Re: [rules-users] Identify Rule on Attributes
On Mon, Mar 16, 2009 at 6:24 AM, Nikhil_dev k.nik...@verchaska.com wrote: As you guys have suggested to combine all the rule base into one then for example(one which i have already mentioned) i will combine Rule1 , rule 2 and rule3 into 1 rule base then, when i pass the variables to the rulebase who will i come to know which rules were executed. Knowing (as you say) about the execution of rules may be used by the system you build in several ways. In any case, the right hand side of a rule (after the when keyword) is the place to program the actions that preserve the knowledge that this rule has fired. If nothing is done on the right hand side, then the effect of the execution of a rule is indeed lost. The most important ways of making use of the firing of a rule are: (1) To assert a (new) fact into the Working Memory. This is done if one expects these new facts to combine with each other or the original facts in more rule firings. (2) To modify an existing fact that has been found (matched) by the rule. This may, in turn, fire other rules. (3) To make use of some application service to inform the user of your system that the system has concluded a result. A very simple way would be to print a message on the terminal; a more sophisticated way might be to send a message; etc. Certainly any combination of these basic techniques is to be considered as well. You have, so far, shown us examples of very simple rules; it is not clear to me what the purpose of this system will ultimately be. Therefore, I cannot advise you about what is best in your case. things i would like to know if i am going to execute this idea, the number of rules that i will using say around 10, is it advisable to include all of them in to 1 rulebase!!! will there be any performance issues. Performance is not only a question of the number of rules; it is also a question of the quality of the conditions, the number of patterns and the number of facts that are asserted. 10 rules is certainly a big number. Memory consumption will be high. Loading facts and firing depends on the way patterns are written, and how many facts you'll have in a session. But for me the main point is how you'll manage to produce this many rules. Even if you manage to think up, write and test one rule per minute then this would take 1666 hours or about 10 months of work! Moreover, you'll have to make sure that this set of rules is consistent in their combination, e.g., that it doesn't miss a combination of facts that it should react upon. To build a good rule based system isn't easier than building any other complex software system; perhaps it is even more difficult. There are some good books around that describe the designs that might be applied with such systems; some of them are referenced on this page: http://www.jboss.org/drools/documentation.html -W Anstis, Michael (M.) wrote: Furthermore a rulebase can contain rules from many resources (e.g. DRL's). So I guess the cause of your pain is why do you need multiple rulebases!??! -Original Message- From: rules-users-boun...@lists.jboss.org [mailto:rules-users-boun...@lists.jboss.org] On Behalf Of Scott Reed Sent: 13 March 2009 14:41 To: Rules Users List Subject: Re: [rules-users] Identify Rule on Attributes A RuleBase can contain many rules, not just one. Generally we take all the rules we need for an application and we assemble them into one rulebase, so we don't have to figure out which rulebase to use. Does that help? Nikhil_dev [3/13/2009 8:16 AM] wrote: Perfect this is the situation but the only difference is the last part, Rulebase for all the 3 Rules are stored in memory. Now i have is attributes(implemented as bean class), but the issue is i dont know which Rulebase to use out of the three which is present in the memory, fetching them one by one and executing it individually is possible but a long procedure which i want to avoid.(executing 3 Rule is ok what if i have 10 rules it will be very slow process) ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users - Regards, :working:Nikhil -- View this message in context: http://www.nabble.com/Identify-Rule-on-Attributes-tp22471473p22532090.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
[rules-users] single binding for or CE flagged by compiler
As far as I know, this should work:
package orel;
import orel.Main.Trigger;
rule ror1
when
$t : (or Trigger(fa == 1)
Trigger(fa == 2))
then
System.out.println( fired + $t.getName() );
end
This is what Drools-5.0.0 kbuilder.getErrors().toString() returns:
[5,11]: [ERR 102] Line 5:11 mismatched input 'Trigger' expecting '(' in rule
ror1 in pattern or[6,14]: [ERR 102] Line 6:14 mismatched input 'Trigger'
expecting ')' in rule ror1[6,30]: [ERR 102] Line 6:30 mismatched input ')'
expecting 'then' in rule ror1
Shouldn't toString() insert line ends? As it is, the result is pretty much
useless.
