Problem with JPA session persistence in Drools Flow (5.0.1)
by Alan.Gairey＠tessella.com
I'm currently using Drools Flow with JPA session persistence enabled as
described in section 5.1 of the User Guide.
As a process executes, session information is saved to the H2 database
correctly.
The problem comes if a process only executes part way through, and I then
try to finish the process by recreating a session using the code:
// recreate the session from database using the sessionId
ksession = JPAKnowledgeService.loadStatefulKnowledgeSession( sessionId,
kbase, null, env );
This gives me a NullPointerException.
Having looked into the Drools Flow source code, I think the problem is in
the class
drools-persistence-jpa\src\main\java\org\drools\persistence\session\SingleSessionCommandService.java.
The 4th constructor of this class is called as part of the loading of a
knowledge session from the H2 database; this in turn leads to the
afterCompletion method of the inner class SynchronizationImpl being
called. The final two lines of this method are:
((JPAProcessInstanceManager) ((ReteooWorkingMemory)
session).getProcessInstanceManager()).clearProcessInstances();
((JPAWorkItemManager) ((ReteooWorkingMemory)
session).getWorkItemManager()).clearWorkItems();
However, when called via the route described above, the session member
variable of SingleSessionCommandService has not been set, thus causing the
NullPointerException.
(Interestingly, running the unit tests for drools-persistence-jpa does
result in the NullPointerException being thrown multiple times, although
the tests are still listed as having passed.)
I believe enclosing the above two lines as follows will fix the problem:
if (session != null) {
((JPAProcessInstanceManager) ((ReteooWorkingMemory)
session).getProcessInstanceManager()).clearProcessInstances();
((JPAWorkItemManager) ((ReteooWorkingMemory)
session).getWorkItemManager()).clearWorkItems();
}
Also, in the 4th constructor of SingleSessionCommandService, after the
session has been set, the following line needs to be added to ensure the
session id is the same as the session info id:
((ReteooStatefulSession) this.session).setId( this.sessionInfo.getId() );
(This line is present at the end of the 3rd constructor.)
It would be great if this fix could make it into the Drools 5.1 release.
Thanks.
16 years, 6 months
Using Drools for modeling with rule-driven agents
by Russ Abbott
Hi,
I'm interested in developing (if it doesn't already exist) and then using a
framework for agent-based modeling in which the agents are rule driven. An
important feature is that the agents and their rules must be dyanically
manipulable. That is, both the agents and the rules must be first class
objects that can be manipulated as the system is running. Can Drools support
that?
As someone not familiar with Drools I did my best to find out by looking at
the Drools Expert User's
Manual<http://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/tr...>.
>From what I could tell, the Template
feature<http://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/tr...>in
which one uses Java objects as Template data sources comes close. I'd
like your advice before putting too much development effort into attempting
to use it for that purpose.
In particular, would it be possible to set up a mechanism that could: create
and delete agents on the fly; associate rule sets with agents on the fly;
and modify the rules associated with an agent on the fly? After each such
action the system would change to reflect the change in agents and rules.
Thanks for your help.
-- Russ Abbott
P.S. If Drools would not be a good choice, is there some other system that
you could recommend?
16 years, 6 months
Maven Plugin to build pkg files
by Bernd Rücker
Hi all.
I wonder if there exists a maven plugin to build pkg files out of the rule
base during the maven packaging. Because we dont use the Guvnor
repository in this project and I want to package the pkg files with the
overall ear.
I searched a bit, but didnt found anything
Okay, not hard to write
ourself, but would be nicer to reuse existing stuff
Thanks
Bernd
16 years, 6 months
OSGI, classloading, and imports in KnowledgeBuilder
by msully
So I'm playing with Drools in Equinox OSGi, and so far it's behaving quite
nicely - one bit of weirdness though.
What I'm trying to do:
I have a bundle with a 'flow manager' that listens for instances of
WorkItemHandler in the service broker (well, really my own subinterface that
has a getName method). It also listens for new bundles with a
META-INF/drools directory with *.rf files in them, and parses the .rf files
it finds there.
The Flow Manager is itself published as an OSGI Service with a 'perform'
method. It encapsulates all of its Drools calls within the perform method
though - they aren't exposed to clients.
My test involves a simple start->work item->end workflow.
I pass in an instance of a class "Tablex" that can be saved to hibernate. I
also pass in a String that has the table name, and an empty List to get the
results.
My .rf file tries to import Tablex. It declares the three values I mention
above, and maps them to the work item in the work item definition.
<p>
<imports>
<import name="my.pkg.Tablex" />
</imports>
...
<variable name="my.pkg.newrecord" >
<type
name="org.drools.process.core.datatype.impl.type.ObjectDataType"
className="my.pkg.Tablex"/>
</variable>
...
