Browser/driver processes remain in Geb 8 after tests despite using CachingDriverFactory.clearCacheAndQuitDriver()

[martin-ober]

e2e-test setup: gebish, cucumber, and webdrivermanager

I use e2e tests which contain several hundred scenarios, and there are technical requirements for the test cases that I need a “fresh” browser.

For this scenario I use CachingDriverFactory.clearCacheAndQuitDriver()

And there is obviously a different behavior in geb 8.0.0.

I did a random sample with a few selected tests and checked after each scenario how many processes there were for the WebDriver and the browser.
Therfore i use

ps -A -o pid,rss,comm | grep -i 'Google Chrome' | grep -v grep for the browser processes

and

ps -A -o pid,rss,comm | grep -i './cache/selenium' | grep -v grep for the WebDriver processes

With geb 7: everything runs as expected and after each browser restart there is only one browser and WebDriver process.
With geb 8: every created browser and driver process is still remaing also after calling CachingDriverFactory.clearCacheAndQuitDriver() which forces the ci-jobs to terminate in cause of a memory issue

ext {
	gebVersion 				= '7.0'
    seleniumVersion 		= '4.34.0'
    groovyVersion 			= '4.0.28'
    cucumberVersion 		= '6.10.4'
    cucumberCoreVersion 	= '7.28.2'
    webDriverManagerVersion = '6.3.2'
    logbackVersion 			= '1.5.18'
    jacksonCoreVersion 		= '2.20.0'
}

dependencies {
    testImplementation "org.gebish:geb-core:$gebVersion"

    testImplementation "org.apache.groovy:groovy-all:$groovyVersion"
    testImplementation "io.github.bonigarcia:webdrivermanager:$webDriverManagerVersion"
    testImplementation "org.seleniumhq.selenium:selenium-firefox-driver:$seleniumVersion"
    testImplementation "org.seleniumhq.selenium:selenium-chrome-driver:$seleniumVersion"
    testImplementation "org.seleniumhq.selenium:selenium-ie-driver:$seleniumVersion"
    testImplementation "org.seleniumhq.selenium:selenium-edge-driver:$seleniumVersion"
    testImplementation "org.seleniumhq.selenium:selenium-java:$seleniumVersion"
    testImplementation group: 'io.cucumber:'cucumber-groovy$cucumberVersion"
    testImplementation group: 'io.cucumber:'cucumber-core:$cucumberCoreVersion"
    testImplementation group: 'io.cucumber:'cucumber-junit:$cucumberCoreVersion"
    testImplementation group: 'ch.qos.logback:'logback-classic:$logbackVersion"
}

sample date here:

Gebish 7:

browswer-processes:

timestamp;scenario;env;pid;rssMB;command;status
2025-09-25 13:31:57;scenario 1;chromehl;21915;195.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:31:58;scenario 2;chromehl;21915;203.9;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;CURRENT

2025-09-25 13:32:00;scenario 3;chromehl;21948;196.4;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:32:03;scenario 4;chromehl;21971;200.6;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:32:06;scenario 5;chromehl;21992;201.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:32:09;scenario 6;chromehl;22018;204.8;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:32:12;scenario 7;chromehl;22018;210.4;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;CURRENT

2025-09-25 13:32:15;scenario 8;chromehl;22048;204.6;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

driver-processes:

timestamp;scenario;pid;rssMB;command;status;
2025-09-25 13:31:57;scenario 1;21914;19.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:31:58;scenario 2;21914;20.3;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;CURRENT

2025-09-25 13:32:00;scenario 3;21947;19.6;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:32:03;scenario 4;21970;24.8;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:32:06;scenario 5;21991;24.6;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:32:09;scenario 6;22017;25.4;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:32:12;scenario 7;22017;25.4;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;CURRENT

2025-09-25 13:32:15;scenario 8;22047;25.0;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

Gebish 8:

browswer-processes:

timestamp;scenario;env;pid;rssMB;command;status
2025-09-25 13:39:15;scenario 1;chromehl;22665;195.1;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:39:17;scenario 2;chromehl;22665;204.0;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;CURRENT

2025-09-25 13:39:19;scenario 3;chromehl;22665;204.7;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:19;scenario 3;chromehl;22703;193.9;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:39:21;scenario 4;chromehl;22665;190.5;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:21;scenario 4;chromehl;22703;200.3;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:21;scenario 4;chromehl;22728;201.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:39:24;scenario 5;chromehl;22665;178.4;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:24;scenario 5;chromehl;22703;184.4;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:24;scenario 5;chromehl;22728;206.8;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:24;scenario 5;chromehl;22757;201.1;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:39:27;scenario 6;chromehl;22665;180.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:27;scenario 6;chromehl;22703;172.3;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:27;scenario 6;chromehl;22728;189.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:27;scenario 6;chromehl;22757;206.3;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:27;scenario 6;chromehl;22777;207.8;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

2025-09-25 13:39:30;scenario 7;chromehl;22665;180.0;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:30;scenario 7;chromehl;22703;174.6;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:30;scenario 7;chromehl;22728;184.9;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:30;scenario 7;chromehl;22757;204.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:30;scenario 7;chromehl;22777;212.8;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;CURRENT

2025-09-25 13:39:34;scenario 8;chromehl;22665;180.6;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:34;scenario 8;chromehl;22703;173.9;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:34;scenario 8;chromehl;22728;178.3;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:34;scenario 8;chromehl;22757;205.2;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:34;scenario 8;chromehl;22777;218.3;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;STALE
2025-09-25 13:39:34;scenario 8;chromehl;22813;204.6;/Applications/Google Chrome.app/Contents/MacOS/Google Chrome;NEW

driver-processes:

timestamp;scenario;pid;rssMB;command;status;
2025-09-25 13:39:15;scenario 1;22664;19.6;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:39:17;scenario 2;22664;19.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;CURRENT

