How to Access and Execute Rules from Database
by Ashish Soni
Hi All ,
I am able to configure oracle database in drools but now i am not able to
find how can i load rules from the DB and execute them , I gone through the
documentation but not able to get much information or might be i am missing
something.
If any one can provide me a example or some pointer ,hints then it would be
helpful.
Regards,
Ashish
15 years, 3 months
About for and inheritance
by Chris Woodrow
Hi,
I recently find out a few issues using for, and I wanted to share it with
you. I made a simple exemple to illustrate my purpose.
My classes are (I did not represent accessors & constructors):
public class Cheese {
protected String name;
}
public class FrenchCheese extends Cheese{
private String smell;
}
public class Person {
private Cheese likes;
}
Here is my rule set :
package rules
rule "likes cheese"
when
$person : Person ()
Cheese( ) from $person.getLikes()
then
System.out.println("likes cheese");
end
rule "likes french cheese"
when
$person : Person ()
FrenchCheese( ) from $person.getLikes()
then
System.out.println("likes french cheese");
end
First test :
Cheese cheese = new FrenchCheese("good", "camembert");
Person person = new Person();
person.setLikes(cheese);
Output :
likes french cheese
likes cheese
Wich is expected...
Second test :
Cheese cheese = new Cheese();
Person person = new Person();
person.setLikes(cheese);
Output :
likes french cheese
likes cheese
That's the first strange thing. As far as I am concerned, rule "likes french
cheese" should not match (since a Cheese is not a FrenchCheese).
I made a change to the second rule :
rule "likes french cheese"
when
$person : Person ()
FrenchCheese( smell == "good" ) from $person.getLikes()
then
System.out.println("likes french cheese");
end
Third test :
Cheese cheese = new Cheese();
Person person = new Person();
person.setLikes(cheese);
output :
It throwed an exception : Exception in thread "main"
java.lang.ClassCastException: rules.Cheese
I am not saying the ClassCastException is not to expect in such a case but I
think I would simply expect it not to match (as far as a Cheese is not a
FrenchCheese).
Chris
15 years, 9 months
Drools 4.0, Support for multiple pattern in accumulate source pattern
by Juergen
It appears as if accumulate does support only a single pattern CE as
source pattern, e.g.:
Number() from accumulate(
Cheese(
price : price
),
sum( price )
)
Is it possible to have more than one pattern in the source pattern, e.g.:
Number() from accumulate(
Cheese(
price : price,
type : type
)
Person(
favouriteCheese == type,
age > 30
),
sum( price )
)
The same could be said for collect, but there the problem to specify
which item of a matching tuple is to be collected, but this could be
handled recreating collect via accumulate, e.g.:
Collection() from accumulate(
cheese : Cheese(
type : type
)
Person(
favouriteCheese == type,
age > 30
),
collect( cheese )
)
15 years, 10 months
Blurring the lines of jBPM and Drools
by keithnielsen
I have been researching both jBPM and Drools for sometime now and am
wondering what the future holds for jBPM. This is based on my research of
Drools 5, which is bringing what I would consider more BPM constructs into
the core engine, things such as Wait States, Human Tasks, etc. One of the
main things I don't see yet is the whole persistence and support of long
running processes. My question is will the trend with Drools continue,
eventually consuming jBPM?
I must say that my perception is that Drools is more active which makes me
wonder if I should go with Drools hoping that it builds out more BPM
features going forward.
Thanks
--
View this message in context: http://www.nabble.com/Blurring-the-lines-of-jBPM-and-Drools-tp20099731p20...
Sent from the drools - user mailing list archive at Nabble.com.
15 years, 11 months
Decision Tree input?
by Wilson O Ojwang
All,
Is there something in the works to support Decision Tree Inputs in
addition to Decision Table?
Regards
Wilson
16 years, 2 months
Drools Roadmap - Planned Release 5.1 release date
by McDonald, Daniel
Hi,
I was wondering if there is a planned release date for Release 5.1?
Thank you,
Daniel McDonald
Fidelity National Information Services - Research & Development
Office phone: (972) 691-6593
Mobile phone (214) 697-8163
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16 years, 4 months
ANT Compile issues
by Bhamidi, Krishna
Hi,
I am using DROOLs 5.0.0 CR1 and use the compiler from Drools-Ant. When I attempt to execute the rules using a rule agent, I get an exception that in part reads
java.lang.NullPointerException
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1820)
(Full stack follows this e-mail.) However, when I download the pkg file for the same ruleset from Guvnor and use it in the rule agent, it runs fine.
