MIP stopped for a long time in one iteration
AnsweredHi,
I am solving an MIP model for a facility layout problem. I found it strange that the model takes very long at the iteration at 1010 seconds. That iteration took almost 8000 seconds, while most of the other iterations took less than 20 seconds. Below is the log. May I know if I should reformulate my model to solve this problem, or I should change some parameters? Thank you in advance!
Gurobi Optimizer version 11.0.2 build v11.0.2rc0 (win64 - Windows Server 2019.0 (17763.2))
CPU model: AMD EPYC-Rome Processor, instruction set [SSE2|AVX|AVX2]
Thread count: 2 physical cores, 60 logical processors, using up to 6 threadsOptimize a model with 31928 rows, 9555 columns and 141527 nonzeros
Model fingerprint: 0xe29b310d
Model has 6861 general constraints
Variable types: 2213 continuous, 7342 integer (7342 binary)
Coefficient statistics:
Matrix range [1e+00, 6e+04]
Objective range [4e-05, 2e-02]
Bounds range [1e+00, 1e+00]
RHS range [1e+00, 1e+07]
GenCon rhs range [1e+01, 5e+01]
GenCon coe range [1e+00, 1e+00]
Using branch priorities.
Presolve added 4546 rows and 77 columns
Presolve time: 0.58s
Presolved: 36474 rows, 9632 columns, 164798 nonzeros
Variable types: 2297 continuous, 7335 integer (7335 binary)Root relaxation: objective 4.459022e+01, 8130 iterations, 0.27 seconds (0.23 work units)
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time0 0 44.59022 0 363 - 44.59022 - - 2s
0 0 45.38574 0 574 - 45.38574 - - 4s
0 0 45.58274 0 496 - 45.58274 - - 5s
0 0 46.71185 0 637 - 46.71185 - - 7s
0 0 46.82233 0 721 - 46.82233 - - 8s
0 0 46.83417 0 725 - 46.83417 - - 8s
0 0 46.83417 0 745 - 46.83417 - - 9s
0 0 47.06229 0 715 - 47.06229 - - 10s
0 0 47.21860 0 679 - 47.21860 - - 11s
0 0 47.21892 0 690 - 47.21892 - - 12s
0 0 47.79721 0 645 - 47.79721 - - 13s
0 0 47.80729 0 623 - 47.80729 - - 14s
0 0 47.80729 0 625 - 47.80729 - - 14s
0 0 47.80729 0 625 - 47.80729 - - 15s
0 0 47.80731 0 523 - 47.80731 - - 16s
0 0 47.80731 0 731 - 47.80731 - - 18s
0 0 47.80731 0 660 - 47.80731 - - 19s
0 0 47.80731 0 685 - 47.80731 - - 19s
0 0 47.80731 0 717 - 47.80731 - - 20s
0 0 47.80731 0 468 - 47.80731 - - 22s
0 0 47.80731 0 445 - 47.80731 - - 22s
0 0 47.80731 0 471 - 47.80731 - - 24s
0 0 47.80898 0 480 - 47.80898 - - 25s
0 0 47.80898 0 452 - 47.80898 - - 29s
0 0 47.80898 0 445 - 47.80898 - - 30s
0 2 47.80898 0 445 - 47.80898 - - 35s
84 95 48.64649 14 573 - 47.80898 - 654 40s
343 385 56.06274 37 570 - 47.80898 - 285 45s
677 736 58.28371 70 542 - 47.80898 - 217 50s
1259 1278 51.99546 93 519 - 47.80898 - 157 55s
1816 1744 47.80898 25 445 - 47.80898 - 145 61s
1818 1745 48.79506 34 376 - 47.80898 - 145 66s
1819 1746 59.97921 68 461 - 47.80898 - 144 76s
1820 1747 52.31931 9 530 - 48.44027 - 144 81s
1821 1747 48.99029 34 463 - 48.80530 - 144 89s
1822 1748 48.88544 11 598 - 48.88544 - 144 94s
1823 1749 48.92297 32 379 - 48.92297 - 144 102s
1824 1749 48.92691 63 453 - 48.92691 - 144 105s
1825 1750 49.99323 66 353 - 48.96102 - 144 110s
1827 1751 55.87670 155 371 - 48.98265 - 144 117s
1829 1753 48.99864 39 355 - 48.99864 - 144 124s
1830 1753 49.00715 58 460 - 49.00715 - 144 126s
1831 1754 49.03583 16 419 - 49.03583 - 143 130s
1833 1755 50.08746 97 464 - 49.06690 - 143 141s
1835 1757 49.08606 18 517 - 49.08606 - 143 148s
1836 1757 59.97120 87 611 - 49.09100 - 143 150s
1837 1758 57.66908 102 442 - 49.10549 - 143 156s
1839 1759 49.14044 28 606 - 49.14044 - 143 164s
1840 1760 58.96956 194 774 - 49.14981 - 143 167s
1841 1761 60.09338 71 672 - 49.14981 - 143 171s
1842 1761 49.14981 65 751 - 49.14981 - 143 175s
1844 1763 58.76770 35 756 - 49.17538 - 142 182s
1846 1764 58.62066 73 755 - 49.19727 - 142 185s
1848 1765 50.51022 64 691 - 49.22162 - 142 191s
1850 1767 64.87105 130 659 - 49.23665 - 142 197s
1852 1768 69.74104 151 707 - 49.24135 - 142 203s
1853 1769 55.28304 24 630 - 49.24135 - 142 205s
1854 1769 49.24135 68 763 - 49.24135 - 142 210s
1856 1771 64.75550 139 778 - 49.24135 - 142 218s
