4:48 a.m.
First the specifics: JDK 1.6, Mac OSX, using Drools 5.5 Final
The full source code and rules are pasted below but here's the gist, I have
a stateful knowledge session to which I am inserting events and running an
accumulate on the input events. I have a for loop generating the events and
inserting them as rapidly as possible. In the rules I use an accumulator to
calculate the average of the values contained within the events. The
behavior I'm observing is that if I insert ~120 events without any waiting I
receive an NPE. If I Thread.sleep for even just 1ms the test goes off
without a hitch. Have I uncovered a bug which should be logged in JIRA? I
would check through JIRA to see if something similar has been logged but I'm
so unfamiliar with the codebase, not to mention it could all just be user
error.
The NPE is as follows:
Exception in thread "main" java.lang.NullPointerException
at org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:1050)
at
org.drools.reteoo.AccumulateNode.modifyLeftTuple(AccumulateNode.java:345)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyChildLeftTuple(SingleLeftTupleSinkAdapter.java:259)
at
org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:676)
at
org.drools.reteoo.ReteooWorkingMemory$EvaluateResultConstraints.execute(ReteooWorkingMemory.java:590)
at
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:350)
at
org.drools.rule.SlidingLengthWindow.assertFact(SlidingLengthWindow.java:119)
at org.drools.rule.BehaviorManager.assertFact(BehaviorManager.java:94)
at org.drools.reteoo.WindowNode.assertObject(WindowNode.java:167)
at
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
at
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:127)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:55)
at drools5fusioneval.Average.main(Average.java:66)
### Average.java ###
package drools5fusioneval;
import java.io.IOException;
import java.util.Random;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseConfiguration;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.conf.EventProcessingOption;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;
class AvgDFEChannel implements org.drools.runtime.Channel {
@Override
public void send(Object o) {
System.err.println ("Recieved channel message: "+ o);
}
}
public class Average {
public static void main(String[] args) throws InterruptedException,
IOException {
KnowledgeBaseConfiguration kbconfig =
KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
kbconfig.setOption(EventProcessingOption.STREAM);
KnowledgeBase kbase =
KnowledgeBaseFactory.newKnowledgeBase(kbconfig);
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource("drools5fusioneval/average.drl"),
ResourceType.DRL);
if (kbuilder.hasErrors()) {
System.err.println(kbuilder.getErrors().toString());
}
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
final StatefulKnowledgeSession session =
kbase.newStatefulKnowledgeSession();
session.registerChannel("heartbeat", new AvgDFEChannel ());
WorkingMemoryEntryPoint ep01 =
session.getWorkingMemoryEntryPoint("ep01");
new Thread() {
public void run() {
session.fireUntilHalt();
}
}.start();
Thread.sleep (5000); // give the engine time to get setup
Server hiwaesdk = new Server ("hiwaesdk");
session.insert(hiwaesdk);
long LIMIT = 120;
Random rnd = new Random (System.nanoTime());
for (long i = LIMIT; i > 0; i--) {
int j = rnd.nextInt (212);
ep01.insert (new IntEvent (j));
//Thread.sleep (0x1);
}
System.out.println (hiwaesdk);
}
}
### average.drl ###
package drools5fusioneval
declare IntEvent
@role ( event )
@expires(15s)
end
declare Statistics
opsec : long
total : long
end
global Statistics stats;
rule "Init engine"
salience 100
when
then
stats = new Statistics ();
stats.setTotal (0);
stats.setOpsec (0);
drools.getWorkingMemory ().setGlobal ("stats", stats);
System.out.println ("Engine initialized");
end
rule "number rule"
when
$e : IntEvent () from entry-point ep01
$s : Server (hostname == "hiwaesdk")
then
$s.currentTemp = $e.data;
stats.setOpsec (stats.getOpsec () + 1);
stats.setTotal (stats.getTotal () + 1);
end
rule "average temp"
when
Number ($avg : intValue) from accumulate (
IntEvent ($temp : data) over window:length(10) from entry-point
ep01, average ($temp)
)
$s : Server (hostname == "hiwaesdk")
then
$s.avgTemp = $avg;
end
rule "Heartbeat"
timer ( int: 5s 5s)
when
then
channels["heartbeat"].send ("Heartbeat: "+ stats.getOpsec () / 5
+", "+
stats.getTotal ());
stats.setOpsec (0);
end
--
View this message in context:
http://drools.46999.n3.nabble.com/NPE-from-reteoo-AccumulateNode-tp402381...
