我正在使用FastAPI框架,由Uvicorn服务器提供支持。我的应用程序需要在给定的终端点(/run)上运行一些耗时的数字计算。为此,我使用了FastAPI中的'background_task'(它基本上是Starlette中的'background_task')。
当应用程序运行一段时间后,服务器出于某种原因关闭。
应用程序的日志如下:
我真的不明白为什么会发生这种情况。我不知道该尝试什么来修复它。
我的代码长这样。
当应用程序运行一段时间后,服务器出于某种原因关闭。
应用程序的日志如下:
INFO: Started server process [922]
INFO: Waiting for application startup.
DEBUG: None - ASGI [1] Started
DEBUG: None - ASGI [1] Sent {'type': 'lifespan.startup'}
DEBUG: None - ASGI [1] Received {'type': 'lifespan.startup.complete'}
INFO: Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
DEBUG: ('10.0.2.111', 57396) - Connected
DEBUG: ('10.0.2.111', 57397) - Connected
DEBUG: ('10.0.2.111', 57396) - ASGI [2] Started
DEBUG: ('10.0.2.111', 57396) - ASGI [2] Received {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
INFO: ('10.0.2.111', 57396) - "GET /run HTTP/1.1" 200
DEBUG: ('10.0.2.111', 57396) - ASGI [2] Received {'type': 'http.response.body', 'body': '<32 bytes>'}
DEBUG: ('10.0.2.111', 57396) - ASGI [3] Started
DEBUG: ('10.0.2.111', 57396) - ASGI [3] Received {'type': 'http.response.start', 'status': 404, 'headers': '<...>'}
INFO: ('10.0.2.111', 57396) - "GET /favicon.ico HTTP/1.1" 404
DEBUG: ('10.0.2.111', 57396) - ASGI [3] Received {'type': 'http.response.body', 'body': '<22 bytes>'}
DEBUG: ('10.0.2.111', 57396) - ASGI [3] Completed
...
DEBUG: ('10.0.2.111', 57396) - Disconnected
... The background task is completed.
DEBUG: ('10.0.2.111', 57396) - ASGI [2] Completed
DEBUG: ('10.0.2.111', 57397) - Disconnected
DEBUG: ('10.0.2.111', 57405) - Connected
...
The application goes on, with requests and completed background tasks.
At some point, during the execution of a background task:
INFO: Shutting down
DEBUG: ('10.0.2.111', 57568) - Disconnected
DEBUG: ('10.0.2.111', 57567) - Disconnected
INFO: Waiting for background tasks to complete. (CTRL+C to force quit)
DEBUG: ('10.0.2.111', 57567) - ASGI [6] Completed
INFO: Waiting for application shutdown.
DEBUG: None - ASGI [1] Sent {'type': 'lifespan.shutdown'}
DEBUG: None - ASGI [1] Received {'type': 'lifespan.shutdown.complete'}
DEBUG: None - ASGI [1] Completed
INFO: Finished server process [922]
我真的不明白为什么会发生这种情况。我不知道该尝试什么来修复它。
我的代码长这样。
#!/usr/bin/env python3.7
import time
from fastapi import FastAPI, BackgroundTasks
import uvicorn
from starlette.responses import JSONResponse
import my_imports_from_project
analysis_api = FastAPI()
@analysis_api.get("/")
def root():
return {"message": "root"}
@analysis_api.get("/test")
def test():
return {"message": "test"}
@analysis_api.get("/run")
def run(name: str, background_task: BackgroundTasks):
try:
some_checks(name)
except RaisedExceptions:
body = {"running": False,
"name": name,
"cause": "Not found in database"}
return JSONResponse(status_code=400, content=body)
body = {"running": True,
"name": name}
background_task.add_task(run_analysis, name)
return JSONResponse(status_code=200, content=body)
if __name__ == "__main__":
uvicorn.run("api:analysis_api", host="0.0.0.0", log_level="debug")