feat: 服务化基础设施 - 有界队列/超时/优雅关闭/metrics

- astrai/inference/scheduler.py: 有界队列 (max_queue_size) 拒绝满时入队抛 RuntimeError
    -> 请求超时检测 (deadline + _abort_expired_tasks),超时任务 abort 释放页并通知回调
    -> stop() 改为 drain 模式:等待活跃任务自然结束再强制清理
    -> get_stats() 扩展 latency P50/P95/P99 + cache hit rate
- astrai/inference/engine.py: generate/generate_async 新增 timeout 参数
    -> _generate_streaming/_generate_non_streaming 捕获 add_task 异常并清理
- astrai/inference/server.py: 新增 /metrics 端点 (Prometheus 格式)
    -> chat completions 端点捕获 RuntimeError 返回 503
    -> configure_server 传递 max_queue_size/request_timeout
- astrai/inference/cache.py: 新增 lookup_hits/lookup_misses 计数器
- tests/: fix stats key total_tasks -> total_requests
This commit is contained in:
ViperEkura 2026-05-10 18:16:51 +08:00
parent 3da428e0e4
commit a3bde30fb1
5 changed files with 217 additions and 54 deletions

View File

@ -61,6 +61,8 @@ class PagedCache:
self._hash_to_page: Dict[int, int] = {}
self._lru: List[int] = []
self._pin: List[bool] = [False] * n_pages
self.lookup_hits: int = 0
self.lookup_misses: int = 0
def _touch(self, idx: int) -> None:
if self._refs[idx] == 0 and idx in self._lru:
@ -98,7 +100,9 @@ class PagedCache:
h = page_hash(token_ids, i, self.page_size)
p = self._hash_to_page.get(h)
if p is None:
self.lookup_misses += 1
break
self.lookup_hits += 1
self._touch(p)
hits.append(p)
return hits