1857 1771 49.24135 41 631 - 49.24135 - 141 221s
1862 1776 50.17293 92 445 - 49.24135 - 242 226s
1864 1777 52.10136 109 352 - 49.24135 - 242 235s
1865 1778 50.58515 85 452 - 49.24135 - 241 244s
1866 1779 58.95528 80 706 - 49.24135 - 241 249s
1867 1779 49.39814 13 485 - 49.39814 - 241 259s
1868 1780 58.76770 35 519 - 49.39814 - 241 262s
1869 1781 54.39987 156 601 - 49.39814 - 241 268s
1870 1781 59.10604 52 577 - 49.39814 - 241 272s
1871 1782 61.30439 84 520 - 49.39814 - 241 277s
1872 1783 51.34670 52 703 - 49.39814 - 241 282s
1873 1783 49.39814 37 488 - 49.39814 - 240 287s
1874 1784 51.12697 78 626 - 49.39814 - 240 290s
1876 1785 59.26292 41 610 - 49.39814 - 240 295s
1878 1787 55.68932 32 623 - 49.39814 - 240 301s
1879 1787 56.62192 179 544 - 49.39814 - 240 306s
1880 1788 59.99513 66 687 - 49.39814 - 240 310s
1881 1789 49.39814 52 524 - 49.39814 - 239 316s
1883 1790 59.47278 16 596 - 49.39814 - 239 323s
1884 1791 49.39814 28 714 - 49.39814 - 239 325s
1885 1791 54.20063 135 587 - 49.39814 - 239 330s
1887 1793 49.74458 78 600 - 49.39814 - 239 336s
1889 1794 49.39814 22 635 - 49.39814 - 238 343s
1890 1795 51.35958 85 702 - 49.39814 - 238 345s
1893 1797 49.39814 46 598 - 49.39814 - 238 352s
1895 1798 54.51522 171 624 - 49.39814 - 238 356s
1898 1800 49.57840 45 738 - 49.57840 - 237 360s
1901 1802 49.58163 54 643 - 49.58163 - 237 366s
1904 1804 58.56420 8 664 - 49.58163 - 237 371s
1907 1806 49.58764 35 600 - 49.58764 - 236 376s
1912 1810 50.82274 60 341 - 49.58764 - 317 388s
1913 1811 49.58764 47 440 - 49.58764 - 317 396s
1914 1812 52.98207 99 650 - 49.58764 - 317 405s
1915 1812 58.56420 15 451 - 49.58764 - 317 411s
1916 1813 49.58764 25 506 - 49.58764 - 316 416s
1917 1814 67.55151 165 521 - 49.58764 - 316 424s
1918 1814 49.58764 34 625 - 49.58764 - 316 433s
1919 1815 59.97921 68 513 - 49.58764 - 316 442s
1920 1816 52.31931 9 647 - 49.58764 - 316 450s
1921 1816 49.58764 34 563 - 49.58764 - 316 458s
1922 1817 49.58764 11 676 - 49.58764 - 315 468s
1923 1818 49.58764 32 627 - 49.58764 - 315 477s
1924 1818 49.58764 63 714 - 49.58764 - 315 485s
1925 1819 49.99323 66 685 - 49.58764 - 315 495s
1926 1820 53.09041 105 663 - 49.58764 - 315 503s
1927 1820 55.87670 155 548 - 49.58764 - 315 513s
1928 1821 55.51207 177 662 - 49.58764 - 314 519s
1929 1822 49.58764 39 700 - 49.58764 - 314 524s
1930 1822 49.58764 58 637 - 49.58764 - 314 530s
1931 1823 49.58764 16 687 - 49.58764 - 314 535s
1933 1824 50.08746 97 719 - 49.58764 - 314 544s
1934 1825 54.17695 135 673 - 49.58764 - 314 548s
1935 1826 49.58764 18 659 - 49.58764 - 313 550s
1939 1828 49.58764 28 663 - 49.58764 - 313 555s
1943 1831 50.20527 72 713 - 49.58764 - 312 561s
1947 1834 51.54902 88 745 - 49.58764 - 311 566s
1950 1836 64.87105 130 736 - 49.58764 - 311 570s
1953 1838 55.28304 24 752 - 49.58764 - 310 576s
1956 1845 49.58764 43 810 - 49.58764 - 245 580s
1978 1861 49.68903 46 641 - 49.68903 - 251 588s
1990 1869 49.68903 47 614 - 49.68903 - 252 590s
2070 1928 49.68904 55 617 - 49.68903 - 259 595s
2171 2008 49.75449 63 607 - 49.68903 - 253 600s
2299 2102 49.74013 71 578 - 49.68903 - 245 605s
2437 2191 50.09625 80 572 - 49.68903 - 236 610s
2467 2198 50.09625 82 577 - 49.68903 - 235 615s
2611 2319 50.58021 90 594 - 49.68903 - 227 621s
2756 2420 50.70809 98 604 - 49.68903 - 220 625s
2927 2537 51.85791 111 572 - 49.68903 - 212 630s
3256 2758 52.77372 129 650 - 49.68903 - 199 636s
3423 3095 53.37672 135 509 - 49.68903 - 195 641s
4051 3392 71.05185 152 617 - 49.68903 - 173 646s
4539 3332 49.77088 69 573 - 49.68903 - 160 658s
4561 3438 49.82421 72 542 - 49.68903 - 160 660s
4916 3782 51.23811 104 531 - 49.68903 - 158 666s
5394 3903 52.97649 132 428 - 49.68903 - 152 671s
5608 4028 54.88964 136 729 - 49.68903 - 156 676s
5859 4113 59.95174 140 418 - 49.68903 - 159 682s
5926 4184 64.03166 142 679 - 49.68903 - 160 685s
6300 4449 66.91614 148 417 - 49.68903 - 158 691s
6686 4653 49.99874 99 504 - 49.68903 - 156 698s
6855 4736 50.53383 127 534 - 49.68903 - 157 700s
