[rules-users] Firiing explicit rules

[Edson Tirelli]

   Chris,

   The decision between A and B must be taken on the basis of: do you need
to join objects from the different streams together? If so, you need A. If
not, better go with B.

   Regarding threads, the engine works with a single thread, unless you
activate the KnowledgeBase partitioning option (check the Drools Fusion
documentation), in which case the engine spawns a pool of worker threads.
The threads are not assigned to specific streams. They are used as a pool
for processing of all required rules in the knowledge base.

   In any case, as long as you don't have multiple threads concurrently
inserting facts/events into a single entry-point, everything else is thread
safe.

   []s
   Edson


2009/6/24 Chris Richmond <crichmond at referentia.com>

>  Hello,
>
>
>
>
>
> For performance reasons, assuming I am using STREAM mode, is it better to :
>
>
>
> A.     create several streams in my rule file and inject objects into
> various streams depending on my needs
>
>
>
> or
>
>
>
> B.     create a different session for each stream that I might have had in
> A. above?
>
>
>
>
>
> And if I do use option A, is my understanding correct that each stream will
> be processed on it’s own thread?
>
>
>
> And if so, I notice that I am able to update a common statistical object
> that I created within my rule file and update it from consequences on
> different streams.  If each stream is processed on it’s own thread, is
> updating of this in rule defined statistics object synchronized/thread safe?
>
>
>
> For example in my rule file I have the following “stats” object:
>
>
>
> # stats object
>
> declare ObjectStats
>
>     id : String @key
>
>     name: String
>
>     lastReadingA : int
>
>     lastReadingB : int
>
>
>
> end
>
>
>
>
>
> ….then I have the following two rules……
>
>
>
> rule "update stats from objects A”
>
>     lock-on-active
>
> when
>
>
>
>     $stats : ObjectStats( $id : id)
>
>     $a : ObjectTypeA(parentId == $id, $aValue : value) from entry-point
> “stream for objects of type a”
>
>
>
> then
>
>
>
>     modify($stats) { lastReadingA = $aValue };
>
>
>
>
>
> end
>
>
>
>
>
> rule "update stats from objects B”
>
>     lock-on-active
>
> when
>
>
>
>     $stats : ObjectStats( $id : id)
>
>     $b : ObjectTypeB(parentId == $id, $bValue : value) from entry-point
> “stream for objects of type b”
>
>
>
> then
>
>
>
>     modify($stats) { lastReadingB= $bValue };
>
>
>
> end
>
>
>
>
>
> This is working fine and the lock-on-active seems to be preventing me from
> getting the “cross product” problem, but is each of these streams processed
> independantly on their own thread?
>
>
>
> Thanks,
>
>
>
> Chris
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>


-- 
 Edson Tirelli
 JBoss Drools Core Development
 JBoss by Red Hat @ www.jboss.com
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