[Cbc] Parallell CBC

Wed Jul 13 10:06:20 EDT 2016

Hi,

AFAIK the visual studio build does not includes pthread and is not 
parallel.

It is possible to build in windows a parallel version using MINGW 
(http://www.mingw.org/) by adding --enable-cbc-parallel .

I strongly suggest that you update to version 2.9.8, many bugs were solved.

I think that CMPL provides the 2.9.8 CBC version for windows bundled.
https://projects.coin-or.org/Cmpl

Cheers,

Em 13-07-2016 03:54, Bjørn Sigurd Johansen (Spider Solutions AS) escreveu:
> Dear CBC,
>
>
>
> I am using CBC 2.9.4 for MILP problem, but is not able to run in
> parallel.  Using the option “-threads <some number>” makes CBC hang
> after a few seconds.
>
> Is there a new Win64 cbc.exe that properly handles the “-threads”
> option?  (And possibly with improved MILP performance?)
>
>
>
>
>
> *CBC stops after the following print:*
>
> C:\Users\bjorn_000>C:\Users\bjorn_000\AppData\Roaming\Microsoft\AddIns\Solvers\win64\cbc.exe
> -threads 2 -directory "C:\Dropbox\kh\Optimize\ModelsAndSolutions"
> -import "C:\Dropbox\kh\Optimize\ModelsAndSolutions\ModelForGurobi.lp"
> -seconds 20 -maxIterations 50000 -ratioGap 0 -solve -solution
> "C:\Dropbox\kh\Optimize\ModelsAndSolutions\Solution.txt"
>
> Welcome to the CBC MILP Solver
>
> Version: 2.9.4
>
> Build Date: May 18 2015
>
>
>
> command line -
> C:\Users\bjorn_000\AppData\Roaming\Microsoft\AddIns\Solvers\win64\cbc.exe -threads
> 2 -directory C:\Dropbox\kh\Optimize\ModelsAndSolutions -import
> C:\Dropbox\kh\Optimize\ModelsAndSolutions\ModelForGurobi.lp -seconds 20
> -maxIterations 50000 -ratioGap 0 -solve -solution
> C:\Dropbox\kh\Optimize\ModelsAndSolutions\Solution.txt (default strategy 1)
>
> threads was changed from 0 to 2
>
> seconds was changed from 1e+100 to 20
>
> maxIterations was changed from 2147483647 to 50000
>
> ratioGap was changed from 0 to 0
>
> Continuous objective value is 178.167 - 0.09 seconds
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 5 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 1 strengthened rows, 0 substitutions
>
> Cgl0004I processed model has 2400 rows, 2976 columns (2973 integer (1497
> of which binary)) and 43145 elements
>
> Cbc0038I Initial state - 16 integers unsatisfied sum - 3.95151
>
> Cbc0038I Pass   1: suminf.    1.27858 (7) obj. 786.122 iterations 1458
>
> Cbc0038I Pass   2: suminf.    0.82530 (3) obj. 1498.29 iterations 288
>
> Cbc0038I Solution found of 1498.29
>
> Cbc0038I Branch and bound needed to clear up 3 general integers
>
> Cbc0038I Full problem 2400 rows 2976 columns, reduced to 19 rows 17 columns
>
> Cbc0038I Cleaned solution of 1092.61
>
> Cbc0038I Before mini branch and bound, 2948 integers at bound fixed and
> 1 continuous of which 1 were internal integer and 0 internal continuous
>
> Cbc0038I Full problem 2400 rows 2976 columns, reduced to 32 rows 24 columns
>
> Cbc0038I Mini branch and bound did not improve solution (1.10 seconds)
>
> Cbc0038I Freeing continuous variables gives a solution of 1092.61
>
> Cbc0038I Round again with cutoff of 1001.22
>
> Cbc0038I Reduced cost fixing fixed 31 variables on major pass 2
