AMPL.exe stops working.

[Krishnendranath Mitra]

Hello,

AMPL stops working after hanging for about 40-45 mins on a model I am trying to run. I have presented below the stats of this program as received from AMPL. I am not sure what is the problem. Can anybody please point out the possible reason.

sw: ampl

ampl: model home2.mod;

ampl: data home221.dat;

ampl: option solver cplex;

ampl: option times 1;

# incremental total

#phase seconds memory memory

#execute 0.0625 310720 310720

ampl: option gentimes 1;

### option ...

#execute 0 0 310720

ampl: option show_stats 1;

### option ...

#execute 0 0 310720

ampl: solve;

### solve ...

#compile 0 1040 311760

##genmod times:

##seq      seconds    cum. sec.    mem. inc.  name

## 85            0            0            0  derstage

## 89            0            0            0  sstatus

## 103            0            0            0  time

## 104            0            0            0  app

## 105            0            0            0  T

## 106            0            0            0  e

## 107            0            0            0  l

## 108            0            0          520  C

## 109            0            0            0  x

## 110            0            0            0  M

## 111            0            0            0  N

## 112            0            0       232120  I

## 114            0            0        65552  I1

## 116            0            0        65552  I2

## 118            0            0            0  s

## 120            0            0          520  p

## 122            0            0         1032  r

## 124            0            0         2064  z

## 126     0.015625     0.015625      1041904  expenditure

## 128            0     0.015625            0  earlystart

## 130            0     0.015625         1040  lateend

## 132            0     0.015625       626000  cond1

## 134     0.015625      0.03125       655680  cond2

## 136            0      0.03125       819600  cond3

## 138            0      0.03125        51720  limit

## 140            0      0.03125        51200  optime

## 142            0      0.03125         3624  seq2

## 144            0      0.03125         2584  seq3

## 146     0.015625     0.046875        79384  price

## 148            0     0.046875         2584  rebate

## 150            0     0.046875        53784  consumption

#genmod 0.046875 3756984 4068744

#merge 0 131080 4199824

#collect 0.015625 4812336 9012160

Presolve eliminates 80 arithmetic and 1152 logical constraints,

and 1156 variables.

Adjusted problem:

10114 variables:

9922 nonlinear variables

192 linear variables

610 algebraic constraints, all linear; 13824 nonzeros

322 equality constraints

288 inequality constraints

9792 logical constraints

1 nonlinear objective; 3 nonzeros.

#presolve 0.0625 2702464 11714624

#output 0.109375 0 11714624

CPLEX 12.5.1.0: #Total 0.296875

exit code 255

#execute 0.015625 0 11714624

<BREAK>

ampl: 

Regards,

K.Mitra.

[Krishnendranath Mitra]

Is this a memory related problem? What does 'exit code 255' signify in this case?

[Robert Fourer]

To see what is happening in CPLEX, set

option cplex_options 'mipdisplay 2';

before "solve;", to get a detailed log of CPLEX's progress. Then you will see that CPLEX is truly "hanging" or whether it is merely taking a long time to reach a solution. Also you will see information on the number of nodes remaining in the search tree and the amount of memory taken. You can post the logs to this forum if you need some help in interpreting them.

(There does not appear to be any problem with memory in AMPL, so you can omit "option times 1;" and "option gentimes 1;" to reduce the amount of output.)

Bob Fourer
am...@googlegroups.com

=======

From: am...@googlegroups.com [mailto:am...@googlegroups.com] On Behalf Of Krishnendranath Mitra
Sent: Monday, April 20, 2015 12:27 AM
To: am...@googlegroups.com
Subject: [AMPL 10320] Re: AMPL.exe stops working.

Is this a memory related problem? What does 'exit code 255' signify in this case?

