FastAPI+Uvicorn部署AWS Fargate后运行1-2分钟自动关闭求助

我在AWS Fargate上通过Application Load Balancer部署了FastAPI 0.81.0 + uvicorn 0.18.3（基于Python 3.10.1）的服务。该服务在本地Docker中可正常持续运行，但在AWS环境下总会在1-2分钟后自动关闭。

Docker启动命令 #

CMD ["uvicorn", "--host", "0.0.0.0", "--port", "8000", "--log-level", "trace", "app.main:app"]

FastAPI应用代码 #

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

app = FastAPI()

app = FastAPI()
origins = [
    "*"
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

@app.get("/")
async def root():
    return {"Hello": "World"}

排查情况 #

Fargate服务的内存占用并不高，问题可能与负载均衡有关。常见的原因是使用TCP而非HTTP进行健康检查，但据我所知，Fargate任务定义或EC2目标组默认已采用HTTP健康检查。

Fargate任务日志 #

2022-09-22 18:43:46 INFO: Finished server process [1]
2022-09-22 18:43:46 INFO: Waiting for application shutdown.
2022-09-22 18:43:46 TRACE: ASGI [1] Receive {'type': 'lifespan.shutdown'}
2022-09-22 18:43:46 TRACE: ASGI [1] Send {'type': 'lifespan.shutdown.complete'}
2022-09-22 18:43:46 TRACE: ASGI [1] Completed
2022-09-22 18:43:46 INFO: Application shutdown complete.
2022-09-22 18:43:45 INFO: Shutting down
2022-09-22 18:43:39 TRACE: 172.31.21.3:16662 - ASGI [7] Send {'type': 'http.response.body', 'body': '<17 bytes>'}
2022-09-22 18:43:39 TRACE: 172.31.21.3:16662 - ASGI [7] Completed
2022-09-22 18:43:39 TRACE: 172.31.21.3:16662 - HTTP connection lost
2022-09-22 18:43:39 INFO: 172.31.21.3:16662 - "GET / HTTP/1.1" 200 OK
2022-09-22 18:43:39 TRACE: 172.31.21.3:16662 - HTTP connection made
2022-09-22 18:43:39 TRACE: 172.31.21.3:16662 - ASGI [7] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('172.31.30.157', 8000), 'client': ('172.31.21.3', 16662), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/', 'raw_path': b'/', 'query_string': b'', 'headers': '<...>'}
2022-09-22 18:43:39 TRACE: 172.31.21.3:16662 - ASGI [7] Send {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
2022-09-22 18:43:39 INFO: 172.31.47.71:3856 - "GET / HTTP/1.1" 200 OK
2022-09-22 18:43:39 TRACE: 172.31.47.71:3856 - ASGI [6] Send {'type': 'http.response.body', 'body': '<17 bytes>'}
2022-09-22 18:43:39 TRACE: 172.31.47.71:3856 - ASGI [6] Completed
2022-09-22 18:43:39 TRACE: 172.31.47.71:3856 - HTTP connection lost
2022-09-22 18:43:39 TRACE: 172.31.47.71:3856 - HTTP connection made
2022-09-22 18:43:39 TRACE: 172.31.47.71:3856 - ASGI [6] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('172.31.30.157', 8000), 'client': ('172.31.47.71', 3856), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/', 'raw_path': b'/', 'query_string': b'', 'headers': '<...>'}
2022-09-22 18:43:39 TRACE: 172.31.47.71:3856 - ASGI [6] Send {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
2022-09-22 18:43:09 TRACE: 172.31.21.3:39448 - ASGI [5] Completed
2022-09-22 18:43:09 TRACE: 172.31.21.3:39448 - HTTP connection lost
2022-09-22 18:43:09 TRACE: 172.31.21.3:39448 - ASGI [5] Send {'type': 'http.response.body', 'body': '<17 bytes>'}
2022-09-22 18:43:09 TRACE: 172.31.21.3:39448 - HTTP connection made
2022-09-22 18:43:09 TRACE: 172.31.21.3:39448 - ASGI [5] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('172.31.30.157', 8000), 'client': ('172.31.21.3', 39448), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/', 'raw_path': b'/', 'query_string': b'', 'headers': '<...>'}
