CODEWITHSUNDEEP
optimizationlinear-programmingscip
Manish
Manish

Reputation: 127

SCIP Solver Running Indefinitely

I am Using the SCIP interactive shell, to solve a problem from an LP file, the solver is running since hours with no improvements in optimality GAP, normally this MIP problem is solved by free Solvers in under one second.

Here is part of console log it's same for hours

 7564s|682700 |669166 | 20689k|  30.3 |4674M| 241 | 110 |1276 |1664 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7565s|682800 |669266 | 20693k|  30.3 |4675M| 241 |  61 |1276 |1670 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7565s|682900 |669354 | 20699k|  30.3 |4675M| 241 | 129 |1276 |1687 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7566s|683000 |669454 | 20701k|  30.3 |4675M| 241 | 102 |1276 |1677 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7567s|683100 |669554 | 20706k|  30.3 |4675M| 241 | 149 |1276 |1677 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7567s|683200 |669652 | 20709k|  30.3 |4676M| 241 | 106 |1276 |1666 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7568s|683300 |669746 | 20713k|  30.3 |4676M| 241 | 112 |1276 |1660 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7569s|683400 |669834 | 20716k|  30.3 |4679M| 241 | 139 |1276 |1656 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7569s|683500 |669934 | 20721k|  30.3 |4680M| 241 |  93 |1276 |1649 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 time | node  | left  |LP iter|LP it/n| mem |mdpt |frac |vars |cons |cols |rows |cuts |confs|strbr|  dualbound   | primalbound  |  gap   
 7570s|683600 |670034 | 20724k|  30.3 |4680M| 241 |  92 |1276 |1646 |1276 |1395 |   1 |  31k|  20k| 2.876849e+05 | 2.342078e+05 |  22.83%
 7571s|683700 |670134 | 20727k|  30.3 |4680M| 241 |  78 |1276 |1643 |1276 |1395 |   1 |  31k|  20k| 2.876848e+05 | 2.342078e+05 |  22.83%
 7571s|683800 |670234 | 20730k|  30.3 |4681M| 241 | 141 |1276 |1649 |1276 |1395 |   1 |  31k|  20k| 2.876848e+05 | 2.342078e+05 |  22.83%
 7572s|683900 |670318 | 20733k|  30.3 |4682M| 241 |   - |1276 |1642 |1276

Is there is some kind termination parameter that I am missing, apart form time limit and optimality gap as they provide the non-global solution

Upvotes: 0

Views: 658

Answers (1)

mueldgog
mueldgog

Reputation: 383

If you want to have full control over the solving process, then you could use an event handler to check the progress in the dual and primal bound by yourself. Here you find an example that shows how to add an event handler to SCIP. In your case, I would suggest catching the SCIP_EVENTTYPE_NODESOLVED event, which is thrown after processing each node of the branch-and-bound tree.

Upvotes: 1

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