=======

On Monday, April 20, 2015 at 9:35:52 AM UTC+5:30, Krishnendranath Mitra wrote:

AMPL stops working after hanging for about 40-45 mins on a model I am trying to run. I have presented below the stats of this program as received from AMPL. I am not sure what is the problem. Can anybody please point out the possible reason.

sw: ampl
ampl: model home2.mod;
ampl: data home221.dat;
ampl: option solver cplex;
ampl: option times 1;
# incremental total
#phase seconds memory memory
#execute 0.0625 310720 310720
ampl: option gentimes 1;
### option ...
#execute 0 0 310720
ampl: option show_stats 1;
### option ...
#execute 0 0 310720
ampl: solve;
### solve ...

.......

[Krishnendranath Mitra]

Sir,

This command was really helpful as I could see that the process is indeed going on. However, as you can find from the log below, the process stopped without reaching a final solution. A pop-up window came up noting "cplex.exe has stopped working   -    A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available. "  I tried once again from the beginning and this time it stopped with the same message at time = 1643.77 sec.

What can be the possible cause for this problem?

sw: ampl

ampl: model home2.mod;

ampl: data home221.dat;

ampl: option solver cplex;

ampl: option cplex_options 'mipdisplay 2';

ampl: solve;

CPLEX 12.5.1.0: mipdisplay 2

MIQP Presolve eliminated 330 rows and 5495 columns.

MIQP Presolve added 6156 rows and 3078 columns.

MIQP Presolve modified 5610 coefficients.

Reduced MIQP has 9013 rows, 8132 columns, and 30396 nonzeros.

Reduced MIQP has 4394 binaries, 34 generals, 0 SOSs, and 838 indicators.

Found incumbent of value 72.403754 after 2.83 sec. (320.69 ticks)

Probing fixed 580 vars, tightened 975 bounds.

Probing changed sense of 60 constraints.

Probing time = 0.91 sec. (50.99 ticks)

Cover probing fixed 0 vars, tightened 3717 bounds.

Clique table members: 22802.

Tightened 84 constraints.

MIP emphasis: balance optimality and feasibility.

MIP search method: dynamic search.

Parallel mode: deterministic, using up to 2 threads.

Root relaxation solution time = 2.38 sec. (177.15 ticks)

        Nodes                                         Cuts/

   Node  Left     Objective  IInf  Best Integer    Best Bound    ItCnt     Gap

*     0+    0                           72.4038                   5583     --- 

      0     0       70.0642  1177       72.4038       70.0642     5583    3.23%

*     0+    0                           72.3205       70.0642     7353    3.12%

      0     0       70.1296   888       72.3205    Cuts: 2353     7353    3.03%

      0     0       70.6229   878       72.3205    Cuts: 1930     9748    2.35%

      0     0       71.1179  1042       72.3205    Cuts: 1030    11454    1.66%

*     0+    0                           72.0196       71.1179    11454    1.25%

      0     0       71.2825   841       72.0196    Cuts: 1194    12702    1.02%

      0     0       71.3378   828       72.0196     Cuts: 825    14715    0.95%

      0     0       71.3651   868       72.0196     Cuts: 926    15414    0.91%

      0     0       71.3829   949       72.0196     Cuts: 641    16322    0.88%

      0     0       71.3961   915       72.0196     Cuts: 661    17237    0.87%

      0     0       71.3989   893       72.0196     Cuts: 617    18317    0.86%

      0     0       71.4061   945       72.0196     Cuts: 435    19568    0.85%

      0     0       71.4070   914       72.0196     Cuts: 606    19906    0.85%

      0     0       71.4108   975       72.0196     Cuts: 473    20416    0.85%

*     0+    0                           71.7222       71.4108    20416    0.43%

*     0+    0                           71.7188       71.4108    20416    0.43%

*     0+    0                           71.7023       71.4108    20416    0.41%

*     0+    0                           71.6930       71.4108    20416    0.39%

*     0+    0                           71.6806       71.4108    20416    0.38%

*     0+    0                           71.6751       71.4108    20416    0.37%

      0     2       71.4108   975       71.6751       71.4108    20416    0.37%

Elapsed time = 65.11 sec. (4855.33 ticks, tree = 0.01 MB)

