[BugFix] fix too many open files problem (#3256)

* Update cache_messager.py

* fix too many open files problem

* fix too many open files problem

* fix too many open files problem

* fix ci bugs

* Update api_server.py

* add parameter

* format

* format

* format

* format

* Update parameters.md

* Update parameters.md

* Update serving_completion.py

* Update serving_chat.py

* Update envs.py

---------

Co-authored-by: Jiang-Jia-Jun <163579578+Jiang-Jia-Jun@users.noreply.github.com>

fastdeploy/entrypoints/openai/api_server.py

@@ -14,15 +14,17 @@
 # limitations under the License.
 """
 
+import asyncio
 import os
 import threading
 import time
+from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
 from multiprocessing import current_process
 
 import uvicorn
 import zmq
-from fastapi import FastAPI, Request
+from fastapi import FastAPI, HTTPException, Request
 from fastapi.responses import JSONResponse, Response, StreamingResponse
 from prometheus_client import CONTENT_TYPE_LATEST
 
@@ -49,6 +51,7 @@ from fastdeploy.metrics.trace_util import fd_start_span, inject_to_metadata, ins
 from fastdeploy.plugins.model_register import load_model_register_plugins
 from fastdeploy.utils import (
     FlexibleArgumentParser,
+    StatefulSemaphore,
     api_server_logger,
     console_logger,
     is_port_available,
@@ -61,6 +64,13 @@ parser.add_argument("--host", default="0.0.0.0", type=str, help="host to the htt
 parser.add_argument("--workers", default=1, type=int, help="number of workers")
 parser.add_argument("--metrics-port", default=8001, type=int, help="port for metrics server")
 parser.add_argument("--controller-port", default=-1, type=int, help="port for controller server")
+parser.add_argument(
+    "--max-waiting-time",
+    default=-1,
+    type=int,
+    help="max waiting time for connection, if set value -1 means no waiting time limit",
+)
+parser.add_argument("--max-concurrency", default=512, type=int, help="max concurrency")
 parser = EngineArgs.add_cli_args(parser)
 args = parser.parse_args()
 args.model = retrive_model_from_server(args.model, args.revision)
@@ -92,6 +102,12 @@ def load_engine():
     return engine
 
 
+app = FastAPI()
+
+MAX_CONCURRENT_CONNECTIONS = (args.max_concurrency + args.workers - 1) // args.workers
+connection_semaphore = StatefulSemaphore(MAX_CONCURRENT_CONNECTIONS)
+
+
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     """
@@ -117,10 +133,11 @@ async def lifespan(app: FastAPI):
         args.reasoning_parser,
         args.data_parallel_size,
         args.enable_logprob,
+        args.workers,
     )
     app.state.dynamic_load_weight = args.dynamic_load_weight
-    chat_handler = OpenAIServingChat(engine_client, pid, args.ips)
-    completion_handler = OpenAIServingCompletion(engine_client, pid, args.ips)
+    chat_handler = OpenAIServingChat(engine_client, pid, args.ips, args.max_waiting_time)
+    completion_handler = OpenAIServingCompletion(engine_client, pid, args.ips, args.max_waiting_time)
     engine_client.create_zmq_client(model=pid, mode=zmq.PUSH)
     engine_client.pid = pid
     app.state.engine_client = engine_client
@@ -142,6 +159,21 @@ app = FastAPI(lifespan=lifespan)
 instrument(app)
 
 
+@asynccontextmanager
+async def connection_manager():
+    """
+    async context manager for connection manager
+    """
+    try:
+        await asyncio.wait_for(connection_semaphore.acquire(), timeout=0.001)
+        yield
+    except asyncio.TimeoutError:
+        api_server_logger.info(f"Reach max request release: {connection_semaphore.status()}")
+        if connection_semaphore.locked():
+            connection_semaphore.release()
+        raise HTTPException(status_code=429, detail="Too many requests")
+
+
 # TODO 传递真实引擎值 通过pid 获取状态
 @app.get("/health")
 def health(request: Request) -> Response:
@@ -195,6 +227,22 @@ def ping(raw_request: Request) -> Response:
     return health(raw_request)
 
 
+def wrap_streaming_generator(original_generator: AsyncGenerator):
+    """
+    Wrap an async generator to release the connection semaphore when the generator is finished.
+    """
+
+    async def wrapped_generator():
+        try:
+            async for chunk in original_generator:
+                yield chunk
+        finally:
+            api_server_logger.debug(f"release: {connection_semaphore.status()}")
+            connection_semaphore.release()
+
+    return wrapped_generator
+
+
 @app.post("/v1/chat/completions")
 async def create_chat_completion(request: ChatCompletionRequest):
     """
@@ -204,16 +252,23 @@ async def create_chat_completion(request: ChatCompletionRequest):
         status, msg = app.state.engine_client.is_workers_alive()
         if not status:
             return JSONResponse(content={"error": "Worker Service Not Healthy"}, status_code=304)
-    inject_to_metadata(request)
-    generator = await app.state.chat_handler.create_chat_completion(request)
+    try:
+        async with connection_manager():
+            inject_to_metadata(request)
+            generator = await app.state.chat_handler.create_chat_completion(request)
+            if isinstance(generator, ErrorResponse):
+                connection_semaphore.release()
+                return JSONResponse(content={"detail": generator.model_dump()}, status_code=generator.code)
+            elif isinstance(generator, ChatCompletionResponse):
+                connection_semaphore.release()
+                return JSONResponse(content=generator.model_dump())
+            else:
+                wrapped_generator = wrap_streaming_generator(generator)
+                return StreamingResponse(content=wrapped_generator(), media_type="text/event-stream")
 
-    if isinstance(generator, ErrorResponse):
-        return JSONResponse(content=generator.model_dump(), status_code=generator.code)
-
-    elif isinstance(generator, ChatCompletionResponse):
-        return JSONResponse(content=generator.model_dump())
-
-    return StreamingResponse(content=generator, media_type="text/event-stream")
+    except HTTPException as e:
+        api_server_logger.error(f"Error in chat completion: {str(e)}")
+        return JSONResponse(status_code=e.status_code, content={"detail": e.detail})
 
 
 @app.post("/v1/completions")
@@ -225,14 +280,20 @@ async def create_completion(request: CompletionRequest):
         status, msg = app.state.engine_client.is_workers_alive()
         if not status:
             return JSONResponse(content={"error": "Worker Service Not Healthy"}, status_code=304)
-
-    generator = await app.state.completion_handler.create_completion(request)
-    if isinstance(generator, ErrorResponse):
-        return JSONResponse(content=generator.model_dump(), status_code=generator.code)
-    elif isinstance(generator, CompletionResponse):
-        return JSONResponse(content=generator.model_dump())
-
-    return StreamingResponse(content=generator, media_type="text/event-stream")
+    try:
+        async with connection_manager():
+            generator = await app.state.completion_handler.create_completion(request)
+            if isinstance(generator, ErrorResponse):
+                connection_semaphore.release()
+                return JSONResponse(content=generator.model_dump(), status_code=generator.code)
+            elif isinstance(generator, CompletionResponse):
+                connection_semaphore.release()
+                return JSONResponse(content=generator.model_dump())
+            else:
+                wrapped_generator = wrap_streaming_generator(generator)
+                return StreamingResponse(content=wrapped_generator(), media_type="text/event-stream")
+    except HTTPException as e:
+        return JSONResponse(status_code=e.status_code, content={"detail": e.detail})
 
 
 @app.get("/update_model_weight")