7135 4866 54.12889 137 538 - 49.68903 - 160 708s
7254 5040 56.79693 141 525 - 49.68903 - 160 712s
7475 5328 57.27612 146 508 - 49.68903 - 161 716s
7913 5483 infeasible 153 - 49.68903 - 157 720s
8437 5971 50.12037 84 599 - 49.68903 - 155 727s
8628 6067 51.43963 123 564 - 49.68903 - 156 732s
8768 6195 51.66939 137 548 - 49.68903 - 158 737s
8900 6362 53.34923 145 516 - 49.68903 - 160 741s
9067 6465 80.21222 146 701 - 49.68903 - 163 746s
9174 6574 65.82076 154 504 - 49.68904 - 164 751s
9339 6909 49.71334 52 525 - 49.68904 - 164 757s
9724 6981 50.77645 109 545 - 49.68904 - 162 765s
9830 7325 51.21656 124 535 - 49.68904 - 161 772s
10196 7768 57.76476 136 493 - 49.68922 - 159 777s
10676 8202 50.03681 73 571 - 49.68922 - 158 784s
11146 8532 55.62498 131 551 - 49.68922 - 158 790s
11502 8741 infeasible 156 - 49.69316 - 160 796s
11781 9819 50.68673 78 572 - 49.71334 - 161 806s
13073 10569 infeasible 149 - 49.71334 - 155 823s
13907 11979 56.23002 135 531 - 49.71334 - 154 837s
15540 12820 50.68755 130 581 - 49.71334 - 147 845s
16598 13762 66.98316 164 461 - 49.71334 - 144 855s
17712 14088 53.65430 129 533 - 49.71334 - 140 865s
18062 14416 61.74278 146 489 - 49.71334 - 141 880s
18431 15410 infeasible 162 - 49.71334 - 141 892s
19748 15795 52.31407 100 581 - 49.71334 - 137 901s
20187 16421 59.62810 144 577 - 49.71334 - 137 910s
20901 16620 49.71659 54 579 - 49.71334 - 138 919s
21201 17528 50.16832 80 529 - 49.71334 - 138 927s
22167 17826 64.02500 131 455 - 49.71334 - 137 936s
22507 18697 68.58940 139 437 - 49.71334 - 139 946s
23476 19074 59.56112 138 446 - 49.71334 - 139 958s
23917 19379 74.73226 158 466 - 49.71334 - 140 966s
24316 20318 51.52089 81 589 - 49.71334 - 141 977s
25326 20405 infeasible 155 - 49.71334 - 140 999s
25433 20716 51.03786 94 504 - 49.71334 - 141 1010s
25840 21730 52.41323 134 439 - 49.71334 - 142 8879s
26990 22634 49.92831 78 563 - 49.71334 - 140 8893s
28022 23002 infeasible 151 - 49.71334 - 141 8906s
28434 23757 49.75085 61 612 - 49.71334 - 141 8918s
29303 24784 61.26809 137 512 - 49.71334 - 142 8933s
30521 25154 51.52066 129 529 - 49.71334 - 141 8945s
30915 26192 63.81563 139 484 - 49.71334 - 143 8960s
32158 26566 52.58776 136 522 - 49.71334 - 142 8971s
32558 27597 71.23477 148 415 - 49.71334 - 143 8986s
33795 28417 53.21269 139 777 - 49.71334 - 142 8999s
34782 28835 54.57928 132 829 - 49.71334 - 143 9011s
35270 29367 50.08026 83 548 - 49.71334 - 144 9050s
H35781 29367 2697.0763437 49.71334 98.2% 143 9050s
35826 29775 infeasible 145 2697.07634 49.71334 98.2% 143 9067s
H35828 29775 151.8538621 49.71334 67.3% 143 9067s
H36096 29642 132.4912835 49.71334 62.5% 143 9067s
36348 30916 51.79584 111 499 132.49128 49.71334 62.5% 143 9086s
H37834 32078 128.1275757 49.71334 61.2% 141 9106s
H38828 32078 128.1173224 49.71334 61.2% 140 9107s
H39236 32892 126.9689490 49.71334 60.8% 139 9126s
H39610 32885 125.5705596 49.71357 60.4% 139 9127s
H40229 33773 121.7516404 49.71357 59.2% 139 9151s
H40229 33725 119.5184458 49.71357 58.4% 139 9151s
H40396 33414 115.5093358 49.71357 57.0% 139 9151s
H41372 33120 112.1495252 49.71357 55.7% 139 9184s
H41372 32998 110.9688489 49.71357 55.2% 139 9184s
H41438 32776 107.6372573 49.71357 53.8% 139 9184s
41461 33129 55.67794 134 541 107.63726 49.71357 53.8% 139 9201s
H41487 32943 103.7331325 49.71357 52.1% 139 9201s
H41487 32897 102.8221064 49.71357 51.7% 139 9201s
H41560 32867 102.3310282 49.71357 51.4% 139 9201s
H41712 32817 101.4179645 49.71357 51.0% 139 9201s
H41774 32746 99.8251154 49.71357 50.2% 139 9201s
H41938 33673 94.7697311 49.71357 47.5% 139 9228s
H43467 34376 94.0213430 49.71357 47.1% 138 9256s
H43467 34315 93.3015301 49.71357 46.7% 138 9256s
H43467 33964 87.3937114 49.71357 43.1% 138 9256s
H43807 33959 87.2493054 49.71357 43.0% 138 9256s
H44439 34057 83.7290255 49.71357 40.6% 137 9276s
H45048 34001 83.3458136 49.71357 40.4% 138 9276s
H45141 34695 83.2543715 49.71357 40.3% 138 9302s
H45141 34635 82.4544198 49.71357 39.7% 138 9302s
