planner-core | conference planning tool is used by event planning | Microservice library

We have been using OptaPlanner for a potential On-Prem/Cloud solution. We are currently using drools-rules that are compiled at runtime (i think the default behaviour?).

OptaPlanner is pulling in the "Eclipse ECJ" dependency via the Drools compiler.

optaplanner-core -> drools-compiler -> ecj

ECJ uses the EPL 1.0 licence which we have been instructed should not be distributed.

My question(s):

• Does OptaPlanner support pre-compiled drools rules?
• Are there any alternatives if we were to exclude 'ecj'?

I have a test program that uses optaplanner. There is no direct use of KIE API's but it looks like they are being invoked behind the scenes. This may be related to the fact that I am using DROOLS for the score calculation. The program works from the IDE or through maven, but I want to create a standalone jar that will not require maven. I used the maven assembly plugin to build a fat jar with all dependencies included to be run standalone.

When I run java -jar target/OptaPlannerTest-1.4-SNAPSHOT-jar-with-dependencies.jar I get :

I want to do a custom change move to chained planning entities. When certain conditions are met suppose I want to move E such that it comes after B as in the example below.

A <- B <- C and D <- E <- F become A <- C and D <- B <- E <-F

To achieve this I implemented a CustomChangeMove:

My program works fine from my IDE (IntelliJ) but for some reason, when I try to create a jar file I get following error when I run the program from a terminal:

Exception in thread "main" java.lang.NullPointerException at org.optaplanner.core.config.score.director.ScoreDirectorFactoryConfig.buildDroolsScoreDirectorFactory(ScoreDirectorFactoryConfig.java:461)

org.optaplanner.core.config.score.director.ScoreDirectorFactoryConfig.buildScoreDirectorFactory(ScoreDirectorFactoryConfig.java:331)

org.optaplanner.core.config.solver.SolverConfig.buildSolver(SolverConfig.java:220)

org.optaplanner.core.impl.solver.AbstractSolverFactory.buildSolver(AbstractSolverFactory.java:57)

org.optaplanner.EmployeeRoster.main(EmployeeRoster.java:31)

This is my line 31 in EmployeeRoster:

I have an Object like this:

What i want to achieve

Currently i am running large inputs in my OptaPlanner project and with the current implementation of the constraints they are taking a long time even to calculate the initial score. So a given solver destroys the whole benchmark because it gets stuck and can not terminate. As a score calculation type i am using Drools.

I am trying to achieve an early termination of a solver that after a certain amount of time still has not passed the initial score calculation(no "Solving started" is displayed). So in a single benchmark i want to run multiple different inputs and for each of them i want to have a given timer and if that timer expires before the initial score calculation is done i want the solver to be terminated immediately. A desirable option would be to have a percentage of how much of the score calculation was completed.

The reason why i'm not just jumping on to doing optimizations is because i want to have a baseline for comparison and keep track of the results as the optimizations go on. So the information how much percentage of the initial score calculation has passed is vital for me.

What i have/know currently

1. The version of OptaPlanner that i'm using is the one from GitHub that has the whole source code open(it is not the official version from the website which is compiled in JAR's and the core is not editable)
2. Implemented timers for each solver of the benchmark which after a given time period call the solver.terminateEarly() method.
3. Each solver runs on it's unique thread. So the relation solver : thread is 1:1. The way i am finding out which solver is currently executing the code is by doing a lookup in a Map solverMap where the key is the value of the hashCode of the thread executing the solver -> Thread.currentThread().hashCode(). As the solvers start and finish this Map is being updated. This way i am able to do the lookup from all the places (optaplanner-examples, optaplanner-core, optaplanner-benchmark projects and Drools rules(example below))
4. Found out kcontext.getKieRuntime().halt() from the Drools documentation which is used to terminate rule execution immediately.
5. Implemented specialized rules that will reach the then part after each change of a planning/shadow entity and from the then part checks first is the solver terminated early(by the corresponding Timer) and if it is calls kcontext.getKieRuntime().halt(). For example:

In the rule below the then part will be reached after each change in a ShiftAssignment instance and the rule execution will be stopped if the solver is set to be terminated early.