This works:
rule ror1
when
(or $t : Trigger(fa == 1)
$t : Trigger(fa == 2))
then
System.out.println( fired + $t.getName() );
end
-W
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RE: [rules-users] Identify Rule on Attributes
You should create a new class that implements AgendaEventListener and then add it to your execution session. The snippet below shows how to add the listener to the session if you create a new class called ExecutionAgendaEventListener. This is 4.7, probably pretty similar concept in 5. StatelessSession session = ruleBase.newStatelessSession(); //add agenda event listener to capture the fired rules session.addEventListener(new ExecutionAgendaEventListener()); -Original Message- From: rules-users-boun...@lists.jboss.org [mailto:rules-users-boun...@lists.jboss.org] On Behalf Of Nikhil_dev Sent: Monday, March 16, 2009 1:25 AM To: rules-users@lists.jboss.org Subject: RE: [rules-users] Identify Rule on Attributes As you guys have suggested to combine all the rule base into one then for example(one which i have already mentioned) i will combine Rule1 , rule 2 and rule3 into 1 rule base then, when i pass the variables to the rulebase who will i come to know which rules were executed. things i would like to know if i am going to execute this idea, the number of rules that i will using say around 10, is it advisable to include all of them in to 1 rulebase!!! will there be any performance issues. Anstis, Michael (M.) wrote: Furthermore a rulebase can contain rules from many resources (e.g. DRL's). So I guess the cause of your pain is why do you need multiple rulebases!??! -Original Message- From: rules-users-boun...@lists.jboss.org [mailto:rules-users-boun...@lists.jboss.org] On Behalf Of Scott Reed Sent: 13 March 2009 14:41 To: Rules Users List Subject: Re: [rules-users] Identify Rule on Attributes A RuleBase can contain many rules, not just one. Generally we take all the rules we need for an application and we assemble them into one rulebase, so we don't have to figure out which rulebase to use. Does that help? Nikhil_dev [3/13/2009 8:16 AM] wrote: Perfect this is the situation but the only difference is the last part, Rulebase for all the 3 Rules are stored in memory. Now i have is attributes(implemented as bean class), but the issue is i dont know which Rulebase to use out of the three which is present in the memory, fetching them one by one and executing it individually is possible but a long procedure which i want to avoid.(executing 3 Rule is ok what if i have 10 rules it will be very slow process) ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users - Regards, :working:Nikhil -- View this message in context: http://www.nabble.com/Identify-Rule-on-Attributes-tp22471473p22532090.ht ml Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
RE: [rules-users] single binding for or CE flagged by compiler
Not getting into whether this is a bad practice, the only language I've
ever seen support this syntax is COBOL. Every other language I've worked
in (and there are many) do not support this technique, so it seems
reasonable that this syntax should be disallowed in drools as well.
From: rules-users-boun...@lists.jboss.org
[mailto:rules-users-boun...@lists.jboss.org] On Behalf Of Edson Tirelli
Sent: Monday, March 16, 2009 9:58 AM
To: Rules Users List
Subject: Re: [rules-users] single binding for or CE flagged by compiler
This is an old discussion. Single binding on or is a non-orthogonal
special case on the language syntax that was introduced in the early
days when we only had infix CEs. When we started to support prefix CE,
the special case was not updated, and as a result, the single binding
works only with infix.
IMO, this syntax promotes bad practices and should be disallowed.
Although, some people like it and it is still in there. Just to clarify
why I think it promotes bad practice:
* When you have the same object type for all the patterns inside an or
group, you should be using constraint connector ||, not the or CE.
Using your example:
$t : Trigger( fa == 1 || == 2 ) // or any variation of the syntax.
This keeps the network smaller and prevents unexpected behavior when
the constraints are not mutually exclusive and in some cases people
forget that the rule will fire once for each logical branch when using
or.
* If the object types are different, then you can't use single binding
anyway:
$o : ( Cheese() or Wine() ) // this will lead to ClassCastExceptions on
the usage of $o.
So, I really think that the single binding or fulfilled its purpose
on Drools 3, when we didn't had all the flexibility in the language we
have today. But now, the only thing it achieves is promoting bad
practices.
Just my 0.02c.
[]s
Edson
2009/3/16 Wolfgang Laun wolfgang.l...@gmail.com
As far as I know, this should work:
package orel;
import orel.Main.Trigger;
rule ror1
when
$t : (or Trigger(fa == 1)
Trigger(fa == 2))
then
System.out.println( fired + $t.getName() );
end
This is what Drools-5.0.0 kbuilder.getErrors().toString() returns:
[5,11]: [ERR 102] Line 5:11 mismatched input 'Trigger' expecting '(' in
rule ror1 in pattern or[6,14]: [ERR 102] Line 6:14 mismatched input
'Trigger' expecting ')' in rule ror1[6,30]: [ERR 102] Line 6:30
mismatched input ')' expecting 'then' in rule ror1
Shouldn't toString() insert line ends? As it is, the result is pretty
much useless.
