Re: [rules-users] Future events
You shouldn't base a streamed CEP application on time stamps dealt out by various systems with clocks that aren't properly synchronized using NTP or whatever. If your data doesn't conform to the very reasonable premises of some system, your application will have to handle that. (You can't tell the engineer to start the train just because your clock is fast, right?) window:time is based on the notion of CEP in real time, and the clock of the machine running the engine reads, by definition, true Time. But you can run the engine in cloud mode and reason over arbitrary intervals, e.g., by inserting Inverval facts. True, you won't have window:x any more, but from/accumulate and from/collect should suffice. -W On 14/03/2012, lexsoto lexs...@gmail.com wrote: Well, yes that is how the engine works. But should it work this way? Why fire the rule if not in the appropriate time window? This still looks wrong to me, as the intention of the rule is not observed. On the per hand, the engine does queue events in other scenarios, so it seems arbritrary. Too bad because this would be a ver nice way to model scheduled events using the temporal operators. Thanks Edson -- View this message in context: http://drools.46999.n3.nabble.com/Future-events-tp3826236p3827065.html Sent from the Drools: User forum mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
[rules-users] Future events
Hello: I have this rule: An event is inserted that has a timestamp in the future, the rule is fired. This looks like a bug, because the sliding time window has not yet met the timestamp of the event. I expect the rule to fire not immediately but only when the time reaches the event time. Is my assumption/understanding correct? -- View this message in context: http://drools.46999.n3.nabble.com/Future-events-tp3826236p3826236.html Sent from the Drools: User forum mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] Future events
An event represents something that already happened (past), so there is no such thing as a future event. You can have a fact that represents something that is scheduled to happen in the future, but that is not an event, and it can change as it is just data. Events are immutable. For instance: airport. You can have a flight scheduled to leave tomorrow at 08:00am, from gate B1. That schedule might change, because the flight can be delayed, cancelled, change gates, etc. It is just a fact in your system (e.g. ScheduledFlight). But when the flight actually departs the gate, then the system can have an event like FlightDepartedFromGate() that says the flight left the gate B1 at 08:02am. This is immutable, because it registers something that happened. Edson On Wed, Mar 14, 2012 at 1:44 PM, lexsoto lexs...@gmail.com wrote: Hello: I have this rule: An event is inserted that has a timestamp in the future, the rule is fired. This looks like a bug, because the sliding time window has not yet met the timestamp of the event. I expect the rule to fire not immediately but only when the time reaches the event time. Is my assumption/understanding correct? -- View this message in context: http://drools.46999.n3.nabble.com/Future-events-tp3826236p3826236.html Sent from the Drools: User forum mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -- Edson Tirelli JBoss Drools Core Development JBoss by Red Hat @ www.jboss.com ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] Future events
The reason is because the engine will not queue up events and wait for the correct time to deal with them. The engine assumes events always represent past times. But for past events, I am sure the window is respected. If you have a rule that counts the number of events in the last 5 hours, an event that happened 5 hours and 1 minute ago will not be in the total count. Edson On Wed, Mar 14, 2012 at 4:58 PM, lexsoto lexs...@gmail.com wrote: Thanks Edson for your reply, however I am still not clear about why the rule is firing if the time stamp of the event falls outside the time window. This can happen, for example, if the event originates in a machine with clock slightly ahead. I think the problem also occurs if the time is in the past; I would not want to take action on a future or old event. I understand that events are immutable, and I am not changing the event in any way. However, I expect the sliding time window to be changing along with the system clock until it reaches the timestamp of the event. My question still unanswered, why is the rule firing outside its time window? Is there a way to make this work? Any advice about how to address this use case? Thanks -- View this message in context: http://drools.46999.n3.nabble.com/Future-events-tp3826236p3826759.html Sent from the Drools: User forum mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -- Edson Tirelli JBoss Drools Core Development JBoss by Red Hat @ www.jboss.com ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] Future events
Well, yes that is how the engine works. But should it work this way? Why fire the rule if not in the appropriate time window? This still looks wrong to me, as the intention of the rule is not observed. On the per hand, the engine does queue events in other scenarios, so it seems arbritrary. Too bad because this would be a ver nice way to model scheduled events using the temporal operators. Thanks Edson -- View this message in context: http://drools.46999.n3.nabble.com/Future-events-tp3826236p3827065.html Sent from the Drools: User forum mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
