Topic
7 replies Latest Post - ‏2013-02-09T10:22:44Z by SystemAdmin
SystemAdmin
SystemAdmin
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Pinned topic Warning: MIP starts not constructed because of out-of-memory status.

‏2013-01-10T18:17:12Z |
Hi everyone

I have the attach formulation and get the following message. I change to /fastdetect switch: /3GB but I obtained the same result. Can anyone help me? Any suggestions?
IBM ILOG CPLEX Optimization Studio Academic Research Edition
Welcome to IBM(R) ILOG(R) CPLEX(R) Interactive Optimizer 12.4.0.0
with Simplex, Mixed Integer & Barrier Optimizers
5725-A06 5725-A29 5724-Y48 5724-Y49 5724-Y54 5724-Y55
Copyright IBM Corp. 1988, 2011. All Rights Reserved.

Type 'help' for a list of available commands.
Type 'help' followed by a command name for more
information on commands.

CPLEX> read lp.lp
Problem 'lp.lp' read.
Read time = 1.73 sec.
CPLEX> mipopt
Tried aggregator 1 time.
MIP Presolve eliminated 0 rows and 80 columns.
Reduced MIP has 7614 rows, 517014 columns, and 2436241 nonzeros.
Reduced MIP has 148191 binaries, 368823 generals, 0 SOSs, and 0 indicators.
Presolve time = 1.00 sec.
Probing time = 0.25 sec.
Clique table members: 144442.
MIP emphasis: balance optimality and feasibility.
MIP search method: dynamic search.
Parallel mode: deterministic, using up to 8 threads.
Root relaxation solution time = 1.22 sec.

Nodes Cuts/
Node Left Objective IInf Best Integer Best Bound ItCnt Gap

0 0 1.77962e+007 83 1.77962e+007 276
  • 0+ 0 2.14170e+007 1.77962e+007 861 16.91%
0 0 1.77962e+007 199 2.14170e+007 Cuts: 163 861 16.91%
Elapsed time 10.05 sec. for 144 of 199 candidates for Gomory cuts
0 0 1.77962e+007 176 2.14170e+007 Cuts: 149 2062 16.91%
  • 0+ 0 2.09745e+007 1.77962e+007 3936 15.15%
0 0 1.77963e+007 123 2.09745e+007 Cuts: 185 3936 15.15%
0 0 1.77985e+007 217 2.09745e+007 Cuts: 162 4840 15.14%
  • 0+ 0 2.07515e+007 1.77985e+007 11431 14.23%
0 0 1.77997e+007 274 2.07515e+007 Cuts: 164 11431 14.22%
  • 0+ 0 2.05285e+007 1.77997e+007 14998 13.29%
0 0 1.78036e+007 273 2.05285e+007 Cuts: 174 14998 13.27%
0 0 1.78076e+007 286 2.05285e+007 Cuts: 170 16143 13.25%
0 0 1.78112e+007 363 2.05285e+007 Cuts: 171 17609 13.24%
  • 0+ 0 2.04541e+007 1.78112e+007 20563 12.92%
0 0 1.78163e+007 375 2.04541e+007 Cuts: 178 20563 12.90%
0 0 1.78188e+007 368 2.04541e+007 Cuts: 170 21196 12.88%
0 0 1.78223e+007 405 2.04541e+007 Cuts: 188 22493 12.87%
0 0 1.78260e+007 428 2.04541e+007 Cuts: 193 24501 12.85%
0 0 1.78304e+007 419 2.04541e+007 Cuts: 187 25920 12.83%
0 0 1.78337e+007 490 2.04541e+007 Cuts: 173 28166 12.81%
0 0 1.78366e+007 495 2.04541e+007 Cuts: 191 30548 12.80%
0 0 1.78402e+007 480 2.04541e+007 Cuts: 180 32522 12.78%
0 0 1.78444e+007 456 2.04541e+007 Cuts: 178 34799 12.76%
0 0 1.78461e+007 500 2.04541e+007 Cuts: 170 36069 12.75%
Heuristic still looking.