This works:
rule ror1
when
(or $t : Trigger(fa == 1)
$t : Trigger(fa == 2))
then
System.out.println( fired + $t.getName() );
end
-W
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--
Edson Tirelli
JBoss Drools Core Development
JBoss, a division of Red Hat @ www.jboss.com
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[rules-users] Drools Boot Camp and San Francisco
I'm still trying to get budget approval. We are looking at the Hilton at the moment as expedia have rooms at $103 per day, which is very good value. I can get travel and room budget for my team, but not meeting room budget. The meeting room is $400 per day, I might be able to negotiate a little off that, and we will need sponsors to cover the price of the meeting room for the week, if this is to go ahead. We are looking at a date range of: arriving - 31 of May departure - 8th of June So we'll need a room from the 1st to the 7th, inclusive. If you are able to sponsor the meeting room for a day or two, or more :), please do let me know as soon as possible. Thanks Mark ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] Problem with updated facts
Hi, these are the rules : Rule A : rule ID_15202 ruleflow-group RG_A when i : Item(name==cheese) t : Bill(anItem==i); then t.setAmount(t.getAmount() - 100); update(t); end Rule B: rule ID_15203 ruleflow-group RG_T when t : Bill($amount : totalAmount, totalAmount (new Double(150.0).doubleValue())); then System.out.println(tot : + $tot); end It gives the correct result if shadow proxy is turned on. But all the rules are re-evaluated with the update(t). Is there another way that no-loop or lock-on-active that prevents from re-evaluating all the rules ? Thanks for your interest 2009/3/12 surya_n2007 surya_n2...@yahoo.co.in Please post the complete rule where you are updating fact. -- View this message in context: http://www.nabble.com/Problem-with-updated-facts-tp22458416p22477032.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
[rules-users] Null safe MVEL expressions
Folks, it seems that since 2.0 MVEL supports null-safe MVEL expressions, ie. fact.?property.subproperty == foo will evaluate to false (instead of failing) if property is null. I tried this some time ago and it seems that the drools parser does not like the ?. Is anybody using this? Cheers, Ingomar ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
[rules-users] Missing libs for persistence in 5.0.0CR1
Hi I have been trying to get persistence to work in 5.0.0CR1, but I have noticed that many of libs decribed in the documentation (chapter 5.1.3) are missing As they were present in M5 I'm just wondering why this is the case? Best regards Jan Petersen ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
RE: [rules-users] Identify Rule on Attributes
Responses inline below. --- On Mon, 3/16/09, Nikhil_dev k.nik...@verchaska.com wrote: From: Nikhil_dev k.nik...@verchaska.com Subject: RE: [rules-users] Identify Rule on Attributes To: rules-users@lists.jboss.org Date: Monday, March 16, 2009, 12:44 AM Greg, As of now the solutions that i have got from everyone in this forum are 1. Greg : use a rules engine that implements rete the functionality. I couldn't any for the same on any drool doc that i have (gave you the link that i am referring to.) If the verb missing in the sentence above is find then I don't think you searched hard enough: http://downloads.jboss.com/drools/docs/4.0.7.19894.GA/html_single/index.html#d0e665 Take a few minutes to read section 2.4 Rete Algorithm which is directly linked above. It specifically addresses how rules are selected to fire based on the state of your data. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] Problem with updated facts
Not addressing your stated problem, but I have one question: why are you using this expression: new Double(150.0).doubleValue() Why not just use 150.0? --- On Mon, 3/16/09, thomas moncieu thomas.monc...@gmail.com wrote: From: thomas moncieu thomas.monc...@gmail.com Subject: Re: [rules-users] Problem with updated facts To: Rules Users List rules-users@lists.jboss.org Date: Monday, March 16, 2009, 9:39 AM Hi, these are the rules : Rule A : rule ID_15202 ruleflow-group RG_A when i : Item(name==cheese) t : Bill(anItem==i); then t.setAmount(t.getAmount() - 100); update(t); end Rule B: rule ID_15203 ruleflow-group RG_T when t : Bill($amount : totalAmount, totalAmount (new Double(150.0).doubleValue())); then System.out.println(tot : + $tot); end It gives the correct result if shadow proxy is turned on. But all the rules are re-evaluated with the update(t). Is there another way that no-loop or lock-on-active that prevents from re-evaluating all the rules ? Thanks for your interest 2009/3/12 surya_n2007 surya_n2...@yahoo.co.in Please post the complete rule where you are updating fact. -- View this message in context: http://www.nabble.com/Problem-with-updated-facts-tp22458416p22477032.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
RE: [rules-users] Identify Rule on Attributes
