[rules-users] How to query a stream of events with a dynamic event pattern

[Malinda Kaushalye]

Dear All,
I have been trying to figure our the best strategy to query a stream of events.
Basically what I need to do is match a given event pattern based on the events injected to the working memory so far. 
Event pattern is a simple expressions like (EventId=001 && EventId=023 ). I need to support AND, OR, XOR relationships of two pr more events.

e.g. (EventId=001 && EventId=023 ) || EventId=013

All the input events are of the same type but can be distinguished based on its Id attribute. They keep coming from a event source.
The event patterns are formed dynamically. These dynamic event patterns are evaluated like a query against the events so far recorded in working memory.
Im sure this is is usual requirement and there is a simple answer from Drools fusion. But so far failed to do it and now Im investigating drools template too.
If anyone has done this earlier OR know a solution for this I highly appreciate if you can share it. 
Cheers,
Malinda 


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