Originally posted by: SystemAdmin

[hernan said:]

Hi everybody,

I've been testing an IP with some instances and it works ok, but now I'm testing with bigger instances and get a Bus error (core dumped) when I call CPXmipopt.

I'm using CPLEX Callable Library, and I've been commented my settings (cuts, variable/node selection strategy, custom callbacks, etc.) and use everything by default, only set: CPXsetintparam (env, CPX_PARAM_SCRIND, CPX_ON), CPXsetintparam (env, CPX_PARAM_CONFLICTDISPLAY, 2), CPXsetintparam(env, CPX_PARAM_MIPINTERVAL, 1), to see if I get some useful information.

I think I've an error somewhere in my code or in stack segment (I don't know if CPXmipopt uses it heavily?), because, when I comment some constraints I don't get core dumped, but I've not found it. Moreover, before run CPXmipopt, I call CPXwriteprob and write the model to a .lp file. If I read the file using cplex command line it works ok!!!. I've been checked the indices and values vectors, the values, number of elements, etc. and I didn't found anything.

About the problem size:
number of variables: 7429 (most of them binaries, the remainders integer)
number of constraints: 13147
number of nonzero values in the constraint matrix: 259295

SunOS 5.9 / CPLEX 10.1 / GNU C++ 3.4.6

I'm not admin in the server, and for some reason I get a cored dumped when I run gdb.

Any idea??

Thanks in advance!

#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

[jgregory said:]

You did a reasonable thing by writing out the .lp file and then running it for comparison within the Interactive Optimizer.  However a slightly better thing to do is write it as a .sav file instead.  This gives you an exact binary snapshot of what's in the matrix arrays etc.  LP format differs in a couple of ways - fractional data may be truncated, and the ordering of the variables (when read back in) may result in a different solution path.

If you can reproduce the coredump using the SAV file then you have something our tech support team will be interested in investigating.  If a SAV file doesn't abort in the Interactive Optimizer then it's strong evidence that something in your program is clobbering memory.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

[hernan said:]

I can reproduce the coredump using the SAV file in CPLEX interactive optimizer. How could I contact the tech support?
Thanks for your response!

#CPLEXOptimizers
#DecisionOptimization