2025-09-25 13:39:19;scenario 3;22664;19.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:19;scenario 3;22702;19.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:39:21;scenario 4;22664;18.2;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:21;scenario 4;22702;19.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:21;scenario 4;22723;24.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:39:24;scenario 5;22664;16.1;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:24;scenario 5;22702;17.8;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:24;scenario 5;22723;24.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:24;scenario 5;22756;24.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:39:27;scenario 6;22664;16.2;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:27;scenario 6;22702;15.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:27;scenario 6;22723;23.8;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:27;scenario 6;22756;24.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:27;scenario 6;22776;24.6;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:39:30;scenario 7;22664;16.2;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:30;scenario 7;22702;15.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:30;scenario 7;22723;23.1;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:30;scenario 7;22756;24.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:30;scenario 7;22776;24.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

2025-09-25 13:39:34;scenario 8;22664;16.2;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:34;scenario 8;22702;15.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:34;scenario 8;22723;21.4;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:34;scenario 8;22756;24.9;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:34;scenario 8;22776;24.7;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;STALE
2025-09-25 13:39:34;scenario 8;22812;24.8;~/.cache/selenium/chromedriver/mac-arm64/140.0.7339.207/chromedriver;NEW

[martin-ober]

After a first quick look at a diff to version 7.0, I suspect that the change in CachingDriverFactory.clearCache() does not return a driver instance and therefore driver.quit() is not executed.
I made a test call in my restart handling

    if (doRestart) {
        println "#### CachingDriverFactory.clearCache(): ${CachingDriverFactory.clearCache()}"
        CachingDriverFactory.clearCacheAndQuitDriver()
    }

And so i can verify my assumption that the cache handling is not working like before, when i can see the output

#### CachingDriverFactory.clearCache(): null

the problem is in CachingDriverFactory.clearCache():

    static WebDriver clearCache() {
        GLOBAL_CACHE.get { null }?.clear()
        PER_THREAD_CACHE.get { null }?.clear()
    }

    static WebDriver clearCacheAndQuitDriver() {
        def driver = clearCache()
        driver?.quit()
        driver
    }

because the cache used private final Cache<WebDriver> cache is either from GLOBAL_CACHE or from PER_THREAD_CACHE. The new implementation of static WebDriver clearCache() is conceptually incorrect here and probably did not take into account that the cached value is returned and used further for the driver?.quit() call.

[jonnybot0]

The changes you mentioned were introduced here: #270

Your description of the problem makes sense, though it's going to be thorny to fix. While there are no other references to geb.driver.CachingDriverFactory#clearCache in Geb itself, anyone who was using it could have been depending on that method to return a WebDriver instance. Now that it's dealing with two distinct caches, each with its own WebDriver, the behaviour doesn't really match the implicit contract. 🤔

[jonnybot0]

Had a go at this with https://github.com/apache/groovy-geb/pull/new/bugfix/288-driver-cache.

That should at least have a bit more sense about which cached driver it returns to the quit method. Frankly, it seems a bit fraught keeping these cached web drivers in a static cache field on this factory class, but I haven't thought of something better yet.

Would the changes in the linked branch solve for your case, @martin-ober ?

[martin-ober]

@jonnybot0:
Yes, that looks correct and should solve the problem.

However, I am not familiar with the entire project and therefore may not see the necessity of the chosen implementation with the "static cached caches".

[martin-ober]

@jonnybot0 - It seems to me that this "static cached cache" construction was only used for testing purposes.
The clearCacheCache() call is made exclusively from *Spec.groovy files.

[jonnybot0]

@martin-ober - that may be true in the Geb codebase, but given that these methods are public, it's not certain what is getting called out in "the wild". I'm going to see if I can get a review from @Vampire on #289.

[martin-ober]

Hi @jonnybot0,
Any idea when this will be fixed?
I can't upgrade my pipelines and am still stuck with geb 7 and selenium 4.34.0.
You had a simple, pragmatic solution for the error, but it didn't make it into 8.0.1.

[jonnybot0]

Hey, @martin-ober - apologies that I've been quiet on your question. The past few weeks I've been a bit slammed from various quarters (work and home). Being unable to promise a timeline, I didn't respond.

Having dug into this reasonably deeply today, I'm beginning to think that the better course is to revert the PR that originally introduced the bug. I've opened a PR for that here (#299). I'm going to seek a review from @Vampire , as he's got as much context on this as me.

If you're in a jam, and can't wait for the release train (which I can't make timeline promises on just now), my best suggestion would be to build your own internal release candidate from that branch and use that to upgrade your pipelines in the interim. That should restore the original behavior of the clearCacheAndQuitDriver method, but should otherwise have all the Geb 8 updates you're needing. Otherwise, keep an eye on the Groovy mailing list, this repo, or the Geb website for the next release.

Thanks for your patience and interest in Geb.

[jonnybot0]

Just to follow up, here's my plan at this point:

1. I'm going to spend some time today trying to sort out why our test of the support for JUnit 5's parallel execution is flaky. I need to suss out whether it's the test that's flaky or the implementation itself.
2. If I can't sort that out, I'm going to disable the flaky test in CI for now.
3. Pending some feedback from @Vampire (who authored the original support for JUnit 5 parallelism in Geb in Improve Spock and Jupiter parallel running support #181), we'll plan on a release in January which should fix this issue.