[rules-users] Implementing Timers With Drools Persistence Enabled

[Tan Hui Onn]

I just found out that this is a (fixed) known issue:
https://jira.jboss.org/browse/JBRULES-2552
Deadlock when using fireUntilHalt on SingleSessionCommandService


On Tue, Jul 13, 2010 at 7:49 PM, Tan Hui Onn <huionn at gmail.com> wrote:
> Hi Nick,
>
> You are absolutely right that the timer is not triggered in
> CommandBasedStatefulKnowledgeSession (which is used for JPA
> persistence). I have spent some time to troubleshoot it. There is some
> finding regarding to this problem. Maybe other experts are willing to
> solve it.
>
> In org.drools.persistence.processinstance.JPASignalManager, when the
> signal is triggered in method
> signalEvent(long processInstanceId,
>                            String type,
>                            Object event),
> the thread is blocked in
>    >> commandService.execute(command);
>
> I used debugger to trace it, and found that
> SingleSessionCommandService.execute(GenericCommand<T>) is
> synchronized.
>
>
> I think the cause of untriggered timer is due to blocked
> "commandService.execute(command)" in JPASignalManager.
>
> (I am using drools-5.1.0.M2)
> On Tue, Jul 13, 2010 at 6:09 AM, nanic23 <nanic23 at hotmail.com> wrote:
>>
>> Hi cafebabe,
>>
>> Thanks for your comment. I agree with you that work item ids are database
>> primary keys but in this simple (very simple) case I just decided to
>> harcoded as I know for a fact that the work item id is 1 because that is the
>> only work item and each time I run the test the tables are dropped and
>> recreated. So, there is never more than one row in the workItemInfo table
>> and the only row always has 1 as its id.
>> I could have stored the work item id or a work item object as a variable
>> (like you mentioned) but in this case wouldn't make a difference for the
>> timers.
>>
>> Are timers working for you when you use persistence? I do complete work
>> items by workItem.getId() in all my code (other than this simple example
>> :)). My problem is NOT completing the work item, my problem is triggering
>> timers when persistence is enabled. The timers don't even trigger, thing
>> that should happen before even trying to complete the work item.
>>
>> Thanks,
>>
>> Nick.
>>
>>
>> --
>> View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Implementing-Timers-With-Drools-Persistence-Enabled-tp923142p961658.html
>> Sent from the Drools - User mailing list archive at Nabble.com.
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>