Pyomo breaks when solving iteratively

Question

I am doing a loop across year, and for each year I solve an optimization problem. Inside the loop I do:

        #Optimization
        opt = SolverFactory("ipopt")
        results = opt.solve(model3 , keepfiles=False, load_solutions=False)
        model3.solutions.load_from(results)

The program works well, but I am having some times (randomly) this problem:

File "", line 47, in results = opt.solve(model3 , keepfiles=False, load_solutions=False)

File "C:\Users\escriva\AppData\Local\Continuum\anaconda3\lib\site-packages\pyomo\opt\base\solvers.py", line 631, in solve result = self._postsolve()

File "C:\Users\escriva\AppData\Local\Continuum\anaconda3\lib\site-packages\pyomo\opt\solver\shellcmd.py", line 282, in _postsolve os.remove(self._soln_file)

PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\Users\escriva\tmpc2aly83o.pyomo.sol'

Then, I run it again and it works, but it breaks again (randomly) several years later. I think that it's related to the next iteration of the optimization having problems because the past optimization is not totally cleared up.

Any help?

Thanks so much in advance!

Alvar Escriva-Bou Alvar Escriva-Bou · Accepted Answer · 2019-03-04T23:42:21

I think that I solved my question:

I was working on my Dropbox directory an someone told me that this might be the cause of the slow response when deleting solver files.

So I moved my directory to my C drive and now I don't have any problem.

Hope this is helpful!

Pyomo breaks when solving iteratively

1 Answers