title: Sequencing the facts for rules processing
body: <p>We have a scenario where facts need to be processed in insertion sequence or as per date associated with the fact. To be precise, I need to add the transactions till the sum reaches a threshold. The moment the threshold is reached, I need to ignore rest of the transactions. Hence the order of transactions by time is important. 
  Here is the sample code that I am working with:</p>
  
  <pre><code>declare HasTransactionDetails
      @role(event)
      @expires(1d)
      @timestamp (txnDate)
  end
  
  dialect "mvel" 
  
  rule "Max per day"
      agenda-group "evaluate"
      no-loop true
      lock-on-active true
      when
          tp : TransactionProfile(maxAmount != null,
                  maxAmountPeriod.value == "Day")
          tr : HasTransactionDetails() from entry-point "transactionEntry"
          helper : ProfileTransactionMatchHelper(profileId == tp.id, txnId == tr.txnId)
  then
  ...
  ...
  </code></pre>
  
  <p>And the way I invoke it:</p>
  
  <pre><code>KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
  KieBaseConfiguration kieConfiguration = KieServices.Factory.get().newKieBaseConfiguration();
  kieConfiguration.setOption(EventProcessingOption.STREAM);
  KieServices ks = KieServices.Factory.get();
  KieContainer kContainer = ks.getKieClasspathContainer();
  KnowledgeBase kieBase = KnowledgeBaseFactory.newKnowledgeBase(kieConfiguration);
  
  kieBase.addKnowledgePackages(kbuilder.getKnowledgePackages());
  KieSessionConfiguration sessionConfiguration = KnowledgeBaseFactory.newKnowledgeSessionConfiguration();
  sessionConfiguration.setOption(ClockTypeOption.get("realtime"));
  
  KieSession session = kContainer.newKieSession("TransactionSession", sessionConfiguration);
  EntryPoint entry = session.getEntryPoint("transactionEntry");
  for (Object fact : facts) {
    if (fact instanceof HasTransactionDetails) {
      entry.insert(fact);
    }
    session.insert(fact);
  }
    session.fireAllRules();
  </code></pre>
  
  <p>So, I have set the mode to STREAM, defined a stream 'transactionEntry', added all transaction facts to this stream and rest of the facts to session, marked the timestamp on the transaction fact, and fired rules in the end. 
  My expectation was that all the transaction facts would be processed in the order of the 'txnDate' specified on the transaction fact but the order is always random.</p>
  
  <p>I did read this <a href="https://dzone.com/articles/introduction-to-complex-event-processing-using-dro" rel="nofollow noreferrer">example</a> where to ensure facts are processed in order, rules were being fired after adding a fact in session and this was done for each fact. This did not make sense to me.
  Can someone please guide me if my expectation was wrong or any step I missed?</p>