NPE on fact insertion if rule has sliding window
by John
Hello,
I've been messing with this for days now and can't get to the bottom of
this. I'm using drools 5.2.0 Final and setting up my KnowledgeBase with a
KnowledgeAgent which is pulling a package from guvnor (also 5.2.0 Final). I
do NOT get this error if I use a KnowledgeBuilder and add the exact same drl
file as a resource.
If the DRL in guvnor has a rule that uses a sliding window, i get an NPE
when trying to insert an object and the following stack trace:
java.lang.NullPointerException
at
org.drools.reteoo.ReteooFactHandleFactory.newFactHandle(ReteooFactHandleFactory.java:56)
at
org.drools.common.AbstractFactHandleFactory.newFactHandle(AbstractFactHandleFactory.java:80)
at
org.drools.common.AbstractFactHandleFactory.newFactHandle(AbstractFactHandleFactory.java:65)
at org.drools.common.NamedEntryPoint.createHandle(NamedEntryPoint.java:705)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:282)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:905)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:864)
at
org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:255)
at john.DroolsError.runRules(DroolsError.java:48)
at john.DroolsError.main(DroolsError.java:40)
Here is the DRL:
1. | package drools
2. | import simple.SimpleType
3. |
4. |
5. |
6. |
7. |
8. |
9. | import simple.SimpleType;
10. |
11. | declare SimpleType
12. | @role(event)
13. | end
14. |
15. | rule "timer"
16. | timer (cron:5/5 * * * * ?)
17. | when
18. | $newest : Number()
19. | from accumulate( SimpleType ($num : number) over
window:time(5s),
20. | max($num) )
21. | $st : SimpleType( number == $newest.intValue )
22. | then
23. | System.out.println("SimpleType: " + $st.number);
24. | end
(note: the first import of simple.SimpleType comes from the package
configuration in guvnor, the second is in the drl file itself. the file will
not validate without the import explicitly listed there, saying the type is
not declared as an event...)
Here is the Java code:
ResourceChangeScannerConfiguration sconf = ResourceFactory
.getResourceChangeScannerService()
.newResourceChangeScannerConfiguration();
sconf.setProperty("drools.resource.scanner.interval", "20");
ResourceFactory.getResourceChangeScannerService().configure(sconf);
KnowledgeBaseConfiguration config = KnowledgeBaseFactory
.newKnowledgeBaseConfiguration();
config.setOption(EventProcessingOption.STREAM);
KnowledgeAgentConfiguration aconf = KnowledgeAgentFactory
.newKnowledgeAgentConfiguration();
aconf.setProperty("drools.agent.scanDirectories", "true");
aconf.setProperty("drools.agent.scanResources", "true");
aconf.setProperty("drools.agent.newInstance", "false");
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(config);
KnowledgeAgent kagent = KnowledgeAgentFactory.newKnowledgeAgent(
"drools agent", kbase, aconf);
String urlString =
"http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/package/droo...";
try {
URL url = new URL(urlString);
UrlResource urlResource = (UrlResource) ResourceFactory
.newUrlResource(url);
urlResource.setBasicAuthentication("enabled");
urlResource.setUsername("John");
urlResource.setPassword("");
kagent.applyChangeSet(urlResource);
} catch (Exception e) {
System.out.println("Caught exception: " + e.getMessage());
e.printStackTrace();
}
ResourceFactory.getResourceChangeNotifierService().start();
ResourceFactory.getResourceChangeScannerService().start();
StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
System.out.println("Initialize drools complete");
SimpleType simp = new SimpleType();
simp.setNumber(5);
ksession.insert(simp);
Thanks,
John
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12 years, 6 months
Drools 5 PseudoClock with StatelessKnowledgeSession
by Ben Scott
_______________________________________________________________________________________
Note: This e-mail is subject to the disclaimer contained at the bottom of this message.
_______________________________________________________________________________________
I'm wanting to use the date-effective and date-expiry rule metadata to add date specific rule variants within my app. To test these I was planning on using the pseudo clock and setting the expected date prior to executing the rules within a StatelessKnowledgeSession. I can set the clock easily enough, but can't understand why the getSessionClock() method is missing? It's on the StatefulKnowledgeSession, but not on the Stateless.
I'm initialising the session like this:
SessionConfiguration sessionConfiguration = new SessionConfiguration();
sessionConfiguration.setClockType( ClockType.PSEUDO_CLOCK );
StatelessKnowledgeSession session = _testKnowledgeBase.newStatelessKnowledgeSession(sessionConfiguration);
The only thing I could think of to set the pseudo clock was to write a command something like:
private static class SetPseudoClockCommand implements org.drools.process.command.Command<Boolean> {
public Boolean execute(ReteooWorkingMemory session) {
// Set the clock to the current date
pseudoSessionClock.advanceTime(new DateTime().getMillis(), TimeUnit.MILLISECONDS);
// Add a couple of days
pseudoSessionClock.advanceTime(2, TimeUnit.DAYS);
return true;
}
}
But this doesn't appear to take any effect whilst rules are running.
