[rules-users] Fusion and open-ended intervals?

A fusion design question: I have events that represent intervals. Initially the intervals are open-ended (kind a like the current state of an entity). Other events are matched "during" the interval and correlated. At some point the interval will be closed (eg, a specific downtime interval is closed because the device is no online again). All the events in this system are immutable -- so if some property of an event changes, it is cloned and modified in working-memory. For the case of the interval events, initially the interval is inserted open-ended, and at some point later closed and then modified. This does not work with fusion however, since an event's duration is maintained by the fact-handle not the event itself. Hence a modify with a now closed interval (ie, a finite @duration) has no effect. I'm guessing the temporal values are maintained the handle to ensure stable values for the behaviors that trigger based on temporal values, which is reasonable. So I'm looking for alternative designs. Some are: 1) Modeled the intervals as begin/end events, but that gets messy real fast (have to correlate the begin/end events somehow, can't use evaluators like 'includes' or 'during', etc). 2) Retract the interval event when it is closed (this way closed intervals no longer correlate with other incoming events). But then we really have a manually maintained state machine using only facts, and there can be no reasoning over a series these interval events. (eg, 3 downtimes longer than 2 minutes in the last hour). Opinions? -barry -- View this message in context: http://n3.nabble.com/Fusion-and-open-ended-intervals-tp719076p719076.html Sent from the Drools - User mailing list archive at Nabble.com.