Improving Root Node Time
Answered
I have a large scale optimization problem (~12million binary) that I'm solving through a Lagrangian-relaxation based decomposition. The overview is that in each iteration, 90% of the binary variables are fixed and the remaining 10% are solved. In the early iterations, the time to solve the root node is quite good, but as it converges, solving the root node balloons. My assumption is that, as the multipliers converge, Gurobi has to spend more time on the fractional values. The root relaxation is stable through iterations.
Iteration 3 looks something like this:
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 122308.639 0 318 - 122308.639 - - 1402s
H 0 0 122313.12973 122308.639 0.00% - 1423s
Explored 1 nodes (977756 simplex iterations) in 1428.97 seconds (2614.60 work units)
Thread count was 8 (of 64 available processors)
But by iteration 33, it looks like:
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 340482.823 0 77510 - 340482.823 - - 1390s
0 0 340482.823 0 77510 - 340482.823 - - 4872s
H 0 0 340517.44429 340482.823 0.01% - 11598s
Explored 1 nodes (1022414 simplex iterations) in 11605.09 seconds (18907.75 work units)
Thread count was 8 (of 64 available processors)
Does my explanation seem reasonable? Is there any recommendations on increasing the performance? I understand the problem I'm trying to solve is just big and there's only so much that can be done, but preventing the ballooning of iteration time could save several hours.
I noticed that each iteration solved in root so I turned off cuts. Other than 'MIPFocus': 1, 'Threads': 8 and 'Method': 2, the other parameters are stock.
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You could try experimenting with the NoRelHeurTime parameter which turns on the so-called "No Relaxation Heuristic". This heuristic tries to find a good feasible point even before the root relaxation is solved. You could also try experimenting with the Heuristics parameter.
Could you show the log of the root relaxation solve?
0 -
Thanks Jaromił. I have in the past experimented with NoRelHeurTime, but I've made changed since so I'll give it another try. Regarding the Heuristics parameter, I noticed that it always showed 'H' on the solved B&C line. I've tried both extremes (close to 0, close to 1) and haven't noticed large differences in the iteration time. I'll give experimenting with Heuristics another chance as well.
I'll also remark that I spent quite a bit of time on improving the numerical ranges from really large to still somewhat large. It considerably helped the root relaxation time.
Is Gurobi solving the LP during the root node? If so, could this be an option for parameter tuning? I know that simplex is the default node method because of warm start but in my case it seems barrier is much faster and I seemingly don't need branching.
Here's the full log for an early/quick iteration. To my eye, the root relaxation log doesn't change much for late/slow iterations in terms of warnings and barrier/crossover times, but I'd be happy to post.
Gurobi Optimizer version 10.0.1 build v10.0.1rc0 (linux64)
CPU model: AMD Ryzen Threadripper 3970X 32-Core Processor, instruction set [SSE2|AVX|AVX2]
Thread count: 32 physical cores, 64 logical processors, using up to 8 threadsOptimize a model with 83067661 rows, 102888816 columns and 537616399 nonzeros
Model fingerprint: 0xe396c365
Variable types: 91074444 continuous, 11814372 integer (11814372 binary)
Coefficient statistics:
Matrix range [1e-06, 6e+02]
Objective range [1e-04, 5e+03]
Bounds range [1e-04, 3e+01]
RHS range [2e-03, 3e+03]
Presolve removed 0 rows and 0 columns (presolve time = 15s) ...
Presolve removed 32256 rows and 1101 columns (presolve time = 21s) ...
Presolve removed 46728 rows and 64592287 columns (presolve time = 31s) ...
Presolve removed 47486348 rows and 64592287 columns (presolve time = 40s) ...
Presolve removed 72648306 rows and 77180953 columns (presolve time = 50s) ...
Presolve removed 72648306 rows and 77180953 columns (presolve time = 50s) ...
Presolve removed 72963086 rows and 91644465 columns (presolve time = 57s) ...
Presolve removed 73006900 rows and 91644465 columns (presolve time = 62s) ...
Presolve removed 73255652 rows and 92307511 columns (presolve time = 67s) ...
Presolve removed 73647847 rows and 92307511 columns (presolve time = 70s) ...
Presolve removed 73790475 rows and 92374929 columns (presolve time = 76s) ...
Presolve removed 73805278 rows and 92395409 columns (presolve time = 81s) ...
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Presolve removed 74949805 rows and 94900000 columns (presolve time = 170s) ...
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Presolve removed 76746477 rows and 96522741 columns (presolve time = 245s) ...
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Presolve removed 76748172 rows and 96522746 columns (presolve time = 256s) ...
Presolve removed 76748172 rows and 96522746 columns (presolve time = 260s) ...
Presolve removed 76748172 rows and 96522746 columns (presolve time = 265s) ...
Presolve removed 76748172 rows and 96522746 columns (presolve time = 270s) ...
