Hi,

I'm very new to drools and am trying to understand how "facts" are managed by the knowledge session. I've been experimenting with a simple example using drools 5.3.0. I created a simple Account class that has a single "balance" attribute. My rule tests the balance and prints a message if it is less than 100. I am creating a new instance of Account in my main method and inserting it into a stateful knowledge session.   I put this into a loop that runs 3 times and never dispose of the session. Each of my Account instances has a balance less that 100. Here is a portion of the code:

    public static final void main(String[] args) throws InterruptedException
    {
        KnowledgeBase knowledgeBase = createKnowledgeBase();
        StatefulKnowledgeSession session = knowledgeBase.newStatefulKnowledgeSession();

        for (int i = 0; i < 3; i++)
        {
            try
            {
                Account account = new Account();
                switch (i)
                {
                   case 0: account.setBalance(95);
                           break;
                   case 1: account.setBalance(85);
                           break;
                   case 2: account.setBalance(80);
                           break;
                   default: account.setBalance(80);
                }
                session.insert(account);
                session.fireAllRules();
            }
            catch (Exception e)
            {
                System.out.println("Exception: " + e.toString());
            }
            Thread.sleep(1000);
        }
    }

My rule is:
rule "basic rule"
when $a : Account (balance < 100) // condition
then System.out.println("Account balance " + $a.getBalance() + " is less than 100"); // consequence
end

What I see is that each time the loop executes only the last instance of Account seems to get triggered. I expected that each time I call "fireAllRules" it would examine all the facts in the session and execute them. So I thought the first time the loop runs I would get 1 activation, the second time the loop runs I get 2 activations, etc.

Are all 3 instances of Account still in the working memory or is the latest instance replacing the existing one? Or, once a fact triggers the rules engine, does it not trigger it again?

Thanks for any insights,
Anne