*     4+    4                           71.6098       71.4108    21772    0.28%

      4     6       71.4949  1007       71.6098       71.4108    21772    0.28%

     30    32       71.4122   833       71.6098       71.4109    23911    0.28%

     61    51       71.5275   769       71.6098       71.4109    25570    0.28%

     77    65       71.4114   923       71.6098       71.4109    28524    0.28%

    139   107       71.4212   740       71.6098       71.4109    31160    0.28%

    149   113       71.4126   921       71.6098       71.4113    34788    0.28%

    164   125       71.4172   982       71.6098       71.4113    36743    0.28%

*   193+  139                           71.6081       71.4113    37994    0.27%

    197   142       71.4439   914       71.6081       71.4113    38302    0.27%

    243   179       71.4822   637       71.6081       71.4113    40995    0.27%

    345   242       71.4113   905       71.6081       71.4113    46456    0.27%

Elapsed time = 121.22 sec. (9023.28 ticks, tree = 2.63 MB)

    409   294       71.4676  1097       71.6081       71.4113    55775    0.27%

    416   301       71.4114  1054       71.6081       71.4113    63270    0.27%

    421   305       71.4115  1025       71.6081       71.4113    70990    0.27%

    459   339       71.4114  1002       71.6081       71.4113    75628    0.27%

    528   402       71.4666   667       71.6081       71.4113    85812    0.27%

    638   478       71.4238   727       71.6081       71.4114    93924    0.27%

    768   573       71.4115   913       71.6081       71.4114   104443    0.27%

    898   692       71.5420   697       71.6081       71.4114   112509    0.27%

    944   729       71.4115  1008       71.6081       71.4114   123051    0.27%

   1043   824       71.4114  1116       71.6081       71.4114   134657    0.27%

Elapsed time = 252.50 sec. (19877.41 ticks, tree = 10.22 MB)

   1062   841       71.4115  1091       71.6081       71.4114   142665    0.27%

   1103   875       71.4366   806       71.6081       71.4114   152008    0.27%

   1187   945       71.4116   955       71.6081       71.4114   160482    0.27%

   1292  1024       71.4647   695       71.6081       71.4114   173486    0.27%

   1449  1153       71.4115   834       71.6081       71.4114   180607    0.27%

   1547  1241       71.4206   846       71.6081       71.4114   191317    0.27%

*  1621+ 1297                           71.6056       71.4114   196515    0.27%

*  1621+ 1297                           71.6056       71.4114   196515    0.27%

*  1622+ 1298                           71.6043       71.4114   196586    0.27%

*  1622+ 1298                           71.6043       71.4114   196586    0.27%

   1622  1300       71.4734   798       71.6043       71.4114   196586    0.27%

   1623  1287       71.4368   658       71.6043       71.4368   213008    0.23%

   1624  1287       71.4368   796       71.6043       71.4368   214913    0.23%

   1625  1287       71.4368   775       71.6043       71.4368   215048    0.23%

Elapsed time = 445.25 sec. (37331.46 ticks, tree = 12.86 MB)

   1626  1288       71.4368   775       71.6043       71.4368   218751    0.23%

   1627  1289       71.4368   771       71.6043       71.4368   218752    0.23%

   1631  1289       71.4369   811       71.6043       71.4368   219584    0.23%

   1635  1291       71.4369   782       71.6043       71.4368   219813    0.23%

   1641  1295       71.4383   752       71.6043       71.4368   221289    0.23%

   1646  1298       71.4528   783       71.6043       71.4368   224242    0.23%

   1653  1301       71.4618   672       71.6043       71.4368   228444    0.23%

   1669  1309       71.5223   557       71.6043       71.4368   230359    0.23%

   1768  1180       71.4368   781       71.6043       71.4368   233971    0.23%

   1789  1158       71.4379   768       71.6043       71.4368   237098    0.23%

Elapsed time = 561.50 sec. (49277.58 ticks, tree = 11.27 MB)

