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Improving Root Node Time

Answered

Comments

3 comments

  • Jaromił Najman
    Gurobi Staff Gurobi Staff

    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
  • Osten Anderson
    Gurobi-versary
    First Comment
    First Question

    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 threads

    Optimize 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) ...
    Presolve removed 73883737 rows and 92478375 columns (presolve time = 85s) ...
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    Presolve removed 73951739 rows and 92495332 columns (presolve time = 96s) ...
    Presolve removed 73951739 rows and 92495332 columns (presolve time = 104s) ...
    Presolve removed 73951739 rows and 92773142 columns (presolve time = 107s) ...
    Presolve removed 73951739 rows and 92881835 columns (presolve time = 120s) ...
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    Presolve removed 73951811 rows and 93902006 columns (presolve time = 150s) ...
    Presolve removed 73951811 rows and 93902006 columns (presolve time = 155s) ...
    Presolve removed 73951811 rows and 93902006 columns (presolve time = 165s) ...
    Presolve removed 74949805 rows and 94900000 columns (presolve time = 170s) ...
    Presolve removed 75025583 rows and 95104290 columns (presolve time = 175s) ...
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    Presolve removed 75364762 rows and 95304089 columns (presolve time = 215s) ...
    Presolve removed 76450097 rows and 95707345 columns (presolve time = 220s) ...
    Presolve removed 76672922 rows and 96138938 columns (presolve time = 225s) ...
    Presolve removed 76672922 rows and 96261377 columns (presolve time = 231s) ...
    Presolve removed 76685535 rows and 96306542 columns (presolve time = 237s) ...
    Presolve removed 76685535 rows and 96308098 columns (presolve time = 240s) ...
    Presolve removed 76746477 rows and 96522741 columns (presolve time = 245s) ...
    Presolve removed 76748172 rows and 96522746 columns (presolve time = 250s) ...
    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) ...
    Presolve removed 77194373 rows and 96773473 columns (presolve time = 286s) ...
    Presolve removed 77197178 rows and 96776303 columns (presolve time = 290s) ...
    Presolve removed 77197871 rows and 96785463 columns (presolve time = 296s) ...
    Presolve removed 77218834 rows and 96825463 columns (presolve time = 300s) ...
    Presolve removed 77218855 rows and 96826472 columns (presolve time = 305s) ...
    Presolve removed 77220057 rows and 96829812 columns (presolve time = 311s) ...
    Presolve removed 77227209 rows and 96844371 columns (presolve time = 316s) ...
    Presolve removed 77227322 rows and 96845681 columns (presolve time = 320s) ...
    Presolve removed 77227354 rows and 96845681 columns (presolve time = 325s) ...
    Presolve removed 77230138 rows and 96851438 columns (presolve time = 332s) ...
    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: 8.38s

    Barrier 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    : 8

                      Objective                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  1100s

    Barrier 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              1119s

      192478 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              1124s

      Push 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: 40

    Use 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              1136s

       68126 PPushes remaining with PInf 6.9354417e-05              1136s
           0 PPushes remaining with PInf 1.7193987e-01              1139s

      Push 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: 40

    Root 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 = 1182.80s

        Nodes    |    Current Node    |     Objective Bounds      |     Work
     Expl Unexpl |  Obj  Depth IntInf | Incumbent    BestBd   Gap | It/Node Time

         0     0 301988.135    0 2381          - 301988.135      -     - 1187s
    H    0     0                    302234.98028 301988.135  0.08%     - 1288s

    Explored 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%

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  • Jaromił Najman
    Gurobi Staff Gurobi Staff

    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.

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