H45252 34631 82.3782772 49.71357 39.7% 138 9302s
H45975 35036 82.1505211 49.71357 39.5% 138 9330s
H46368 35015 81.8831390 49.71357 39.3% 137 9330s
H46426 35057 80.8412977 49.71357 38.5% 137 9361s
H46680 35458 80.7860973 49.71357 38.5% 138 9403s
H46836 35447 80.7322977 49.71357 38.4% 138 9403s
H47072 35355 80.3524955 49.71357 38.1% 138 9403s
H47194 35952 80.3166205 49.71357 38.1% 138 9439s
H47824 35932 80.2434955 49.71357 38.0% 138 9439s
H47977 36387 80.0650810 49.71357 37.9% 138 9468s
H48260 36385 80.0513968 49.71357 37.9% 138 9468s
H48569 36725 80.0509758 49.71357 37.9% 138 9505s
H48592 36718 80.0303881 49.71357 37.9% 138 9505s
H49080 37559 79.8943574 49.71357 37.8% 137 9540s
H50121 38180 79.8646552 49.71367 37.8% 137 9571s
50831 38983 51.12168 88 587 79.86466 49.71367 37.8% 137 9603s
H51847 39913 79.8310517 49.71367 37.7% 136 9641s
H52442 39900 79.7487012 49.71368 37.7% 136 9642s
H52982 40129 79.7150977 49.71368 37.6% 136 9672s
H53218 40127 79.6843613 49.71368 37.6% 136 9672s
H53296 40573 79.6733438 49.71368 37.6% 136 9710s
H53296 40553 79.5926701 49.71368 37.5% 136 9710s
H53901 41247 79.5014701 49.71368 37.5% 136 9748s
H54579 41224 79.4119201 49.71368 37.4% 136 9748s
H54746 42067 79.3904043 49.71368 37.4% 136 9786s
55826 42991 50.73458 83 579 79.39040 49.71368 37.4% 136 9828s
H56576 42991 79.3900534 49.71368 37.4% 136 9829s
H56970 43456 79.1623506 49.71368 37.2% 136 9852s
57598 44333 53.38285 104 540 79.16235 49.71369 37.2% 136 9892s
58752 44696 51.32782 92 561 79.16235 49.71380 37.2% 136 9939s
59230 45408 50.13856 86 669 79.16235 49.71380 37.2% 136 9985s
60246 46334 50.37476 92 631 79.16235 49.71391 37.2% 136 10014s
H60772 46326 79.1417321 49.71391 37.2% 136 10014s
61275 47141 50.14110 61 616 79.14173 49.71391 37.2% 136 10047s
H61443 47127 79.0919778 49.71391 37.1% 136 10047s
H61767 47125 79.0834093 49.71391 37.1% 136 10047s
62192 48165 67.84884 144 485 79.08341 49.71391 37.1% 136 10082s
H62644 48165 79.0833328 49.71391 37.1% 136 10082s
H63502 48630 79.0745328 49.71391 37.1% 136 10126s
H64005 48619 79.0405670 49.71392 37.1% 136 10126s
64085 49404 51.06173 75 565 79.04057 49.71411 37.1% 136 10167s
H64242 49383 78.9579802 49.71411 37.0% 136 10167s
H64384 49366 78.9083262 49.71420 37.0% 136 10167s
H65039 49948 78.9038315 49.71455 37.0% 136 10217s
H65257 49941 78.8802315 49.71479 37.0% 136 10217s
H65608 49933 78.8632315 49.71479 37.0% 136 10217s
65754 50696 70.58822 141 614 78.86323 49.71526 37.0% 136 10252s
H65970 50687 78.8299262 49.71526 36.9% 136 10252s
66728 51527 61.55541 139 474 78.82993 49.71637 36.9% 136 10306s
H66908 51527 78.8271473 49.71637 36.9% 136 10306s
H67311 51521 78.8211262 49.71637 36.9% 136 10306s
67759 52605 50.12212 69 539 78.82113 49.71637 36.9% 136 10354s
H67958 52605 78.8200525 49.71637 36.9% 136 10354s
H68169 52603 78.8163789 49.71637 36.9% 136 10354s
H68729 52555 78.6352227 49.71637 36.8% 136 10354s
H68989 53201 78.5921148 49.71637 36.7% 136 10399s
H69776 53984 78.5561039 49.71637 36.7% 136 10451s
H70360 53918 78.3571411 49.71637 36.6% 136 10451s
70674 54517 61.73658 135 526 78.35714 49.71637 36.6% 136 10501s
H70737 54514 78.3551727 49.71637 36.5% 136 10501s
H71047 54504 78.3318681 49.71637 36.5% 136 10501s
71330 55542 75.13414 152 495 78.33187 49.71637 36.5% 136 10550s
H71729 55482 78.2228550 49.71637 36.4% 136 10550s
H72627 56325 78.2208865 49.71659 36.4% 136 10591s
73615 57020 66.74253 138 596 78.22089 49.71659 36.4% 136 10632s
H73720 56821 77.7703441 49.71659 36.1% 136 10632s
H74319 56758 77.6416908 49.71659 36.0% 136 10632s
74473 57238 cutoff 118 77.64169 49.71659 36.0% 136 10672s
75113 57819 infeasible 152 77.64169 49.71659 36.0% 136 10707s
H75355 57698 77.3527434 49.71659 35.7% 136 10707s
75827 58761 cutoff 162 77.35274 49.71659 35.7% 136 10745s
H76247 58750 77.3167325 49.71659 35.7% 136 10745s
H77129 59416 77.2894910 49.71659 35.7% 136 10816s
H77368 59383 77.2186763 49.71659 35.6% 136 10816s
H77841 60104 77.0765184 49.71659 35.5% 136 10868s
