Firefox spontaneous launch in Selenium - selenium

Question

Environment:
selenium-server-standalone-3.8.1.jar
geckodriver-v0.24.0
firefox 60.6.1
Everything was set up 6 months ago and everything worked well, the tests passed through the Selenium and there were no problems.
Since 08/23/2019 problems began. Without any launches test inside the Selenium process, started to run spontaneously browsers (firefox) and did not turn off.
These processes overload the processor on the server, after which the server starts to brake and also the site that is on the server. These "browser launches" continue until Selenium is reloaded by open browsers after which our automatic tests are blocked and display an error: "unable to create new native thread".
As soon as one such browser spontaneously opens, the processor load becomes 100%.
These browser launches occur approximately 1 time in 4-5 minutes.
All tests are disabled, but Selenium lives its own life, and continues to launch the browsers.
Maybe someone faced a similar problem? Any ideas why this is happening and how to fix it?
The launch of selenium occurs on command:
su screener -c "/usr/bin/java -Dwebdriver.gecko.driver=/usr/local/bin/geckodriver -jar /usr/lib/selenium/selenium-server-standalone-3.8.1.jar -enablePassThrough false -port 4444 >/var/log/selenium/selenium_std.log 2>/var/log/selenium/selenium_error.log &"

Answer 1

Term yourself lucky to have sailed smoothly with geckodriver-v0.24.0 and selenium-server-standalone-3.8.1.jar till 08/23/2019.
As per the documentation:
To work with geckodriver-v0.24.0 you need:
Selenium Python client version greater then 3.14
Firefox client version minimum 57 (which seems to be okay)
You can find the detailed GeckoDriver, Selenium and Firefox Browser compatibility chart in the discussion Which Firefox browser versions supported for given Geckodriver version?
Additional considerations
As a part of the best practices:
Upgrade JDK to recent levels JDK 8u222.
Upgrade Selenium to current levels Version 3.141.59.
Upgrade GeckoDriver to GeckoDriver v0.24.0 level.
GeckoDriver is present in the desired location.
GeckoDriver is having executable permission for non-root users.
Upgrade Firefox version to Firefox v65.0.2 levels.
Clean your Project Workspace through your IDE and Rebuild your project with required dependencies only.
http://www.yourownlinux.com/2013/10/how-to-free-up-release-unused-cached-memory-in-linux.html) before and after the execution of your Test Suite.
If your base Web Client version is too old, then uninstall it through Revo Uninstaller and install a recent GA and released version of Web Client.
Take a System Reboot.
Execute your Test as a non-root user.
Always invoke driver.quit() within tearDown(){} method to close & destroy the WebDriver and Web Client instances gracefully.
You can find a detailed discussion in PhantomJS web driver stays in memory
If the stale WebDriver instances still persist you may require to forcefully remove them.
You can find a detailed discussion in Selenium : How to stop geckodriver process impacting PC memory, without calling driver.quit()?
Outro
Limit chrome headless CPU and memory usage