Is there another way to get programmatic access to the session clock, or some better way of changing the underlying date prior to rule execution?
Ben.
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12 years, 7 months
Date validation in Guvnor
by mick00
Hi,
I want to validate the date format in my rule. I just want to check whether
my date is in the given format(yyyy-mm-dd) in my rule in Guvnor. Is it
possible to do such validation in Guvnor? I tried the same but got an
exception stating that the date is not in the given format(dd-MMM-yyyy). Can
someone suggest a solution as to how to validate the date in Guvnor?
Thanks,
mick
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12 years, 7 months
Fusion and open-ended intervals?
by Barry Kaplan
A fusion design question:
I have events that represent intervals. Initially the intervals are
open-ended (kind a like the current state of an entity). Other events are
matched "during" the interval and correlated. At some point the interval
will be closed (eg, a specific downtime interval is closed because the
device is no online again).
All the events in this system are immutable -- so if some property of an
event changes, it is cloned and modified in working-memory. For the case of
the interval events, initially the interval is inserted open-ended, and at
some point later closed and then modified.
This does not work with fusion however, since an event's duration is
maintained by the fact-handle not the event itself. Hence a modify with a
now closed interval (ie, a finite @duration) has no effect. I'm guessing the
temporal values are maintained the handle to ensure stable values for the
behaviors that trigger based on temporal values, which is reasonable.
So I'm looking for alternative designs. Some are:
1) Modeled the intervals as begin/end events, but that gets messy real
fast (have to correlate
the begin/end events somehow, can't use evaluators like 'includes' or
'during', etc).
2) Retract the interval event when it is closed (this way closed intervals
no longer correlate
with other incoming events). But then we really have a manually
maintained state machine
using only facts, and there can be no reasoning over a series these
interval events.
(eg, 3 downtimes longer than 2 minutes in the last hour).
Opinions?
-barry
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12 years, 7 months
Persistence of events
by Maciej Prochniak
Hello,
Is it possible to persist events (from drools fusion) with default jpa
mechanism? When I try to do this 'just like that' I get exception
like
org.drools.common.DefaultFactHandle incompatible with
org.drools.common.EventFactHandle
It seems that session marshaller is not really aware of certain objects
being events, not facts.
The code I try is more or less like:
UserTransaction ut = ...
StatefulKnowledgeSession session = JPAKnowledgeService
.newStatefulKnowledgeSession(kbase, null, env);
ut.begin()
session.insert(e1);
ut.commit();
StatefulKnowledgeSession sessionPersisted =
JPAKnowledgeService.loadStatefulKnowledgeSession( session.getId(),
kbase, null, env );
ut.begin()
sessionPersisted.insert(e2); (*) <- fails
ut.commit();
When I use session instead of sessionPersisted - it works fine, when
e2 is a fact, not an event - it also works
I know that it may be awkward to persist events which have time
limitations, but I want to use time limits in rules which are like few
days - so I want to have some persistence in case of server shutdown.
I would be grateful for any comment,
br,
maciek prochniak
12 years, 7 months
Guvnor test scenarios for rules that use globals
by Lisa Horton
In Guvnor 5.1 I have several rules that invoke services defined as globals. Rules that invoke methods on these globals run OK when deployed, but a test scenario that triggers such a rule gets an exception.
For example, with a global named "logger" a rule that has in its THEN clause:
logger.debug("customer was added to session");
Test Scenario that triggers this rule gets the error:
[Error: unable to access property (null parent): debug]
Thanks for your help.
12 years, 7 months
Log4j in the rules?
by granz＠MIT.EDU
Hi,
Is it possible to use Log4j inside the rules (RHS)?? (drl file)
Thanks,
Fabrice
12 years, 7 months
Client code using RuleAgent API - Guvnor 5.1.1 - getting 401 error
by Achyutha, Venkata
Hi,
This error would be basic one but it's very frustrating to me to debug this, few days ago it use to work.
I deployed guvnor 5.1.1 war into web logic 10.3, created package with 4 rules, build and deploy, got package url.
Started using package url in properties file and passing file to RuleAgent api, suddenly it started giving HTTP response code: 401 for URL.
Any thoughts on this issue would be greatly appreciated.
Below is the content of properties file and Client code.
