[rules-users] [FUSION] Detect the absence of an event when you don't know that the event is missing.

[Tina Vießmann]

Hi,

I'm working on a use case where I want to know if 20 events with a 
specific value are contained in at maximum the last 150 events. So far I 
know what have to do. ;-)
My problem is that as extension to my condition, the rule shall also 
trigger if one ore more events are missing. But I don't know the time 
interval with which the events arrive, so that I don't know when a new 
event should arrive and by implication I don't know about the absence of 
an event.

In our environment events arrive in "counts" and not in a specific time 
interval as e.g. ever 1 second.  So we talk about the last two or 150 
counts if we talk about the last two ore 150 data packages received. 
Yes, behind a count always is a time interval, but only the data source 
knows about the time interval. My recipient doesn't
Also the data of a data package is inserted in the working memory 
independently, so that I have e.g. 10 data events instead of a single 
package event.
(Now that you know that, my first sentence would be correctly: I want to 
know if 20 counts of the max. last 150 counts have contained a specific 
event.)

If my explanation (or my attempt to explain) is difficult to understand, 
please ask me what you want to know.

I would be very happy about any ideas.

Thank you.
Tina