python - 在 aiohttp 或 httpx 中，我是否需要在应用程序关闭时关闭会话/客户端

Question

我正在使用httpx库，但我认为aiohttp的原理是相同的。如果我在应用程序的整个生命周期中为多个请求创建和重用 AsyncClient，我是否需要在应用程序关闭事件中调用aclose()（或者如果使用客户端）？close或者这些联系会自行消失。

如果我在 Docker 容器中运行应用程序会怎样？这也会是一个因素吗？

我不明白 AsyncClient 或 Client（或 aoihttp 中的 ClientSession）对象下面发生了什么。

感谢帮助。

Answer 1

I suggest you to use the triggers on startup and shutdown. They are described in the docs https://fastapi.tiangolo.com/advanced/events/#events-startup-shutdown.

Below an adaptation of the example taken from the docs:

from fastapi import FastAPI
import httpx

app = FastAPI()

items = {}
client = None


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}
    client = httpx.AsyncClient()

@app.on_event("shutdown")
async def shutdown_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}
    await client.aclose()

EDIT

Sorry, misunderstood the question.

Anyway, as @Klaus D commented, the system should kill the child process(es if many are spawned) that keep open ports.

In my experience, this may not always be the case, as I remember when programming with php, I had to manually kill all the database connections, otherwise on application restart I got "The process is already using that port".

Although it was the case of a database connection and not an HTTP connection, it is always good practice to close all unused connections, since the OS may have a delay in noticing the running process with the open port and killing it. So your app (or whatever you have) would be stopped, but the process still running after a while.

Updates to the OS may change the behavior of the process watcher and depend on the OS itself. So, take what I say with a grain of salt.