Question

Drools分数计算是否应该比EasyScoreCalculator更快？

根据我正在研究的问题大小，我注意到Drools的速度比EasyScoreCalculator慢2-5倍。

例如流口水

2019-09-04 04:53:47,681 [main] INFO  Solving started: time spent (86), best score (-306init/[0]hard/[0/0]soft), environment mode (REPRODUCIBLE), random (JDK with seed 0).
2019-09-04 04:53:50,263 [main] INFO  Construction Heuristic phase (0) ended: time spent (2671), best score ([0]hard/[9272/0]soft), score calculation speed (24149/sec), step total (306).
2019-09-04 04:54:02,592 [main] INFO  Local Search phase (1) ended: time spent (15000), best score ([0]hard/[9272/0]soft), score calculation speed (31552/sec), step total (38993).
2019-09-04 04:54:02,593 [main] INFO  Solving ended: time spent (15001), best score ([0]hard/[9272/0]soft), score calculation speed (30079/sec), phase total (2), environment mode (REPRODUCIBLE).

EasyScoreCalculator

2019-09-04 04:53:10,282 [main] INFO  Solving started: time spent (8), best score (-306init/[-306]hard/[0]soft), environment mode (REPRODUCIBLE), random (JDK with seed 0).
2019-09-04 04:53:10,972 [main] INFO  Construction Heuristic phase (0) ended: time spent (699), best score ([0]hard/[9272]soft), score calculation speed (90657/sec), step total (306).
2019-09-04 04:53:25,273 [main] INFO  Local Search phase (1) ended: time spent (15000), best score ([0]hard/[9272]soft), score calculation speed (109948/sec), step total (193419).
2019-09-04 04:53:25,273 [main] INFO  Solving ended: time spent (15000), best score ([0]hard/[9272]soft), score calculation speed (108976/sec), phase total (2), environment mode (REPRODUCIBLE).

我在该测试中使用的唯一Drools规则如下：

rule "Maximise number of picked up parcels"
    when
      $job: Job(vehicle != null && vehicle.getVehicleType() != VehicleType.DUMMY)
    then
    scoreHolder.addSoftConstraintMatch(kcontext, 0, $job.getNumberOfParcels());
end

在EasyScoreCalculator中，它看起来像：

public void calculateScore(VehicleRoutingSolution solution) {

    int numberOfPickedUpParcels = 0;

    List<Job> jobsList = solution.getJobs();

    for (Job job : jobsList) {

      Vehicle vehicle = job.getVehicle();

      if (vehicle!= null) {
        if (VehicleType.DUMMY != vehicle.getVehicleType()) {
          numberOfPickedUpParcels += job.getNumberOfParcels();
        }

    }

    int[] constraints = new int[1];
    int[] objectives = new int[1];

    constraints[0] = 0;
    objectives[0] = numberOfPickedUpParcels;

    return BendableScore.of(constraints, objectives);
  }

这不是很奇怪吗？是因为我的规则效率低下，还是Drools分数计算比简单容易慢？

Answer 1

Drools分数计算是增量式的，因此它的扩展性比EasyScoreCalculator（非增量式）好得多。

但是，Drools确实会带来性能开销，因此对于较小的数据集，该开销可能会抵消缩放增益。使用optaplanner-benchmark来尝试3个不同的数据集，每次将其大小加倍，并查看基准测试报告中的效果图。

流口水比EasyScoreCalculator [OptaPlanner]慢得多

1 个答案: