[rules-users] Semantic of rules with not and coincide

[Wolfgang Laun]

The "second" event hasn't happened at the time the first has happened.
Thus, the negation (no Event coincides) *is* true.

Perhaps it helps to read "not" as "does not exist" (which is what it
actually stands for) when looking at the rule. Indeed, there *is* no
coinciding event at the time the Event is inserted.

-W


On 06/12/2013, IK81 <ml at kofler.me> wrote:
> Yes, this was my assumption and it is also what I want. I don't care if
> code C1 is reported before C2 or vice versa. They just have to happen
> within 1 minute.
>
> However, the semantic of coincide in combination with not is unclear to
> me. Why can the rule fire
> at event insertion time when the engine does not know if the second
> event will not happen without
> waiting for an additional minute?
>
> Ingo
>
> On 2013-12-06 09:22, Wolfgang Laun wrote:
>> Coincides is symmetric in time. You might want to use before or
>> after.
>> -W
>>
>>
>> On 06/12/2013, IK81 <ml at kofler.me> wrote:
>>> Dear all,
>>>
>>> I am currently stuck with a problem concerning the use of not and
>>> conincide. I want to analyze a stream of error code events from a
>>> set of
>>> devices and detect the following situations. Every event has a
>>> timestamp
>>> (long), a device id (String) and an error code (String).
>>>
>>> What I want to detect is the following
>>> - If I get two events, one with code C1 and one with C2 from a
>>> single
>>> device within 1 minute, it represents a special event combination.
>>> The
>>> order of their appearence is not relevant.
>>> - If I just get C1 (without the C2 within the time frame), just
>>> report
>>> C1
>>> - If I just get C2 (without the C1 within the time frame), just
>>> report
>>> C2
>>>
>>>
>>> I can successfully detect the special event combination with the
>>> following rule
>>>
>>> rule "Detect combination"
>>> when
>>>      $e1 : Event ($d: device, code == "C1")
>>>      $e2 : Event (device == $d, code == "C2", this coincides [1m]
>>> $e1)
>>> then
>>>      ... do some output
>>> end
>>>
>>>
>>> Then I tried to implement the detection of C1 only as follows
>>>
>>> rule "Detect code C1"
>>> when
>>> 	$e1 : Event ($d: device, code == "C1")
>>> 	not ( $e2 : Event (device == $d, code == "C2", this coincides [1m]
>>> $e1))
>>> then
>>>      ... do some other output
>>> end
>>>
>>> My understanding of the rule is that it should fire, if I get the
>>> event
>>> with code C1 and there is no other event with error code C2 for the
>>> same
>>> device that happens within one minute before and after the C1 event.
>>> To
>>> my surprise, the rule fires immediately when I insert an event with
>>> error code C1. Shouldn't the implementation wait at least 1 minute
>>> to be
>>> sure that no C2 error event will be inserted?
>>>
>>>
>>> BTW this is how I insert the events in my test case:
>>>
>>> 	clock.advanceTime(70,  TimeUnit.SECONDS);
>>> 	FactHandle handle1 = ksession.insert( new Event(65000, "A", "C1")
>>> );
>>> 	ksession.fireAllRules();
>>> 	clock.advanceTime( 10, TimeUnit.SECONDS );
>>> 	FactHandle handle2 = ksession.insert( new Event(75000, "A", "C2")
>>> );
>>> 	ksession.fireAllRules();
>>> 	clock.advanceTime( 2, TimeUnit.SECONDS );
>>>
>>> And this is mainly the output I get:
>>>
>>> detected code C1 @ 70000
>>>    event id=44b895e5-7287-404b-8204-3de5690b2360 timestamp=65000
>>> device=A code=C1
>>> detected combination @ 80000
>>>    event id=44b895e5-7287-404b-8204-3de5690b2360 timestamp=65000
>>> device=A code=C1
>>>    event id=fc89715b-fc30-4b12-ab31-a3884dcd4886 timestamp=75000
>>> device=A code=C2
>>>
>>> Any ideas concerning an alternative solution are highly welcomed.
>>>
>>> Thanks,
>>> Ingo
>>>
>>>
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
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