Presolve removed 77084178 rows and 96645102 columns (presolve time = 275s) ...
Presolve removed 77186733 rows and 96762018 columns (presolve time = 282s) ...
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Presolve removed 77230138 rows and 96851438 columns (presolve time = 335s) ...
Presolve removed 78795565 rows and 98399978 columns (presolve time = 344s) ...
Presolve removed 78795565 rows and 98400527 columns (presolve time = 347s) ...
Presolve removed 78795565 rows and 98400527 columns (presolve time = 352s) ...
Presolve removed 78795565 rows and 98400545 columns (presolve time = 357s) ...
Presolve removed 78795654 rows and 98400547 columns (presolve time = 360s) ...
Presolve removed 78795654 rows and 98400547 columns (presolve time = 368s) ...
Presolve removed 78795654 rows and 98400547 columns (presolve time = 371s) ...
Presolve removed 78795780 rows and 98400608 columns (presolve time = 375s) ...
Presolve removed 78795812 rows and 98400741 columns (presolve time = 380s) ...
Presolve removed 78795848 rows and 98401615 columns (presolve time = 385s) ...
Presolve removed 78797430 rows and 98405156 columns (presolve time = 390s) ...
Presolve removed 78797430 rows and 98405156 columns (presolve time = 395s) ...
Presolve removed 78797466 rows and 98405156 columns (presolve time = 406s) ...
Presolve removed 78797466 rows and 98405156 columns (presolve time = 410s) ...
Presolve removed 78797466 rows and 98405156 columns (presolve time = 418s) ...
Presolve removed 78797466 rows and 98405156 columns (presolve time = 424s) ...
Presolve removed 78797466 rows and 98405156 columns (presolve time = 425s) ...
Presolve removed 79325309 rows and 98941843 columns (presolve time = 431s) ...
Presolve removed 79325223 rows and 98937460 columns
Presolve time: 435.00s
Presolved: 3742438 rows, 3951356 columns, 16669044 nonzeros
Variable types: 3516597 continuous, 434759 integer (434753 binary)
Root barrier log...Elapsed ordering time = 5s
Ordering time: 8.38sBarrier statistics:
Dense cols : 677
AA' NZ : 1.450e+07
Factor NZ : 8.756e+07 (roughly 3.0 GB of memory)
Factor Ops : 2.008e+10 (less than 1 second per iteration)
Threads : 8Objective Residual
Iter Primal Dual Primal Dual Compl Time
0 5.33896090e+10 -8.54160673e+12 4.87e+06 3.12e+02 2.82e+08 527s
1 4.24972814e+10 -7.52374498e+12 3.67e+06 6.08e+03 2.09e+08 529s
2 3.47456123e+10 -6.51894079e+12 2.84e+06 3.93e+03 1.63e+08 530s
3 2.74799914e+10 -4.89408541e+12 2.22e+06 1.48e+03 1.29e+08 532s
4 1.71906898e+10 -3.53379916e+12 1.36e+06 2.99e+02 8.17e+07 533s
5 8.20058503e+09 -2.11813340e+12 6.32e+05 1.76e+02 3.86e+07 534s
6 3.10024465e+09 -1.01947312e+12 2.23e+05 1.16e+02 1.37e+07 536s
7 2.28451986e+09 -8.75631022e+11 1.57e+05 6.09e+01 9.99e+06 537s
8 8.60715619e+08 -6.27924592e+11 4.36e+04 1.21e+01 2.83e+06 538s
9 7.43030996e+08 -3.47058038e+11 3.43e+04 2.04e+00 2.26e+06 539s
10 5.64954217e+08 -2.83035147e+11 2.02e+04 1.05e+00 1.34e+06 540s
11 5.61351988e+08 -2.79145366e+11 1.99e+04 1.07e+00 1.32e+06 541s
12 5.51083265e+08 -2.75349296e+11 1.93e+04 1.06e+00 1.28e+06 542s
13 4.71554013e+08 -2.70445459e+11 1.79e+04 1.02e+00 1.19e+06 544s