2022-09-22 18:43:09 TRACE: 172.31.21.3:39448 - ASGI [5] Send {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
2022-09-22 18:43:09 INFO: 172.31.21.3:39448 - "GET / HTTP/1.1" 200 OK
2022-09-22 18:43:09 TRACE: 172.31.47.71:50778 - ASGI [4] Completed
2022-09-22 18:43:09 TRACE: 172.31.47.71:50778 - HTTP connection lost
2022-09-22 18:43:09 TRACE: 172.31.47.71:50778 - ASGI [4] Send {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
2022-09-22 18:43:09 INFO: 172.31.47.71:50778 - "GET / HTTP/1.1" 200 OK
2022-09-22 18:43:09 TRACE: 172.31.47.71:50778 - ASGI [4] Send {'type': 'http.response.body', 'body': '<17 bytes>'}
2022-09-22 18:43:09 TRACE: 172.31.47.71:50778 - HTTP connection made
2022-09-22 18:43:09 TRACE: 172.31.47.71:50778 - ASGI [4] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('172.31.30.157', 8000), 'client': ('172.31.47.71', 50778), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/', 'raw_path': b'/', 'query_string': b'', 'headers': '<...>'}
2022-09-22 18:42:39 INFO: 172.31.47.71:55984 - "GET / HTTP/1.1" 200 OK
2022-09-22 18:42:39 TRACE: 172.31.47.71:55984 - ASGI [3] Send {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
2022-09-22 18:42:39 TRACE: 172.31.47.71:55984 - ASGI [3] Send {'type': 'http.response.body', 'body': '<17 bytes>'}
2022-09-22 18:42:39 TRACE: 172.31.47.71:55984 - ASGI [3] Completed
2022-09-22 18:42:39 TRACE: 172.31.47.71:55984 - HTTP connection lost
2022-09-22 18:42:39 TRACE: 172.31.21.3:59240 - HTTP connection lost
2022-09-22 18:42:39 TRACE: 172.31.47.71:55984 - ASGI [3] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('172.31.30.157', 8000), 'client': ('172.31.47.71', 55984), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/', 'raw_path': b'/', 'query_string': b'', 'headers': '<...>'}
2022-09-22 18:42:39 TRACE: 172.31.21.3:59240 - ASGI [2] Completed
2022-09-22 18:42:39 TRACE: 172.31.47.71:55984 - HTTP connection made
2022-09-22 18:42:39 INFO: 172.31.21.3:59240 - "GET / HTTP/1.1" 200 OK
2022-09-22 18:42:39 TRACE: 172.31.21.3:59240 - ASGI [2] Send {'type': 'http.response.body', 'body': '<17 bytes>'}
2022-09-22 18:42:39 TRACE: 172.31.21.3:59240 - ASGI [2] Started scope={'type': 'http', 'asgi': {'version': '3.0', 'spec_version': '2.3'}, 'http_version': '1.1', 'server': ('172.31.30.157', 8000), 'client': ('172.31.21.3', 59240), 'scheme': 'http', 'method': 'GET', 'root_path': '', 'path': '/', 'raw_path': b'/', 'query_string': b'', 'headers': '<...>'}
2022-09-22 18:42:39 TRACE: 172.31.21.3:59240 - ASGI [2] Send {'type': 'http.response.start', 'status': 200, 'headers': '<...>'}
2022-09-22 18:42:39 TRACE: 172.31.21.3:59240 - HTTP connection made
2022-09-22 18:42:30 INFO: Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
2022-09-22 18:42:30 INFO: Waiting for application startup.
2022-09-22 18:42:30 TRACE: ASGI [1] Started scope={'type': 'lifespan', 'asgi': {'version': '3.0', 'spec_version': '2.0'}}
2022-09-22 18:42:30 TRACE: ASGI [1] Receive {'type': 'lifespan.startup'}
2022-09-22 18:42:30 TRACE: ASGI [1] Send {'type': 'lifespan.startup.complete'}
2022-09-22 18:42:30 INFO: Application startup complete.
2022-09-22 18:42:30 INFO: Started server process [1]

恳请各位提供解决该问题的建议，谢谢！

内容的提问来源于stack exchange，提问作者JoN