Originally posted by: Rommelds

Hello members,

We are experiencing a problem using the time-limit parameter.

In particular, we have verified that sometimes the CPLEX solver doesn't stop the search process at the desired time-limit. In particular, we fixed a time limit of 120 seconds but CPLEX stops the search at 300+ seconds.

To control the time, I'm using

execute  {
 cplex.tilim = 120;
}

How can I solve this problem?

Thanks!

Rommel.
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

That is weird. What version of CPLEX do you use?
Could you post the engine log for the offending example?
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Originally posted by: Rommelds

Daniel,

I'm using the version 12.4

I have a project in Java which calls the .mod file. The Java project contains the data to solve the model. I use de handler to get the data from the project.

However, I also consider a matrix with 60.000 lines and 5 columns!!! This data is uploaded in the .mod from a .txt file.

I use the time limit because sometimes the matrix is too big. So, I stop the model.

I use the following code:

double result = 0.0; IloOplFactory.setDebugMode(

true); IloOplFactory oplF = 

new IloOplFactory(); IloOplErrorHandler errHandler = oplF.createOplErrorHandler(System.out); IloOplModelSource modelSource = oplF.createOplModelSource(DATADIR + 
"/3D.mod"); IloCplex cplex = 

null; 

try 
{ cplex = oplF.createCplex(); 
} 

catch (IloException e) 
{ e.printStackTrace(); 
} IloOplSettings settings = oplF.createOplSettings(errHandler); IloOplModelDefinition def=oplF.createOplModelDefinition(modelSource,settings); IloOplModel opl=oplF.createOplModel(def,cplex); IloCustomOplDataSource dataSource = 

new MyCustomDataSource(oplF,cromossomo,numeroDeTipos,numeroDeCortes,quantidade,base,cuts,X,Y,Z); opl.addDataSource(dataSource); opl.generate(); 

try 
{ 

if (cplex.solve())    
{         
//time limit < 120 seconds result = opl.getCplex().getObjValue(); 
} 

else    
{                       
//time limit > 120 seconds result = 0.0; 
} ...

The tilim parameter is written in the 3D.mod
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#OPLusingCPLEXOptimizer

Originally posted by: Rommelds

Sometimes the matrix has few lines and the model uploads it fast...
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

in the 120 s do you include

opl.generate();

?

The time limit only applies to the cplex.solve();

Regards
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: Rommelds

Alex,

Thanks for the answer.

I thought the tilim was applied for all the steps to solve the model.

How can I verify if the data is loaded in 120 sec?

My model is solved very fast! But my variable matrix][, which data is taken from a .txt file, when it is too big, takes a long time to be calculated. So, if it gets 120 sec or more, I want to stop the model and return 0.0 as result.

Thanks.
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

well,

before and after

opl.generate();

you could measure the time and check whether the difference is more than 120s.
If you want the generation itself to stop if it takes too long, you could check the time in execute blocks with

execute
{
d=new Date();
}

and if the time is too big then you do fail() in order to stop the execution.

Regards
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: Rommelds

Alex,

Thanks for the answer!

It will solve my problem.

Rommel.
#DecisionOptimization
#OPLusingCPLEXOptimizer