Originally posted by: JanChing

Hello everybody
I have a question about QP memory. There will be about 750,000 Conditions. I was using java parameters adjusted as follows.

IloCplex cplex = new IloCplex();
cplex.setParam(IloCplex.IntParam.NodeFileInd, 3);
cplex.setParam(IloCplex.Param.WorkDir, "C:\\CPLEX\\");
cplex.setParam(IloCplex.BooleanParam.MemoryEmphasis, true);

It appears an error code :

Writing 1702876MB factor matrix and 588658MB update matrix
ilog.cplex.CpxException: CPLEX Error  1801: Could not open temporary file.

When reducing conditions can be calculated by way of writes hard disk. In addition to reducing conditions than I can also adjust the parameters of what makes memory usage reduction?

Thanks a lot.

Lin

Does the directory "C:\CPLEX" exist and is writable for your application?

Originally posted by: JanChing

Yes, because I can execute reduction conditions.
I was thinking CPLEX write a lot of information temporarily(1702876MB)

The error message refers to opening the file, so even before writing anything to disk, CPLEX fails to create one of the files. Reasons for this can be:

- The directory specified via the WorkDir parameter does not exist, is not writable, or does not allow creation of additional files. Can you try without specifying the WorkDir parameter, or just setting it to "."?

- CPLEX attempts to open a file but the application has hit the maximum number of open files. What is the limit on open files per application on your system?

Could you post the full CPLEX log output? What operating system do you use?

Originally posted by: JanChing

I apologize for not making my points clear.
I conditional amount will be calculated with the goal, So some of the objectives have only 30GB can be implemented.