14 2.23323770e+08 -1.65319208e+11 6.42e+03 6.06e-01 4.39e+05 546s
15 1.81279524e+08 -9.21393871e+10 4.55e+03 2.81e-01 3.03e+05 548s
16 1.42972553e+08 -5.48161138e+10 3.01e+03 7.23e-01 1.97e+05 550s
17 1.19723338e+08 -4.86696685e+10 2.06e+03 5.67e-01 1.36e+05 551s
18 1.18274301e+08 -4.79297794e+10 2.01e+03 5.49e-01 1.33e+05 552s
19 1.05707941e+08 -4.70128365e+10 1.56e+03 5.25e-01 1.04e+05 553s
20 8.46852639e+07 -2.87900933e+10 7.65e+02 8.26e-02 5.05e+04 554s
21 8.08425715e+07 -2.59704645e+10 5.79e+02 7.41e-02 3.82e+04 555s
22 8.04688686e+07 -2.53755167e+10 5.67e+02 7.51e-02 3.73e+04 557s
23 7.99527590e+07 -2.49049350e+10 5.52e+02 7.06e-02 3.62e+04 558s
24 7.95015714e+07 -2.43187408e+10 5.38e+02 6.99e-02 3.52e+04 559s
25 7.84715434e+07 -2.35965253e+10 5.09e+02 6.57e-02 3.31e+04 560s
26 7.69882105e+07 -2.28422213e+10 4.67e+02 6.01e-02 3.04e+04 562s
27 7.50610337e+07 -2.10145041e+10 4.12e+02 4.58e-02 2.65e+04 564s
28 7.28814196e+07 -1.94508324e+10 3.56e+02 3.52e-02 2.27e+04 566s
29 7.08424725e+07 -1.78293709e+10 3.17e+02 2.60e-02 1.99e+04 568s
30 6.57391378e+07 -1.56506189e+10 2.15e+02 1.53e-02 1.35e+04 570s
31 6.36154151e+07 -1.47958564e+10 1.89e+02 1.26e-02 1.19e+04 572s
32 5.95406363e+07 -1.42777039e+10 1.45e+02 1.01e-02 9.37e+03 574s
33 5.62126349e+07 -1.27473454e+10 1.24e+02 4.01e-03 7.86e+03 576s
34 4.97692513e+07 -1.11987383e+10 9.67e+01 2.67e-03 6.03e+03 578s
35 4.80720388e+07 -9.05306210e+09 8.78e+01 2.18e-03 4.97e+03 580s
36 4.44250630e+07 -8.18677994e+09 7.42e+01 1.95e-03 4.15e+03 582s
37 3.85693832e+07 -6.82500359e+09 5.89e+01 3.75e-03 3.15e+03 584s
38 3.20550729e+07 -4.71045489e+09 4.51e+01 2.76e-03 2.07e+03 586s
39 2.76836488e+07 -3.80074011e+09 3.51e+01 3.29e-03 1.53e+03 588s
40 2.46592265e+07 -3.38133301e+09 2.90e+01 3.30e-03 1.25e+03 590s
41 2.26484502e+07 -3.10963554e+09 2.54e+01 2.89e-03 1.09e+03 592s
42 2.19008992e+07 -2.85598691e+09 2.40e+01 2.62e-03 9.86e+02 593s
43 1.95488148e+07 -1.85444874e+09 1.69e+01 3.53e-04 5.96e+02 595s
44 1.78705567e+07 -1.48867294e+09 1.49e+01 2.71e-04 4.67e+02 597s
45 1.27104093e+07 -1.38064381e+09 8.92e+00 2.42e-04 3.44e+02 598s
46 9.68700962e+06 -9.61396705e+08 5.80e+00 3.17e-04 2.17e+02 600s
47 7.29430753e+06 -5.49711914e+08 3.18e+00 3.67e-04 1.13e+02 601s
48 5.87226723e+06 -3.22732411e+08 2.04e+00 2.45e-04 6.31e+01 603s
49 4.14186228e+06 -2.18255527e+08 9.79e-01 1.58e-04 3.86e+01 604s
50 3.15296096e+06 -1.33374161e+08 5.18e-01 1.26e-04 2.27e+01 605s
51 2.43845327e+06 -1.13155880e+08 3.09e-01 1.07e-04 1.82e+01 606s
52 1.98220854e+06 -6.78584985e+07 2.09e-01 6.23e-05 1.07e+01 607s
53 1.56298780e+06 -5.77752248e+07 1.27e-01 5.67e-05 8.79e+00 608s
54 1.29363447e+06 -4.99384010e+07 7.91e-02 5.03e-05 7.43e+00 609s
55 1.23759403e+06 -3.00682288e+07 7.00e-02 3.39e-05 4.53e+00 611s
56 1.08451663e+06 -2.65595807e+07 5.03e-02 3.12e-05 3.96e+00 612s
57 1.01317441e+06 -2.07145246e+07 4.22e-02 2.42e-05 3.10e+00 613s
58 1.00361595e+06 -1.80598833e+07 4.11e-02 2.07e-05 2.72e+00 614s
59 9.48329911e+05 -1.57144230e+07 3.62e-02 1.77e-05 2.37e+00 615s
60 9.08743507e+05 -1.44496667e+07 3.26e-02 1.65e-05 2.18e+00 616s
61 8.06845787e+05 -1.33750808e+07 2.36e-02 1.55e-05 2.00e+00 617s
