Introduction

When running Selenium WebDriver tests, encountering a “Connection Reset” warning or error can be frustrating. This issue often occurs when the browser abruptly loses its connection to the WebDriver server, leading to test failures. Understanding the causes and implementing proper solutions is crucial for stable automation testing.

Causes of Connection Reset Warnings

The “Connection Reset” warning can arise due to various factors, including:

1. Unstable Network Connection – A slow or intermittent network may cause the browser to lose its connection with the WebDriver.
2. Browser or WebDriver Incompatibility – Running outdated versions of Selenium, the WebDriver, or the browser can cause communication failures.
3. Antivirus or Firewall Restrictions – Security software may block or interfere with the WebDriver’s network communication.
4. High Test Execution Load – Running too many tests in parallel can overwhelm system resources, causing crashes.
5. Server Timeout Issues – The WebDriver may time out when waiting for a response from the browser.
6. Website-Specific Issues – Some websites may have security policies that terminate WebDriver-based automation sessions.

Solutions to Fix Connection Reset Warnings

1. Update Browser and WebDriver

Ensure that you are using compatible versions of Selenium WebDriver, the browser, and the WebDriver binary.

• Check the latest ChromeDriver version for Google Chrome here
• Ensure Firefox, Edge, or Safari WebDrivers are updated to match the browser version.

from selenium import webdriver

options = webdriver.ChromeOptions()
options.add_argument("--disable-dev-shm-usage")  # Helps avoid crashes on Linux
options.add_argument("--no-sandbox")  # Useful in CI/CD environments

driver = webdriver.Chrome(options=options)

2. Implement Retry Logic

If the issue is intermittent, adding a retry mechanism can help recover from failures.

import time

def retry_driver_initialization(retries=3):
    for attempt in range(retries):
        try:
            driver = webdriver.Chrome()
            return driver
        except Exception as e:
            print(f"Attempt {attempt + 1}: Failed to initialize WebDriver. Retrying...")
            time.sleep(2)
    raise Exception("Failed to initialize WebDriver after multiple attempts.")

driver = retry_driver_initialization()

3. Configure WebDriver Timeout Settings

Increasing the timeout values can help prevent unexpected disconnects.

driver.set_page_load_timeout(60)  # Wait up to 60 seconds for a page to load
driver.implicitly_wait(10)  # Implicitly wait for 10 seconds

4. Disable Antivirus or Firewall Interference

Some security software blocks WebDriver connections. Try:

• Temporarily disabling the antivirus/firewall and running tests.
• Whitelisting WebDriver executables in the firewall settings.

5. Run WebDriver in Headless Mode

If GUI rendering is causing connection resets, running the browser in headless mode can help.

options = webdriver.ChromeOptions()
options.add_argument("--headless")  # Run browser in headless mode
options.add_argument("--disable-gpu")  # Disable GPU rendering
driver = webdriver.Chrome(options=options)

6. Reduce Parallel Execution Load

If running tests in parallel, reduce the number of threads or parallel executions.

For pytest-xdist, limit concurrency:

pytest -n 2  # Run tests with only 2 parallel processes

For Selenium Grid, ensure the hub and node have sufficient resources.

7. Check System Resources

If memory or CPU usage is high, try:

• Closing unnecessary applications.
• Increasing system memory if running tests on a virtual machine.
• Using a cloud-based Selenium Grid like Selenium Grid, BrowserStack, or Sauce Labs.

8. Handle Website Security Policies

If a website detects Selenium automation and terminates the session:

• Randomize browser fingerprints using tools like undetected-chromedriver.
• Use proxy servers or VPNs to simulate real users.
• Implement human-like interactions using ActionChains.

from selenium.webdriver.common.action_chains import ActionChains

actions = ActionChains(driver)
actions.move_by_offset(10, 10).perform()  # Simulate human-like cursor movement

9. Restart WebDriver and Retry

If all else fails, restarting the WebDriver instance when a connection reset occurs can help.

try:
    driver.get("https://example.com")
except Exception as e:
    print("Connection reset error. Restarting WebDriver...")
    driver.quit()
    driver = webdriver.Chrome()
    driver.get("https://example.com")

Conclusion

Handling Connection Reset Warnings in Selenium requires a combination of version compatibility, network stability, resource management, and security settings. By applying these solutions, you can improve the stability and reliability of your Selenium test automation.

Would you like any additional details or code examples? 😊