Gurobi stuck in ordering

Awaiting user input

Yuheng Zhang

• October 01, 2023 14:47

I have encountered such a problem recently. There is a large scale model describing energy transport between several locations, of which the gurobi log is as follow:

Set parameter BarHomogeneous to value 1
Set parameter AggFill to value 10
Set parameter BarConvTol to value 0.0001
Set parameter Presolve to value 1

Gurobi Optimizer version 10.0.1 build v10.0.1rc0 (linux64)

CPU model: AMD EPYC 9654 96-Core Processor, instruction set [SSE2|AVX|AVX2|AVX512]
Thread count: 192 physical cores, 384 logical processors, using up to 32 threads

Optimize a model with 14658229 rows, 12974713 columns and 40584777 nonzeros
Model fingerprint: 0x2842f5da
Coefficient statistics:
Matrix range [2e-03, 5e+01]
Objective range [1e-03, 2e+06]
Bounds range [0e+00, 0e+00]
RHS range [1e+00, 1e+08]

Presolve time: 23.91s
Presolved: 10351811 rows, 9520721 columns, 31756203 nonzeros

Concurrent LP optimizer: primal simplex, dual simplex, and barrier

Showing barrier log only...
Warning: Concurrent optimizer requires crossover - forcing it on
Elapsed ordering time = 5s
Elapsed ordering time = 17s
Elapsed ordering time = 20s
Ordering time: 125.12s

 

After the ordering, it seems to be stuck in ordering and no solving process is performed. I tried several methods including setting method parameter to 2 and 3.

Related to

• Barrier

0

• 

  David Torres Sanchez

  Gurobi Staff

  • October 02, 2023 08:17

  Hi Yuheng Zhang,

  Have you tried with default parameters (i.e. removing all of your parameter settings)?
  You can also try Method = 2 with BarOrder = 0, or switch to a less memory-intensive Method = 1 if you have limited RAM on your machine.

  Cheers, 
  David

  0

Please sign in to leave a comment.