The easiest way to do this is to use a custom helper object eg RuleLatch(fact, "name"). You would write your rules so that for each group of mutually exclusive rules then for the fact they match against they check the absence of an appropriate RuleLatch, as part of their result part they then insert the appropriate rule latch - thereby preventing any other rule from running. The easiest way to stop processing a particular fact is to retract it. If you do need to keep it in your working memory then use the RuleLatch concept as above - each rule may check for two latches, one latch for a particular group of rules as described above, the other latch is a more global control which only a couple of rules insert. Hope that makes sense, Thomas From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of tom ska Sent: 22 July 2010 14:27 To: rules-users(a)lists.jboss.org Subject: [rules-users] Problem with DRL language/ XLS decision tables. Hello, I have a problem with defining rules. I insert many, many objects (facts) to ksession object (StatefulKnowledgeSession). I want to fire rules for all of them(facts), but I want to fire only one rule from all rules for each one fact(not always this same rule is fired, because I use salience). activation-group is not appropriate, because it works only with one object (fact) - rest is not processed by engine. Second question is: how can I stop processing rules, bot only for one fact, not for all of them. Thanks, tom. P.S. forgive me my English... :) P.S.2 Firstly I want to do this in DRL, then, I'll try with XLS, and write post if I would find problems... ________________________________ ************************************************************************************** This message is confidential and intended only for the addressee. If you have received this message in error, please immediately notify the postmaster(a)nds.com and delete it from your system as well as any copies. The content of e-mails as well as traffic data may be monitored by NDS for employment and security purposes. To protect the environment please do not print this e-mail unless necessary. NDS Limited. Registered Office: One London Road, Staines, Middlesex, TW18 4EX, United Kingdom. A company registered in England and Wales. Registered no. 3080780. VAT no. GB 603 8808 40-00 **************************************************************************************

Hi, thanks for so quick answer. I think, that using StatelessSession could be a solution, but as I understood, I have to insert only one fact to the facts base. But, I have about 2 billions of facts that I want to process with Drools, and execution time, is for me really important. A think, that inserting one fact at time means for me additional time to initialise engine (when adding a new fact, and removing old one). Am I right? Thanks :) 2010/7/22 Pavel Tavoda <pavel.tavoda(a)gmail.com&gt;

You could always have a pool of StatefulSessions that you reuse. (This would allow you to run concurrently in multiple threads as well.)  As long as these billions of facts don't need to interact that'll work fine.  However I'd suggest that you try the "rule latch" method that Thomas suggested.  That way you could tune the number of data objects you insert into a single pooled session, instead of inserting one at a time.  And I'm guessing that, no matter how efficient you get, throwing 2 billion in memory at once won't scale. :) --- On Thu, 7/22/10, tom ska <tiberium.linux(a)gmail.com&gt; wrote: From: tom ska <tiberium.linux(a)gmail.comSubject: Re: [rules-users] Problem with DRL language/ XLS decision tables. To: "Rules Users List" <rules-users(a)lists.jboss.orgDate: Thursday, July 22, 2010, 9:17 AM Hi, thanks for so quick answer. I think, that using StatelessSession could be a solution, but as I understood, I have to insert only one fact to the facts base. But, I have about 2 billions of facts that I want to process with Drools, and execution time, is for me really important. A think, that inserting one fact at time means for me additional time to initialise engine (when adding a new fact, and removing old one). Am I right? Thanks :) 2010/7/22 Pavel Tavoda <pavel.tavoda(a)gmail.com Don't know details of your problem but it's typical situation where you can use StatelessSession, insert one fact at time and use activation-group. Pavel 2010/7/22 tom ska <tiberium.linux(a)gmail.com&gt;: _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -----Inline Attachment Follows----- _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Considering that googling on "rule latch" will return this thread on gmane as the 2nd link, you might find research difficult. :)  I think Tom coined that term in this context, but it fits.  The basic idea is that you use an object as an indicator of what processing has happened, and whether or not rules should fire. class RuleLatch {   public final String name;   public final DataObject dataObject;   public RuleLatch(String name, DataObject dataObject) {     this.name = name; this.dataObject = dataObject;   } } when   data: DataObject(...selection conditions for data...)   level1Latch: RuleLatch(name == "level1Foo", dataObejct == data)   level2Latch: RuleLatch(name == "level2Bar", dataObject == data) then   ...if this rule wants to cancel all subsequent "level1Foo" it retracts level1Latch...   ...if this rule wants to cancel all subsequent "level2Bar" it retractslevel2Latch... end An alternative, more efficient, but not as OO happy way, is to put the control information into the DataObject itself.  Drools does a lot of optimization on the == tests with hashing, but if speed is a priority it might not be enough.  So... class DataObject {   public boolean level1Foo = true;   public boolean level2Bar = true; } when   data: DataObject(level1Foo == true, level2Bar == true, ...selection conditions for data... ) then   ...if this rule wants to cancel all subsequent "level1Foo" it updates level1Foo = false...   ...if this rule wants to cancel all subsequent "level2Bar" it updates level2Bar = false... end --- On Thu, 7/22/10, tom ska <tiberium.linux(a)gmail.com&gt; wrote: From: tom ska <tiberium.linux(a)gmail.com&gt; Subject: Re: [rules-users] Problem with DRL language/ XLS decision tables. To: "Rules Users List" <rules-users(a)lists.jboss.org&gt; Date: Thursday, July 22, 2010, 11:50 AM Thanks for reacting ;) I did some simulations, and after them, I want of course to parallelize this process of processing 2 billions facts. But as far as I wrote, Drools engine, can't do this. And I have to create threads manually in application (with pool of sessions). Am I right? Tuning number of data sounds fine to me, so I will try method with "rule latch" too (but I have to read about this, because, I don't know what is it, and I don't want to waste your time ;) But still I don't know how to use StatefulSessions to do this... Summarising, there are 3 methods to do, what I want to do (apart of a scalability problem - yet ;) 1.)with StatelessSession for one fact at time and "activation group" 2.)"rule latch" - I have to read more about it 3.)with a pool of StatefulSessions that I reuse - but I still don't know how to do it using StatefulSessions Really thanks for help ;) P.S. I use Drools 5 :) _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -----Inline Attachment Follows----- _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users