62 8.02598867e+05 -1.21638599e+07 2.33e-02 1.43e-05 1.83e+00 618s
63 7.71464305e+05 -1.17955710e+07 2.11e-02 1.38e-05 1.77e+00 619s
64 7.61565569e+05 -1.15778428e+07 2.04e-02 1.36e-05 1.74e+00 620s
65 7.56016222e+05 -1.12879918e+07 2.00e-02 1.32e-05 1.70e+00 621s
66 6.95126537e+05 -1.09019365e+07 1.54e-02 1.28e-05 1.63e+00 622s
67 5.96214185e+05 -6.28197939e+06 6.61e-03 6.50e-06 9.60e-01 624s
68 4.97268631e+05 -4.33069304e+06 2.44e-03 4.19e-06 6.72e-01 626s
69 4.55330071e+05 -2.05656335e+06 1.35e-03 1.97e-06 3.49e-01 628s
70 4.47726930e+05 -1.70192373e+06 1.23e-03 2.07e-06 2.99e-01 630s
71 4.29883814e+05 -1.49591874e+06 9.57e-04 2.00e-06 2.68e-01 631s
72 4.26868045e+05 -1.47156547e+06 9.15e-04 1.98e-06 2.64e-01 632s
73 4.23472992e+05 -1.37850468e+06 8.68e-04 1.94e-06 2.50e-01 633s
74 4.18376365e+05 -1.07593804e+06 7.98e-04 1.60e-06 2.08e-01 634s
75 4.11221770e+05 -1.04569712e+06 7.05e-04 1.56e-06 2.02e-01 635s
76 4.03688865e+05 -9.13036617e+05 6.11e-04 1.42e-06 1.83e-01 636s
77 3.91645338e+05 -7.24512084e+05 4.95e-04 1.49e-06 1.55e-01 638s
78 3.82920412e+05 -4.40273870e+05 4.12e-04 1.36e-06 1.14e-01 640s
79 3.74838772e+05 -3.50407336e+05 3.43e-04 1.23e-06 1.01e-01 642s
80 3.67673895e+05 -3.01778359e+05 2.85e-04 1.50e-06 9.30e-02 644s
81 3.63525024e+05 -1.88758759e+05 2.54e-04 1.07e-06 7.67e-02 646s
82 3.60721745e+05 -1.21230175e+05 2.36e-04 9.63e-07 6.69e-02 648s
83 3.58878028e+05 -9.71935178e+04 2.24e-04 8.73e-07 6.33e-02 650s
84 3.55936508e+05 -7.53533290e+04 2.03e-04 8.83e-07 5.99e-02 652s
85 3.50766306e+05 -5.82750776e+04 1.75e-04 8.80e-07 5.68e-02 653s
86 3.47545694e+05 1.02810571e+04 1.56e-04 6.68e-07 4.68e-02 655s
87 3.42806019e+05 9.18484089e+04 1.32e-04 7.16e-07 3.49e-02 657s
88 3.39759177e+05 1.25392333e+05 1.20e-04 7.47e-07 2.98e-02 659s
89 3.37065330e+05 1.58191426e+05 1.09e-04 9.79e-07 2.48e-02 661s
90 3.35529715e+05 1.70886545e+05 1.04e-04 1.44e-06 2.29e-02 663s
91 3.33523886e+05 1.83153139e+05 9.62e-05 1.74e-06 2.09e-02 666s
92 3.31720301e+05 1.84587927e+05 8.91e-05 1.79e-06 2.04e-02 667s
93 3.30428883e+05 1.89925050e+05 8.44e-05 1.77e-06 1.95e-02 669s
94 3.29368637e+05 1.95911648e+05 8.05e-05 2.11e-06 1.85e-02 671s
95 3.28024105e+05 1.99945311e+05 7.53e-05 2.19e-06 1.78e-02 673s
96 3.26776749e+05 2.00908305e+05 7.05e-05 2.21e-06 1.75e-02 675s
97 3.25921713e+05 2.11845937e+05 6.76e-05 2.06e-06 1.58e-02 677s
98 3.24568589e+05 2.13114197e+05 6.34e-05 2.07e-06 1.55e-02 678s
99 3.24288554e+05 2.18415016e+05 6.25e-05 2.05e-06 1.47e-02 680s
100 3.23552631e+05 2.19840877e+05 6.00e-05 1.99e-06 1.44e-02 681s
101 3.22957331e+05 2.29985916e+05 5.80e-05 1.87e-06 1.29e-02 684s
102 3.21935445e+05 2.39203043e+05 5.47e-05 8.64e-07 1.15e-02 686s
103 3.20036282e+05 2.44420503e+05 4.91e-05 1.20e-06 1.05e-02 688s
104 3.18811356e+05 2.49395734e+05 4.52e-05 1.51e-06 9.64e-03 689s
105 3.17983744e+05 2.49978566e+05 4.24e-05 1.65e-06 9.44e-03 691s
106 3.17365784e+05 2.54428448e+05 4.07e-05 2.02e-06 8.74e-03 693s
107 3.16596051e+05 2.54819099e+05 3.84e-05 1.99e-06 8.58e-03 695s
108 3.16141435e+05 2.55931523e+05 3.63e-05 1.94e-06 8.36e-03 697s
109 3.15273521e+05 2.56603196e+05 3.39e-05 1.98e-06 8.15e-03 699s
