Remote end closed connection without response on successive Session requests

I’m issuing successive GET requests to a Django server and I get Remote end closed connection without response on the second request. If I pause for one second it works fine.

Expected Result

>>> s = requests.Session()
>>> s.get('http://localhost:8000/'); time.sleep(1); s.get('http://localhost:8000')
<Response [404]>
<Response [404]>

Works as expected without Session:

>>> requests.get('http://localhost:8000/'); requests.get('http://localhost:8000')
<Response [404]>
<Response [404]>

Actual Result

>>> s.get('http://localhost:8000/'); s.get('http://localhost:8000')
<Response [404]>
Traceback (most recent call last):
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 600, in urlopen
    chunked=chunked)
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 384, in _make_request
    six.raise_from(e, None)
  File "<string>", line 2, in raise_from
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 380, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib64/python3.6/http/client.py", line 1331, in getresponse
    response.begin()
  File "/usr/lib64/python3.6/http/client.py", line 297, in begin
    version, status, reason = self._read_status()
  File "/usr/lib64/python3.6/http/client.py", line 266, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
http.client.RemoteDisconnected: Remote end closed connection without response

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "...local/lib/python3.6/site-packages/requests/adapters.py", line 445, in send
    timeout=timeout
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 638, in urlopen
    _stacktrace=sys.exc_info()[2])
  File "...local/lib/python3.6/site-packages/urllib3/util/retry.py", line 367, in increment
    raise six.reraise(type(error), error, _stacktrace)
  File "...local/lib/python3.6/site-packages/urllib3/packages/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 600, in urlopen
    chunked=chunked)
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 384, in _make_request
    six.raise_from(e, None)
  File "<string>", line 2, in raise_from
  File "...local/lib/python3.6/site-packages/urllib3/connectionpool.py", line 380, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib64/python3.6/http/client.py", line 1331, in getresponse
    response.begin()
  File "/usr/lib64/python3.6/http/client.py", line 297, in begin
    version, status, reason = self._read_status()
  File "/usr/lib64/python3.6/http/client.py", line 266, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
urllib3.exceptions.ProtocolError: ('Connection aborted.', RemoteDisconnected('Remote end closed connection without response',))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "...local/lib/python3.6/site-packages/requests/sessions.py", line 525, in get
    return self.request('GET', url, **kwargs)
  File "...local/lib/python3.6/site-packages/requests/sessions.py", line 512, in request
    resp = self.send(prep, **send_kwargs)
  File "...local/lib/python3.6/site-packages/requests/sessions.py", line 622, in send
    r = adapter.send(request, **kwargs)
  File "...local/lib/python3.6/site-packages/requests/adapters.py", line 495, in send
    raise ConnectionError(err, request=request)
requests.exceptions.ConnectionError: ('Connection aborted.', RemoteDisconnected('Remote end closed connection without response',))

System Information

$ python -m requests.help

{
  "chardet": {
    "version": "3.0.4"
  },
  "cryptography": {
    "version": "2.3"
  },
  "idna": {
    "version": "2.7"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.6.6"
  },
  "platform": {
    "release": "4.17.19-200.fc28.x86_64",
    "system": "Linux"
  },
  "pyOpenSSL": {
    "openssl_version": "1010008f",
    "version": "17.3.0"
  },
  "requests": {
    "version": "2.19.1"
  },
  "system_ssl": {
    "version": "1010008f"
  },
  "urllib3": {
    "version": "1.23"
  },
  "using_pyopenssl": true
}

It might be related to #4664.

[rvernica]

@kingbuzzman I reported the issue to Django here but there seem to be some issues with reproducing it. Maybe you can help confirm it.

[sigmavirus24]

Seems that @jaap3 found https://github.com/django/django/commit/934acf1126995f6e6ccba5947ec8f7561633c27f to be the commit that fixes this in master.