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November 23, 2011 7:27am UTC

Error in multiphysics compilation

I got error message "Error in multiphysics compilation"


I am working with Heat transfer in solid module.

Can you help?

Thanks

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November 23, 2011 7:57am UTC in response to Ivar Kjelberg

Re: Error in multiphysics compilation

Dear Ivar.

Thanks for replying.

There was no problem before i changed the value in parameter(<Global Definitions).

The error message "Error in multiphysics compilation" occured just after changing the parameter value.

Can you help?

Thanks

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November 29, 2011 6:48am UTC in response to Paris von Lockette

Re: Error in multiphysics compilation

Hi

that is strange, what I do, when I have struggled for a few days, is to ask "support" for help ;)

--
Good luck
Ivar

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February 9, 2012 5:23pm UTC in response to Martin Brummund

Re: Error in multiphysics compilation

Eventually I got it figured out.

It is a multi-issue problem.

1. Fix the issues with the heapspace in the setup files. Note there are multiple setup files and all of them should be fixed. Different solver formulations pick up difference setup files.

2. Even so, comsol keeps previous solutions in the heap space . I have not yet determined when, why, or how many but it keeps some of them. So - you will eventually run out of heap space, period!! I was told this by folks from comsol. What will happen is that it may run fine for a full parameter set (has not hit the limit). Next time you get a partial parameter set (yu hit the limit) . Then you get 0 or one set (you are at the limit).

3. In versions before 4.2a you must perodocially delete previous solutions. I do not *think* clear solutions will work consistently. I was told to drill down into the study and delete the solvers themselves! This will allow you to use the full value of your heap space each run. I still had to to my sweeps in multiple stages, but I knew reliably where it would stop (since I had a full heap sapce for each run).

4. in version 4.2a they tell me you can tell the program to (a) save the current solution in the sweep to disk and (b) dump the heap space. This will take more time but will free up heap space. In version 4.2 and earlier you can not do this (the comsol people told me this too).

good luck!!!!!

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March 29, 2012 5:32pm UTC in response to Xie Yazhuo

Re: Error in multiphysics compilation

I think you are having the same problems I did. I was using 24GB machines and first got out I memory errors (heapspace problems) then "error in multiphysics compilation" (issues with retained solutions *in the solver*). Here is what I did.


You want To increase the heaps space so that heapspace+max working memory equals about 80-90% of available memory. The working memory is that little number in the bottom right of the comsol window. I have my heapspace set to 4GB and my sims max out at 16-18GB of working mem.

this will get your sims running with as much RAM usage in computing (working mem) and storing (heapspace) as needed. I am not completely sure what the distinction is but I think the heapspace stores things needed from one run to the next.

CRITICAL STEP- see my previous post. You must still delete the solvers periodically because stuff is being stored and building up there in parameter sweeps. If you delete the solvers before each run you will get the same number of parameter combinations each time in your sweeps because you are starting with an empty memory set. You just have to pick up in our sweeps were you left off.

Let me know if this works for you!!

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April 8, 2012 2:04pm UTC in response to Paris von Lockette

Re: Error in multiphysics compilation

Thanks for your reply.I had solved this problem.As you said,there's something maybe wrong with the heapspace.The program i want to run,is larger than the heaps space i set.And thanks a lot!

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