(self, addr: str | None, ft_spec: Optional[Dict[str, Any]] = None):
self.engine = sgl.Engine(**self.engine_args)
self.rollout_thread = threading.Thread(target=self._rollout_thread)
self.rollout_thread.start()
def destroy(self):
self.exiting.set()
self.rollout_thread.join()
if hasattr(self, "engine") and self.engine is not None:
try:
self.engine.shutdown()
except Exception as e:
logger.warning(f"Error shutting down engine: {e}")
def set_version(self, version):
with self.lock:
self._version = version
def get_version(self):
with self.lock:
return self._version
def _rollout_thread(self):
"""Thread that runs the rollout loop."""
try:
asyncio.run(self._rollout_thread_async())
except Exception as e:
traceback.print_exc()
raise e
async def _rollout_thread_async(self):
data = None
rollout_tasks: Dict[str, asyncio.Task] = {}
rid = 0
try:
while not self.exiting.is_set():
# Load next data from controller
if data is None:
try:
data, workflow = self.input_queue.get_nowait()
logger.info(f"Get data from puller: {data}")
except Empty:
logger.debug(f"No data from puller stream.")
# Check capacity
if dist.is_initialized():
world_size = dist.get_world_size()
else:
world_size = 1
cannot_rollout_reason = []
capacity = max(1, self.config.max_concurrent_rollouts // world_size)
can_rollout = len(rollout_tasks) < capacity
if not can_rollout:
cannot_rollout_reason.append(
f"Exceeding capacity: # running tasks {len(rollout_tasks)} >= capacity {capacity}"
)
# Staleness control
version = self.get_version()
ofp = self.config.max_head_offpolicyness
with self.lock:
sample_cnt = self.rollout_stat.accepted + self.rollout_stat.running
expected_version = sample_cnt // self.config.consumer_batch_size
not_staled = expected_version <= ofp + version
can_rollout &= not_staled
if not not_staled:
cannot_rollout_reason.append(
f"Staled: expected version ({expected_version}) = "
f"global sample cnt ({sample_cnt}) // batch size ({self.config.consumer_batch_size}), "
f"current latest version {version}, "
f"offpolicyness {self.config.max_head_offpolicyness}."
)
if not can_rollout:
logger.debug(
f"Cannot submit new rollouts. "
+ "\n".join(cannot_rollout_reason)
)
# Create new rollout task
if can_rollout and data is not None:
task = asyncio.create_task(
workflow.arun_episode(self, data), name=str(rid)
)
rollout_tasks[str(rid)] = task
with self.lock:
self.rollout_stat.submitted += 1
self.rollout_stat.running += 1
logger.info(
f"Submit rollout rid {rid}. "
f"Submit: {self.rollout_stat.submitted}, "
f"running: {self.rollout_stat.running}, "
f"accepted: {self.rollout_stat.accepted}."
)
rid += 1
data = None
# Wait for rollout completion
tasks = list(rollout_tasks.values())
done = []
if tasks:
done, _ = await asyncio.wait(
tasks,
timeout=ROLLOUT_POLL_WAIT_TIME,
return_when=asyncio.FIRST_COMPLETED,
)
else:
await asyncio.sleep(ROLLOUT_POLL_WAIT_TIME)
# Collect done results
for task in done:
traj = await task
traj: TensorDict
task_rid = task.get_name()
rollout_tasks.pop(task_rid)
self.rollout_stat.accepted += 1
try:
self.output_queue.put_nowait(traj)
except Full:
raise RuntimeError(
"Output queue full. Please increase queue_size."
)
with self.lock:
self.rollout_stat.running -= 1
logger.info(
f"Finish rollout {task_rid}. "
f"Submit: {self.rollout_stat.submitted}, "
f"running: {self.rollout_stat.running}, "
f"accepted: {self.rollout_stat.accepted}."
)
finally:
# Cancel remaining tasks
for task in rollout_tasks.values():
if not task.done():
task.cancel()
try:
await task
except asyncio.CancelledError:
pass
async def agenerate(self, req: LLMRequest) -> LLMResponse:
"""Async version of generate using local sglang engine."""
if not hasattr(self, "engine") or self.engine is None:
raise RuntimeError(
"Local SGLang engine is not initialized, cannot generate."
)
# Prepare request payload
gconfig = req.gconfig
stop_token_ids = gconfig.stop_token_ids
if gconfig.n_samples != 1:
raise ValueError(
"LocalSGLangEngine does not support n_samples > 1. "
"Please call generate for multiple times with n_samples = 1."