<workItem id="2" name="DBWorkItem" x="165" y="374" width="80"
height="40" >
<work name="DBWorkItem" >
</work>
<mapping type="in" from="my.pkg.tablename" to="my.pkg.tablename" />
<mapping type="in" from="my.pkg.newrecord" to="my.pkg.newrecord"/>
<mapping type="in" from="my.pkg.outlist" to="my.pkg.outlist"/>
</workItem>
</p>
In my manifest for my .rf file and for the flow manager (where the parsing
occurs) I Import-Package Tablex's package.
When my flow manager tries parsing the rule, it gives an error saying the
the import failed. BUT, everything still works, and my WorkItemHandler works
correctly (the WorkItemHandler imports Tablex itself, since it needs to
manipulate it).
If I declare my Tablex variable as a java.util.Object in the ruleflow then I
don't get the error and things also still work.
If I declare my Tablex as Tablex in the rule flow AND import it in the class
that does the parsing (it's already 'OSGI' imported to the parsing bundle,
but now I'm doing a plain old Java import on it) then everything works fine
with no error message.
Kind of a hybrid question but I figured I'd start with the Drools folks.
Any ideas would be appreciated.
Thanks,
Mike
--
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16 years, 6 months
Re: [rules-users] not able to debug drools flow
by Jakob Marovt
Hi,
I`m experiencing the same problems as Vishal. I am using Eclipse 3.5
and newest Drools. I am only able to debug project as Java
application, but when I want to debug it as Drools application all I
get is this problem. I also tried disabling firewall and changing its
settings but as it seems it does not help.
So if anyone has figured out a solution to this problem, I would
really appreciate an answer.
Thanks,
Jakob
probably related to your personal firewall:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6303969
http://www.techienuggets.com/Comments?tx=3786
I don't think this is a Drools specific issue.
Mark
Vishal Anand wrote:
>
**>* Hi,*
>
**>* *
>
**>* I am using Drools 5.0 and have create a simple application using *
>* drools flow, it runs perfectly but when trying to debug it as n drools *
>* application I get the following error:*
>
**>* *
>
**>* FATAL ERROR in native method: JDWP No transports initialized, *
>* jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197)*
>
**>* ERROR: transport error 202: connect failed: Connection refused*
>
**>* ERROR: JDWP Transport dt_socket failed to initialize,
TRANSPORT_INIT(510)*
>
**>* JDWP exit error AGENT_ERROR_TRANSPORT_INIT(197): No transports *
>* initialized [../../../src/share/back/debugInit.c:690]*
>
**>* *
>
**>* *
>
**>* While stack trace shows the following:*
>
**>* *
>
**>* *
>
**>* java.lang.IncompatibleClassChangeError: Expected static method *
>*org.drools.eclipse.launching.DroolsVMDebugger.renderCommandLine([Ljava/lang/String;)Ljava/lang/String;
*
>
**>* at org.drools.eclipse.launching.DroolsVMDebugger.run(Unknown Source)*
>
**>* at *
>*org.eclipse.jdt.launching.JavaLaunchDelegate.launch(JavaLaunchDelegate.java:101)
*
>
**>* at *
>*org.drools.eclipse.launching.DroolsLaunchConfigurationDelegate.launch(Unknown
*
>* Source)*
>
**>* at *
>*org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:853)
*
>
**>* at *
>*org.eclipse.debug.internal.core.LaunchConfiguration.launch(LaunchConfiguration.java:703)
*
>
**>* at *
>*org.eclipse.debug.internal.ui.DebugUIPlugin.buildAndLaunch(DebugUIPlugin.java:866)
*
>
**>* at *
>*org.eclipse.debug.internal.ui.DebugUIPlugin$8.run(DebugUIPlugin.java:1069)
*
>
**>* at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)*
>
**>* *
>
**>* *
>
**>* I am using eclipse 3.4*
>
**>* *
>
**>* What could be the issue ?*
>
**>* *
>
**>* Thanks*
>
**>* Vishal*
>
**>*------------------------------------------------------------------------
*
>
**>* _______________________________________________*
>* rules-users mailing list*
>* rules-users at lists.jboss.org<http://lists.jboss.org/mailman/listinfo/rules-users>
*
**>* https://lists.jboss.org/mailman/listinfo/rules-users*
**>* *
16 years, 6 months
Guvnor fails to vaildate rule, though same rule compiles and run successfully when compiled command line with ANT.
by Codedrop
Recently upgraded from Drools 4.0.7 to 5.1.0 and have imported our rules into
Guvnor. Unable to determine why the same rules will not correctly validate
in Guvnor which prevents building a package for deployment.