There may be further error information in the clone logs.

Clique cuts applied: 37
Cover cuts applied: 159
Implied bound cuts applied: 397
Flow cuts applied: 19
Mixed integer rounding cuts applied: 127
Zero-half cuts applied: 1

Root node processing (before b&c):
Real time = 668.35
Parallel b&c, 8 threads:
Real time = 4.48
Sync time (average) = 0.00
Wait time (average) = 0.00

Total (root+branch&cut) = 672.83 sec.
Warning: MIP starts not constructed because of out-of-memory status.
CPLEX Error 1001: Out of memory.

Solution pool: 5 solutions saved.

MIP - Error termination, integer feasible: Objective = 2.0454120000e+007
Current MIP best bound = 1.7846090819e+007 (gap = 2.60803e+006, 12.75%)
Solution time = 674.08 sec. Iterations = 36069 Nodes = 0
Deterministic time = 528186.95 ticks (783.57 ticks/sec)

Attachments

Updated on 2013-02-09T10:22:44Z at 2013-02-09T10:22:44Z by SystemAdmin
  • SystemAdmin
    SystemAdmin
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    Re: Warning: MIP starts not constructed because of out-of-memory status.

    ‏2013-01-11T06:29:44Z  in response to SystemAdmin
    Looks like you are running out of memory either during the root node or right before starting the tree search. Does it help to reduce the number of threads (using only 1 thread in the extreme case)?
    • SystemAdmin
      SystemAdmin
      7929 Posts
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      Re: Warning: MIP starts not constructed because of out-of-memory status.

      ‏2013-01-11T10:34:45Z  in response to SystemAdmin
      I have tried with only 1 thread and I get the same result.

      Best regards
    • SystemAdmin
      SystemAdmin
      7929 Posts
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      Re: Warning: MIP starts not constructed because of out-of-memory status.

      ‏2013-01-11T10:36:25Z  in response to SystemAdmin
      I have tried with only 1 thread and I get the same result.

      Best regards
      • SystemAdmin
        SystemAdmin
        7929 Posts
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        Re: Warning: MIP starts not constructed because of out-of-memory status.

        ‏2013-02-05T07:13:00Z  in response to SystemAdmin
        Is the log file you get the same? I.e., does the out of memory happen at the same place? I ran your model here and it never consumed more than 1 GB of memory during the root node. How much RAM do you have on your machine? What memory consumption does the task memory report?
        Another thing you can try is to reduce the number of cuts that are generated by setting CPX_PARAM_CUTPASS to -1.
        • SystemAdmin
          SystemAdmin
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          Re: Warning: MIP starts not constructed because of out-of-memory status.

          ‏2013-02-08T10:12:37Z  in response to SystemAdmin
          If I set the setting CPX_PARAM_CUTPASS to -1 works even worse.

          I have a Intel Core i7-3770k CP @ 3.5 Ghz with 4,00 GB.

          If I try to solve the formulation with default settings the memory starts over 1 GH and increase slowly until I get the error.

          If I set the setting CPX_PARAM_CUTPASS to -1 starts over 3 GHZ and 10 seconds later I get the Out of memory error.

          Have you been able to solve the formulation? with which parameters? how many threads do you use?

          Thank you very much for your attention.
        • SystemAdmin
          SystemAdmin
          7929 Posts
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          Re: Warning: MIP starts not constructed because of out-of-memory status.

          ‏2013-02-08T16:29:02Z  in response to SystemAdmin
          If I set the setting CPX_PARAM_CUTPASS to -1 works even worse.

          I have a Intel Core i7-3770k CP @ 3.5 Ghz with 4,00 GB.

          If I try to solve the formulation with default settings the memory starts over 1 GH and increase slowly until I get the error.