>
> Cbc0038I Pass   3: suminf.    1.27858 (7) obj. 786.122 iterations 0
>
> Cbc0038I Pass   4: suminf.    1.24256 (7) obj. 1001.22 iterations 961
>
> Cbc0038I Pass   5: suminf.    0.73804 (7) obj. 1001.22 iterations 5
>
> Cbc0038I Pass   6: suminf.    1.20089 (5) obj. 1001.22 iterations 1597
>
> Cbc0038I Pass   7: suminf.    1.24057 (5) obj. 1001.22 iterations 622
>
> Cbc0038I Solution found of 1001.22
>
> Cbc0038I Branch and bound needed to clear up 5 general integers
>
> Cbc0038I Mini branch and bound could not fix general integers
>
> Cbc0038I No solution found this major pass
>
> Cbc0038I Before mini branch and bound, 2941 integers at bound fixed and
> 1 continuous
>
> Cbc0038I Full problem 2400 rows 2976 columns, reduced to 42 rows 32 columns
>
> Cbc0038I Mini branch and bound did not improve solution (1.69 seconds)
>
> Cbc0038I After 1.69 seconds - Feasibility pump exiting with objective of
> 1092.61 - took 0.94 seconds
>
> Cbc0012I Integer solution of 1092.6135 found by feasibility pump after 0
> iterations and 0 nodes (1.69 seconds)
>
> Cbc0038I Full problem 2400 rows 2976 columns, reduced to 32 rows 24 columns
>
> Cbc0012I Integer solution of 719.2773 found by RINS after 0 iterations
> and 0 nodes (1.84 seconds)
>
> Cbc0031I 11 added rows had average density of 528.81818
>
> Cbc0013I At root node, 11 cuts changed objective from 178.71006 to
> 179.04079 in 10 passes
>
> Cbc0014I Cut generator 0 (Probing) - 0 row cuts average 0.0 elements, 1
> column cuts (1 active)  in 0.598 seconds - new frequency is 1
>
> Cbc0014I Cut generator 1 (Gomory) - 12 row cuts average 1499.0 elements,
> 0 column cuts (0 active)  in 0.095 seconds - new frequency is 1
>
> Cbc0014I Cut generator 2 (Knapsack) - 0 row cuts average 0.0 elements, 0
> column cuts (0 active)  in 0.054 seconds - new frequency is -100
>
> Cbc0014I Cut generator 3 (Clique) - 0 row cuts average 0.0 elements, 0
> column cuts (0 active)  in 0.002 seconds - new frequency is -100
>
> Cbc0014I Cut generator 4 (MixedIntegerRounding2) - 14 row cuts average
> 652.2 elements, 0 column cuts (0 active)  in 0.166 seconds - new
> frequency is 1
>
> Cbc0014I Cut generator 5 (FlowCover) - 8 row cuts average 4.5 elements,
> 0 column cuts (0 active)  in 0.023 seconds - new frequency is 1
>
> Cbc0014I Cut generator 6 (TwoMirCuts) - 2 row cuts average 6.0 elements,
> 0 column cuts (0 active)  in 0.058 seconds - new frequency is -100
>
> Cbc0010I After 0 nodes, 1 on tree, 719.2773 best solution, best possible
> 179.04079 (3.24 seconds)
>
> Cbc0012I Integer solution of 266.2883 found by DiveCoefficient after 104
> iterations and 1 nodes (3.38 seconds)
>
> Cbc0012I Integer solution of 266.2883 found by heuristic after 98
> iterations and 0 nodes (3.56 seconds)
>
>
>
> Best regards,
>
>
>
>
>
> _______________________________________________
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> Cbc at list.coin-or.org
> http://list.coin-or.org/mailman/listinfo/cbc
>

-- 
==================================================
Haroldo Gambini Santos
D.Sc, Computer Science
Universidade Federal de Ouro Preto
http://www.decom.ufop.br/haroldo/