Sent from the Drools: User forum mailing list archive at Nabble.com.
5:29 a.m.
Looks like a bug in Drools to me. It has the classic hallmark of a
race condition: the NPE does not happen with every run (on my system),
perhaps only with 85%.
Moreover, with 5.4.0 I get a similar NPE and also:
Exception in thread "main" java.util.NoSuchElementException
at java.util.LinkedList.remove(LinkedList.java:788)
at java.util.LinkedList.removeFirst(LinkedList.java:134)
at
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:344)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:342)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:298)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:123)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:53)
at overrun.Main.main(Main.java:64)
5.3.0 is the last version without this bug.
-W
On 14/05/2013, jpbarto <Jason.P.Barto(a)gmail.com> wrote:
First the specifics: JDK 1.6, Mac OSX, using Drools 5.5 Final
The full source code and rules are pasted below but here's the gist, I have
a stateful knowledge session to which I am inserting events and running an
accumulate on the input events. I have a for loop generating the events
and
inserting them as rapidly as possible. In the rules I use an accumulator
to
calculate the average of the values contained within the events. The
behavior I'm observing is that if I insert ~120 events without any waiting
I
receive an NPE. If I Thread.sleep for even just 1ms the test goes off
without a hitch. Have I uncovered a bug which should be logged in JIRA? I
would check through JIRA to see if something similar has been logged but
I'm
so unfamiliar with the codebase, not to mention it could all just be user
error.
The NPE is as follows:
Exception in thread "main" java.lang.NullPointerException
at
org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:1050)
at
org.drools.reteoo.AccumulateNode.modifyLeftTuple(AccumulateNode.java:345)
at
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyChildLeftTuple(SingleLeftTupleSinkAdapter.java:259)
at
org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:676)
at
org.drools.reteoo.ReteooWorkingMemory$EvaluateResultConstraints.execute(ReteooWorkingMemory.java:590)
at
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:350)
at
org.drools.rule.SlidingLengthWindow.assertFact(SlidingLengthWindow.java:119)
at org.drools.rule.BehaviorManager.assertFact(BehaviorManager.java:94)
at org.drools.reteoo.WindowNode.assertObject(WindowNode.java:167)
at
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
at
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:127)
at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:55)
at drools5fusioneval.Average.main(Average.java:66)
### Average.java ###
package drools5fusioneval;
import java.io.IOException;
import java.util.Random;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseConfiguration;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.conf.EventProcessingOption;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;
class AvgDFEChannel implements org.drools.runtime.Channel {
@Override
public void send(Object o) {
System.err.println ("Recieved channel message: "+ o);
}
}
public class Average {
public static void main(String[] args) throws InterruptedException,
IOException {
KnowledgeBaseConfiguration kbconfig =
KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
kbconfig.setOption(EventProcessingOption.STREAM);
KnowledgeBase kbase =
KnowledgeBaseFactory.newKnowledgeBase(kbconfig);
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource("drools5fusioneval/average.drl"),
ResourceType.DRL);
if (kbuilder.hasErrors()) {
System.err.println(kbuilder.getErrors().toString());
}
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
