SEVERE: The web application [] created a ThreadLocal with key of type [scala.concurrent.forkjoin.ForkJoinPool.ThreadSubmitter] (value [scala.concurrent.forkjoin.ForkJoinPool$ThreadSubmitter@603fe663]) and a value of type [scala.concurrent.forkjoin.ForkJoinPool.Submitter] (value [scala.concurrent.forkjoin.ForkJoinPool$Submitter@32e9ef3]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.

    @Override
    public void destroy() {
        final SpringContextHelper springContextHelper = new SpringContextHelper(getServletContext());
        final ActorSystem system = springContextHelper.getBean("localActorSystem", ActorSystem.class);
        system.shutdown();
        system.awaitTermination();
        super.destroy();
    }