)
sample_params = {
"top_p": gconfig.top_p,
"top_k": gconfig.top_k,
"max_new_tokens": gconfig.max_new_tokens,
"temperature": 0.0 if gconfig.greedy else gconfig.temperature,
"stop_token_ids": stop_token_ids,
}
completions = ""
prompt = req.text if req.text else None
input_ids = req.input_ids if req.input_ids else None
# Make request
start_time = time.perf_counter()
accumulated_output_tokens = []
accumulated_output_logprobs = []
accumulated_versions = []
stop_reason = "length"
while (
stop_reason != "stop"
and len(accumulated_output_tokens) < gconfig.max_new_tokens
):
try:
outputs = await self.engine.async_generate(
prompt=prompt,
input_ids=input_ids,
sampling_params=sample_params,
return_logprob=True,
)
completions += outputs["text"]
if prompt is None:
prompt = outputs["text"]
else:
prompt += outputs["text"]
meta_info = outputs["meta_info"]
output_tokens = [x[1] for x in meta_info["output_token_logprobs"]]
output_logprobs = [x[0] for x in meta_info["output_token_logprobs"]]
finish_reason = meta_info.get("finish_reason", {})
stop_reason = finish_reason.get("type", "length")
accumulated_output_tokens.extend(output_tokens)
accumulated_output_logprobs.extend(output_logprobs)
accumulated_versions.extend([-1] * len(output_tokens))
except Exception as e:
raise RuntimeError(f"Local SGLang engine generation failed: {e}")
latency = time.perf_counter() - start_time
return LLMResponse(
completions=completions,
input_tokens=req.input_ids if req.input_ids else [],
output_tokens=accumulated_output_tokens,
output_logprobs=accumulated_output_logprobs,
output_versions=accumulated_versions,
stop_reason=stop_reason,
latency=latency,
ttft=latency,
)
def update_weights(self, meta):
executor = ThreadPoolExecutor(max_workers=1)
return executor.submit(self._update_weights, meta)
def _update_weights(self, meta: WeightUpdateMeta):
if not hasattr(self, "engine") or self.engine is None:
raise RuntimeError(
"Local SGLang engine is not initialized, cannot update weights."
)
if meta.type == "disk":
try:
update_name = names.update_weights_from_disk(
self.config.experiment_name,
self.config.trial_name,
meta.model_version,
)
save_timestamp = int(name_resolve.wait(update_name, timeout=120))
load_timestamp = time.time_ns()
logger.info(
f"Begin update weights from {meta.path}, responded in {(load_timestamp - save_timestamp)/1e6:.2f} ms"
)
# Update weights from disk,
self.engine.update_weights_from_disk(model_path=meta.path)
logger.info(
f"Loading weights done in {(time.time_ns() - load_timestamp)/1e6:.2f} ms"
)
self.set_version(meta.model_version)
except Exception as e:
logger.error(f"Failed to update weights: {e}")
raise
else:
raise NotImplementedError(f"Unsupported weight update type: {meta.type}")
def submit(self, data: Dict[str, Any], workflow: "RolloutWorkflow") -> None:
try:
self.input_queue.put_nowait((data, workflow))
except Full:
raise RuntimeError("Input queue full. Please increase queue_size.")
def wait(self, count: int, timeout: float, should_accept: Callable) -> TensorDict:
tik = time.perf_counter()
accepted = len(self.result_cache)
while (
accepted < count
and not self.exiting.is_set()
and time.perf_counter() - tik < timeout
):
try:
result = self.output_queue.get(timeout=ROLLOUT_POLL_WAIT_TIME)
if should_accept(result):
self.result_cache.append(result)
accepted += 1
else:
with self.lock:
self.rollout_stat.accepted -= 1
except Empty:
time.sleep(ROLLOUT_POLL_WAIT_TIME)
if self.exiting.is_set():
raise RuntimeError("Rollout engine is exiting, cannot wait for results.")
if accepted < count:
raise TimeoutError(
f"Timed out waiting for {count} rollouts, " f"only received {accepted}."
)
results, self.result_cache = (
self.result_cache[:count],
self.result_cache[count:],
)
return TensorDict.cat(results, dim=0)
def rollout(
self, data: List[Dict[str, Any]], workflow: "RolloutWorkflow"
) -> TensorDict:
"""Submit a batch of requests to the inference engine and wait for the results."""
for item in data:
self.submit(item, workflow)
return self.wait(
count=len(data),
timeout=self.config.request_timeout,
should_accept=lambda x: True,
)