final StatefulKnowledgeSession session =
kbase.newStatefulKnowledgeSession();
session.registerChannel("heartbeat", new AvgDFEChannel ());
WorkingMemoryEntryPoint ep01 =
session.getWorkingMemoryEntryPoint("ep01");
new Thread() {
public void run() {
session.fireUntilHalt();
}
}.start();
Thread.sleep (5000); // give the engine time to get setup
Server hiwaesdk = new Server ("hiwaesdk");
session.insert(hiwaesdk);
long LIMIT = 120;
Random rnd = new Random (System.nanoTime());
for (long i = LIMIT; i > 0; i--) {
int j = rnd.nextInt (212);
ep01.insert (new IntEvent (j));
//Thread.sleep (0x1);
}
System.out.println (hiwaesdk);
}
}
### average.drl ###
package drools5fusioneval
declare IntEvent
@role ( event )
@expires(15s)
end
declare Statistics
opsec : long
total : long
end
global Statistics stats;
rule "Init engine"
salience 100
when
then
stats = new Statistics ();
stats.setTotal (0);
stats.setOpsec (0);
drools.getWorkingMemory ().setGlobal ("stats", stats);
System.out.println ("Engine initialized");
end
rule "number rule"
when
$e : IntEvent () from entry-point ep01
$s : Server (hostname == "hiwaesdk")
then
$s.currentTemp = $e.data;
stats.setOpsec (stats.getOpsec () + 1);
stats.setTotal (stats.getTotal () + 1);
end
rule "average temp"
when
Number ($avg : intValue) from accumulate (
IntEvent ($temp : data) over window:length(10) from entry-point
ep01, average ($temp)
)
$s : Server (hostname == "hiwaesdk")
then
$s.avgTemp = $avg;
end
rule "Heartbeat"
timer ( int: 5s 5s)
when
then
channels["heartbeat"].send ("Heartbeat: "+ stats.getOpsec () / 5
+", "+
stats.getTotal ());
stats.setOpsec (0);
end
--
View this message in context:
http://drools.46999.n3.nabble.com/NPE-from-reteoo-AccumulateNode-tp402381...
Sent from the Drools: User forum mailing list archive at Nabble.com.
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
8:43 a.m.
Thanks Wolfgang. I'll change over to the 5.3 libraries and carry on with my
testing. I'll also enter this issue into jira if it doesn't yet exist.
Sincerely,
Jason
On May 14, 2013 11:30 AM, "Wolfgang Laun" <wolfgang.laun(a)gmail.com>
wrote:
Looks like a bug in Drools to me. It has the classic hallmark of a
race condition: the NPE does not happen with every run (on my system),
perhaps only with 85%.
Moreover, with 5.4.0 I get a similar NPE and also:
Exception in thread "main" java.util.NoSuchElementException
at java.util.LinkedList.remove(LinkedList.java:788)
at java.util.LinkedList.removeFirst(LinkedList.java:134)
at
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:344)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:342)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:298)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:123)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:53)
at overrun.Main.main(Main.java:64)
5.3.0 is the last version without this bug.
-W
On 14/05/2013, jpbarto <Jason.P.Barto(a)gmail.com> wrote:
> First the specifics: JDK 1.6, Mac OSX, using Drools 5.5 Final
>
> The full source code and rules are pasted below but here's the gist, I
have
> a stateful knowledge session to which I am inserting events and running
an
> accumulate on the input events. I have a for loop generating the events
> and
> inserting them as rapidly as possible. In the rules I use an accumulator
> to
> calculate the average of the values contained within the events. The
> behavior I'm observing is that if I insert ~120 events without any
waiting
> I
> receive an NPE. If I Thread.sleep for even just 1ms the test goes off
> without a hitch. Have I uncovered a bug which should be logged in JIRA?
I
> would check through JIRA to see if something similar has been logged but
> I'm
> so unfamiliar with the codebase, not to mention it could all just be user
> error.
