[rules-users] Rules Engine always running

[Jones, Alan R]

Mike,
 
Thanks for you rresponse, however I'm not sure based on what we are
wanting to do that we should use a single working memory. The proposed
approach is: 
 
a rule has been added to the rule base, then a Fact (object) comes along
and we instantiate a working memory and fire all rules relative to this
working memory. The outcome from Drools is evaluated by another sw
component, and it is decided to try a different rule with a given Fact.
 
So, a new rule, rule #2, comes along with slightly different specifics
on what it is supposed to match, so it is added to the rule base. Then,
Fact #2 comes down the pipeline.  A new working memory #2 is
instantiated against the existing rulebase, Fact #2 is asserted, and
fireAllRules() called against the working memory #2.
 
The desired behavior is that only rule #2 is actually kicked into action
(against Fact #2), since the first rule and fact is done with. We don't
want the previous rules/facts in the rule base operating any longer. 
 
Maybe I just don't know enough about the proper application of rules
when solving particular problems to ask the right questions -- my task
is to expose JBoss rules as a service so I'm trying to understand a bit
about it's operation.
 
Thanks,



aj 


-------------------------------------------- 
Alan R Jones 
Boeing S&IS Mission Systems 
Denver Engineering Center (BDEC) 
303.307.3415 

 

________________________________

From: Anstis, Michael (M.) [mailto:manstis1 at ford.com] 
Sent: Wednesday, March 28, 2007 2:23 AM
To: Rules Users List
Subject: RE: [rules-users] Rules Engine always running


Hi Alan,
 
A working memory is in essence always available\running whilst there is
a reference to it; other than the "main" thread (on which your public
static void main executes) you don't need to use other threads (but this
obviously depends upon what exactly you're trying to achieve). The
Rulebase can contain all of your production rules (in fact this is
probably the recommended approach as, assuming some rules share a common
pattern, the resulting RETE network will be optimised); and you can feed
incoming objects (Facts in JBoss Rules terms) into one working memory
created from the one Rulebase. As objects are asserted patterns (LHS)
defining the rules are matched and, once fully matched, rules are
activated for execution (RHS). Unfortunately I don't have any experience
of JBoss Rules in a multi-threaded environment.
 
For example:-

	public static void main(String args[]) {
	 
	    Rulebase rb = loadRuleBase();
	    WorkingMemory wm = rb.newWorkingMemory();
	 
	    while (!exit()) {
	 
	        Collection c = getObjectsFromWherever();
	        assertObjectsIntoWorkingMemory(c, wm);
	        wm.fireAllRules();
	 
	                try {
	                    Thread.sleep(1000);
	                }
	                catch(InterruptedException ie) {
	        }
	 
	    }
	 
	}

With kind regards,
 
Mike


________________________________

	From: rules-users-bounces at lists.jboss.org
[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of Jones, Alan R
	Sent: 27 March 2007 19:05
	To: Rules Users List
	Subject: [rules-users] Rules Engine always running
	
	
	Kind of new to JBoss Rules...I'm trying to fiigure out from what
i have read so far if the following scenario is possible:
	 
	 
	1. Start up an instance of a working memory (say, with dummy
rule?) and keep it running, feeding it data objects to operate on from
time to time.
	2. As needed, kick off as many instance of working memory within
the single rule base (in a separate thread) and keep them going as in
step 1
	 
	The idea is to keep the rules engine running constantly, but
kick off separate working-memory threads for the injection of various
incoming rule sets and the objects those rule sets work on as needed.
Can anyone provide some insight to this? Pointers to examples, perhaps?
	 



	Alan J. 


	 

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