Could not spawn gamscmex error

Problems with syntax of GAMS
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roys
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Could not spawn gamscmex error

Post by roys »

Hello,
I was trying to run a fairly large MIP on my university's linux cluster and I keep running into the following error:
'Error: Could not spawn gamscmex rc=1'. I have attached a screenshot as well.
gamserror1.JPG
Any ideas on what might be causing this error would be greatly appreciated.
Fred
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Re: Could not spawn gamscmex error

Post by Fred »

Maybe you are running short of memory? How much RAM does the machine have? The log shows that 76+GB are allocated just to generate the model.

Fred
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dirkse
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Re: Could not spawn gamscmex error

Post by dirkse »

Roys,

Fred's comment on running out of memory points to one likely cause. But if that's the case then GAMS should be giving you some sort of message and a cleaner exit. The output you have sent makes me suspect it could be some other sort of limit hit internally - we should be detecting and handling this more cleanly.

Any chance you can send this example in reproducible form to support@gams.com? If so, we can have a look at it more closely.

-Steve
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roys
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Re: Could not spawn gamscmex error

Post by roys »

Hello Fred and dirkse,
Thank you for your inputs.
I have sent an email to GAMS support with my model and gdx files.
The model formulation is definitely rudimentary and could be a reason why the memory requirements are so overwhelming. However the 'rc=1' bit worries me. According to the docs rc=1 means that "Solver is to be called, the system should never return this number".
I have been trying to run it on a linux server with 252 GB memory with 40 cores each with a specification shown below.
gamserror2.JPG
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