>
> The NPE is as follows:
> Exception in thread "main" java.lang.NullPointerException
> at
> org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:1050)
> at
> org.drools.reteoo.AccumulateNode.modifyLeftTuple(AccumulateNode.java:345)
> at
>
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyChildLeftTuple(SingleLeftTupleSinkAdapter.java:259)
> at
>
org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:676)
> at
>
org.drools.reteoo.ReteooWorkingMemory$EvaluateResultConstraints.execute(ReteooWorkingMemory.java:590)
> at
>
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:350)
> at
>
org.drools.rule.SlidingLengthWindow.assertFact(SlidingLengthWindow.java:119)
> at
org.drools.rule.BehaviorManager.assertFact(BehaviorManager.java:94)
> at org.drools.reteoo.WindowNode.assertObject(WindowNode.java:167)
> at
>
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
> at
>
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
> at
org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
> at
org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:127)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:55)
> at drools5fusioneval.Average.main(Average.java:66)
>
> ### Average.java ###
> package drools5fusioneval;
>
> import java.io.IOException;
> import java.util.Random;
> import org.drools.KnowledgeBase;
> import org.drools.KnowledgeBaseConfiguration;
> import org.drools.KnowledgeBaseFactory;
> import org.drools.builder.KnowledgeBuilder;
> import org.drools.builder.KnowledgeBuilderFactory;
> import org.drools.builder.ResourceType;
> import org.drools.conf.EventProcessingOption;
> import org.drools.io.ResourceFactory;
> import org.drools.runtime.StatefulKnowledgeSession;
> import org.drools.runtime.rule.WorkingMemoryEntryPoint;
>
> class AvgDFEChannel implements org.drools.runtime.Channel {
> @Override
> public void send(Object o) {
> System.err.println ("Recieved channel message: "+ o);
> }
> }
>
> public class Average {
> public static void main(String[] args) throws InterruptedException,
> IOException {
> KnowledgeBaseConfiguration kbconfig =
> KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
> kbconfig.setOption(EventProcessingOption.STREAM);
>
> KnowledgeBase kbase =
> KnowledgeBaseFactory.newKnowledgeBase(kbconfig);
>
> KnowledgeBuilder kbuilder =
> KnowledgeBuilderFactory.newKnowledgeBuilder();
>
>
kbuilder.add(ResourceFactory.newClassPathResource("drools5fusioneval/average.drl"),
> ResourceType.DRL);
> if (kbuilder.hasErrors()) {
> System.err.println(kbuilder.getErrors().toString());
> }
> kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
>
> final StatefulKnowledgeSession session =
> kbase.newStatefulKnowledgeSession();
> session.registerChannel("heartbeat", new AvgDFEChannel ());
> WorkingMemoryEntryPoint ep01 =
> session.getWorkingMemoryEntryPoint("ep01");
>
> new Thread() {
> public void run() {
> session.fireUntilHalt();
> }
> }.start();
>
> Thread.sleep (5000); // give the engine time to get setup
>
> Server hiwaesdk = new Server ("hiwaesdk");
> session.insert(hiwaesdk);
> long LIMIT = 120;
> Random rnd = new Random (System.nanoTime());
>
> for (long i = LIMIT; i > 0; i--) {
> int j = rnd.nextInt (212);
> ep01.insert (new IntEvent (j));
> //Thread.sleep (0x1);
> }
>
> System.out.println (hiwaesdk);
> }
> }
>
>
> ### average.drl ###
> package drools5fusioneval
>
> declare IntEvent
> @role ( event )
> @expires(15s)
> end
>
> declare Statistics
> opsec : long
> total : long
> end
> global Statistics stats;
>
> rule "Init engine"
> salience 100
> when
> then
> stats = new Statistics ();
> stats.setTotal (0);
> stats.setOpsec (0);
> drools.getWorkingMemory ().setGlobal ("stats", stats);
> System.out.println ("Engine initialized");
> end
>
> rule "number rule"
> when
> $e : IntEvent () from entry-point ep01
> $s : Server (hostname == "hiwaesdk")
> then
> $s.currentTemp = $e.data;
> stats.setOpsec (stats.getOpsec () + 1);
> stats.setTotal (stats.getTotal () + 1);
> end
>
> rule "average temp"
> when
> Number ($avg : intValue) from accumulate (
> IntEvent ($temp : data) over window:length(10) from
entry-point
> ep01, average ($temp)
> )
> $s : Server (hostname == "hiwaesdk")
> then
> $s.avgTemp = $avg;
> end
>
> rule "Heartbeat"
> timer ( int: 5s 5s)
> when
> then
> channels["heartbeat"].send ("Heartbeat: "+ stats.getOpsec ()
/ 5 +",
"+
> stats.getTotal ());
> stats.setOpsec (0);
> end
>
>
>
> --
> View this message in context:
>
http://drools.46999.n3.nabble.com/NPE-from-reteoo-AccumulateNode-tp402381...