          If I set the setting CPX_PARAM_CUTPASS to -1 starts over 3 GHZ and 10 seconds later I get the Out of memory error.

          Have you been able to solve the formulation? with which parameters? how many threads do you use?

          Thank you very much for your attention.
          • SystemAdmin
            SystemAdmin
            7929 Posts
            ACCEPTED ANSWER

            Re: Warning: MIP starts not constructed because of out-of-memory status.

            ‏2013-02-09T10:22:44Z  in response to SystemAdmin
            I did not solve to optimality but I got well beyond the root node on two different machines:
            1. Intel dual core, Linux, 4 GB RAM, 2 threads, CPLEX 12.5.0.0:
            
            Tried aggregator 1 time. MIP Presolve eliminated 0 rows and 80 columns. Reduced MIP has 7614 rows, 517014 columns, and 2436241 nonzeros. Reduced MIP has 148191 binaries, 368823 generals, 0 SOSs, and 0 indicators. Presolve time = 1.70 sec. (658.50 ticks) Found incumbent of value 2.8538916e+08 after 5.25 sec. (1887.01 ticks) Probing time = 0.58 sec. (77.43 ticks) Clique table members: 144442. MIP emphasis: balance optimality and feasibility. MIP search method: dynamic search. Parallel mode: deterministic, using up to 2 threads. Root relaxation solution time = 1.67 sec. (637.45 ticks)   Nodes                                         Cuts/  Node  Left     Objective  IInf  Best Integer    Best Bound    ItCnt     Gap   *     0+    0                       2.85389e+08        0.0000      276  100.00% *     0+    0                       3.03209e+07        0.0000      276  100.00% 0     0   1.77962e+07    83   3.03209e+07   1.77962e+07      276   41.31% *     0+    0                       2.32755e+07   1.77962e+07     1168   23.54% 0     0   1.77962e+07   191   2.32755e+07     Cuts: 121     1168   23.54% *     0+    0                       2.22135e+07   1.77962e+07     2643   19.89% 0     0   1.77962e+07   220   2.22135e+07     Cuts: 134     2643   19.89% 0     2   1.77962e+07   140   2.22135e+07   1.77962e+07     2643   19.89% Elapsed time = 206.11 sec. (57674.62 ticks, tree = 0.01 MB, solutions = 4) 3     5   1.77963e+07   126   2.22135e+07   1.77962e+07     3167   19.89% 4     6   1.77967e+07   179   2.22135e+07   1.77962e+07     3863   19.89% 7     9   1.77962e+07   128   2.22135e+07   1.77962e+07     4293   19.89% 8    10   1.77972e+07   158   2.22135e+07   1.77962e+07     4437   19.89% 11    13   1.77967e+07   183   2.22135e+07   1.77962e+07     5298   19.89% 20    22   1.77966e+07   140   2.22135e+07   1.77962e+07    10778   19.89% 26    28   1.77962e+07   128   2.22135e+07   1.77962e+07    11418   19.89% 28    30   1.77962e+07   127   2.22135e+07   1.77962e+07    11426   19.89% 30    32   1.77966e+07   137   2.22135e+07   1.77962e+07    11774   19.89% *    32+   32                       2.10468e+07   1.77962e+07    11963   15.44% 54    56   1.93027e+07    28   2.10468e+07   1.77962e+07    13086   15.44% Elapsed time = 293.04 sec. (94102.70 ticks, tree = 11.52 MB, solutions = 4) 64    66   1.77971e+07   120   2.10468e+07   1.77962e+07    13358   15.44% 84    86   1.89276e+07    47   2.10468e+07   1.77962e+07    13963   15.44% 99   101   1.77993e+07   165   2.10468e+07   1.77962e+07    14845   15.44% 120   120   1.77994e+07   139   2.10468e+07   1.77962e+07    15459   15.44% 142   142   1.93998e+07    69   2.10468e+07   1.77962e+07    16190   15.44% 168   168   1.77997e+07   134   2.10468e+07   1.77962e+07    17039   15.44% 178   178   1.77997e+07   145   2.10468e+07   1.77962e+07    17632   15.44% ...
            