110 3.14664191e+05 2.59615552e+05 3.16e-05 2.07e-06 7.64e-03 700s
111 3.13755180e+05 2.63135019e+05 2.91e-05 2.63e-06 7.03e-03 702s
112 3.12752688e+05 2.66824480e+05 2.58e-05 2.84e-06 6.38e-03 704s
113 3.12452008e+05 2.67268815e+05 2.44e-05 2.82e-06 6.27e-03 706s
114 3.11875345e+05 2.69229572e+05 2.29e-05 2.89e-06 5.92e-03 708s
115 3.11534815e+05 2.70767439e+05 2.19e-05 3.58e-06 5.66e-03 710s
116 3.11105076e+05 2.73969650e+05 2.07e-05 5.44e-06 5.16e-03 712s
117 3.10709232e+05 2.77882279e+05 1.96e-05 5.69e-06 4.56e-03 714s
118 3.10598998e+05 2.78350559e+05 1.92e-05 5.82e-06 4.48e-03 715s
119 3.09839043e+05 2.81968572e+05 1.69e-05 7.68e-06 3.87e-03 718s
120 3.09376779e+05 2.83830951e+05 1.57e-05 7.32e-06 3.55e-03 720s
121 3.09223373e+05 2.85799510e+05 1.53e-05 1.00e-05 3.25e-03 722s
122 3.08874437e+05 2.86234584e+05 1.45e-05 1.03e-05 3.14e-03 723s
123 3.08823103e+05 2.86988843e+05 1.43e-05 9.03e-06 3.03e-03 725s
124 3.08403270e+05 2.88267463e+05 1.33e-05 8.43e-06 2.80e-03 728s
125 3.07863520e+05 2.89523916e+05 1.19e-05 6.27e-06 2.55e-03 730s
126 3.07695351e+05 2.90232225e+05 1.15e-05 6.34e-06 2.42e-03 732s
127 3.07518410e+05 2.90963317e+05 1.10e-05 6.91e-06 2.30e-03 733s
128 3.06921583e+05 2.93089381e+05 9.65e-06 7.53e-06 1.92e-03 735s
129 3.06407180e+05 2.94518565e+05 8.50e-06 6.54e-06 1.65e-03 737s
130 3.06068617e+05 2.95556228e+05 7.78e-06 6.06e-06 1.46e-03 739s
131 3.05894626e+05 2.95588622e+05 7.40e-06 6.03e-06 1.43e-03 741s
132 3.05679037e+05 2.96189601e+05 6.98e-06 5.59e-06 1.32e-03 743s
133 3.05539703e+05 2.96522032e+05 6.69e-06 5.75e-06 1.25e-03 745s
134 3.05343759e+05 2.96686924e+05 6.28e-06 5.62e-06 1.20e-03 746s
135 3.05175550e+05 2.97537734e+05 5.92e-06 6.61e-06 1.06e-03 748s
136 3.04946147e+05 2.97602273e+05 5.42e-06 6.56e-06 1.02e-03 749s
137 3.04860546e+05 2.97770432e+05 5.24e-06 6.44e-06 9.84e-04 751s
138 3.04780373e+05 2.98154594e+05 5.08e-06 6.59e-06 9.20e-04 753s
139 3.04539486e+05 2.98404144e+05 4.63e-06 6.01e-06 8.52e-04 755s
140 3.04338070e+05 2.98527011e+05 4.22e-06 5.51e-06 8.07e-04 757s
141 3.04095139e+05 2.99154955e+05 3.74e-06 4.59e-06 6.86e-04 759s
142 3.03945029e+05 2.99237103e+05 3.45e-06 4.33e-06 6.54e-04 761s
143 3.03754444e+05 2.99472025e+05 3.09e-06 3.98e-06 5.95e-04 763s
144 3.03634616e+05 2.99801097e+05 2.87e-06 3.46e-06 5.32e-04 765s
145 3.03485870e+05 3.00199071e+05 2.59e-06 3.38e-06 4.56e-04 767s
146 3.03290682e+05 3.00393997e+05 2.24e-06 3.70e-06 4.02e-04 769s
147 3.03142685e+05 3.00485291e+05 1.97e-06 3.50e-06 3.69e-04 771s
148 3.03086907e+05 3.00534709e+05 1.87e-06 3.39e-06 3.54e-04 773s
149 3.02968646e+05 3.00705917e+05 1.66e-06 3.04e-06 3.14e-04 775s
150 3.02776236e+05 3.00872874e+05 1.32e-06 2.79e-06 2.64e-04 777s
151 3.02715430e+05 3.01078544e+05 1.22e-06 2.28e-06 2.27e-04 779s
152 3.02623486e+05 3.01237664e+05 1.06e-06 1.87e-06 1.92e-04 781s
153 3.02558089e+05 3.01355929e+05 9.54e-07 1.57e-06 1.67e-04 783s
154 3.02495564e+05 3.01446156e+05 8.53e-07 1.34e-06 1.46e-04 786s
155 3.02430065e+05 3.01568806e+05 7.44e-07 1.01e-06 1.20e-04 788s
156 3.02402777e+05 3.01652040e+05 7.01e-07 9.09e-07 1.04e-04 791s
157 3.02320969e+05 3.01697944e+05 5.92e-07 7.78e-07 8.65e-05 794s
