cannot allocate memory - RSelenium and EC2

I am trying to implement a Selenium test to perform automated actions on a website (looping through pages). I am using R and RSelenium package as well as a PostgreSQL database using DBI package. All this using EC2 AWS server.

My problem is that after a few minutes that the script was launched, my RStudio session freezes (as well as my Linux session) and I can see a message like "cannot allocate memory".
So this is clearly a memory issue without a doubt, and by doing top I could see that my Selenium docker was using most of the resources.

But my question is how can I reduce the amount of memory used by the Selenium test?

Don't forget drive.close() in your code, if you don't close your driver, you will have a lot instance of Chrome.

IMHO there is no practical way for a test to use less memory than the memory required by the given test. You can try to simplify the given test by breaking it up into 2 or more tests. Check for memory leaks, as suggested in another answer.

It would be much easier to use the next largest instance type with more memory, and shut down the instance when not in use to save money, if that is an issue.