   1846  1100       71.4368   764       71.6043       71.4368   239408    0.23%

   1909  1091       71.4368   756       71.6043       71.4368   244112    0.23%

   1955  1082       71.5851   373       71.6043       71.4368   250258    0.23%

   1997  1081       71.4477   708       71.6043       71.4368   255416    0.23%

   2089  1094       71.4392   806       71.6043       71.4368   263795    0.23%

   2097  1098       71.4622   783       71.6043       71.4368   269986    0.23%

   2185  1134       71.4369   814       71.6043       71.4368   279454    0.23%

*  2197+  910                           71.6016       71.4368   280224    0.23%

   2218   909       71.4930   422       71.6016       71.4368   282426    0.23%

   2284   933       71.4368   726       71.6016       71.4368   287502    0.23%

   2339   942       71.4470   828       71.6016       71.4368   292915    0.23%

Elapsed time = 668.61 sec. (60762.21 ticks, tree = 6.50 MB)

   2397   966       71.5407   509       71.6016       71.4368   299511    0.23%

   2427   970       71.4398   783       71.6016       71.4368   301624    0.23%

   2440   966       71.4455   811       71.6016       71.4368   308752    0.23%

   2448   973       71.4702   634       71.6016       71.4368   312494    0.23%

   2500   991       71.4369   790       71.6016       71.4368   316053    0.23%

*  2522+  899                           71.5993       71.4368   317104    0.23%

   2562   906       71.4369   808       71.5993       71.4368   322061    0.23%

   2580   907       71.4429   597       71.5993       71.4368   326641    0.23%

   2603   915       71.4416   915       71.5993       71.4368   331730    0.23%

   2653   940       71.4368   765       71.5993       71.4368   335097    0.23%

   2680   941       71.4390   777       71.5993       71.4369   340885    0.23%

Elapsed time = 792.53 sec. (71651.93 ticks, tree = 4.74 MB)

   2704   954       71.4610   526       71.5993       71.4369   346101    0.23%

   2783   992       71.4369   814       71.5993       71.4369   351790    0.23%

   2814   993       71.4438   703       71.5993       71.4369   356428    0.23%

   2863  1022       71.5350   426       71.5993       71.4369   364308    0.23%

   2958  1077       71.4382   918       71.5993       71.4369   371372    0.23%

   2973  1084       71.4741   648       71.5993       71.4369   376495    0.23%

   3001  1112       71.4953   746       71.5993       71.4369   381352    0.23%

   3074  1179       71.4426   826       71.5993       71.4369   388248    0.23%

   3127  1222       71.4391   743       71.5993       71.4369   393367    0.23%

   3161  1247       71.4401   858       71.5993       71.4369   402162    0.23%

Elapsed time = 911.39 sec. (83052.84 ticks, tree = 5.40 MB)

   3217  1296       71.4377   801       71.5993       71.4369   406803    0.23%

   3281  1345       71.4498   784       71.5993       71.4369   412693    0.23%

   3315  1375       71.4443   803       71.5993       71.4369   415423    0.23%

   3380  1434       71.4393   829       71.5993       71.4369   421708    0.23%

   3398  1446       71.4439   946       71.5993       71.4369   426611    0.23%

   3433  1479       71.4960   623       71.5993       71.4369   433278    0.23%

   3543  1568       71.4446   794       71.5993       71.4369   440825    0.23%

   3592  1613       71.4392   781       71.5993       71.4369   449248    0.23%

*  3654+ 1668                           71.5985       71.4369   452574    0.23%

   3702  1706       71.4371   968       71.5985       71.4369   458396    0.23%

   3716  1711       71.4389   913       71.5985       71.4369   463338    0.23%

Elapsed time = 1022.97 sec. (94706.44 ticks, tree = 7.45 MB)

   3735  1723       71.4370   806       71.5985       71.4369   467872    0.23%

   3745  1730       71.4593   719       71.5985       71.4369   473309    0.23%

   3809  1787       71.4678   774       71.5985       71.4369   478358    0.23%

*  3824+ 1799                           71.5934       71.4369   480044    0.22%

*  3824+ 1799                           71.5882       71.4369   480044    0.21%

   3824  1801       71.5424   564       71.5882       71.4369   480044    0.21%

   3949  1786       71.4608   600       71.5882       71.4369   485878    0.21%

   3962  1795       71.4371   860       71.5882       71.4369   488703    0.21%

   4010  1835       71.4372   778       71.5882       71.4369   492626    0.21%

   4068  1891       71.4429   722       71.5882       71.4369   496964    0.21%

   4117  1930       71.4373   912       71.5882       71.4369   500564    0.21%

   4182  1995       71.5113   452       71.5882       71.4369   503696    0.21%

Elapsed time = 1125.88 sec. (105512.96 ticks, tree = 25.48 MB)

