GUROBI+gurobipy crashes python interpreter
sascha...@googlemail.com
Hi,
I’m using
Gurobi 6.0 together with the bundled gurobipy python-api, called in "my
own" python version: (before: Anaconda with Python 2.7.7 64bit; now:
Anaconda/Miniconda 2.7.8 64bit like the bundled one -> both fail!) within Win7 64-bit.
My problem: Gurobi is crashing my python interpreter (no feedback about the error; feels like a segfault in some classic c-code).
As my code will generate and solve some problem within some loop, sometimes it crashes, sometimes it doesn't (at least i thought so until today, but today my error-rate is 100%; maybe i changed some parameters without noticing).
Interesting observation: it seems, that this crash is always happening, when gurobi is stopping/cleaning-up. I'm using a MIPGap of 0.01 and the last print of my python-code/gurobi is always some line describing a state with a MIPGap > 0.01 followed by all the cutting-plane statistics. Then it crashes! (Without further explanation: it feels like gurobi/gurobipy or something on a c/asm-level is doing something wrong, not my python code after the optimization-process).
So i got
several questions:
1. Did
someone experience something similar?
2. How should i proceed to handle my problem?
3. I know, that i should try the bundled python interpreter when observing problems like that, but: this will cost me so much time (if i even succeed), as all this big-stuff like numpy, scipy, matplotlib and much more isn't fun to install on windows (therefore i'm using Miniconda).
PLUS: the bundled interpreter (python 2.7 coming with Gurobi 6.0) even fails to install the official "get-pip.py" file ('No module named logging')
Any ideas?
Thanks in advance
Sascha
Greg Glockner
sascha...@googlemail.com
print 'Statistics'
model.printStats()
model.setParam('Presolve', 2)
model.setParam('PreSparsify', 1)
model.setParam('Threads',1)
model.setParam('MIPGap',0.01)
print 'DEBUG: pre-optimize'
model.optimize()
print 'DEBUG: optimized'--------------------
DEBUG: pre-optimize
Optimize a model with 146890 rows, 256200 columns and 14177912 nonzeros
Coefficient statistics:
Matrix range [1e+00, 9e+04]
Objective range [2e+00, 8e+01]
Bounds range [1e+00, 9e+04]
RHS range [1e+00, 2e+04]
Presolve removed 106491 rows and 183759 columns (presolve time = 5s) ...
Presolve removed 118187 rows and 200120 columns (presolve time = 10s) ...
Presolve removed 118190 rows and 200120 columns (presolve time = 23s) ...
Presolve removed 118190 rows and 200120 columns (presolve time = 25s) ...
Presolve removed 118190 rows and 206028 columns (presolve time = 30s) ...
Presolve removed 118190 rows and 206028 columns (presolve time = 35s) ...
Presolve removed 122959 rows and 209518 columns (presolve time = 49s) ...
Presolve removed 122959 rows and 209518 columns (presolve time = 50s) ...
Presolve removed 122959 rows and 209518 columns (presolve time = 55s) ...
Presolve removed 122959 rows and 209518 columns (presolve time = 63s) ...
Sparsify removed 297354 nonzeros (69%)
Presolve removed 130129 rows and 223661 columns
Presolve time: 64.65s
Presolved: 16761 rows, 33146 columns, 94580 nonzeros
Variable types: 16698 continuous, 16448 integer (16448 binary)
Presolve removed 2481 rows and 4952 columns
Presolved: 14280 rows, 28194 columns, 84687 nonzeros
Root simplex log...
Iteration Objective Primal Inf. Dual Inf. Time
0 6.3270147e+06 6.531195e+03 0.000000e+00 66s
1037 8.5616515e+06 0.000000e+00 0.000000e+00 66s
1037 8.5616515e+06 0.000000e+00 0.000000e+00 66s
Root relaxation: objective 8.561652e+06, 1037 iterations, 0.17 seconds
Nodes | Current Node | Objective Bounds | Work
Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time
0 0 8561651.53 0 33 - 8561651.53 - - 65s
0 0 8571006.17 0 48 - 8571006.17 - - 66s
0 0 8576333.26 0 50 - 8576333.26 - - 66s
0 0 8577856.68 0 51 - 8577856.68 - - 66s
0 0 8578325.69 0 53 - 8578325.69 - - 67s
0 0 8580278.10 0 54 - 8580278.10 - - 67s
H 0 0 9080499.4049 8580278.10 5.51% - 67s
0 0 8580333.49 0 53 9080499.40 8580333.49 5.51% - 67s
0 0 8581063.01 0 50 9080499.40 8581063.01 5.50% - 67s
0 0 8582869.40 0 57 9080499.40 8582869.40 5.48% - 68s
0 0 8582925.31 0 55 9080499.40 8582925.31 5.48% - 68s
0 0 8583007.76 0 59 9080499.40 8583007.76 5.48% - 68s
0 0 8583007.76 0 54 9080499.40 8583007.76 5.48% - 70s
H 0 0 9000117.6990 8583007.76 4.63% - 70s
H 0 0 8990009.3356 8583007.76 4.53% - 71s
0 0 8583007.76 0 33 8990009.34 8583007.76 4.53% - 73s
0 0 8583007.76 0 52 8990009.34 8583007.76 4.53% - 73s
0 0 8583007.76 0 52 8990009.34 8583007.76 4.53% - 73s
0 0 8583007.76 0 60 8990009.34 8583007.76 4.53% - 73s
0 0 8583486.94 0 55 8990009.34 8583486.94 4.52% - 74s
0 0 8583637.61 0 53 8990009.34 8583637.61 4.52% - 74s
0 0 8583978.29 0 63 8990009.34 8583978.29 4.52% - 74s
0 0 8583978.29 0 55 8990009.34 8583978.29 4.52% - 75s
0 2 8585058.40 0 55 8990009.34 8585058.40 4.50% - 75s
123 28 8966143.82 9 21 8990009.34 8625719.63 4.05% 144 80s
318 78 8746547.41 1 43 8990009.34 8725568.28 2.94% 147 85s
520 139 8980956.38 7 30 8990009.34 8767027.01 2.48% 160 90s
698 182 cutoff 7 8990009.34 8802937.63 2.08% 172 95s
Cutting planes:
Gomory: 3
Implied bound: 3
MIR: 39
Flow cover: 29
Observation: print of 'DEBUG: optimized' is not reached -> program seem to crash on gurobis behalf. No more python-code after is executed.