Error in CPLEX

[Johanna Amaya]

Hi, I am running couple of models and I got this message: "CPLEX 12.6.2.0: unrecoverable failure: CPLEX error # 1803."

Does anyone know how to fix it? I am using mipdisplay and the mode does not return the best solution found. It makes everything "0".

Thanks,

Johanna

[Victor Zverovich]

According to the documentation, error 1803 means "Failure on temporary file write":

  CPLEX was unable to write a temporary file in the directory specified by CPX_PARAM_WORKDIR.

Make sure you have permissions to write to the work directory and sufficient space on the drive that contains it. You can also change the directory via the workfiledir option.

HTH,

Victor

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[Johanna Amaya]

Got it.

Thanks

[özcan aytaç]

Hi Victor

 I have same problem in AMPL , The computer that I use  has more many accounts so I cant use the computer as a administrator and I thing that is why I get this error

I used the following codes

 "  cplex_options workfiledir 'C:\Users\zayta\Desktop\AMpL_model\temp';"

"option TEMP 'C:\Users\zayta\Desktop\AMpL_model\temp';

option TEMPDIR 'C:\Users\zayta\Desktop\AMpL_model\temp';"              

still I couldnt solve the error, 

Have you any advice different than before to solve this error ?                          

17 Şubat 2016 Çarşamba 23:44:08 UTC+1 tarihinde Victor yazdı:

[Robert Fourer]

You should be writing

option cplex_options 'workfiledir C:\Users\zayta\Desktop\AMpL_model\temp';

since the version given in your message gives an "unknown keyword" error in CPLEX. Then are you saying that, when you DO NOT give this option command, you get the "CPLEX was unable to write a temporary file in the directory" error? And also when you DO give this option command you still get the error?

If this is the situation, you should check whether these directories (folders) are writeable, by trying to create a new file in C:\Users\zayta\Desktop\AMpL_model and in C:\Users\zayta\Desktop\AMpL_model\temp. If they are not writeable, then the only solution is to find a different directory that you have permission to write in. You might try, at the beginning of your AMPL session, giving the command

option TEMP;

to see what the default temporary directory is on your system; it is likely to be something like C:\Users\zayta\AppData\Local\Temp. Then try assigning this also as the CPLEX workfiledir.

Bob Fourer
am...@googleroups.com

=======

[özcan aytaç]

Hi, Bob

I tried  the code you advised and I checked all folders can wirteble and readble also I put the my files in the default folder and with a code and without code( workfiledir, temp) I get same error. The model works very well in my personel computer but in the super computer has error. You can see the error in the picture. How can solve this ?

thanks

 
20 Ekim 2016 Perşembe 17:49:34 UTC+2 tarihinde Robert Fourer yazdı:

[Robert Fourer]

The log that you posted suggests that CPLEX ran successfully for about 35 minutes and was able to write to the temporary node file. Then the run was terminated with CPLEX error #1803, "Failure on temporary file write". Just before this error occurred, CPLEX reported the node file size as "19480.36 MB" -- over 19 gigabytes. So I suggest first investigating whether you have run out of space on the filesystem where you are trying to write the temporary file; there must be a lot more space than 19 gigabytes available on the supercomputer, but you may have to request it.

The log also shows that before the error occurred, CPLEX had stopped making any progress. The gap between the best known integer-feasible solution (36336.0500) and the best known lower bound (19668.7089) was very large (47.3%) and was being closed only very slowly, while the number of active nodes in the search tree (almost 2 million) continued to increase. Thus it is unlikely that CPLEX will complete a proof of optimality in any reasonable amount of time. You could set a time limit or node limit and accept the integer-feasible solution that CPLEX has finds, even though it has not been proved to be optimal. Or you could consider adding some constraints to tighten the formulation and improve the lower bound; see for example the suggestions in http://inside.mines.edu/~anewman/MIP_practice120212.pdf.

Bob Fourer
am...@googlegroups.com