H78150 60100 77.0708184 49.71659 35.5% 136 10868s
H78593 60092 77.0512454 49.71659 35.5% 136 10868s
78927 60238 54.28238 105 549 77.05125 49.71659 35.5% 136 10923s
H79001 60020 76.7417261 49.71659 35.2% 136 10923s
H79141 60401 76.4828261 49.71659 35.0% 136 10975s
H79697 60745 76.4420261 49.71659 35.0% 135 11077s
80153 61579 infeasible 153 76.44203 49.71659 35.0% 135 11148s
81255 62395 50.97993 87 555 76.44203 49.71659 35.0% 135 11200s
82253 63417 54.68962 91 518 76.44203 49.71659 35.0% 136 11252s
83526 64464 50.48213 73 530 76.44203 49.71659 35.0% 135 11313s
H83755 64442 76.4063656 49.71659 34.9% 135 11313s
H84906 65334 76.4043971 49.71659 34.9% 135 11362s
85927 65752 56.09092 146 486 76.40440 49.71660 34.9% 135 11424s
H86221 65642 76.1775033 49.71660 34.7% 135 11424s
H86399 66854 76.1335033 49.71660 34.7% 135 11479s
87979 67420 51.24331 84 513 76.13350 49.71660 34.7% 135 11523s
H88424 67419 76.1328717 49.71660 34.7% 135 11523s
H88669 68345 76.1293980 49.71660 34.7% 135 11564s
H89370 68342 76.1204612 49.71660 34.7% 135 11564s
89749 68958 53.34426 100 558 76.12046 49.71660 34.7% 135 11640s
H90208 68957 76.1195173 49.71660 34.7% 135 11640s
H90487 70067 76.1083678 49.71660 34.7% 134 11688s
91898 70475 55.35521 140 556 76.10837 49.71660 34.7% 134 11736s
92413 70966 52.66622 86 580 76.10837 49.71660 34.7% 134 11774s
H92928 70963 76.0984581 49.71660 34.7% 134 11774s
93010 71689 62.08915 169 516 76.09846 49.71660 34.7% 134 11819s
H93507 71687 76.0917520 49.71660 34.7% 134 11819s
93986 72493 cutoff 130 76.09175 49.71660 34.7% 134 11858s
H94173 72493 76.0906664 49.71660 34.7% 134 11858s
94988 73366 51.33136 90 553 76.09067 49.71660 34.7% 134 11897s
96007 73406 63.51500 108 573 76.09067 49.71660 34.7% 134 11999s
96047 73805 63.93272 122 523 76.09067 49.71660 34.7% 134 12037s
96569 74572 53.32202 111 459 76.09067 49.71660 34.7% 134 12085s
97520 75433 55.26883 135 711 76.09067 49.71660 34.7% 134 12126s
98491 76328 cutoff 109 76.09067 49.71660 34.7% 134 12173s
99499 76719 60.51938 147 652 76.09067 49.71660 34.7% 134 12209s
H99934 76717 76.0889586 49.71660 34.7% 134 12209s
H100002 77591 76.0828796 49.71660 34.7% 134 12260s
101160 77961 52.58361 62 541 76.08288 49.71660 34.7% 134 12337s
101576 78890 58.36364 104 516 76.08288 49.71660 34.7% 134 12389s
102654 79364 55.03471 101 526 76.08288 49.71660 34.7% 133 12423s
103214 80416 56.36656 135 506 76.08288 49.71660 34.7% 133 12474s
104529 81131 57.20028 138 537 76.08288 49.71662 34.7% 133 12524s
105431 81860 59.89581 158 534 76.08288 49.71663 34.7% 133 12555s
106275 82565 56.20446 112 516 76.08288 49.71664 34.7% 133 12599s
107128 82948 58.75745 143 506 76.08288 49.71665 34.7% 133 12650s
107600 83748 54.79020 96 559 76.08288 49.71666 34.7% 133 12692s
108539 84492 52.92659 92 573 76.08288 49.71666 34.7% 133 12729s
108984 84492 57.07998 91 545 76.08288 49.71666 34.7% 133 12730s
109425 84867 74.07173 174 484 76.08288 49.71666 34.7% 133 12773s
109916 85744 56.28388 122 576 76.08288 49.71666 34.7% 133 12812s
111054 86267 50.82372 78 549 76.08288 49.71666 34.7% 133 12858s
111673 86790 51.11001 89 555 76.08288 49.71666 34.7% 133 12898s
112348 87656 51.93805 90 562 76.08288 49.71666 34.7% 133 12953s
113333 88089 52.91547 97 623 76.08288 49.71666 34.7% 133 13004s
113805 88146 62.05110 138 788 76.08288 49.71666 34.7% 133 13142s
113868 88823 infeasible 143 76.08288 49.71666 34.7% 133 13177s
114689 89363 52.24121 105 573 76.08288 49.71666 34.7% 133 13223s
115401 90399 54.18163 123 541 76.08288 49.71666 34.7% 133 13266s
116684 90947 51.68370 84 557 76.08288 49.71667 34.7% 133 13319s
117338 92414 52.31438 105 556 76.08288 49.71669 34.7% 133 13377s
119185 92782 50.88199 78 536 76.08288 49.71669 34.7% 133 13441s
119581 93630 65.92733 143 616 76.08288 49.71669 34.7% 133 13492s
120542 93911 76.07729 118 682 76.08288 49.71675 34.7% 133 13539s
H120757 93910 76.0796586 49.71675 34.7% 133 13539s
120794 93910 65.04471 128 709 76.07966 49.71675 34.7% 133 13540s