158 3.02300443e+05 3.01722268e+05 5.57e-07 7.12e-07 8.03e-05 797s
159 3.02285636e+05 3.01749518e+05 5.62e-07 6.36e-07 7.44e-05 800s
160 3.02249907e+05 3.01763550e+05 5.39e-07 5.99e-07 6.75e-05 803s
161 3.02224356e+05 3.01783239e+05 5.06e-07 5.47e-07 6.12e-05 807s
162 3.02209334e+05 3.01796703e+05 4.85e-07 5.12e-07 5.73e-05 811s
163 3.02199850e+05 3.01806421e+05 4.64e-07 4.87e-07 5.46e-05 813s
164 3.02179658e+05 3.01824306e+05 4.46e-07 4.47e-07 4.93e-05 817s
165 3.02176515e+05 3.01840050e+05 4.40e-07 4.05e-07 4.67e-05 820s
166 3.02170663e+05 3.01841493e+05 4.28e-07 4.01e-07 4.57e-05 824s
167 3.02155647e+05 3.01866814e+05 4.01e-07 3.23e-07 4.01e-05 829s
168 3.02134898e+05 3.01883933e+05 5.04e-07 2.74e-07 3.48e-05 831s
169 3.02129728e+05 3.01887308e+05 5.29e-07 2.65e-07 3.37e-05 835s
170 3.02121379e+05 3.01891042e+05 5.72e-07 2.55e-07 3.20e-05 838s
171 3.02114276e+05 3.01894402e+05 5.89e-07 2.46e-07 3.05e-05 841s
172 3.02109674e+05 3.01897493e+05 6.06e-07 2.36e-07 2.95e-05 844s
173 3.02092219e+05 3.01908549e+05 6.72e-07 2.00e-07 2.55e-05 847s
174 3.02079398e+05 3.01919387e+05 7.07e-07 1.65e-07 2.22e-05 850s
175 3.02068389e+05 3.01930868e+05 6.93e-07 1.38e-07 1.91e-05 853s
176 3.02059428e+05 3.01936551e+05 6.87e-07 1.22e-07 1.71e-05 856s
177 3.02055513e+05 3.01937680e+05 6.77e-07 1.19e-07 1.64e-05 859s
178 3.02050014e+05 3.01948170e+05 6.64e-07 9.81e-08 1.41e-05 863s
179 3.02043755e+05 3.01950714e+05 6.34e-07 9.19e-08 1.29e-05 867s
180 3.02038630e+05 3.01953641e+05 6.13e-07 8.56e-08 1.18e-05 872s
181 3.02033856e+05 3.01955829e+05 5.85e-07 8.02e-08 1.08e-05 876s
182 3.02030275e+05 3.01957754e+05 5.53e-07 7.54e-08 1.01e-05 881s
183 3.02029809e+05 3.01960469e+05 5.49e-07 6.87e-08 9.63e-06 885s
184 3.02027473e+05 3.01963305e+05 5.29e-07 6.16e-08 8.91e-06 891s
185 3.02023704e+05 3.01965491e+05 5.01e-07 5.62e-08 8.08e-06 895s
186 3.02020511e+05 3.01967444e+05 4.82e-07 5.14e-08 7.37e-06 900s
187 3.02018712e+05 3.01969090e+05 4.69e-07 4.73e-08 6.89e-06 905s
188 3.02016526e+05 3.01969385e+05 4.49e-07 4.65e-08 6.55e-06 909s
189 3.02013785e+05 3.01970948e+05 4.29e-07 4.26e-08 5.95e-06 914s
190 3.02011379e+05 3.01972285e+05 4.00e-07 3.93e-08 5.43e-06 918s
191 3.02010412e+05 3.01972836e+05 3.89e-07 3.79e-08 5.22e-06 923s
192 3.02008031e+05 3.01974237e+05 3.61e-07 3.45e-08 4.69e-06 927s
193 3.02007096e+05 3.01975799e+05 3.48e-07 3.06e-08 4.35e-06 931s
194 3.02005980e+05 3.01976949e+05 3.33e-07 2.78e-08 4.03e-06 936s
195 3.02004407e+05 3.01977440e+05 3.11e-07 2.65e-08 3.74e-06 940s
196 3.02002600e+05 3.01978497e+05 2.85e-07 2.39e-08 3.35e-06 944s
197 3.01999649e+05 3.01980115e+05 2.42e-07 1.98e-08 2.71e-06 948s
198 3.01998694e+05 3.01982396e+05 2.25e-07 1.41e-08 2.26e-06 953s
199 3.01996743e+05 3.01983821e+05 1.87e-07 1.05e-08 1.79e-06 957s
200 3.01996289e+05 3.01984374e+05 1.77e-07 9.12e-09 1.65e-06 962s
201 3.01994643e+05 3.01984860e+05 1.44e-07 7.93e-09 1.36e-06 967s
202 3.01994050e+05 3.01985706e+05 1.33e-07 5.87e-09 1.16e-06 972s
203 3.01992760e+05 3.01986414e+05 1.10e-07 4.14e-09 8.81e-07 977s
204 3.01992119e+05 3.01986830e+05 1.22e-07 3.13e-09 7.34e-07 983s
