url 调用内部函数导致超时

Question

因为当我尝试通过本地主机调用函数时URL，会导致超时错误吗？

示例代码：

import tornado.ioloop
import tornado.web
import requests
import os
from threading import Timer, Thread

class MainHandler(tornado.web.RequestHandler):
    def get(self):
        self.write("Hello, world")

class TestTornado(tornado.web.RequestHandler):
    def get(self):
        url = "http://localhost:8888"
        requests.get(url, timeout=5)
        self.write("OK!")

def make_app():
    return tornado.web.Application([
        (r"/", MainHandler),
        (r"/test", TestTornado),
    ])

if __name__ == "__main__":
    app = make_app()
    app.listen(8888)
    tornado.ioloop.IOLoop.current().start()

我尝试调用 http://127.0.0.1:8888/test，但生成了此错误：

`
Traceback (most recent call last):
  File "/home/mpimentel/envtornado/lib/python3.6/site-packages/tornado/web.py", line 1590, in _execute
    result = method(*self.path_args, **self.path_kwargs)
  File "server.py", line 14, in get
    requests.get(url, timeout=5)
  File "/home/mpimentel/envtornado/lib/python3.6/site-packages/requests/api.py", line 75, in get
    return request('get', url, params=params, **kwargs)
  File "/home/mpimentel/envtornado/lib/python3.6/site-packages/requests/api.py", line 60, in request
    return session.request(method=method, url=url, **kwargs)
  File "/home/mpimentel/envtornado/lib/python3.6/site-packages/requests/sessions.py", line 524, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/mpimentel/envtornado/lib/python3.6/site-packages/requests/sessions.py", line 637, in send
    r = adapter.send(request, **kwargs)
  File "/home/mpimentel/envtornado/lib/python3.6/site-packages/requests/adapters.py", line 529, in send
    raise ReadTimeout(e, request=request)
requests.exceptions.ReadTimeout: HTTPConnectionPool(host='localhost', port=8888): Read timed out. (read timeout=5)
`

进行此调用的正确方法是什么？

Answer 1

这是一个请求错误。

将此代码粘贴到您的程序中：

来自 requests.packages.urllib3.exceptions 导入 InsecureRequestWarning requests.packages.urllib3.disable_warnings(InsecureRequestWarning)

Answer 2

requests 是一个同步库，而 Tornado 是一个异步框架。你不应该从 Tornado IOLoop 线程中调用像 requests.get() 这样的阻塞同步函数。您必须使 get() 成为协程并从线程池调用 requests.get()：

async def get(self):
    resp = await IOLoop.current().run_in_executor(None, lambda: requests.get(...))

或将 requests 的使用替换为类似 Tornado 的 AsyncHTTPClient:

的非阻塞等价物

async def get(self):
    client = tornado.httpclient.AsyncHTTPClient()
    resp = await client.fetch(url, ...)

url 调用内部函数导致超时

call internal function by url causes timeout

python

tornado