            2. Intel single core, Windows, 4 GB RAM, 1 thread, CPLEX 12.5.0.0:
            
            Tried aggregator 1 time. MIP Presolve eliminated 0 rows and 80 columns. Reduced MIP has 7614 rows, 517014 columns, and 2436241 nonzeros. Reduced MIP has 148191 binaries, 368823 generals, 0 SOSs, and 0 indicators. Presolve time = 2.66 sec. (658.50 ticks) Found incumbent of value 2.8538916e+008 after 8.08 sec. (1886.50 ticks) Probing time = 0.64 sec. (77.43 ticks) Clique table members: 144442. MIP emphasis: balance optimality and feasibility. MIP search method: dynamic search. Parallel mode: deterministic, using up to 2 threads. Root relaxation solution time = 2.03 sec. (637.42 ticks)   Nodes                                         Cuts/  Node  Left     Objective  IInf  Best Integer    Best Bound    ItCnt     Gap   *     0+    0                      2.85389e+008        0.0000      276  100.00% *     0+    0                      3.03209e+007        0.0000      276  100.00% 0     0  1.77962e+007    83  3.03209e+007  1.77962e+007      276   41.31% *     0+    0                      2.32755e+007  1.77962e+007     1168   23.54% 0     0  1.77962e+007   191  2.32755e+007     Cuts: 121     1168   23.54% 0     0  1.77962e+007   199  2.32755e+007     Cuts: 134     1478   23.54% *     0+    0                      2.18403e+007  1.77962e+007     1478   18.52% *     0+    0                      2.10851e+007  1.77962e+007     1478   15.60% *     0+    0                      2.10061e+007  1.77962e+007     1478   15.28% 0     2  1.77962e+007   113  2.10061e+007  1.77962e+007     1478   15.28% Elapsed time = 164.19 sec. (35731.44 ticks, tree = 0.01 MB, solutions = 6) 3     5  1.77962e+007    98  2.10061e+007  1.77962e+007     1918   15.28% 4     6  1.77962e+007   118  2.10061e+007  1.77962e+007     2000   15.28% 6     8  1.77971e+007   160  2.10061e+007  1.77962e+007     2360   15.28% 7     9  1.77970e+007   150  2.10061e+007  1.77962e+007     3349   15.28% 14    16  1.77983e+007   147  2.10061e+007  1.77962e+007     3765   15.28% 15    17  1.77962e+007   103  2.10061e+007  1.77962e+007     4206   15.28% 21    23  1.77971e+007   114  2.10061e+007  1.77962e+007     4786   15.28% 23    25  1.77966e+007   115  2.10061e+007  1.77962e+007     4979   15.28% 25    27  1.77974e+007   113  2.10061e+007  1.77962e+007     5224   15.28% 46    48  1.78001e+007   126  2.10061e+007  1.77962e+007     6111   15.28% Elapsed time = 195.78 sec. (51870.69 ticks, tree = 7.68 MB, solutions = 6) 49    51  1.77974e+007   115  2.10061e+007  1.77962e+007     6457   15.28% 64    66  1.77976e+007   107  2.10061e+007  1.77962e+007     6923   15.28% 88    90  1.77987e+007   116  2.10061e+007  1.77962e+007     8198   15.28% ...
            

            The solve on Windows eventually ran out of memory but that can probably be fixed by using node files.
            I also tried CPLEX 12.4.0.1 on the Linux box (2 threads) and there I had no issues as well. I did not try 12.4 on Windows.
            Is it an option for you to upgrade to 12.5?
            Otherwise you may try to enable memory emphasis or set CPX_PARAM_HEURFREQ to -1 to disable heuristics (although the latter may affect performance in a bad way).