205 3.01991514e+05 3.01986988e+05 1.14e-07 2.70e-09 6.28e-07 988s
206 3.01991094e+05 3.01987090e+05 1.06e-07 2.45e-09 5.56e-07 994s
207 3.01990821e+05 3.01987271e+05 9.52e-08 2.02e-09 4.93e-07 1000s
208 3.01990228e+05 3.01987373e+05 9.34e-08 1.76e-09 3.96e-07 1005s
209 3.01989365e+05 3.01987529e+05 1.13e-07 1.38e-09 2.55e-07 1010s
210 3.01988779e+05 3.01987773e+05 1.28e-07 7.97e-10 1.40e-07 1016s
211 3.01988585e+05 3.01987908e+05 1.29e-07 4.98e-10 9.40e-08 1021s
212 3.01988345e+05 3.01988024e+05 1.15e-07 2.30e-10 4.45e-08 1025s
213 3.01988287e+05 3.01988088e+05 8.19e-08 7.07e-09 2.77e-08 1028s
214 3.01988225e+05 3.01988101e+05 7.55e-08 2.85e-08 1.72e-08 1030s
215 3.01988215e+05 3.01988104e+05 6.74e-08 2.27e-08 1.55e-08 1032s
216 3.01988191e+05 3.01988111e+05 6.45e-08 9.04e-08 1.11e-08 1035s
217 3.01988180e+05 3.01988116e+05 6.85e-08 7.20e-08 8.95e-09 1036s
218 3.01988180e+05 3.01988116e+05 9.85e-08 7.41e-08 8.84e-09 1038s
219 3.01988168e+05 3.01988123e+05 7.33e-08 1.12e-07 6.22e-09 1040s
220 3.01988159e+05 3.01988124e+05 7.40e-08 1.11e-07 4.84e-09 1042s
221 3.01988152e+05 3.01988127e+05 7.56e-08 7.99e-08 3.42e-09 1044s
222 3.01988152e+05 3.01988128e+05 7.57e-08 7.83e-08 3.26e-09 1045s
223 3.01988149e+05 3.01988129e+05 7.78e-08 6.21e-08 2.91e-09 1047s
224 3.01988148e+05 3.01988130e+05 1.12e-07 6.05e-08 2.55e-09 1049s
225 3.01988147e+05 3.01988130e+05 1.06e-07 5.02e-08 2.39e-09 1051s
226 3.01988145e+05 3.01988131e+05 8.37e-08 4.50e-08 1.95e-09 1052s
227 3.01988144e+05 3.01988131e+05 8.41e-08 4.98e-08 1.72e-09 1054s
228 3.01988142e+05 3.01988131e+05 1.03e-07 4.25e-08 1.41e-09 1056s
229 3.01988142e+05 3.01988133e+05 1.02e-07 3.40e-08 1.24e-09 1057s
230 3.01988140e+05 3.01988133e+05 9.35e-08 2.02e-08 8.60e-10 1059s
231 3.01988138e+05 3.01988134e+05 9.54e-08 3.24e-08 6.43e-10 1060s
232 3.01988138e+05 3.01988134e+05 9.84e-08 8.21e-08 5.59e-10 1062s
233 3.01988137e+05 3.01988134e+05 9.97e-08 8.34e-08 4.44e-10 1064s
234 3.01988136e+05 3.01988134e+05 9.12e-08 9.62e-08 3.01e-10 1065s
235 3.01988136e+05 3.01988134e+05 9.41e-08 8.92e-08 2.40e-10 1067s
236 3.01988135e+05 3.01988135e+05 8.19e-08 5.05e-07 1.31e-10 1069s
237 3.01988135e+05 3.01988135e+05 8.19e-08 4.85e-06 1.31e-10 1070s
238 3.01988135e+05 3.01988135e+05 7.49e-08 4.84e-06 1.28e-10 1071s
239 3.01988135e+05 3.01988135e+05 7.50e-08 4.16e-06 1.25e-10 1073s
240 3.01988135e+05 3.01988135e+05 5.37e-08 2.00e-06 5.71e-11 1076s
241 3.01988135e+05 3.01988135e+05 1.57e-07 1.34e-06 4.12e-11 1078s
242 3.01988135e+05 3.01988135e+05 1.47e-07 3.07e-07 2.10e-11 1081s
243 3.01988135e+05 3.01988135e+05 1.71e-07 2.77e-07 1.99e-11 1083s
244 3.01988135e+05 3.01988135e+05 1.74e-07 2.61e-07 1.96e-11 1085s
245 3.01988135e+05 3.01988135e+05 2.14e-07 1.13e-07 1.13e-11 1087s
246 3.01988135e+05 3.01988135e+05 1.82e-07 8.78e-08 9.15e-12 1089s
247 3.01988135e+05 3.01988135e+05 1.82e-07 8.78e-08 9.15e-12 1091s
248 3.01988135e+05 3.01988135e+05 2.33e-07 8.44e-08 7.99e-12 1093s
249 3.01988135e+05 3.01988135e+05 2.33e-07 2.25e-06 7.99e-12 1095s
250 3.01988135e+05 3.01988135e+05 2.14e-07 1.86e-06 7.30e-12 1096s
251 3.01988135e+05 3.01988135e+05 1.74e-07 1.04e-06 4.86e-12 1098s
