Send Simultaneous Requests python (all at once)

问题

I'm trying to create a script that send's over 1000 requests to one page at the same time. But requests library with threading (1000) threads. Seems to be doing to first 50 or so requests all within 1 second, whereas the other 9950 are taking considerably longer. I measured it like this.

def print_to_cmd(strinng):
    queueLock.acquire()
    print strinng
    queueLock.release()

    start = time.time()
    resp = requests.get('http://test.net/', headers=header)
    end = time.time()

    print_to_cmd(str(end-start))

I'm thinking requests library is limiting how fast they are getting sent.

Doe's anybody know a way in python to send requests all at the same time? I have a VPS with 200mb upload so that is not the issue its something to do with python or requests library limiting it. They all need to hit the website within 1 second of each other.

Thanks for reading and I hope somebody can help.

回答1:

I have generally found that the best solution is to use an asynchronous library like tornado. The easiest solution that I found however is to use ThreadPoolExecutor.

import requests
from concurrent.futures import ThreadPoolExecutor

def get_url(url):
    return requests.get(url)
with ThreadPoolExecutor(max_workers=50) as pool:
    print(list(pool.map(get_url,list_of_urls)))

回答2:

I know this is an old question, but you can now do this using asyncio and aiohttp.

import asyncio
import aiohttp
from aiohttp import ClientSession

async def fetch_html(url: str, session: ClientSession, **kwargs) -> str:
    resp = await session.request(method="GET", url=url, **kwargs)
    resp.raise_for_status()
    return await resp.text()

async def make_requests(url: str, **kwargs) -> None:
    async with ClientSession() as session:
        tasks = []
        for i in range(1,1000):
            tasks.append(
                fetch_html(url=url, session=session, **kwargs)
            )
        results = await asyncio.gather(*tasks)
        # do something with results

if __name__ == "__main__":
    asyncio.run(make_requests(url='http://test.net/'))

You can read more about it and see an example here.

回答3:

Assumed that you know what you are doing, I first suggest you to implement a backoff policy with a jitter to prevent "predictable thundering hoardes" to your server. That said, you should consider to do some threading

import threading
class FuncThread(threading.Thread):
    def __init__(self, target, *args):
        self._target = target
        self._args = args
        threading.Thread.__init__(self)

    def run(self):
        self._target(*self._args)

so that you would do something like

t = FuncThread(doApiCall, url)
t.start()

where your method doApiCall is defined like this

def doApiCall(self, url):

来源：https://stackoverflow.com/questions/40391898/send-simultaneous-requests-python-all-at-once

标签

python

python-requests

simultaneous-calls