{url=http://10.117.39.51:7001/Guvnor5.1.1/org.drools.guvnor.Guvnor/package/com.tmobile.pos.rules/LATEST , name=myrules, username=weblogic, poll=30, newInstance=true, localCacheDir=C:\Installed\workspaces\drools\POC\bin, workspacepath=C://bea/user_projects/domains/posdomain, password=weblogic123, enableBasicAuthentication=true}
Error:
RuleAgent(myrules) INFO (Fri Nov 26 15:19:00 IST 2010): Configuring with newInstance=true, secondsToRefresh=30
RuleAgent(myrules) INFO (Fri Nov 26 15:19:00 IST 2010): Configuring package provider : URLScanner monitoring URLs: http://10.117.39.51:7001/Guvnor5.1.1/org.drools.guvnor.Guvnor/package/com... with local cache dir of C:\Installed\workspaces\drools\POC\bin
RuleAgent(myrules) EXCEPTION (Fri Nov 26 15:19:01 IST 2010): Server returned HTTP response code: 401 for URL: http://10.117.39.51:7001/Guvnor5.1.1/org.drools.guvnor.Guvnor/package/com.... Stack trace should follow.
java.io.IOException: Server returned HTTP response code: 401 for URL: http://10.117.39.51:7001/Guvnor5.1.1/org.drools.guvnor.Guvnor/package/com...
Client Code: (getting error at 3rd line)
File file = new File("C:\\guvnor.properties");
properties.load(new FileInputStream(file));
RuleAgent agent = RuleAgent.newRuleAgent(properties);
RuleBase ruleBase = agent.getRuleBase();
WorkingMemory workingMemory = ruleBase.newStatefulSession();
Thanks
Kumar
12 years, 7 months
Classloading error with AspectJ and Drools 5.2.0.Final
by Steven Williams
Hi,
I have just upgraded to Drools 5.2.0.Final and am getting a weird error when
running unit tests.
java.lang.NullPointerException
at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.parseDefinitions(
ClassLoaderWeavingAdaptor.java:251)
at org.aspectj.weaver.loadtime.DefaultWeavingContext.getDefinitions(
DefaultWeavingContext.java:130)
at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.initialize(
ClassLoaderWeavingAdaptor.java:161)
at
org.aspectj.weaver.loadtime.Aj$ExplicitlyInitializedClassLoaderWeavingAdaptor.initialize(
Aj.java:271)
at
org.aspectj.weaver.loadtime.Aj$ExplicitlyInitializedClassLoaderWeavingAdaptor.getWeavingAdaptor(
Aj.java:276)
at org.aspectj.weaver.loadtime.Aj$WeaverContainer.getWeaver(Aj.java:254)
at org.aspectj.weaver.loadtime.Aj.preProcess(Aj.java:90)
at org.aspectj.weaver.loadtime.ClassPreProcessorAgentAdapter.transform(
ClassPreProcessorAgentAdapter.java:54)
at sun.instrument.TransformerManager.transform(TransformerManager.java:169)
at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:365
)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at org.drools.rule.JavaDialectRuntimeData$PackageClassLoader.fastFindClass(
JavaDialectRuntimeData.java:570)
at org.drools.util.CompositeClassLoader$CachingLoader.load(
CompositeClassLoader.java:258)
at org.drools.util.CompositeClassLoader$CachingLoader.load(
CompositeClassLoader.java:241)
at org.drools.util.CompositeClassLoader.loadClass(
CompositeClassLoader.java:88)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at org.drools.rule.JavaDialectRuntimeData.wire(
JavaDialectRuntimeData.java:405)
at org.drools.rule.JavaDialectRuntimeData.wire(
JavaDialectRuntimeData.java:396)
at org.drools.rule.JavaDialectRuntimeData.onBeforeExecute(
JavaDialectRuntimeData.java:237)
at org.drools.rule.DialectRuntimeRegistry.onBeforeExecute(
DialectRuntimeRegistry.java:132)
at org.drools.compiler.PackageBuilder.reloadAll(PackageBuilder.java:796)
at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:751)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(
PackageBuilder.java:360)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(
PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(
KnowledgeBuilderImpl.java:28)
at au.com.promedicus.rules.KnowledgeBaseBuilder.addPackagesFromList(
KnowledgeBaseBuilder.java:108)
at au.com.promedicus.rules.KnowledgeBaseBuilder.build(
KnowledgeBaseBuilder.java:69)
at au.com.promedicus.rules.KnowledgeBaseBuilder.build(
KnowledgeBaseBuilder.java:54)
I have traced the problem to org.drools.rule.
JavaDialectRuntimeData$PackageClassLoader.getResources. This returns null
whereas AspectJ expects it to at least return an empty enumeration - hence
the NPE. Interestingly the problem does not occur when running our server,
however we can't upgrade unless our unit tests pass and we can't easily turn
off aspectj for these.
regards
Steve
12 years, 7 months