View File

@ -195,6 +195,8 @@ class InferenceEngine:
model: nn.Module,
tokenizer: AutoTokenizer,
max_batch_size: int = 1,
max_queue_size: int = 64,
request_timeout: float = 60.0,
max_seq_len: Optional[int] = None,
max_prompt_len: int = 2048,
page_size: int = 128,
@ -207,7 +209,6 @@ class InferenceEngine:
max_batch_size: Maximum number of concurrent tasks.
max_seq_len: Maximum sequence length.
max_prompt_len: Maximum prompt tokens.
compile: Whether to compile the model with torch.compile.
page_size: Number of tokens per KV cache page.
"""
self.model = model
@ -216,6 +217,8 @@ class InferenceEngine:
model=self.model,
tokenizer=self.tokenizer,
max_batch_size=max_batch_size,
max_queue_size=max_queue_size,
request_timeout=request_timeout,
max_seq_len=max_seq_len,
max_prompt_len=max_prompt_len,
page_size=page_size,
@ -238,6 +241,7 @@ class InferenceEngine:
temperature: float = 1.0,
top_p: float = 1.0,
top_k: int = 50,
timeout: Optional[float] = None,
) -> Union[Generator, str, List[str]]:
"""Generates text from a prompt.
@ -248,6 +252,7 @@ class InferenceEngine:
temperature: Sampling temperature.
top_p: Nucleus sampling probability threshold.
top_k: Top-k sampling count (0 disables).
timeout: Per-request timeout in seconds (None = use scheduler default).
Returns:
stream=False, single prompt: str
@ -260,11 +265,11 @@ class InferenceEngine:
if stream:
return self._generate_streaming(
prompts, is_batch, max_tokens, temperature, top_p, top_k
prompts, is_batch, max_tokens, temperature, top_p, top_k, timeout
)
else:
return self._generate_non_streaming(
prompts, is_batch, max_tokens, temperature, top_p, top_k
prompts, is_batch, max_tokens, temperature, top_p, top_k, timeout
)
def generate_async(
@ -274,6 +279,7 @@ class InferenceEngine:
temperature: float = 1.0,
top_p: float = 1.0,
top_k: int = 50,
timeout: Optional[float] = None,
) -> AsyncGenerator[str, None]:
"""Async streaming generator that does not block the event loop.
@ -286,12 +292,13 @@ class InferenceEngine:
temperature: Sampling temperature.
top_p: Nucleus sampling threshold.
top_k: Top-k sampling count.
timeout: Per-request timeout in seconds.
Yields:
Decoded token strings as they are generated.
"""
sync_gen = self._generate_streaming(
[prompt], False, max_tokens, temperature, top_p, top_k
[prompt], False, max_tokens, temperature, top_p, top_k, timeout
)
async def _agen():
@ -350,6 +357,7 @@ class InferenceEngine:
temperature: float,
top_p: float,
top_k: int,
timeout: Optional[float] = None,
) -> Generator:
"""Internal streaming generator.
@ -363,6 +371,7 @@ class InferenceEngine:
temperature: Sampling temperature.
top_p: Nucleus sampling threshold.
top_k: Top-k sampling count.
timeout: Per-request timeout in seconds.
Yields:
Single prompt: decoded token strings.
@ -372,16 +381,22 @@ class InferenceEngine:
result = _Result(count=n)
task_ids = []
for i, p in enumerate(prompts):
task_id = self.scheduler.add_task(
prompt=p,
max_tokens=max_tokens,
temperature=temperature,
top_p=top_p,
top_k=top_k,
stream_callback=lambda tok, idx=i: result.append(tok, idx),
)
task_ids.append(task_id)
try:
for i, p in enumerate(prompts):
task_id = self.scheduler.add_task(
prompt=p,
max_tokens=max_tokens,
temperature=temperature,
top_p=top_p,
top_k=top_k,
stream_callback=lambda tok, idx=i: result.append(tok, idx),
timeout=timeout,
)
task_ids.append(task_id)
except RuntimeError:
for tid in task_ids:
self.scheduler.remove_task(tid)
raise
remaining = n
finished = [False] * n
@ -415,6 +430,7 @@ class InferenceEngine:
temperature: float,
top_p: float,
top_k: int,
timeout: Optional[float] = None,
) -> Union[str, List[str]]:
"""Internal non-streaming generator.
@ -427,6 +443,7 @@ class InferenceEngine:
temperature: Sampling temperature.
top_p: Nucleus sampling threshold.
top_k: Top-k sampling count.
timeout: Per-request timeout in seconds.
Returns:
Single string for one prompt, list of strings for batch.
@ -434,20 +451,26 @@ class InferenceEngine:
result = _Result(count=len(prompts))
task_ids = []
for i, p in enumerate(prompts):
try:
for i, p in enumerate(prompts):
def make_cb(idx):
return lambda tok: result.append(tok, idx)
def make_cb(idx):
return lambda tok: result.append(tok, idx)
task_id = self.scheduler.add_task(
prompt=p,
max_tokens=max_tokens,
temperature=temperature,
top_p=top_p,
top_k=top_k,
stream_callback=make_cb(i),
)
task_ids.append(task_id)
task_id = self.scheduler.add_task(
prompt=p,
max_tokens=max_tokens,
temperature=temperature,
top_p=top_p,
top_k=top_k,
stream_callback=make_cb(i),
timeout=timeout,
)
task_ids.append(task_id)
except RuntimeError:
for tid in task_ids:
self.scheduler.remove_task(tid)
raise
result.wait_completion()

