[rules-users] CEP accumulate unclear behavior

[Wolfgang Laun]

As to the second test, what you observe is correct. All hell would
break loose in most KBs if rules *not* referring to a certain fact would
fire when such a fact is inserted! But you can easily achieve what
you want by adding the pattern
   ServicePerformanceEvent()
in front of the accumulate CE.

The result of the third rule and test looks like a bug to me. There's
no version 5.0.4. Are you using 5.4.0? Can you try with a later
version?

-W


On 03/12/2013, ters <ters at ukr.net> wrote:
> Hi all. Respected experts of drools, please help me to understand how
> pattern
> + accumulate behave.
> I believe that an example is the best way to explain the problem, maybe it
> will look bulky, but suppose be enough.
> I use CEP and EventProcessingOption.Stream.
>
> Event class:
> /public class ServicePerformanceEvent {
> 	private String serviceName;
> 	private Integer duration;
> 	public ServicePerformanceEvent(String name, Integer duration) {
> 		serviceName = name;
> 		this.duration = duration;
> 	}
> }/
>
> There are 2 tests, 1st - with fireAllRules invocation, 2nd - with
> firwUntilHalt invocation.
> /	@Test
> 	public void *test1_FireAllRules() *throws RuleGeneratorException {
> 		System.out.println("-= 1 =-");
> 		ksession.insert(new ServicePerformanceEvent("MyService", 2));
> 		ksession.fireAllRules();
>
> 		System.out.println("-= 2 =-");
> 		ksession.insert(new ServicePerformanceEvent("AnotherService", 10));
> 		ksession.fireAllRules();
>
> 		System.out.println("-= 3 =-");
> 		ksession.insert(new ServicePerformanceEvent("MyService", 12));
> 		ksession.fireAllRules();
> 		System.out.println("---test1 end---");
> 	}
> 	@Test
> 	public void *test2_FireUntilHalt()* throws RuleGeneratorException,
> InterruptedException {
> 		System.out.println("-= 1 =-");
> 		ksession.insert(new ServicePerformanceEvent("MyService", 2));
>
> 		runFireUntilHaltThread();
> 		Thread.sleep(1000);
>
> 		System.out.println("-= 2 =-");
> 		ksession.insert(new ServicePerformanceEvent("AnotherService", 10));
> 		Thread.sleep(1000);
>
> 		System.out.println("-= 3 =-");
> 		ksession.insert(new ServicePerformanceEvent("MyService", 12));
> 		Thread.sleep(1000);
> 		System.out.println("---test2 end---");
> 	}/
>
>
> There are 3 simple rules for which I performing tests:
>
> *////First Rule:*
> declare com.test.event.ServicePerformanceEvent
>     @role( event )
> end
> rule "ServicePerformanceEvent test rule1"
>     dialect "mvel"
> 	when		
> 		$event : ServicePerformanceEvent(serviceName == "MyService");
> 	then
>         System.out.println("$event.duration = " + $event.duration);
>         System.out.println("----------FIRED----------");
> end
>
> Invocation results of the test1_FireAllRules() and test2_FireUntilHalt()
> the
> same:
> -= 1 =-
> $event.duration = 2
> ----------FIRED----------
> -= 2 =-
> -= 3 =-
> $event.duration = 12
> ----------FIRED----------
> ---test end---
>
> Actual: As expected rule fires for each new inserted event with desired
> serviceName "MyService" (- behavior is clear).
>
> *////Second rule:*
> rule "ServicePerformanceEvent test rule2"
>     dialect "mvel"
> 	when
>         accumulate(ServicePerformanceEvent(serviceName == "MyService",
> $thisDuration : duration);  $avg : average($thisDuration));
> 	then
>         System.out.println("$events avg duration = " + $avg);
>         System.out.println("----------FIRED----------");
> end
>
> Invocation results of the test1_FireAllRules() and the
> test2_FireUntilHalt()
> the same again:
> -= 1 =-
> $events avg duration = 2.0
> ----------FIRED----------
> -= 2 =-
> -= 3 =-
> $events avg duration = 7.0
> ----------FIRED----------
> ---test end---
>
> Actual: Now rule accumulates average only for events from working memory
> with desired serviceName (-this is clear) but fires only for inserted
> events
> with expected serviceName "MyService" (- not clear)
> *My expectation*: rule must fire for each currently inserted event and
> average must be calculated for all events from working memory with
> serviceName=="MyService".
>
> *////Third rule:*
> /rule "ServicePerformanceEvent test rule3"
>     dialect "mvel"
> 	when
> 		$event : ServicePerformanceEvent(serviceName == "MyService");
>                 accumulate(ServicePerformanceEvent(serviceName ==
> "MyService", $thisDuration : duration);
>                                  $avg : average($thisDuration));
> 	then
>         System.out.println("$event.duration = " + $event.duration);
>         System.out.println("$events avg duration = " + $avg);
>         System.out.println("----------FIRED----------");
> end/
>
> Invocation results of the test1_FireAllRules():
> -= 1 =-
> $events avg duration = 2.0
> ----------FIRED----------
> -= 2 =-
> -= 3 =-
> $events avg duration = 7.0
> ----------FIRED----------
> $events avg duration = 7.0
> ----------FIRED----------
> ---test1 end---
>
> Actual: In case -=3=- rule fires for each event into working memory during
> average calculation (- not clear)
> *My expectation*: firing rule only for current/last inserted event and
> calculation average for all events into working memory considering
> sevriceName=="MyService".
>
> Invocation results of the test2_FireUntilHalt():
> -= 1 =-
> $events avg duration = 2.0
> ----------FIRED----------
> -= 2 =-
> -= 3 =-
> $events avg duration = 2.0
> ----------FIRED----------
> $events avg duration = 7.0
> ----------FIRED----------
> $events avg duration = 7.0
> ----------FIRED----------
> ---test2 end---
>
> OR (with another sleep time)
> -= 1 =-
> $events avg duration = 2.0
> ----------FIRED----------
> -= 2 =-
> -= 3 =-
> $events avg duration = 7.0
> ----------FIRED----------
> $events avg duration = 7.0
> ----------FIRED----------
> $events avg duration = 7.0
> ----------FIRED----------
> ---test2 end---
>
> This results I can't explain and understand.
> Could anyone help me to understand this pattern + accumulate behavior.
>
> I spent a lot of time on my actual project task but with no result .
> *The actual task is*:
> Rule must fire for last inserted event if its serviceName equals to
> "MyService" and
> its duration greater than average duration of all events with same
> serviceName from the working memory.
> On the project we use fireUntilHalt strategy.
> I really hope and appreciate any help. Thanks in advance.
>
>
>
>
>
>
> --
> View this message in context:
> http://drools.46999.n3.nabble.com/CEP-accumulate-unclear-behavior-tp4027069.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
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