I currently ran into a problem in our Drools server.

We receive pretty large requests to our drools server farm that throws an OutOfMemoryError. Those large request shouldn't be process (they are bugs), and if a request takes more than 5s it should be canceled.

I've trying to workaround this with a custom timeout DRL rule has explained here:

    rule "Stop the rule engine after 5s"
        timer ( int: 5s )
        salience 0
    when
    then
        System.err.println("*** Stop the rule engine after 5s ***");
        drools.halt();
    end

But this rule is never taking into account. So I've tried another workaround: put my ksession.fireAllRules();in a thread, and if it takes more tahn 5 second, halt drools with ksession.halt();; like this:

    KieSessionConfiguration conf = kieServices.newKieSessionConfiguration();
    final KieSession ksession = kcontainer.newKieSession(conf);

    Thread droolsThread = new Thread(new Runnable() {
        public void run() {
            ksession.fireAllRules();                        
        }
    }, "drools");

    long tStart = System.currentTimeMillis();
    droolsThread.start();

    /*wait until the end of the Thread or 5 seconds max*/
    while (System.currentTimeMillis() - tStart < 5000 && droolsThread.isAlive())
        Thread.sleep(100);

    /*if alive for more than 5 seconds stop it*/
    if (droolsThread.isAlive())
    {
        System.err.println("timeout killing drools");
        ksession.halt();
        ksession.dispose();
    }

In this second scenario, when drools is called with the ksession.fireAllRules();, it starts executing the request, and if this a huge one throws the Exception: java.lang.OutOfMemoryError exception:

[apache-tomcat-9.0.39]: timeout killing drools
[apache-tomcat-9.0.39]:  Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "Catalina-utility-1"
java.lang.OutOfMemoryError: Java heap space

I don't know what to do to stop those large request eating all the server memory. Is it possible to stop a long request currently running in drools?