[rules-users] Maintaining DB/Working Memory Synchronization

[Andrew Waterman]

I was just referring to facts that we're being placed into your
statefulknowledgesession.  As I mentioned, I use a mechanism with an EJB to
manage my JPA entities before injecting them into the session.  I passed on
a blog entry with a ruleflow example as that looks to do a similar thing but
within drools, and I would be interested to hear how such an implementation
would go.  KnowledgeBase (compiled rules) and StatefulSessions (facts) are
stored and serialized independently, btw.

best wishes,

Andrew

2009/11/8 Nestor Tarin Burriel <nestabur at gmail.com>

> So, Do you mean that for serializing the state of a
> StatefulKnowledgeSession we must include our rules into a ruleflow? How do
> you upgrade your KnowledgeBase without loosing the WM state?
>
> Please check this issues:
>
> https://jira.jboss.org/jira/browse/JBRULES-1946
>
> https://jira.jboss.org/jira/browse/JBRULES-2278
>
> Nestor
>
> 2009/11/7 Andrew Waterman <andrew.waterman at gmail.com>
>
> It can depend on how you want to use working memory as well.  If you are
>> working statelessly, you can load objects through some type of transactional
>> framework, insert them into memory (or the ones relevant to you at that
>> moment in time) let Drools evaluate the objects, make changes and then
>> serialize those changes once rules have stopped firing.  I do something like
>> this using EJB and JPA.  I've been interested in pushing this into the rules
>> themselves; which I believe is now possible using the JPA support within
>> Drools flow.  This might work much better if you were using statefull and
>> long running working memory process.  Even in the event of catastrophic
>> failure, your transactionally serialized changes would still remain in the
>> database.  So you could restart and pick up work from where you were last.
>>
>> You may wish to take a look at the following blog entries:
>>
>> http://blog.athico.com/2009/03/drools-50-cr1-new-and-noteworthy.html
>>
>> And the Drools flow documentation.
>>
>> I'm hoping to move our work in this direction so please do pass on your
>> results; unless I'm completely misunderstanding how one can use flow, expert
>> and JPA together with transactions.
>>
>> best wishes,
>>
>> Andrew
>>
>> On Sat, Nov 7, 2009 at 9:23 AM, ken.p <ken.annihilation at gmail.com> wrote:
>>
>>>
>>> I am also looking similar feature. We can currently use AOP to send event
>>> to
>>> stream. However, we have events with relevant duration for days and some
>>> time weeks. If server were to restart for maintenance, how do we restore
>>> to
>>> the same state?
>>>
>>>
>>>
>>> Daniel Miller-9 wrote:
>>> >
>>> > So I hope that someone out here, or many of you, can give me some idea
>>> > of how you do this.
>>> >
>>> > I have about 20+ entities in my database that I want Drools to know
>>> > about.  Obviously my hope is to apply CEP, rules and processes to
>>> > these items.  However, I feel like I'm missing some type of connection
>>> > between how Drools recommends keeping my working memory in sync with
>>> > my database changes.
>>> >
>>> > Ideally, I'd love to be able to just update my entities as I have been
>>> > doing in the database, but have those changes automatically move their
>>> > way over into the working memory.  How do any of you recommend I
>>> > accomplish this?
>>> >
>>> > Thanks in advance for any suggestions.
>>> >
>>> > Dan Miller
>>> >
>>> > _______________________________________________
>>> > rules-users mailing list
>>> > rules-users at lists.jboss.org
>>> > https://lists.jboss.org/mailman/listinfo/rules-users
>>> >
>>> >
>>>
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>>> Sent from the drools - user mailing list archive at Nabble.com.
>>>
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>>
>>
>>
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"Against logic there is no armor like ignorance."
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