[rules-users] Cron Rule doesn't work

[Wolfgang Laun]

Would I claim such a thing without having run some tests?

Here goes. Rule:
   rule "Rule 123"
   timer (cron: 0/5 * * * * ?)
   when
   then
     Action.exec( "Rule 123" ); # prints message, dumps stack 3rd time round.
   end

Running the session:
	kSession = kBase.newStatefulKnowledgeSession(kSessionConfig,null);
	System.out.println( "inserted" );
	kSession.fireAllRules();
	System.out.println( "done firing." );

Output:
inserted
done firing.
exec call 1 for Rule 123
exec call 2 for Rule 123
exec call 3 for Rule 123
java.lang.Exception: Stack trace
	at java.lang.Thread.dumpStack(Thread.java:1249)
	at present.Action.exec(Action.java:11)
	at present.Rule_Rule_123.defaultConsequence(Rule_Rule_123.java:7)
	at present.Rule_Rule_123DefaultConsequenceInvokerGenerated.evaluate(Unknown
Source)
	at present.Rule_Rule_123DefaultConsequenceInvoker.evaluate(Unknown Source)
	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287)
	at org.drools.common.DefaultAgenda.fireTimedActivation(DefaultAgenda.java:1344)
	at org.drools.common.Scheduler$ActivationTimerJob.execute(Scheduler.java:83)
	at org.drools.time.impl.DefaultTimerJobInstance.call(DefaultTimerJobInstance.java:51)
	at org.drools.time.impl.DefaultTimerJobInstance.call(DefaultTimerJobInstance.java:14)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)
exec call 4 for Rule 123
exec call 5 for Rule 123
exec call 6 for Rule 123

Changing to fireUntilHalt() produces the very same stack trace.

-W


On 20/06/2013, Mark Proctor <mproctor at codehaus.org> wrote:
> There must be a mechanism for timers to fire. That is either fire
> fireAllRules or use fireUntilHalt, rules should not fire outside of those
> two things. Even if there is a timer, it simply puts the activation onto the
> agenda, so it fires with the fireAllRules or fireUntilHalt life cycles.
>
> Mark
> On 20 Jun 2013, at 06:05, Wolfgang Laun <wolfgang.laun at gmail.com> wrote:
>
>> Experiments (5.[2345].0) show that it's not necessary to use
>> fireUntilHalt. A rule like
>>
>> rule "Rule 123"
>> timer (cron: 0/15 * * * * ?)
>> when
>> then
>>  System.out.println("Fired 123!");
>> end
>>
>> keeps the timer task alive even when the stateful session isn't
>> evaluating rules. Just don't dispose() the session.
>>
>> @Mark: Not executing a due timer when a session is idle would be a
>> bug, or at least a very severe restriction on the way you run a
>> session with timers. Not everybody is happy with a session continually
>> alive with fireUntilHalt.
>>
>> -W
>>
>> On 20/06/2013, Mark Proctor <mproctor at codehaus.org> wrote:
>>> try fireUntilHalt, or it won't be able to fire the events as they
>>> happen.
>>>
>>> Mark
>>> On 20 Jun 2013, at 02:04, Andy <reliable.android at gmail.com> wrote:
>>>
>>>> *Issue 1*
>>>>
>>>> Steps:
>>>> 1. Add a Rule with cron + when condition always true.
>>>> 2. FireAllRules
>>>>
>>>> Expected: Cron to fire every 15 seconds
>>>>
>>>> Rule:
>>>> "
>>>> rule "Rule 123" dialect "mvel"
>>>> timer (cron:0/15 * * * * ?)
>>>> when
>>>> eval(true)
>>>> then
>>>> System.out.println("Fired!");
>>>> end
>>>> "
>>>>
>>>> Other Details:
>>>> "
>>>>   ...(initialized kagent using changeset)
>>>> 		kbase = kagent.getKnowledgeBase();
>>>> 		ksession = kbase.newStatefulKnowledgeSession();
>>>> 		ksession.fireAllRules();
>>>> "
>>>>
>>>> The same rule works fine when I insert some object.
>>>>
>>>> *Issue 2*
>>>> Inserting some object and then adding a second cron makes the previous
>>>> cron
>>>> fire twice, then thrice and so on...
>>>>
>>>> Is statefulknowledge session right choice for me?
>>>> Are there any known issues with cron rules?
>>>>
>>>> Any help/advice is appreciated. Thx!
>>>>
>>>>
>>>>
>>>> --
>>>> View this message in context:
>>>> http://drools.46999.n3.nabble.com/Cron-Rule-doesn-t-work-tp4024399.html
>>>> Sent from the Drools: User forum mailing list archive at Nabble.com.
>>>> _______________________________________________
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>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
>>>
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