ChromeDriver does not close AsyncHttpClient threads

[ajurge]

🐛 Bug Report

Chrome driver does not close AsyncHttpClient threads and after some time produces

java.lang.OutOfMemoryError: unable to create native thread: possibly out of memory or process/resource limits reached

Build info: version: '4.0.0-beta-1', revision: '9c03156c2b'
System info: os.name: 'Linux', os.arch: 'amd64', os.version: '4.15.0-128-generic', java.version: '11.0.10'
Driver info: org.openqa.selenium.chrome.ChromeDriver
Command: [null, newSession {desiredCapabilities=Capabilities {--whitelisted-ips: , browserName: chrome, ensureCleanSession: true}}]
Capabilities {}
	at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:635)
	at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:252)
	at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:174)
	at org.openqa.selenium.chromium.ChromiumDriver.<init>(ChromiumDriver.java:82)

JConsole Threads (>200 Live Threads after 1 hour, scheduled service execution fixed period 30s):

JName: AsyncHttpClient-234-1
State: RUNNABLE
Total blocked: 0  Total waited: 0
Stack trace: 
java.base@11.0.2/sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
java.base@11.0.2/sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(WindowsSelectorImpl.java:339)
java.base@11.0.2/sun.nio.ch.WindowsSelectorImpl.doSelect(WindowsSelectorImpl.java:167)
java.base@11.0.2/sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:124)
   - locked io.netty.channel.nio.SelectedSelectionKeySet@6d364864
   - locked sun.nio.ch.WindowsSelectorImpl@48886843
java.base@11.0.2/sun.nio.ch.SelectorImpl.select(SelectorImpl.java:141)
app//io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:68)
app//io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:810)
app//io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:457)
app//io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
app//io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
app//io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.base@11.0.2/java.lang.Thread.run(Thread.java:834)

Similar issues:

1. Server does not stop http client threads for closed sessions #9153
2. ChromeDriver does not fully quit when using Selenium for java of 4+ version #8028
3. RemoteDriver.Quit() doesn't finish cromedriver.exe process via selenium-server-4.0.0-alpha-X.jar #7989

To Reproduce

This is just a possible way to reproduce it (we have a very similar setup in our scheduled service), i have not tested it:

seleniumVersion = '4.0.0-beta-1'
nettyVersion = '4.1.59.Final'

for (int i = 0; i < 6000; i++) {
   var driverContext = new EventFiringWebDriver(new ChromeDriver());
   driverContext.close();
   driverContext.quit();
}

Expected behavior

This worked with:
seleniumVersion = '4.0.0-alpha-7'
nettyVersion = '4.1.59.Final'

Environment

OS: Linux, Windows 10
Browser: Chrome
Browser version: 88.0.4324.190
Browser Driver version: ChromeDriver 88.0.4324.96
Language Bindings version: Java 11.0.10
Selenium Grid version (if applicable): 4.0.0-beta-1
Netty version (if applicable): 4.1.59.Final

[diemol]

Thank you for reporting this, seems that creating an http client per connection is not working well. This PR is fixing that #9227

[diemol]

PR has been merged and this will be available in beta-2.

[ajurge]

Thanks for fixing it so fast. Is it already known when beta-2 will be released?

[diemol]

We will know better when a release will happen by the end of next week, my wild guess is end of March.