Sample Rule:
salience 50
agenda-group "idia"
when
Root(identityRequest != null)
then
logger.debug("Main - Main Data Evaluation");
System.out.println("Main - Main Data
Evaluation");
drools.getWorkingMemory().setFocus("mainAnalysis");
Throws the following validation error when you select ‘Validate’:
[Main - Data Evaluation] Unable to create Field Extractor for
'identityRequest' of '[ClassObjectType
class=com.netid.idia.model.natal.rootIdentityRequest.Root]' in rule 'Main -
Data Evaluation'
Unsure why identityRequest is failing. There is a valid getter in the java
file and guvnor displays identityRequest in the list of attributes for
‘Root’. Oddly, if I change the when clause to be
Root(this.identityRequest != null) it validates fine. Did something change
between 4.0.7 and 5.1.0 that I’m missing or do I have error somewhere that
goes undetected outside the guvnor?
--
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16 years, 6 months
sliding time in lhs
by Francesco Chiarelli
Hi!
i'm new to use a drools-fusion, i've a next lhs condition in rule:
$o: Order(status!="EU_C_R1_INIT")
SystemConfig(value:value) from hbnSession.createQuery("from
SystemConfig where name=:name").setString("name","nRicMax").uniqueResult()
$nRic : Number(intValue < value) from accumulate($n:
Order(this==$o) over window:time(1d),count($n))
Data:
1) Order 1 date 28 aug 2009 EU_C_INIT
2) Order 1 date 31 aug 2009 EU_A_INIT
3) Order 1 date 31 aug 2009 EU_B_INIT
4) Order 1 date 30 aug 2009 EU_B_INIT
5) Order 1 date 28 aug 2009 EU_A_INIT
6) Order 1 date 01 aug 2009 EU_A_INIT
7) Order 1 date 28 aug 2009 EU_C_INIT
8) Order 1 date 28 aug 2009 EU_C_INIT
Only the first condition is verified [ Order(status!="EU_C_R1_INIT") ]
altough there are facts that verify Order(this==$o) over window:time(24h) ]
There are n-k facts that don't verify a previous condition but them come
count also:
I espect that drools count a 2-3-4 but it count also 5-6-7: i'm confused
P.S. i did set a stream mode, i' had set a timestamp attribute in event fact
@timestamp(myTimestampLong), i tried with pseudo clock (making it advance
for new Date().getTime() or at origin, therefore 01 jan 1970 [without event
@timestamp attribute] )
Regards
Francesco
16 years, 6 months
Why so many ACTIVATION/DEACTIVATION events?
by Tom.E.Murphy＠wellsfargo.com
We have a fairly complex object model, but we're still puzzled - I thought that the definition of "Activation" was that the data matched on all conditions of a rule, and therefore the rule was entered into the agenda (activated).
If that is true, I cannot figure out why we're experiencing this.
As our number of rules increases, we're seeing exponential increases in repetitive activation/deactivation pairs, even on rules where we know the data does not match the conditions.
Example:
The following rule (abbreviated here) creates an object of type PolicySet if there are none that match the conditions.
I would expect this rule to activate once, then fire, wherein the matching PolicySet is created, and then never activate again since the absence of a matching PolicySet object is never again true.
However, in a rule base of ~4,000 rules, we see this rule activating 975 times and deactivating 975 times. This is just one example - nearly all our rules do this, and it is seriously impacting decisioning performance.
Have I misunderstood the meaning of "activation"? Can anyone help me understand this?
rule "RS6090.1.12_RF7007_50001012"
when
LendingProduct ( $exitStrategyType1 : exitStrategyType )
Features ( $lienPriority1 : lienPriority )
DecisionResultsInfo ( $dealRiskCategory1 : dealRiskCategory )
TransactionDetail ( $parentTransactionDetail1Id : myId )
not
(
PolicySet ( $parentPolicySet_1_Id : myId, parentId == $parentTransactionDetail1Id )
and
PolicySetIdentifier ( parentId == $parentPolicySet_1_Id
, lienPriority == $lienPriority1
, exitStrategyType == $exitStrategyType1
, dealRiskCategory == $dealRiskCategory1)
)
then
// Content removed... rule creates the policy set and the policy set identifier, and initializes all appropriate elements
// After doing so, why does it activate/deactivate 1800+ times in a rule base of 4000 rules?
System.out.println("6090 fired.");
End
Thanks.
Tom Murphy
Business Process Consultant
Wells Fargo HCFG - CORE Deal Decisioning Platform
800 S. Jordan Creek Parkway | West Des Moines, IA 50266
MAC: X2301-01B
Office: 515 324 4853 | Mobile: 941 320 8014
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16 years, 6 months
Calculating minimal value for a group of facts
by kothvandir kothvandir
Hi,
I need to calculate the min time for a set of "jobs" inserted in working
mermory to know wich job is going to be finished first.
Is there any way to obtain within a rule the current facts of some type to
pass then to a function/method?
somethin like this:
Another idea to acomplish this?
gobal MyService myservice
rule "cmdCheckTime" ruleflow-group "comprobarExistencias"
when
Job(time = eval(myService.getMinTime( <jobs in working memory >))
then
go, go, go...
end
Thank you
16 years, 6 months
