import requests
import threading
import time

def req():
    s = time.time()
    r = requests.get('https://www.google.com/')
    e = time.time()
    response_times.append(e - s)

response_times = []
thread_amount = 50
print(f"{thread_amount} parallel threads")
threads = []
s1 = time.time()
for i in range(thread_amount):
    threads.append(threading.Thread(target = req))  
s2 = time.time()
for thread in threads:
    thread.start()
s3 = time.time()
for thread in threads:
    thread.join()
s4 = time.time()

total_time = s4 - s1
spawn_time = s2 -s1
start_time = s3 -s2
finish_time = s4 -s3
average_time_per_thread = sum(response_times) / len(response_times)

print(f"average response time per request: {average_time_per_thread} s")
print(f"total time: {total_time} s")
print(f"spawn time: {spawn_time} s")
print(f"start time: {start_time} s")
print(f"finish time: {finish_time} s")

对于50个并行线程/请求，每个请求的平均响应时间为5.5秒。我已经知道这个问题与SSL证书有关，对于100多个并行请求，我得到一个错误：

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 755, in urlopen
    retries = retries.increment(
  File "/usr/lib/python3/dist-packages/urllib3/util/retry.py", line 574, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='www.google.com', port=443): Max retries exceeded with url: / (Caused by SSLError(SSLZeroReturnError(6, 'TLS/SSL connection has been closed (EOF) (_ssl.c:997)')))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1009, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 946, in run
    self._target(*self._args, **self._kwargs)
  File "/root/speedtest.py", line 7, in req
    r = requests.get('https://www.google.com/')
  File "/usr/lib/python3/dist-packages/requests/api.py", line 76, in get
    return request('get', url, params=params, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 514, in send
    raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='www.google.com', port=443): Max retries exceeded with url: / (Caused by SSLError(SSLZeroReturnError(6, 'TLS/SSL connection has been closed (EOF) (_ssl.c:997)')))

这个问题发生在我在ubuntu22.04服务器上执行以下操作之后：
sudo snap install core; sudo snap refresh core-sudo snap install --classic certbot-sudo ln -s /snap/bin/certbot /usr/bin/certbot-sudo apt-get install nginx-sudo certbot --nginx（在此步骤中，我必须为我的域创建一个证书）-sudo certbot renew --dry-run
在此之前，每个请求的平均响应时间是0.45秒。看起来我崩溃了python请求的SSL证书，但我不知道是哪个文件导致了这个问题。如果我将请求改为requests.get('https://www.google.com/', verify=False)，平均响应时间将再次是0.45秒，但我认为这不是一个好的解决方案。