   4229  2035       71.4390   711       71.5882       71.4369   506786    0.21%

*  4236+ 2040                           71.5870       71.4369   506903    0.21%

*  4236+ 2040                           71.5853       71.4369   506903    0.21%

*  4236+ 2040                           71.5830       71.4369   506903    0.20%

*  4236+ 2040                           71.5814       71.4369   506903    0.20%

   4271  1956       71.4420   598       71.5814       71.4370   511593    0.20%

   4341  2016       71.4374   844       71.5814       71.4370   515112    0.20%

   4373  2045       71.4482   530       71.5814       71.4370   518581    0.20%

   4461  2126       71.4844   533       71.5814       71.4370   523420    0.20%

   4551  2210       71.4489   731       71.5814       71.4370   527592    0.20%

   4691  2328       71.4406   820       71.5814       71.4370   532834    0.20%

   4742  2379       71.5172   405       71.5814       71.4371   536416    0.20%

   4820  2441       71.4672   831       71.5814       71.4371   539866    0.20%

   5005  2594       71.4650   859       71.5814       71.4371   554738    0.20%

Elapsed time = 1256.69 sec. (118963.00 ticks, tree = 48.11 MB)

   5299  2855       71.4628   648       71.5814       71.4373   570783    0.20%

   5542  3068       71.5245   423       71.5814       71.4373   585911    0.20%

   5857  3340       71.4438   853       71.5814       71.4374   604083    0.20%

   6270  3718       71.4559   690       71.5814       71.4375   624117    0.20%

   6446  3878       71.4575   480       71.5814       71.4376   641378    0.20%

   6740  4150       71.4446   678       71.5814       71.4377   655623    0.20%

   7002  4391       71.4646   548       71.5814       71.4378   671976    0.20%

   7246  4602       71.4396   742       71.5814       71.4379   686739    0.20%

   7426  4773       71.4857   392       71.5814       71.4379   700570    0.20%

   7696  5011       71.5065   442       71.5814       71.4380   720194    0.20%

Elapsed time = 1634.41 sec. (157620.07 ticks, tree = 189.15 MB)

Nodefile size = 56.65 MB (40.14 MB after compression)

   7961  5251       71.4771   628       71.5814       71.4381   734288    0.20%

   8316  5569       71.4840   807       71.5814       71.4383   751095    0.20%

*  8656+ 5868                           71.5704       71.4383   769560    0.18%

   8682  5573       71.4428   762       71.5704       71.4384   769894    0.18%

*  8843+ 5661                           71.5657       71.4384   773899    0.18%

*  8843+ 5638                           71.5645       71.4384   773899    0.18%

*  8843+ 5638                           71.5634       71.4384   773899    0.17%

   8980  5519       71.4437   836       71.5634       71.4384   787842    0.17%

*  9019+ 5550                           71.5628       71.4384   790517    0.17%

   9404  5854       71.4608   764       71.5628       71.4386   806806    0.17%

   9657  6083       71.4418   757       71.5628       71.4386   826346    0.17%

   9905  6290       71.4457   821       71.5628       71.4386   844059    0.17%

  10275  6609       71.4399   710       71.5628       71.4387   871274    0.17%

  10575  6872       71.4463   679       71.5628       71.4388   887079    0.17%

  10898  7162       71.4894   446       71.5628       71.4388   902362    0.17%

Elapsed time = 2043.50 sec. (197120.95 ticks, tree = 353.16 MB)

Nodefile size = 208.32 MB (149.82 MB after compression)

