java.lang.OutOfMemoryError: Java heap space

1 year 1 month ago #327 by alfphome
Hello all!

I hope that you are doing well. I am writing to you in order that you help to find a solution for a problem that I got when I run iCP. I have a relatively small model (2400 elements) in Comsol that solves the Darcy law and the solute transport. PhreeqC calculates the equilibrated chemical species and some properties like water phase density that is sent by iCP to Comsol. In this problem, a core (12.5 cm) that contains a resident brine is flooded by an injection water. I need to inject some pore volumes of water in the core, but at some point iCP stopped abruptly showing the following error message (as it is mentioned in the subject):

See Figure 1 in the attachment

I have found in internet, that this problem has been reported before by SKB ( , page 94). For your information, I am running this problem in a computer with 80 Gb of RAM memory.

I have already tested some recommendations suggested by E., Coene (to whom I gratefully acknowledge):
1) Increase the store solution frequency
2) Reduce the number of selected outputs
3) Create a checkpoint at intermediate date
4) Modify the file comsol.ini

Concerning this point, I have already tried to modify the file comsol.ini that is on C:\Users\alfredo\.iCP\v1.6.0\1DDBE77C-9BCC-YYYY-ABCD-XXXXXXXXXXX. I have replaced the original value of -Xmx6g (relate to the heap space) by -Xmx20g as observed below:

See Figure 2 in the attachment

Probably, additional changes must be added…

In summary, I have not found a solution to my problem (yet). Could you give me a hand, please?

Thanks in advance for your time and consideration,


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1 year 1 month ago #328 by ecoene
Dear Alfredo,

I'm sorry to hear that you are still having issues with java heap space. Looking at the problem again, it looks like we need to change the parameters of the java virtual machine, not of Comsol. Try changing the -Xmx parameter in the iCP.l4j.ini and iCP_console.l4j.ini files that you can find in the iCP installation folder (C:\Program Files\iMaGe\iCP-1.6.0).
I hope this helps to solve your issue!

Best regards,


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1 year 1 month ago #329 by alfphome
Dear Emilie,

I hope that you are doing well. Thanks for your reply. I have already tested your recommendation of altering the parameter -Xmx in the two iCP files. This solution has effectively solved my problem. In fact, I think that this parameter limits the size of the output file generated by iCP. If your file is close to this value you will get the Java heap_space error. I have selected to enter a number which is 20% of my total memory. Now, everything is working fine!

Thank you very much!


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