View File

@ -55,6 +55,7 @@ class Task:
self.n_pages: int = 0
self._prefix_cached_tokens: int = 0
self.arrival_time = time.time()
self.deadline: float = 0.0
self.finish_time: Optional[float] = None
self.stream_callback = stream_callback
self._pages_freed: bool = False
@ -86,6 +87,8 @@ class InferenceScheduler:
model: AutoModel,
tokenizer: AutoTokenizer,
max_batch_size: int = 16,
max_queue_size: int = 64,
request_timeout: float = 60.0,
max_seq_len: Optional[int] = None,
max_prompt_len: int = 512,
page_size: int = 64,
@ -97,6 +100,8 @@ class InferenceScheduler:
self.model = model
self.tokenizer = tokenizer
self.max_batch_size = max_batch_size
self.max_queue_size = max_queue_size
self.request_timeout = request_timeout
self.max_seq_len = max_seq_len or config.max_len
self.max_prompt_len = max_prompt_len
self.page_size = page_size
@ -124,11 +129,16 @@ class InferenceScheduler:
self.active_tasks: List[Task] = []
self._running = False
self._draining = False
self._task_event = threading.Event()
self._lock = threading.Lock()
self._total_tasks = 0
self._total_tokens = 0
self._total_requests = 0
self._total_rejected = 0
self._total_timeouts = 0
self._request_latencies: List[float] = []
def _n_pages_for(self, n_tokens: int) -> int:
return (n_tokens + self.page_size - 1) // self.page_size
@ -141,6 +151,7 @@ class InferenceScheduler:
top_p: float = 1.0,
top_k: int = 50,
stream_callback: Optional[Callable[[str], None]] = None,
timeout: Optional[float] = None,
) -> str:
task_id = f"task_{int(time.time())}_{uuid.uuid4().hex[:8]}"
prompt_ids = self.tokenizer.encode(prompt)
@ -156,9 +167,16 @@ class InferenceScheduler:
top_k=top_k,
stream_callback=stream_callback,
)
task.deadline = time.time() + (
timeout if timeout is not None else self.request_timeout
)
with self._lock:
if len(self.waiting_queue) >= self.max_queue_size:
self._total_rejected += 1
raise RuntimeError("Request queue is full")
self.waiting_queue.append(task)
self._total_requests += 1
self._total_tasks += 1
self._task_event.set()
@ -181,6 +199,40 @@ class InferenceScheduler:
for idx in indices:
self.page_cache.free(idx)
def _abort_task(self, task: Task) -> None:
task.status = TaskStatus.ABORTED
task.finish_time = time.time()
if not task._pages_freed:
self._free_pages(task.page_table)
task.page_table.clear()
task.n_pages = 0
task._pages_freed = True
if task.stream_callback:
task.stream_callback(STOP)
def _abort_expired_tasks(self) -> None:
now = time.time()
alive = []
for t in self.active_tasks:
if now > t.deadline:
self._abort_task(t)
self._total_timeouts += 1
else:
alive.append(t)
self.active_tasks = alive
with self._lock:
keep = []
for t in self.waiting_queue:
if now > t.deadline:
t.status = TaskStatus.ABORTED
if t.stream_callback:
t.stream_callback(STOP)
self._total_timeouts += 1
else:
keep.append(t)
self.waiting_queue = keep
def _record_page_hashes(self, task: Task, start_logical_page: int = 0) -> None:
full_pages = len(task.prompt_ids) // self.page_size
for i in range(start_logical_page, full_pages):
@ -194,6 +246,9 @@ class InferenceScheduler:
task.finish_time = time.time()
finished.append(task)
self._total_tokens += task.output_tokens
self._request_latencies.append(task.finish_time - task.arrival_time)
if len(self._request_latencies) > 1000:
self._request_latencies.pop(0)
for task in finished:
if not task._pages_freed:
@ -345,14 +400,19 @@ class InferenceScheduler:
def _run_generation_loop(self) -> None:
try:
while self._running:
while self._running or (self._draining and self.active_tasks):
self._abort_expired_tasks()
self._remove_finished_tasks()
self._refill_active_batch()
if not self._draining:
self._refill_active_batch()
if not self.active_tasks and not self.waiting_queue:
self._task_event.clear()
self._task_event.wait(timeout=1.0)
continue
if not self.active_tasks:
if self._draining:
break
if not self.waiting_queue:
self._task_event.clear()
self._task_event.wait(timeout=1.0)
continue
to_prefill = [t for t in self.active_tasks if t.output_tokens == 0]
if to_prefill:
@ -392,20 +452,54 @@ class InferenceScheduler:
t.start()
self._loop_thread = t
def stop(self) -> None:
def stop(self, timeout: float = 30.0) -> None:
self._draining = True
self._running = False
self._task_event.set()
if hasattr(self, "_loop_thread"):
self._loop_thread.join(timeout=2.0)
self.waiting_queue.clear()
self.active_tasks.clear()
self._loop_thread.join(timeout=timeout)
for task in self.active_tasks:
if not task._pages_freed:
self._free_pages(task.page_table)
task._pages_freed = True
if task.stream_callback:
task.stream_callback(STOP)
with self._lock:
for task in self.waiting_queue:
task.status = TaskStatus.ABORTED
if task.stream_callback:
task.stream_callback(STOP)
self.waiting_queue.clear()
self.active_tasks.clear()
if torch.cuda.is_available():
torch.cuda.empty_cache()
def get_stats(self) -> Dict[str, Any]:
latencies = self._request_latencies
sorted_lat = sorted(latencies) if latencies else []
n = len(sorted_lat)
p50 = sorted_lat[n // 2] if n > 0 else 0.0
p95 = sorted_lat[int(n * 0.95)] if n > 0 else 0.0
p99 = sorted_lat[int(n * 0.99)] if n > 0 else 0.0
cache = self.page_cache
total_lookups = cache.lookup_hits + cache.lookup_misses
hit_rate = cache.lookup_hits / total_lookups if total_lookups > 0 else 0.0
return {
"total_tasks": self._total_tasks,
"total_requests": self._total_requests,
"total_rejected": self._total_rejected,
"total_timeouts": self._total_timeouts,
"total_tokens": self._total_tokens,
"active_tasks": len(self.active_tasks),
"waiting_queue": len(self.waiting_queue),
"latency_p50": p50,
"latency_p95": p95,
"latency_p99": p99,
"cache_hit_rate": hit_rate,
"cache_hits": cache.lookup_hits,
"cache_misses": cache.lookup_misses,
}