> Sent from the Drools: User forum mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
2:22 p.m.
Confirmed as a race condition, hopefully it will be fixed in 5.6
Thanks Jason and Wolfgang
Davide
On 05/14/2013 06:43 AM, Jason Barto wrote:
Thanks Wolfgang. I'll change over to the 5.3 libraries and carry on
with my testing. I'll also enter this issue into jira if it doesn't
yet exist.
Sincerely,
Jason
On May 14, 2013 11:30 AM, "Wolfgang Laun" <wolfgang.laun(a)gmail.com
<mailto:wolfgang.laun@gmail.com>> wrote:
Looks like a bug in Drools to me. It has the classic hallmark of a
race condition: the NPE does not happen with every run (on my system),
perhaps only with 85%.
Moreover, with 5.4.0 I get a similar NPE and also:
Exception in thread "main" java.util.NoSuchElementException
at java.util.LinkedList.remove(LinkedList.java:788)
at java.util.LinkedList.removeFirst(LinkedList.java:134)
at
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:344)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:342)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:298)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:123)
at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:53)
at overrun.Main.main(Main.java:64)
5.3.0 is the last version without this bug.
-W
On 14/05/2013, jpbarto <Jason.P.Barto(a)gmail.com
<mailto:Jason.P.Barto@gmail.com>> wrote:
> First the specifics: JDK 1.6, Mac OSX, using Drools 5.5 Final
>
> The full source code and rules are pasted below but here's the
gist, I have
> a stateful knowledge session to which I am inserting events and
running an
> accumulate on the input events. I have a for loop generating
the events
> and
> inserting them as rapidly as possible. In the rules I use an
accumulator
> to
> calculate the average of the values contained within the events.
The
> behavior I'm observing is that if I insert ~120 events without
any waiting
> I
> receive an NPE. If I Thread.sleep for even just 1ms the test
goes off
> without a hitch. Have I uncovered a bug which should be logged
in JIRA? I
> would check through JIRA to see if something similar has been
logged but
> I'm
> so unfamiliar with the codebase, not to mention it could all
just be user
> error.
>
> The NPE is as follows:
> Exception in thread "main" java.lang.NullPointerException
> at
>
org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:1050)
> at
>
org.drools.reteoo.AccumulateNode.modifyLeftTuple(AccumulateNode.java:345)
> at
>
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyChildLeftTuple(SingleLeftTupleSinkAdapter.java:259)
> at
>
org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:676)
> at
>
org.drools.reteoo.ReteooWorkingMemory$EvaluateResultConstraints.execute(ReteooWorkingMemory.java:590)
> at
>
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:350)
> at
>
org.drools.rule.SlidingLengthWindow.assertFact(SlidingLengthWindow.java:119)
> at
org.drools.rule.BehaviorManager.assertFact(BehaviorManager.java:94)
> at
org.drools.reteoo.WindowNode.assertObject(WindowNode.java:167)
> at
>
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
> at
>
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
> at
org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
> at
org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:127)
> at
org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:55)
> at drools5fusioneval.Average.main(Average.java:66)
>
> ### Average.java ###
> package drools5fusioneval;
>
> import java.io.IOException;
> import java.util.Random;
> import org.drools.KnowledgeBase;
> import org.drools.KnowledgeBaseConfiguration;
> import org.drools.KnowledgeBaseFactory;
> import org.drools.builder.KnowledgeBuilder;
> import org.drools.builder.KnowledgeBuilderFactory;
