[Python] Singleton Selenium Chromedriver randomly decides not to connect. What could be the...

I have a problem with python selenium's chromedriver connection. About half the time I run my tests to connect to a server I am hosting, selenium throws a connection timed out error like this:

tests\certificate\test_mysoftware_Netwrk_ClientGroup.py:56: in setup_method
delete_testClients()
lib\mysoftware_ClientGroup.py:195: in delete_testClients
driver.get(website_url)
venv\lib\site-packages\selenium\webdriver\remote\webdriver.py:363: in get
self.execute(Command.GET, {"url": url})
venv\lib\site-packages\selenium\webdriver\remote\webdriver.py:354: in execute
self.error_handler.check_response(response)
venv\lib\site-packages\selenium\webdriver\remote\errorhandler.py:229: in check_response
raise exception_class(message, screen, stacktrace)
E selenium.common.exceptions.WebDriverException: Message: unknown error: net::ERR_CONNECTION_TIMED_OUT
E (Session info: chrome=128.0.6613.114)
E Stacktrace:
E GetHandleVerifier [0x00007FF72A7BB652+29090]
E (No symbol) [0x00007FF72A72E709]
E (No symbol) [0x00007FF72A5EB1CA]
E (No symbol) [0x00007FF72A5E3204]
E (No symbol) [0x00007FF72A5D4179]
E (No symbol) [0x00007FF72A5D5F42]
E (No symbol) [0x00007FF72A5D443F]
E (No symbol) [0x00007FF72A5D3CD1]
E (No symbol) [0x00007FF72A5D3C10]
E (No symbol) [0x00007FF72A5D1AD3]
E (No symbol) [0x00007FF72A5D214C]
E (No symbol) [0x00007FF72A5EE231]
E (No symbol) [0x00007FF72A6873FE]
E (No symbol) [0x00007FF72A6666EA]
E (No symbol) [0x00007FF72A6865D9]
E (No symbol) [0x00007FF72A666493]
E (No symbol) [0x00007FF72A6309B1]
E (No symbol) [0x00007FF72A631B11]
E GetHandleVerifier [0x00007FF72AAD8CDD+3295277]
E GetHandleVerifier [0x00007FF72AB248C3+3605523]
E GetHandleVerifier [0x00007FF72AB1A787+3564247]
E GetHandleVerifier [0x00007FF72A876F36+797318]
E (No symbol) [0x00007FF72A73988F]
E (No symbol) [0x00007FF72A735474]
E (No symbol) [0x00007FF72A735600]
E (No symbol) [0x00007FF72A724A9F]
E BaseThreadInitThunk [0x00007FFB1DDD7374+20]
E RtlUserThreadStart [0x00007FFB1FADCC91+33]


I initially thought this might be from version mismatch so I set both google chrome and chromedriver versions to 128.0.6613.114. I thought that solved the issue but it is persisting.

I am using Selenium 4.18.1 with Python 3.10 on a windows 10 machine. While half of the time these errors are caused by a specific set of tests.

I am using following driver options

def get_driver_options():
options = webdriver.ChromeOptions()
options.add_argument("--headless=new")
options.add_argument("--window-size=1440, 900")
options.add_argument('--ignore-certificate-errors')
options.add_argument('--allow-running-insecure-content')
options.add_argument("--disable-extensions")
options.add_argument("--proxy-server='direct://'")
options.add_argument("--proxy-bypass-list=*")
options.add_argument("--start-maximized")
options.add_argument('--disable-gpu')
options.add_argument('--disable-dev-shm-usage')
options.add_argument("--FontRenderHinting[none]")
options.add_argument('--no-sandbox')
options.add_argument('log-level=3')
options.add_argument('--ignore-ssl-errors=yes')
options.add_argument('--allow-insecure-localhost')
options.add_argument('--remote-allow-origins=*')
options.add_argument('--disable-search-engine-choice-screen')
return options


Also I am using a singleton webdriver class to keep my tests from getting too much memory.

class SdriverMeta(type):
_instances = {}
_lock: Lock = Lock()

def __call__(cls, *args, **kwargs):
if cls not in cls._instances:
#with cls._lock:

#if cls not in cls._instances:
try:

instance = super().__call__(*args, **kwargs)
cls._instances[cls] = instance
except Exception as e:
# Ensure that the lock and instance are properly cleaned up
if cls in cls._instances:
del cls._instances[cls]
raise
return cls._instances[cls]

@classmethod
def get_lock(cls):
return cls._lock

@classmethod
def reset_instance(cls):
# This method can be called to reset the Singleton instance
with cls._lock:
if cls in cls._instances:
del cls._instances[cls]

class SDriver(metaclass=SdriverMeta):
_instance = None
def __new__(cls,headless = True):
if not hasattr(cls, "_instance") or cls._instance is None:
with cls._lock:

cls._instance = super(SDriver, cls).__new__(cls)
cls._instance.headless = headless
cls._instance.driver = None


return cls._instance

def get_driver(self,headless = True):
#self.close_driver()
with SdriverMeta.get_lock():


if self.driver is None:
if headless:
options = get_driver_options()
else:
options = get_driver_headfull_options()
service = Service()
self.driver = webdriver.Chrome(service=service, options=options)
self.driver.implicitly_wait(90)
return self.driver


def close_driver(self):
with SdriverMeta.get_lock():

if hasattr(self, "driver") and self.driver:
try:
self.driver.close()
self.driver.quit()
except Exception as e:
print(f"Failed to close the driver: {e}")
finally:
self.driver = None
SdriverMeta.reset_instance()
#SDriver._instance = None




And the error part happens here as I try to get the url of my server:


def delete_testClients():
sdriver = SDriver()
headless=True
driver = sdriver.get_driver(headless)
website_url = default_config["website_url"]
driver.get(website_url)


So as it stands I have no Idea what could be causing my webdriver to not to connect to the server address I have for the machine I have. The url is correct as I am getting it from the hosting service and I am using the same json for all the other tests that are working.

The code snippet I posted works half of the time. Other half of the time the singleton driver sdriver cannot establish a connection to the server that I am testing. I have an inkling that this problem is related with the singleton driver but I am not sure. Any help is appreciated.

Update 1: I don't think that the problem is with the driver settings. If that was the case 30 other tests that use the same driver options would cause similar errors.

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