Of course there will be performance issues. :) There are always performance issues. But the whole point of the rete algorithm is to address some performance issues, specifically those created by needing to select the next rule to fire based on how your data changed. 100k rules is a lot, but certainly within the capabilities of a rete based system. One factor that would make that many rules easier to handle would be how homogeneous their conditions are. Do the rules share many condition elements? But in general systems of that size that need to deal with that many rules simultaneously are sequential. (i.e. they don't react to modification of the data) Usually, though, you would not place 100k rules in one set. As a rule of thumb, you place rules in one set if they have tight interaction. i.e. The firing of one rule generally triggers the firing of another. This leads to rulesets that are formed around subject area, type of data processing, or stage of data processing. Just from an application architecture standpoint, it probably wouldn't make sense to have that many rules all active at once. To form sets you basically have to ask this question for each rule: after this rule fires, what other rules will most likely fire? Do that iteratively and add the resulting rules to a set. Once the set stops growing you've probably found a good ruleset. Also, there's no reason why you can't have a set of rules that decides what other rulesets should be routed to and/or loaded. Drools also has many constructs not included in the original rete algorithm for deciding whether rules should fire: no-loop, agenda-group, etc. Food for thought... --- On Mon, 3/16/09, Nikhil_dev k.nik...@verchaska.com wrote: From: Nikhil_dev k.nik...@verchaska.com Subject: RE: [rules-users] Identify Rule on Attributes To: rules-users@lists.jboss.org Date: Monday, March 16, 2009, 12:24 AM As you guys have suggested to combine all the rule base into one then for example(one which i have already mentioned) i will combine Rule1 , rule 2 and rule3 into 1 rule base then, when i pass the variables to the rulebase who will i come to know which rules were executed. things i would like to know if i am going to execute this idea, the number of rules that i will using say around 10, is it advisable to include all of them in to 1 rulebase!!! will there be any performance issues. Anstis, Michael (M.) wrote: Furthermore a rulebase can contain rules from many resources (e.g. DRL's). So I guess the cause of your pain is why do you need multiple rulebases!??! -Original Message- From: rules-users-boun...@lists.jboss.org [mailto:rules-users-boun...@lists.jboss.org] On Behalf Of Scott Reed Sent: 13 March 2009 14:41 To: Rules Users List Subject: Re: [rules-users] Identify Rule on Attributes A RuleBase can contain many rules, not just one. Generally we take all the rules we need for an application and we assemble them into one rulebase, so we don't have to figure out which rulebase to use. Does that help? Nikhil_dev [3/13/2009 8:16 AM] wrote: Perfect this is the situation but the only difference is the last part, Rulebase for all the 3 Rules are stored in memory. Now i have is attributes(implemented as bean class), but the issue is i dont know which Rulebase to use out of the three which is present in the memory, fetching them one by one and executing it individually is possible but a long procedure which i want to avoid.(executing 3 Rule is ok what if i have 10 rules it will be very slow process) ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users - Regards, :working:Nikhil -- View this message in context: http://www.nabble.com/Identify-Rule-on-Attributes-tp22471473p22532090.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] single binding for or CE flagged by compiler
2009/3/16 Edson Tirelli tire...@post.com This is an old discussion. Single binding on or is a non-orthogonal special case on the language syntax that was introduced in the early days when we only had infix CEs. When we started to support prefix CE, the special case was not updated, and as a result, the single binding works only with infix. The example I've posted is practically identical to Example 7.55, or with binding. So, if it's not in the language, it'd better not be in the documentation :-) As for the individual binding, as in (or $t : Trigger(fa == 1) $t : Trigger(fa == 2)) the documentation ought to caution against using different names, at least when these names are used on the RHS. I agree that or groups with bindings on patterns are tricky. But is the form that's now accepted by the compiler less error-prone than the one the compiler refuses? Wolfgang ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] iterating over objects in a StatelessKnowledgeSession
Michal Bali wrote: Hi, I am trying this on trunk. There is currently no way how to iterate objects in a StatelessKnowledgeSession. I've tried to use the GetObjectsCommand, however when it is executes the result is lost in the ether :). The collection of objects is not handed back to the user. I guess it should probably be added to the BatchExecutionResults? It will then be possible to access this collection of objects. You have ot specify what it is you want as an out, either as an 'out' on an inserted fact or global or a query. Please let me know if there is a different way how to iterate over objects in a StatelessKnowledgeSession. I'd like to use an ObjectFilter as well. Extend the Query interface and use that to filter the iterator on a returned query. Best Regards, Michal ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
