Predefined workers

DecisionBrain provides packaged workers that allow to solve optimization problems, with IBM Ilog optimization solver, out of the box. Two different workers are packaged, for compatibility reasons. The first one supports Cplex and CpOptimizer, using IBM ILOG Java API. The second one supports OPL, using IBM ILOG Java API. IBM ILOG CPLEX Optimization Studio 12.9 has been used.

All logs from the solvers are redirected to the Optimization Server master, and available on the web console.

Cplex / CpOptimizer worker

IBM ILOG Cplex is a solver that can handle (Mixed Integer) Linear Problems, and also convex quadratic problems. CpOptimizer, on the other hand, solves Constraint Satisfaction Problems.

Below are all tasks defined in this worker:

  • “CplexTask” can solve any problem in a format Cplex can read. The solution found by Cplex is sent back as an output, in ‘sol’ format (XML). Task inputs are:
    • The model file, in a format readable by Cplex. This is a required parameter.
    • Optionally a file containing parameters to be used by cplex, in ‘prm’ format.
  • “CpoTask” can solve problems in CPO format. This task requires a model file in ‘cpo’ format as a mandatory input. Possible outputs are:
    • The solution found by cpo, in a custom text format.
    • Or if the model is infeasible, the conflict between incompatible constraints, found by the conflict refiner.

OPL worker

OPL is the IBM ILOG Optimization Programming Language that simplifies modeling and solving optimization problems. “OplTask” can solve problems in OPL format. The solution found is sent back as an output, in standard OPL solution text format. Possible task inputs are:

  • An OPL model file, in ‘mod’ format. It is a required parameter.
  • A optional file containing data to be read by OPL, in ‘dat’ format.