RS00468: OPL SCRIPT PERFORMANCE DEGRADES DRASTICALLY OVER TIME WHEN ARRAYS ARE USED

APAR status

• Closed as program error.

Error description

• When large arrays are used in OPL Scripts, the performance may
  degredate over time because garbage collection may be invoked
  too frequently.
  

Local fix

• Allocate arrays as model data.
  
  So for the code below:
  
  execute {
      var b = new Array();
      for (var i=0; i < 1000; i++) {
       b[i] =  new Array();
       for (var j=0; j < 1000; j++) {
        b[i][j]=2*j;
    }
   }
  }
  
  Reformulate it as the following:
  
  range is = 0..999;
  range js = 0..999;
  
  int b[is][js];
  
  execute {
      for (var i in is) {
       for (var j in js) {
        b[i][j]=2*j;
    }
   }
  }
  

Problem summary

• When memory allocation in script exceeds a certain threshold,
  garbage collection can start occurring on every script statement
  hence, slowing down script execution significantly.
  

Problem conclusion

• Issue has been resolved and fix is available with CPLEX
  Optimization Studio 12.3.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  ILOG OPL-CPLEX

• Fixed component ID

  5724Y5400

Applicable component levels

• RC20 PSY

     UP