by, 03-04-2012 at 09:57 AM (1298 Views)
1. Rules – Where conditions are specified (If a then b)
2. Facts – Simple objects (POJOs). E.g, a Bank Account fact consists of an account number, someone’s id and balance.
3. Knowledge Base –is where rules are built and loaded into a structure that gets implemented by the Rete algorithm.
4. Session – Here facts are placed. Facts are inserted into a session. A session can be State less or State full. Facts in the statefull shall be present in a constant rule alignment once they are inserted.
5. Activation – It might be a rule’s “then” part. When you find a rule to be true then place Agenda into activation. It shall be noticed that all the activations are only placed in Agenda.
6. Agenda –Activations wait to get fired in agenda. For state full sessions, all rules are being fired. Once a fact is inserted all of the activations are placed in agenda, already. When fire rules of session are called explicitly the execution of activations take place. When activation gets executed once facts might be update or retracted that may place new activations in agenda. New activations will be fired by the Drools engine until the agenda gets empty.