OptaPlanner - CloudBalancingHelloWorld.java - can't reach solver.getBestSolution ()?

Question:

In the example - CloudBalancing, why can't this application reach solver.getBestSolution()

? The app always runs on solver.solve(unsolvedCloudBalance);

.

Any suggestions?

Some possible solutions here are to end with solver.solve(unsolvedCloudBalance);

and then get solver.getBestSolution()

?

/*
 * Copyright 2012 JBoss Inc
 *
......
 */

......

public class CloudBalancingHelloWorld {

    public static void main(String[] args) {
        // Build the Solver
        SolverFactory solverFactory = SolverFactory.createFromXmlResource(
            "org/optaplanner/examples/cloudbalancing/solver/cloudBalancingSolverConfig.xml");
        Solver solver = solverFactory.buildSolver();

        // Load a problem with 2 computers and 6 processes
        CloudBalance unsolvedCloudBalance = new CloudBalancingGenerator().createCloudBalance(2, 6);

        // Solve the problem
        System.out.println("Test - solver - before");
        solver.solve(unsolvedCloudBalance);
        System.out.println("Test - solver - after");

        // Display the result
        CloudBalance solvedCloudBalance = (CloudBalance) solver.getBestSolution();
        System.out.println("\nSolved cloudBalance with 2 computers and 6 processes:\n"
            + toDisplayString(solvedCloudBalance));
    }

    public static String toDisplayString(CloudBalance cloudBalance) {
        StringBuilder displayString = new StringBuilder();
        for (CloudProcess process : cloudBalance.getProcessList()) {
            CloudComputer computer = process.getComputer();
            displayString.append("  ").append(process.getLabel()).append(" -> ")
                .append(computer == null ? null : computer.getLabel()).append("\n");
        }
        return displayString.toString();
    }

}

      

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2 answers


I am assuming that you have not edited the Solver config file XML.

If you look at the XML file that you load the Solver config from , there is no interrupt clause in it. Basically, you say Solver works forever.



You can edit the XML solver configuration file so that it exits after a certain condition. See the documentation on how to do this.

If you want to do this programmatically, take a look at the JavaDoc: SolverConfig # setTerminationConfig method of the SolverConfig class and the TerminationConfig class . You will need to edit the SolverConfig SolverFactory after loading the XML file: see SolverFactory # getSolverConfig method .

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Thanks a lot oskopek, this issue was resolved after your suggestion.

Your suggestion:

You can edit the XML solver configuration file so that it exits after a certain condition. See the documentation on how to do this.

What I've done:



Modify cloudBalancingSolverConfig.xml

, use completion as shown below. Then the app exits after 120 seconds.

<termination>
    <secondsSpentLimit>120</secondsSpentLimit>
</termination>

      

Below is the output of the application for 2 computers and 6 processes:

09:57:24.791 [main] INFO  o.d.c.k.b.impl.KieRepositoryImpl - KieModule was added: MemoryKieModule[releaseId=org.default:artifact:1.0.0-SNAPSHOT]
09:57:24.963 [main] DEBUG o.drools.core.impl.KnowledgeBaseImpl - Starting Engine in PHREAK mode
Test - solver - before
09:57:25.182 [main] INFO  o.o.core.impl.solver.DefaultSolver - Solving started: time spent (110), best score (uninitialized/0hard/0soft), environment mode (REPRODUCIBLE), random (JDK with seed 0).
09:57:25.213 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (0), time spent (141), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@34abdee4 => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.228 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (1), time spent (156), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@1494b84d => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.228 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (2), time spent (156), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@655a5d9c => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.244 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (3), time spent (172), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@1b5bc39d => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.244 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (4), time spent (172), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@bc57b40 => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.260 [main] DEBUG o.o.c.i.c.DefaultConstructionHeuristicPhase -     CH step (5), time spent (188), score (0hard/-6000soft), selected move count (2), picked move (com.optaplanner.cloudbalancing.domain.CloudProcess@21362712 => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:57:25.260 [main] INFO  o.o.c.i.c.DefaultConstructionHeuristicPhase - Construction Heuristic phase (0) ended: step total (6), time spent (188), best score (0hard/-6000soft).
09:57:25.712 [main] DEBUG o.o.c.i.l.DefaultLocalSearchPhase -     LS step (0), time spent (640), score (0hard/-8000soft),     best score (0hard/-6000soft), accepted/selected move count (1000/1000), picked move ([com.optaplanner.cloudbalancing.domain.CloudProcess@2575f671, com.optaplanner.cloudbalancing.domain.CloudProcess@72bca894, com.optaplanner.cloudbalancing.domain.CloudProcess@503d56b5, com.optaplanner.cloudbalancing.domain.CloudProcess@433ffad1, com.optaplanner.cloudbalancing.domain.CloudProcess@1fc793c2, com.optaplanner.cloudbalancing.domain.CloudProcess@324dcd31] => com.optaplanner.cloudbalancing.domain.CloudComputer@758f4f03).
09:59:25.083 [main] DEBUG o.o.c.i.l.DefaultLocalSearchPhase -     LS step (1), time spent (120011), score (0hard/-6000soft),     best score (0hard/-6000soft), accepted/selected move count (0/10162968), picked move ([com.optaplanner.cloudbalancing.domain.CloudProcess@503d56b5, com.optaplanner.cloudbalancing.domain.CloudProcess@72bca894, com.optaplanner.cloudbalancing.domain.CloudProcess@324dcd31, com.optaplanner.cloudbalancing.domain.CloudProcess@433ffad1, com.optaplanner.cloudbalancing.domain.CloudProcess@2575f671, com.optaplanner.cloudbalancing.domain.CloudProcess@1fc793c2] => com.optaplanner.cloudbalancing.domain.CloudComputer@1f130eaf).
09:59:25.083 [main] INFO  o.o.c.i.l.DefaultLocalSearchPhase - Local Search phase (1) ended: step total (2), time spent (120011), best score (0hard/-6000soft).
09:59:25.083 [main] INFO  o.o.core.impl.solver.DefaultSolver - Solving ended: time spent (120011), best score (0hard/-6000soft), average calculate count per second (84692), environment mode (REPRODUCIBLE).
Test - solver - after

Solved cloudBalance with 2 computers and 6 processes:

      

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