120875 94867 66.78371 168 553 76.07966 49.71675 34.7% 133 13610s
H121101 94867 76.0764375 49.71675 34.6% 133 13610s
122167 95350 67.93179 137 681 76.07644 49.71678 34.6% 133 13662s
122838 96074 54.69187 97 566 76.07644 49.71678 34.6% 133 13721s
123719 96932 59.83495 155 585 76.07644 49.71678 34.6% 133 13786s
124810 97269 52.28849 123 497 76.07644 49.71684 34.6% 133 13848s
125333 98060 50.77249 73 527 76.07644 49.71684 34.6% 133 13908s
126344 98909 61.34125 124 629 76.07644 49.71685 34.6% 133 13964s
127304 98909 53.30319 113 527 76.07644 49.71691 34.6% 133 13965s
127491 99683 56.08335 108 562 76.07644 49.71694 34.6% 133 14021s
128399 100204 54.53839 86 576 76.07644 49.71694 34.6% 133 14062s
129011 101013 55.27418 97 584 76.07644 49.71696 34.6% 133 14123s
129999 102010 56.49180 122 575 76.07644 49.71707 34.6% 133 14175s
131196 102411 62.66790 158 509 76.07644 49.71707 34.6% 133 14255s
131707 103203 66.39307 101 774 76.07644 49.71709 34.6% 133 14303s
132657 103763 50.13539 64 568 76.07644 49.71711 34.6% 133 14360s
133352 104428 57.33621 117 571 76.07644 49.71713 34.6% 133 14451s
H133962 104416 76.0528261 49.71714 34.6% 133 14451s
134288 105167 51.17928 98 537 76.05283 49.71715 34.6% 133 14533s
H134741 105130 75.9841605 49.71715 34.6% 133 14533s
135249 105865 51.41701 85 525 75.98416 49.71721 34.6% 133 14589s
136154 106559 58.61248 147 478 75.98416 49.71731 34.6% 133 14670s
137002 106834 53.36119 116 550 75.98416 49.71734 34.6% 133 14761s
137316 107683 67.10021 130 575 75.98416 49.71748 34.6% 133 14832s
138413 108596 51.98504 123 609 75.98416 49.71757 34.6% 133 14892s
139551 109010 56.63693 86 554 75.98416 49.71773 34.6% 133 14942s
140192 109871 51.30333 71 539 75.98416 49.71773 34.6% 133 15005s
H140396 109870 75.9836746 49.71773 34.6% 133 15005s
141283 110668 50.34892 76 605 75.98367 49.71776 34.6% 133 15069s
142279 111343 54.21488 132 554 75.98367 49.71781 34.6% 133 15145s
143062 111723 53.69454 92 594 75.98367 49.71791 34.6% 133 15216s
143486 113558 53.14591 107 555 75.98367 49.71791 34.6% 133 15320s
145855 114248 52.63978 100 549 75.98367 49.71810 34.6% 133 15373s
146691 115007 54.22792 102 529 75.98367 49.71834 34.6% 133 15424s
147690 115543 67.75457 154 509 75.98367 49.71861 34.6% 133 15476s
148374 116199 62.05804 155 529 75.98367 49.71882 34.6% 133 15547s
149085 116810 73.70618 151 577 75.98367 49.71882 34.6% 133 15613s
149923 117444 50.25365 69 603 75.98367 49.71939 34.6% 133 15652s
150610 118123 60.43294 144 541 75.98367 49.71944 34.6% 133 15720s
151413 118953 56.20117 123 537 75.98367 49.71951 34.6% 133 15768s
152413 119584 70.24783 140 648 75.98367 49.71997 34.6% 133 15828s
153175 120107 53.56881 78 516 75.98367 49.71997 34.6% 133 15878s
153868 120163 51.24035 98 507 75.98367 49.71997 34.6% 133 16034s
153940 120615 51.25866 109 521 75.98367 49.71997 34.6% 133 16099s
154487 121438 53.00559 103 536 75.98367 49.71997 34.6% 133 16162s
155455 122097 53.85146 109 530 75.98367 49.71997 34.6% 133 16222s
156248 122984 52.00278 111 552 75.98367 49.71997 34.6% 132 16283s
157251 123235 53.97616 140 592 75.98367 49.71997 34.6% 132 16328s
157540 124122 59.58687 151 507 75.98367 49.71997 34.6% 132 16381s
158640 124803 54.78931 100 556 75.98367 49.72015 34.6% 132 16435s
159513 124982 56.74529 134 575 75.98367 49.72019 34.6% 132 16489s
159751 125784 52.69712 77 563 75.98367 49.72019 34.6% 132 16544s
160756 126433 67.92997 154 549 75.98367 49.72020 34.6% 132 16603s
161543 126748 infeasible 165 75.98367 49.72024 34.6% 132 16639s
161934 127418 52.10422 117 509 75.98367 49.72024 34.6% 132 16703s
162734 127983 53.46985 135 709 75.98367 49.72025 34.6% 132 16750s
163415 128565 55.91523 136 799 75.98367 49.72026 34.6% 132 16809s
164005 128565 cutoff 148 75.98367 49.72026 34.6% 132 16810s
164143 129084 55.35097 143 517 75.98367 49.72026 34.6% 132 16853s
164790 129271 50.55853 81 540 75.98367 49.72026 34.6% 132 16926s
164998 129834 54.29469 141 960 75.98367 49.72026 34.6% 132 16975s
