Out of memory while executing test suite collection

Hello @All,

While executing suite collection after 10 to 15 minutes facing out for memory issue in the crome session, Even tried to reduce the ‘max concurrent session’ to 2 still same issue
OS: Windows 11
Chrome: Version 121.0.6167.185 (Official Build) (64-bit)

Can someone please help?

Thanks in advance!

1 Like

Hi @p.kayam, You need to provide more information…
Open Katalon, click Help > Error Log, then attach the .log file (you may need to rename the file to Error.log) to your ticket. Also this is not a Tip, please pick the correct category.
Thanks Dave

Also take a look at this post to see if you have enough resources given to Java virtual machine for KS.

Same suggestion as @grylion54

You should try increasing the -Xmx value specified in the katalon.ini file

The screenshot below seems to be a window of some browser process (Chrome, possibly), not a window of Katalon Studio.

The idea of giving a larger memory size in katlaon.ini file will affect only to Katalon Studio and the child processes of your Test Cases forked by Katalon Studio. It might not affect to the browser processes.

Then, why the browser process(es) are getting out of memory? — very curious; I have no idea; only you, @p.kayam, can investigate it.

I have a guess. Possibly you have many zombie processes of Chrome unclosed. A horde of zombies will occupy the physical memory of your machine and cause a momory shortage. If you run so many test cases failing, then your test suite collection will result many unclosed browser windows.

In that case, you should improve your test case scripts to be more robust. You should not leave the failing test cases. That would be the first thing you should do.

Could be that aventuall errors are not handled properly so the testcases / suites does not terminate the webdriver, leading to ‘zombies’.
There is an option to force terminate the drivers in the project settings, may help:
(not sure if it works properly but worth to try)

Anyway, if the drivers are instantiated by pure Selenium commands (not by Katalon keywords) may have no effect, so it depends also on the test-cases design.

Hello @kazurayam @anon46315158 ,
You are right, This issue is on the Chrome session, In the execution of the suite collection I have ‘max concurrent session’ to 4 so four sessions are executing parallelly. However, I tried to reduce this to ‘2’ still the same
Also after the execution of each test suite driver is terminated as well.

Hello @p.kayam,

We also use the following as best practices for dealing with Katalon Studio/Browser memory/cache issues: Mostly works for us… We normally run this after several test cases/suites have been run.

Steps: Open Katalon UI

  • Click Tools > Terminate running WebDrivers > Finish
  • Click > Project > Close and Clean up
  • Click > File Clean up…
  • We also clear Chrome’s Browser Cache by pressing ‘Ctrl + Shift + Delete’ from within Chrome.


Which version of Katalon Studio did you use when the problem occured?

Are you aware that since 15 Feb anyone who used KS version older than v9.3.1 with Chrome browser experienced a lot of failing test cases. See

Katalon released the host fix v9.3.1 on 29 Feb.

If you haven’t updated your Katalon to the v9.3.1, you should upgrade it.

Why do you use the Parallel mode of Test Suite Collection? What sort of benefit do you expect to have? Do you expect that your test suite collection will run 4 times faster than the sequential execution? Have you measured the speed using stopwatch?

I have studied the speed issue a few years ago. I concluded negative.

Katalon offers an alternative approach of parallelism:

Possibly this offering would provide you faster test execution. Beware, you need to purchace enough number of KRE licences for the number of parallelism you want.

I made another post just to express my idea:

I can run 4 suites parallelly, So for Ex: I have 8 suites that take 60 min to execute, If I enable Parallel execution with ‘max concurrent session’ to 4 then Katalon will run 4 suites parallelly and start the remaining suites once the previous suites are done, so in 30 minutes I can complete all 8 suites

I was using 8.6.8 and now updated Katlaon to 9.3.1 Out of memory issue is solved.

Thanks all for the help!