I use the following for building -
<taskdef name="compiler" classname="org.drools.contrib.DroolsCompilerAntTask" classpathref="compiler.classpath" />
<compiler srcdir="../${rulesDirectory}" tofile="../${buildDirectory}/${projectName}_rules.pkg"
classpath="../${buildDirectory}/${projectName}_rules.jar"
binformat="package">
<include name="*.drl" />
<include name="*.brl" />
<include name="*.xml" />
<include name="*.dslr" />
<include name="*.xls" />
</compiler>
What I should do to compile correctly?
Full Stack
java.lang.NullPointerException
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1820)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at org.drools.rule.DialectRuntimeRegistry.readExternal(DialectRuntimeRegistry.java:41)
at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1755)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1717)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at org.drools.rule.Package.readExternal(Package.java:197)
at java.io.ObjectInputStream.readExternalData(ObjectInputStream.java:1755)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1717)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at org.drools.util.DroolsStreamUtils.streamIn(DroolsStreamUtils.java:189)
at org.drools.util.DroolsStreamUtils.streamIn(DroolsStreamUtils.java:158)
at org.drools.agent.FileScanner.readPackage(FileScanner.java:136)
at org.drools.agent.FileScanner.getChangeSet(FileScanner.java:82)
at org.drools.agent.FileScanner.loadPackageChanges(FileScanner.java:56)
at org.drools.agent.DirectoryScanner.loadPackageChanges(DirectoryScanner.java:69)
at org.drools.agent.RuleAgent.checkForChanges(RuleAgent.java:410)
at org.drools.agent.RuleAgent.refreshRuleBase(RuleAgent.java:362)
at org.drools.agent.RuleAgent.configure(RuleAgent.java:347)
at org.drools.agent.RuleAgent.init(RuleAgent.java:247)
at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:187)
at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:147)
16 years, 5 months
Performance of compiler
by Christian Nedregård
Hi.
My environment: Win XP SP3, 2x2.13 GHz cpu, 3GB RAM, Drools 4.0.7, JDK
1.4.2_11, java compiler: JANINO, dialect: java.
We have about 850 drl's with 5 - 10 conditions in each. 0 -2 evals in each.
The drl's only contain one rule each.
We are using Drools programatically by compiling the drls using
PackageBuilder.addPackageFromDrl and adding them to a RuleBase using
RuleBase.addPackage(PackageBuilder.getPackage())
When we are building our rule base we are never able to compile more than 1
-2 rules per second, which means we need over 10 minutes (at 100% cpu) to
build our rulebase.
Profiling shows 68% cpu time in
org.drools.rule.builder.GroupElementBuilder.build and 18% cpu time in
org.codehaus.janino.Compiler.compile.
We have experimented by changing the compiler to ECLIPSE and the dialect to
mvel but the results are the same.
We have experimented using one PackageBuilder instance per drl or grouping
drls by package and sharing a builder per package. Same result in both
scenarios.
We have also expermimented with compiling concurrently in serveral threads.
Again, about the same result.
My question is: Is this the performance we can expect from the compiler or
are we doing something fundamentally wrong?
Below is an example of one of our drls. This one contains no evals, but
still takes more than 1 second to compile. If anyone can spot some issues
with the way we are doing things the feedback would be much apreciated :)
------------------------------------
package domain.core.productoffer.rules.subscriptiontype
import type.productoffer.ProductOfferRuleEvent
import domain.core.subscription.Subscription
import domain.core.subscription.SubscribedService
import type.subscription.ActionTypeEnum
import domain.core.productoffer.ProductOffer
import domain.rules.RuleEvent
global domain.core.productoffer.RuleValidationReport validationResult
rule "RequiredVProducts"
when
ProductOfferRuleEvent(id == '3')
ProductOffer(id.value == 31963)
$subscription:Subscription()
not ( SubscribedService(status != ActionTypeEnum.REMOVE_CANCEL &&
productId.value in (57, 69) ) from
$subscription.getAllChildSubscribedServices())
then
validationResult.addValidationMessage("2069", "For product offer
rule event with id '3' and product offer with id=31963 subscription must
have one of the following VProducts: 57, 69.");
end
------------------------------------
Regards
Christian Nedregård
16 years, 6 months
Upgrade to Drools 5 - loss of performance
by Scott Reed
I just upgraded our app from Drools 4 to 5 libraries. We just use the
rules engine with DRL. The performance of the engine on our rulebase is
unacceptably slow. I assume there is something we need to do to our
rules or the way we are configuring the engine to fix this. I don't see
anything in the release notes about backwards compatibility issues. I
would very much appreciate it if someone would direct me to any
documentation that explains what needs to be done so our 4.0 rules
perform at least as well as they did before the upgrade?
Thanks,
Scott
16 years, 9 months