165807 130366 infeasible 166 75.98367 49.72031 34.6% 132 17027s
166417 130635 55.93704 143 578 75.98367 49.72031 34.6% 132 17105s
166734 131086 56.89675 147 916 75.98367 49.72031 34.6% 132 17175s
167303 131406 54.25474 108 474 75.98367 49.72031 34.6% 132 17233s
167651 131977 58.33380 133 646 75.98367 49.72031 34.6% 132 17279s
168354 132666 53.74574 120 556 75.98367 49.72032 34.6% 132 17334s
168724 132666 55.47273 101 514 75.98367 49.72032 34.6% 132 17335s
169107 133341 54.75548 88 555 75.98367 49.72033 34.6% 132 17391s
170023 133498 66.70806 144 693 75.98367 49.72071 34.6% 132 17463s
170216 134130 52.00157 78 614 75.98367 49.72071 34.6% 132 17510s
170948 134436 50.38587 65 585 75.98367 49.72095 34.6% 132 17563s
171381 135163 73.66628 148 531 75.98367 49.72102 34.6% 132 17620s
172239 135525 51.17533 87 546 75.98367 49.72117 34.6% 132 17684s
172674 136203 50.74073 63 593 75.98367 49.72138 34.6% 132 17734s
173445 136796 55.24182 70 552 75.98367 49.72199 34.6% 132 17784s
174072 137104 cutoff 120 75.98367 49.72273 34.6% 132 17827s
174512 137390 51.22600 88 492 75.98367 49.72329 34.6% 133 17932s
174834 138082 55.63321 133 479 75.98367 49.72427 34.6% 133 17992s
175675 138366 50.11835 56 585 75.98367 49.72488 34.6% 133 18076s
175994 138920 52.58301 130 650 75.98367 49.72488 34.6% 133 18165s
176714 139798 50.67982 84 591 75.98367 49.72488 34.6% 132 18230s
177682 140390 50.11768 50 599 75.98367 49.72553 34.6% 132 18298s
178375 140838 50.35455 64 626 75.98367 49.72651 34.6% 132 18361s
178915 141416 63.92287 144 559 75.98367 49.72758 34.6% 132 18430s
179528 141805 73.03367 151 534 75.98367 49.72758 34.6% 132 18474s
179913 141805 59.83101 120 641 75.98367 49.72758 34.6% 132 18475s
180050 142431 53.25265 125 579 75.98367 49.72758 34.6% 133 18549s
180838 143213 52.13360 75 615 75.98367 49.72758 34.6% 133 18613s
181769 143527 52.56091 122 592 75.98367 49.72771 34.6% 132 18713s
182126 144717 infeasible 165 75.98367 49.72771 34.6% 132 18805s
183616 145014 cutoff 142 75.98367 49.72872 34.6% 132 18855s
183973 145706 54.73547 144 524 75.98367 49.72921 34.6% 133 18914s
184882 146268 71.00166 160 528 75.98367 49.72966 34.6% 132 18976s
185610 146827 50.13978 76 594 75.98367 49.72977 34.6% 132 19037s
186332 147146 50.35693 69 583 75.98367 49.72996 34.6% 132 19084s
186661 147146 50.49859 81 587 75.98367 49.72996 34.6% 132 19085s
186745 147625 68.32980 145 546 75.98367 49.73001 34.6% 132 19156s
187335 147998 54.40207 108 513 75.98367 49.73454 34.5% 133 19244s
187713 148440 cutoff 130 75.98367 49.73454 34.5% 133 19302s
188244 149099 53.09347 103 538 75.98367 49.73454 34.5% 133 19367s
189017 149366 52.03456 116 585 75.98367 49.73500 34.5% 133 19465s
189327 149924 50.13103 64 596 75.98367 49.73500 34.5% 133 19538s
189949 150344 61.45659 116 541 75.98367 49.73500 34.5% 132 19612s
190430 151095 69.81847 131 567 75.98367 49.73642 34.5% 133 19679s
191335 151656 50.40466 67 602 75.98367 49.73691 34.5% 133 19753s
192067 152379 50.23784 70 621 75.98367 49.73714 34.5% 132 19805s
192848 152676 56.12447 146 569 75.98367 49.73714 34.5% 132 19930s
193315 153229 53.98478 81 578 75.98367 49.73714 34.5% 132 19987s
193903 153871 58.05810 131 488 75.98367 49.73714 34.5% 132 20067s
194756 154695 50.33488 70 551 75.98367 49.73714 34.5% 132 20129s
194889 154695 50.14497 63 607 75.98367 49.73714 34.5% 132 20130s
195699 155122 50.69162 73 562 75.98367 49.73720 34.5% 132 20181s
196136 155736 55.52115 110 561 75.98367 49.73720 34.5% 132 20241s
196926 156128 56.30608 132 539 75.98367 49.73720 34.5% 132 20314s
197503 156739 50.31153 78 564 75.98367 49.73720 34.5% 132 20363s
198207 156923 72.08063 129 673 75.98367 49.73720 34.5% 132 20445s
198433 157178 52.09321 73 599 75.98367 49.73720 34.5% 132 20551s
198830 157733 57.40114 127 567 75.98367 49.73720 34.5% 132 20609s
199509 158039 62.62385 146 623 75.98367 49.73726 34.5% 132 20664s
199933 158652 53.70895 92 590 75.98367 49.73729 34.5% 132 20738s
200663 159089 52.67529 72 570 75.98367 49.73730 34.5% 132 20786s