252 3.01988135e+05 3.01988135e+05 1.53e-07 9.94e-07 4.28e-12 1100sBarrier solved model in 252 iterations and 1100.27 seconds (2022.18 work units)
Optimal objective 3.01988135e+05
Root crossover log...500597 DPushes remaining with DInf 1.9787977e-04 1102s
115584 DPushes remaining with DInf 0.0000000e+00 1105s
82937 DPushes remaining with DInf 0.0000000e+00 1110s
37146 DPushes remaining with DInf 0.0000000e+00 1115s
0 DPushes remaining with DInf 0.0000000e+00 1119s192478 PPushes remaining with PInf 5.0130692e-04 1119s
51828 PPushes remaining with PInf 3.1834271e-04 1120s
0 PPushes remaining with PInf 6.5034935e-02 1124sPush phase complete: Pinf 6.5034935e-02, Dinf 6.5551688e-03 1124s
Root simplex log...Iteration Objective Primal Inf. Dual Inf. Time
552808 3.0198813e+05 0.000000e+00 6.555169e-03 1125s
553266 3.0198813e+05 0.000000e+00 0.000000e+00 1127s
553360 3.0198813e+05 0.000000e+00 0.000000e+00 1128s
553400 3.0198813e+05 0.000000e+00 0.000000e+00 1130s
Extra simplex iterations after uncrush: 40Use crossover to convert LP symmetric solution to basic solution...
Root crossover log...
311639 DPushes remaining with DInf 6.5705232e-06 1133s
1604 DPushes remaining with DInf 6.5705232e-06 1135s
0 DPushes remaining with DInf 6.5705232e-06 1136s68126 PPushes remaining with PInf 6.9354417e-05 1136s
0 PPushes remaining with PInf 1.7193987e-01 1139sPush phase complete: Pinf 1.7193987e-01, Dinf 6.7615139e-01 1139s
Root simplex log...Iteration Objective Primal Inf. Dual Inf. Time
929055 3.0198813e+05 0.000000e+00 6.761514e-01 1140s
929272 3.0198813e+05 0.000000e+00 0.000000e+00 1142s
929312 3.0198813e+05 0.000000e+00 0.000000e+00 1145s
Extra simplex iterations after uncrush: 40Root relaxation: objective 3.019881e+05, 929312 iterations, 649.00 seconds (824.73 work units)
Total elapsed time = 1146.50s
Total elapsed time = 1159.62s
Total elapsed time = 1167.77s
Total elapsed time = 1175.85s
Total elapsed time = 1182.80sNodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time0 0 301988.135 0 2381 - 301988.135 - - 1187s
H 0 0 302234.98028 301988.135 0.08% - 1288sExplored 1 nodes (950325 simplex iterations) in 1293.83 seconds (2418.52 work units)
Thread count was 8 (of 64 available processors)Solution count 1: 302235
Optimal solution found (tolerance 1.00e-02)
Warning: max constraint violation (7.6981e-06) exceeds tolerance
Warning: max bound violation (2.8333e-06) exceeds tolerance
Best objective 3.022349802753e+05, best bound 3.019881345721e+05, gap 0.0817%0 -
Is Gurobi solving the LP during the root node? If so, could this be an option for parameter tuning? I know that simplex is the default node method because of warm start but in my case it seems barrier is much faster and I seemingly don't need branching.
Yes, Gurobi solves LPs during the root node. Usually, the LPs are way smaller than the root node LP. You could try setting Method=2, Crossover=0, and NodeMethod=2.
You could also try improving the scaling if possible.
Experimenting with Aggregate=2 and the PreSparsify parameter might be useful.
You could also try using more than 8 Threads if your license allows you to do so.0
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