  11213  7443       71.4847   497       71.5628       71.4389   920489    0.17%

* 11447+ 7649                           71.5626       71.4390   931629    0.17%

  11529  7720       71.5224   559       71.5626       71.4390   936129    0.17%

* 11678+ 7856                           71.5620       71.4390   941067    0.17%

  11898  8003       71.4793   733       71.5620       71.4391   951689    0.17%

  12266  8335       71.4759   668       71.5620       71.4392   970802    0.17%

  12556  8601       71.4559   767       71.5620       71.4393   985383    0.17%

  13043  9042       71.5161   559       71.5620       71.4394  1004504    0.17%

  13378  9337       71.4430   767       71.5620       71.4394  1022117    0.17%

  13718  9641       71.4888   501       71.5620       71.4394  1039410    0.17%

  14201 10057       71.4711   604       71.5620       71.4395  1061639    0.17%

  14593 10415       71.4406   785       71.5620       71.4395  1081993    0.17%

Elapsed time = 2440.42 sec. (236359.27 ticks, tree = 546.89 MB)

Nodefile size = 393.71 MB (281.34 MB after compression)

  14931 10725       71.5306   640       71.5620       71.4397  1103751    0.17%

  15261 11006       71.4730   626       71.5620       71.4398  1122981    0.17%

  15737 11435       71.4509   722       71.5620       71.4398  1144474    0.17%

  16036 11692       71.4635   614       71.5620       71.4399  1163306    0.17%

  16487 12091       71.4537   610       71.5620       71.4400  1186456    0.17%

  16925 12475       71.5439   324       71.5620       71.4400  1206375    0.17%

  17286 12784       71.4605   631       71.5620       71.4401  1225490    0.17%

  17651 13111       71.4529   604       71.5620       71.4402  1245097    0.17%

* 17666+13117                           71.5581       71.4403  1245674    0.16%

* 17666+13117                           71.5575       71.4403  1245674    0.16%

* 17666+13117                           71.5564       71.4403  1245674    0.16%

* 17666+13117                           71.5558       71.4403  1245674    0.16%

  17668 12765       71.4371   685       71.5558       71.4403  1258567    0.16%

  17681 12773       71.4387   731       71.5558       71.4403  1261173    0.16%

Elapsed time = 2907.80 sec. (282817.36 ticks, tree = 127.39 MB)

  17700 12268       71.4374   796       71.5558       71.4403  1265281    0.16%

  17747 12075       71.4622   596       71.5558       71.4403  1274130    0.16%

  17817 11792       71.4373   819       71.5558       71.4403  1284327    0.16%

  17874 11572       71.4373   801       71.5558       71.4403  1294108    0.16%

  17933 11433       71.4490   625       71.5558       71.4403  1306096    0.16%

  17987 11358       71.4526   869       71.5558       71.4403  1312865    0.16%

  18041 11218       71.4924   392       71.5558       71.4403  1322096    0.16%

  18126 11119       71.5443   649       71.5558       71.4403  1328667    0.16%

  18181 10960       71.5218   821       71.5558       71.4403  1340659    0.16%

exit code 255

<BREAK>

ampl: 

Regards,

K. Mitra.

[Krishnendranath Mitra]

Sir,

This command was really helpful as I could see that the process is indeed going on. However, as you can find from the log below, the process stopped without reaching a final solution. A pop-up window came up noting "cplex.exe has stopped working   -    A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available. "  I tried once again from the beginning and this time it stopped with the same message at time = 1643.77 sec.

What can be the possible cause for this problem?

sw: ampl

ampl: model home2.mod;

ampl: data home221.dat;

ampl: option solver cplex;

[Robert Fourer]

This does not appear to be an out-of-memory problem, because the "Nodes Left" count is already decreasing when CPLEX stops working. You should try running the same problem using the latest version of CPLEX, 12.6.1, as the error may already have been fixed in that version. Otherwise, you can send us the files home2.mod and home221.dat (to am...@googlegroups.com or sup...@ampl.com) and we will confirm the problem and report it to the CPLEX developers.

[Krishnendranath Mitra]

Sir, 

The same problem exists with CPLEX 12.6.1.

I have mailed the .mod and .dat files at sup...@ampl.com for your reference.