201210 159628 50.26264 67 580 75.98367 49.73737 34.5% 132 20853s
201849 159968 50.13060 78 589 75.98367 49.73946 34.5% 132 20904s
202326 160422 50.32507 71 603 75.98367 49.74013 34.5% 132 20976s
202926 160869 59.07471 162 482 75.98367 49.74014 34.5% 132 21024s
203406 160869 50.34826 72 623 75.98367 49.74065 34.5% 132 21025s
203476 161266 67.71945 145 465 75.98367 49.74100 34.5% 132 21094s
203964 161562 61.48114 164 523 75.98367 49.74372 34.5% 133 21184s
204300 161783 51.56964 88 535 75.98367 49.74372 34.5% 132 21247s
204611 162373 58.14462 151 473 75.98367 49.74603 34.5% 133 21302s
205352 162603 66.14665 145 532 75.98367 49.74655 34.5% 133 21381s
205637 163091 50.14343 54 599 75.98367 49.74754 34.5% 133 21463s
206241 163460 52.82310 56 682 75.98367 49.75023 34.5% 133 21540s
206666 163808 59.40909 96 676 75.98367 49.75023 34.5% 133 21584s
207080 163841 72.11339 146 543 75.98367 49.75023 34.5% 133 21600sCutting planes:
Learned: 76
Gomory: 189
Cover: 27
Implied bound: 126
Projected implied bound: 22
MIR: 376
Mixing: 3
Flow cover: 2139
Inf proof: 16
Zero half: 674
RLT: 260
Relax-and-lift: 7
BQP: 5Explored 207117 nodes (27784699 simplex iterations) in 21601.22 seconds (3664.36 work units)
Thread count was 6 (of 60 available processors)Solution count 10: 75.9837 75.9842 76.0528 ... 76.0985
Time limit reached
Best objective 7.598367456140e+01, best bound 4.975023349799e+01, gap 34.5251%
-
This rare case may happen if a heuristics gets "stuck" in some improvement loop and takes an unusually high amount of time. Could you please share the model such that we can have a closer look?
May I know if I should reformulate my model to solve this problem, or I should change some parameters?
It seems hard to find a first feasible point for your model. You could try providing a MIP Start, see How do I use MIP start? You could also try experimenting with the NoRelHeurTime parameter to try to find a feasible point early. A value of 600 should be a good start. You could also experiment with the parameters MIPFocus=1 and increase the value of the Heuristics parameter.
Additionally, you might want to have a look at our Tech-Talk about weak and strong MIP formulations, see also General modeling tips to improve a formulation.
Best regards,
Jaromił0 -
Jaromil,
Thank you for your suggestions. I am not able to share the model in here, but I am sure the talk would be helpful. I will look at the talk. Thank you!
0 -
Jaromil,
I watched the tech talk and reformulated my model. It helped a lot. Now it is able to find the first feasible point in about 700 seconds. However, it still stuck at some iteration for a long time.
Since you said it may be some heuristics got stuck, I tried to set the Heuristics parameter to 0. It is strange to me that even without heuristics, the model still got stuck at one of the iterations. Do you think the "stuck" was caused by something else?
0 -
I have a some complex conditional constraints in my model. I wonder if those would caused those problems.
For example, a <= b + (3 - c - d- e) and a >= b + (3 - c - d- e), where all the variables are binary. I meant to make a equals b, when c, d, and e all equal to 1.
0 -
Hi Mingze,
I'll jump in as I know Jaromił is away on leave for a while.
I don't think your conditional constraints are causing an issue here. There are other reasons which can cause the behavior you see, which include restarts (kind of like a recalibration and recalculation of certain things) or a node with numerical issues. I don't see signs of numerical issues in your log, my guess is that it is a restart.
Note that prior to the gap in the log you do not find any solutions, yet relatively soon afterwards you find many. Whatever Gurobi is doing during this gap in the log looks to be a good thing - I would not assume it is something to be avoided (and I don't think you can avoid it).
- Riley
0 -
I see. Thank you, Riley.
0
Please sign in to leave a comment.
Comments
6 comments