Re: [rules-users] Help with event not found over window query

Thanks for your email below. I needed to refactor my code somewhat to get this technique to work but it solved the problem that I had.

I was previously using fireAllRules() but I refactored the code to use fireUntilHalt() instead, which required some additional work to make a couple of other supporting features behave properly. I know you don't strictly need to do this, but it needed to be done anyway and it made sense to do it now.

I would have thought it was quite a common scenario where someone wanted to implement business logic such as: - Something happens - It is expected that something else will happen within a certain time period of the first thing happening - If the second thing doesn't happen within the time period, generate an alert

I ran into trouble because my various rules (from my original email) wouldn't fire an alert as expected when I fed in simulated events. I'm curious as to why you think it's interesting that the four rules below fail to meet my expectation? I suppose it's the fact that I'm a drools newbie and the issue here is probably just my inexperience mapping business logic into drools rules.

daveor On 15 Feb 2014, at 09:49, laune [via Drools] wrote: > It would be interesting to discuss why each of these four rules fails to > meet you expectation. Mostly it's due to the engine not evaluating > exactly one minute after the "certain event" arrives. > > The following rule fires 1 minute after the evaluation of the arrival > of an Event according to constraints and when no second Event > (according to constraints not shown) has arrived since then. > > rule "Something Else" dialect "mvel" > timer ( int: 1m ) > when > $e1: Event($location: properties["location"] && ...) > not Event(..., this after $e1) > then > ... > end > > -W > > On 14/02/2014, daveor <[hidden email]> wrote: > > > Hi there, > > > > I'm a drools newbie and I wonder if someone could help me. I'm using > > drools > > 6.0.1 and I'm trying to write a rule that fires when: > > > > 1) a certain event is seen and > > 2) a second event is not seen within a certain period of time (1 minute > > in > > the examples below) after the first event is seen > > > > I have tried the following LHS patterns: > > > > rule "Something" dialect "mvel" > > when > > $e1: Event($location: properties["location"] && ...) > > not Event(...., this after $e1) > > then > > //do stuff > > end > > > > rule "Something" dialect "mvel" > > when > > $e1: Event($location: properties["location"] && ...) > > not Event(...., this after[0, 1m] $e1) > > then > > //do stuff > > end > > > > rule "Something" dialect "mvel" > > when > > $e1: Event($location: properties["location"] && ...) > > List (size == 0) from collect (Event(..., this after $e1) over > > window:time(1m)) > > then > > //do stuff > > end > > > > > > rule "Something" dialect "mvel" > > when > > $e1: Event($location: properties["location"] && ...) > > List (size == 0) from collect (Event(...) over window:time(1m)) > > then > > //do stuff > > end > > > > The unwanted behaviours are as follows: > > > > In the first case, the rule fires immediately after the first event is > > inserted. > > In the second case, the rule fails to fire if the second event is seen > > (as > > expected) but the rule does not fire if the second event is not seen > > within > > 1 minute. > > In the third and fourth cases, the rule fires immediately after the > > first > > event is inserted. > > > > Event is a java class with a hash map of properties, defined with the > > following metadata: > > > > declare Event > > @role(event) > > end > > > > I would really appreciate if someone could help me out here. > > > > Thanks and let me know if you need any more info. > > > > Dave > > > > > > > > > > -- > > View this message in context: > > http://drools.46999.n3.nabble.com/Help-with-event-not-found-over-window-q... > > Sent from the Drools: User forum mailing list archive at Nabble.com. > > _______________________________________________ > > rules-users mailing list > > [hidden email] > > https://lists.jboss.org/mailman/listinfo/rules-users > > > _______________________________________________ > rules-users mailing list > [hidden email] > https://lists.jboss.org/mailman/listinfo/rules-users > > > If you reply to this email, your message will be added to the discussion > below: > http://drools.46999.n3.nabble.com/Help-with-event-not-found-over-window-q... > To unsubscribe from Help with event not found over window query, click > here. > NAML -- View this message in context: http://drools.46999.n3.nabble.com/Help-with-event-not-found-over-window-q... Sent from the Drools: User forum mailing list archive at Nabble.com.