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javaspringspring-bootoptaplanner

Spring drastically slows down score evaluation speed of Optaplanner solver

I have a following piece of code

@SpringBootApplication
public class ServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ServerApplication.class, args);

        OptimalTerminationTimeFinder.findOptimalTerminationTime(
            8,
            10,
            50,
            Duration.ofSeconds(1),
            Duration.ofMillis(250));
}

where OptimalTerminationFinder solves hundreds of problems and tries to find the best termination time for a given problem size.

The problem is that when I comment the annotation @SpringBootApplication, the score evaluation speed increases from 40k to 80k and vice versa.

Why is Spring slowing down the solver so much? I read the user guide for Spring and the only difference is that they use a SolverManager but that's not the problem, is it? I just use the Solver class.

I cannot afford such a drastic speed decrease with Spring - the time difference is crucial at the production.

Solution

  • I reproduced the performance difference with java-spring-boot quickstart.

    I believe the slower calculation speed is somehow caused by running the application using the spring-boot-maven-plugin (I assume the plugin is also used by your IDE if you try to run a @SpringBootApplication annotated class).

    If you first build an executable JAR of your project and then run the JAR either in your IDE or from the terminal using java -jar ..., you'll see the full speed score calculation.

    I don't have an explanation of why the Spring Boot Maven Plugin prevents full performance but the production build of your application won't suffer from that.