View File

@ -13,7 +13,7 @@ from typing import Any, Dict, List, Optional, Union
import torch
import uvicorn
from fastapi import FastAPI, HTTPException
from fastapi.responses import StreamingResponse
from fastapi.responses import PlainTextResponse, StreamingResponse
from pydantic import BaseModel, Field
from astrai.inference.engine import InferenceEngine
@ -92,6 +92,8 @@ def configure_server(
dtype=dtype,
param_path=param_path,
max_batch_size=max_batch_size,
max_queue_size=64,
request_timeout=60.0,
)
@ -185,6 +187,40 @@ async def get_stats():
return _get_engine().get_stats()
@app.get("/metrics")
async def metrics():
s = _get_engine().get_stats()
lines = [
"# HELP astrai_requests_total Total requests received",
"# TYPE astrai_requests_total counter",
f'astrai_requests_total{{status="accepted"}} {s["total_requests"]}',
f'astrai_requests_total{{status="rejected"}} {s["total_rejected"]}',
f'astrai_requests_total{{status="timeout"}} {s["total_timeouts"]}',
"# HELP astrai_tokens_generated Total generated tokens",
"# TYPE astrai_tokens_generated counter",
f"astrai_tokens_generated {s['total_tokens']}",
"# HELP astrai_active_tasks Currently active tasks",
"# TYPE astrai_active_tasks gauge",
f"astrai_active_tasks {s['active_tasks']}",
"# HELP astrai_queue_depth Waiting queue depth",
"# TYPE astrai_queue_depth gauge",
f"astrai_queue_depth {s['waiting_queue']}",
"# HELP astrai_request_latency_seconds Request latency quantiles",
"# TYPE astrai_request_latency_seconds gauge",
f'astrai_request_latency_seconds{{quantile="0.5"}} {s["latency_p50"]:.3f}',
f'astrai_request_latency_seconds{{quantile="0.95"}} {s["latency_p95"]:.3f}',
f'astrai_request_latency_seconds{{quantile="0.99"}} {s["latency_p99"]:.3f}',
"# HELP astrai_cache_hit_rate Prefix cache hit ratio",
"# TYPE astrai_cache_hit_rate gauge",
f"astrai_cache_hit_rate {s['cache_hit_rate']:.3f}",
"# HELP astrai_cache_lookups_total Prefix cache page lookups",
"# TYPE astrai_cache_lookups_total counter",
f'astrai_cache_lookups_total{{result="hit"}} {s["cache_hits"]}',
f'astrai_cache_lookups_total{{result="miss"}} {s["cache_misses"]}',
]
return PlainTextResponse("\n".join(lines) + "\n")
@app.post("/v1/chat/completions")
async def chat_completion(request: ChatCompletionRequest):
"""OpenAI-compatible chat completion endpoint (streaming + non-streaming)."""
@ -200,13 +236,16 @@ async def chat_completion(request: ChatCompletionRequest):
prompt_tokens = len(engine.tokenizer.encode(prompt))
if request.stream:
agen = engine.generate_async(
prompt=prompt,
max_tokens=request.max_tokens,
temperature=request.temperature,
top_p=request.top_p,
top_k=request.top_k,
)
try:
agen = engine.generate_async(
prompt=prompt,
max_tokens=request.max_tokens,
temperature=request.temperature,
top_p=request.top_p,
top_k=request.top_k,
)
except RuntimeError as e:
raise HTTPException(status_code=503, detail=str(e))
async def event_stream():
yield _make_chunk(
@ -252,13 +291,16 @@ async def chat_completion(request: ChatCompletionRequest):
completion_tokens = 0
chunks: List[str] = []
agen = engine.generate_async(
prompt=prompt,
max_tokens=request.max_tokens,
temperature=request.temperature,
top_p=request.top_p,
top_k=request.top_k,
)
try:
agen = engine.generate_async(
prompt=prompt,
max_tokens=request.max_tokens,
temperature=request.temperature,
top_p=request.top_p,
top_k=request.top_k,
)
except RuntimeError as e:
raise HTTPException(status_code=503, detail=str(e))
async for token in agen:
chunks.append(token)
completion_tokens += 1

View File

@ -173,5 +173,5 @@ def test_scheduler_concurrent_get_stats(mock_model_and_tokenizer):
# Verify stats are consistent
for stats in results["stats"]:
assert "total_tasks" in stats
assert stats["total_tasks"] >= 0
assert "total_requests" in stats
assert stats["total_requests"] >= 0