HTTPSConnectionPool(host='accounts.google.com', port=443): Max retries exceeded with url: /o/oauth2/token (Caused by SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1129)')))

[JhPlayGround]

Traceback (most recent call last):
File "C:\hermes_server\venv\lib\site-packages\urllib3\connectionpool.py", line 699, in urlopen
httplib_response = self._make_request(
File "C:\hermes_server\venv\lib\site-packages\urllib3\connectionpool.py", line 382, in _make_request
self._validate_conn(conn)
File "C:\hermes_server\venv\lib\site-packages\urllib3\connectionpool.py", line 1010, in validate_conn
conn.connect()
File "C:\hermes_server\venv\lib\site-packages\urllib3\connection.py", line 411, in connect
self.sock = ssl_wrap_socket(
File "C:\hermes_server\venv\lib\site-packages\urllib3\util\ssl.py", line 428, in ssl_wrap_socket
ssl_sock = ssl_wrap_socket_impl(
File "C:\hermes_server\venv\lib\site-packages\urllib3\util\ssl.py", line 472, in _ssl_wrap_socket_impl
return ssl_context.wrap_socket(sock, server_hostname=server_hostname)
File "C:\Users\Artience\AppData\Local\Programs\Python\Python39\lib\ssl.py", line 500, in wrap_socket
return self.sslsocket_class._create(
File "C:\Users\Artience\AppData\Local\Programs\Python\Python39\lib\ssl.py", line 1040, in _create
self.do_handshake()
File "C:\Users\Artience\AppData\Local\Programs\Python\Python39\lib\ssl.py", line 1309, in do_handshake
self._sslobj.do_handshake()
ssl.SSLEOFError: EOF occurred in violation of protocol (_ssl.c:1129)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\hermes_server\venv\lib\site-packages\requests\adapters.py", line 439, in send
resp = conn.urlopen(
File "C:\hermes_server\venv\lib\site-packages\urllib3\connectionpool.py", line 755, in urlopen
retries = retries.increment(
File "C:\hermes_server\venv\lib\site-packages\urllib3\util\retry.py", line 573, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='accounts.google.com', port=443): Max retries exceeded with url: /o/oauth2/token (Caused by SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1129)')))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\hermes_server\venv\lib\site-packages\google\auth\transport\requests.py", line 183, in call
response = self.session.request(
File "C:\hermes_server\venv\lib\site-packages\requests\sessions.py", line 542, in request
resp = self.send(prep, **send_kwargs)
File "C:\hermes_server\venv\lib\site-packages\requests\sessions.py", line 655, in send
r = adapter.send(request, **kwargs)
File "C:\hermes_server\venv\lib\site-packages\requests\adapters.py", line 514, in send
raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='accounts.google.com', port=443): Max retries exceeded with url: /o/oauth2/token (Caused by SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1129)')))

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "C:\hermes_server\app\main\modules\api\google\ads_v2\connection.py", line 36, in get_client_by_token
google_ads_client = GoogleAdsClient.load_from_dict(config_dict={"developer_token": developer_token,
File "C:\hermes_server\venv\lib\site-packages\google\ads\googleads\client.py", line 268, in load_from_dict
kwargs = cls._get_client_kwargs(config_data)
File "C:\hermes_server\venv\lib\site-packages\google\ads\googleads\client.py", line 182, in _get_client_kwargs
"credentials": oauth2.get_credentials(config_data),
File "C:\hermes_server\venv\lib\site-packages\google\ads\googleads\oauth2.py", line 114, in get_credentials
return get_installed_app_credentials(
File "C:\hermes_server\venv\lib\site-packages\google\ads\googleads\oauth2.py", line 48, in initialize_credentials_wrapper
credentials.refresh(Request())
File "C:\hermes_server\venv\lib\site-packages\google\oauth2\credentials.py", line 293, in refresh
) = reauth.refresh_grant(
File "C:\hermes_server\venv\lib\site-packages\google\oauth2\reauth.py", line 318, in refresh_grant
response_status_ok, response_data = _client._token_endpoint_request_no_throw(
File "C:\hermes_server\venv\lib\site-packages\google\oauth2_client.py", line 115, in _token_endpoint_request_no_throw
response = request(method="POST", url=token_uri, headers=headers, body=body)
File "C:\hermes_server\venv\lib\site-packages\google\auth\transport\requests.py", line 189, in call
six.raise_from(new_exc, caught_exc)
File "", line 3, in raise_from
google.auth.exceptions.TransportError: HTTPSConnectionPool(host='accounts.google.com', port=443): Max retries exceeded with url: /o/oauth2/token (Caused by SSLError(SSLEOFError(8, 'EOF occurred in violation of protocol (_ssl.c:1129)')))

This is how errors keep happening.
There was no problem before, but this problem occurred two days ago.

[msaniscalchi]

It seems to be raised in the google-auth library. At least based on a similar report in their issue tracker, a high volume of requests produced the error for their configured environment. It appears to have been resolved after updating their OS / SSL installation.