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Usage of GMP::Instance::SetMemoryLimit

  • March 25, 2021
  • 1 reply
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I’m trying to define a limit to RAM memory available to solve a generated mathematical program. Is this function related to this?

 

I tried code below, but it’s stoping my solve before the time_limit defined, before the the GAP defined and also is not using 24 GB available. And before I changed the code to use gmp functions it was taking more than 11 GB.

 

 

 

Best answer by Marcel Hunting

Hi @erika.hashiguti. Using the procedure GMP::Instance::SetMemoryLimit has no effect for CPLEX but that was not mentioned in the documentation. We have updated the Function Reference:

https://documentation.aimms.com/functionreference/algorithmic-capabilities/the-gmp-library/gmp_instance-procedures-and-functions/gmp_instance_setmemorylimit.html

To limit the memory usage by CPLEX, when solving a MIP, you have to use the CPLEX option ‘Tree memory limit’. Note that this option is closely related to the CPLEX option ‘Node file’ as that option determines the action taken by CPLEX when the amount of memory required to store the Branch-and-Bound tree exceeds the limit set by ‘Tree memory limit’.

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Marcel Hunting
AIMMSian
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  • AIMMSian
  • 258 replies
  • Answer
  • March 26, 2021

Hi @erika.hashiguti. Using the procedure GMP::Instance::SetMemoryLimit has no effect for CPLEX but that was not mentioned in the documentation. We have updated the Function Reference:

https://documentation.aimms.com/functionreference/algorithmic-capabilities/the-gmp-library/gmp_instance-procedures-and-functions/gmp_instance_setmemorylimit.html

To limit the memory usage by CPLEX, when solving a MIP, you have to use the CPLEX option ‘Tree memory limit’. Note that this option is closely related to the CPLEX option ‘Node file’ as that option determines the action taken by CPLEX when the amount of memory required to store the Branch-and-Bound tree exceeds the limit set by ‘Tree memory limit’.



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