> import org.drools.builder.ResourceType;
> import org.drools.conf.EventProcessingOption;
> import org.drools.io.ResourceFactory;
> import org.drools.runtime.StatefulKnowledgeSession;
> import org.drools.runtime.rule.WorkingMemoryEntryPoint;
>
> class AvgDFEChannel implements org.drools.runtime.Channel {
> @Override
> public void send(Object o) {
> System.err.println ("Recieved channel message: "+ o);
> }
> }
>
> public class Average {
> public static void main(String[] args) throws
InterruptedException,
> IOException {
> KnowledgeBaseConfiguration kbconfig =
> KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
> kbconfig.setOption(EventProcessingOption.STREAM);
>
> KnowledgeBase kbase =
> KnowledgeBaseFactory.newKnowledgeBase(kbconfig);
>
> KnowledgeBuilder kbuilder =
> KnowledgeBuilderFactory.newKnowledgeBuilder();
>
>
kbuilder.add(ResourceFactory.newClassPathResource("drools5fusioneval/average.drl"),
> ResourceType.DRL);
> if (kbuilder.hasErrors()) {
> System.err.println(kbuilder.getErrors().toString());
> }
> kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
>
> final StatefulKnowledgeSession session =
> kbase.newStatefulKnowledgeSession();
> session.registerChannel("heartbeat", new AvgDFEChannel ());
> WorkingMemoryEntryPoint ep01 =
> session.getWorkingMemoryEntryPoint("ep01");
>
> new Thread() {
> public void run() {
> session.fireUntilHalt();
> }
> }.start();
>
> Thread.sleep (5000); // give the engine time to get setup
>
> Server hiwaesdk = new Server ("hiwaesdk");
> session.insert(hiwaesdk);
> long LIMIT = 120;
> Random rnd = new Random (System.nanoTime());
>
> for (long i = LIMIT; i > 0; i--) {
> int j = rnd.nextInt (212);
> ep01.insert (new IntEvent (j));
> //Thread.sleep (0x1);
> }
>
> System.out.println (hiwaesdk);
> }
> }
>
>
> ### average.drl ###
> package drools5fusioneval
>
> declare IntEvent
> @role ( event )
> @expires(15s)
> end
>
> declare Statistics
> opsec : long
> total : long
> end
> global Statistics stats;
>
> rule "Init engine"
> salience 100
> when
> then
> stats = new Statistics ();
> stats.setTotal (0);
> stats.setOpsec (0);
> drools.getWorkingMemory ().setGlobal ("stats", stats);
> System.out.println ("Engine initialized");
> end
>
> rule "number rule"
> when
> $e : IntEvent () from entry-point ep01
> $s : Server (hostname == "hiwaesdk")
> then
> $s.currentTemp = $e.data;
> stats.setOpsec (stats.getOpsec () + 1);
> stats.setTotal (stats.getTotal () + 1);
> end
>
> rule "average temp"
> when
> Number ($avg : intValue) from accumulate (
> IntEvent ($temp : data) over window:length(10) from
entry-point
> ep01, average ($temp)
> )
> $s : Server (hostname == "hiwaesdk")
> then
> $s.avgTemp = $avg;
> end
>
> rule "Heartbeat"
> timer ( int: 5s 5s)
> when
> then
> channels["heartbeat"].send ("Heartbeat: "+
stats.getOpsec ()
/ 5 +", "+
> stats.getTotal ());
> stats.setOpsec (0);
> end
>
>
>
> --
> View this message in context:
>
http://drools.46999.n3.nabble.com/NPE-from-reteoo-AccumulateNode-tp402381...
> Sent from the Drools: User forum mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org <mailto:rules-users@lists.jboss.org>
> https://lists.jboss.org/mailman/listinfo/rules-users
>
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11:30 a.m.
Davide and Wolfgang, thank you both for your time and feedback into my
questions as well as to other's questions. I'm rather interested in
learning more about the internals of drools in the hopes of making
contribution when and where possible. I'd imagine there's a developer guide
that talks to fusion's architecture that would act as a companion to
reviewing the source code?
Sincerely,
Jason
On May 14, 2013 8:25 PM, "Davide Sottara" <dsotty(a)gmail.com> wrote:
Confirmed as a race condition, hopefully it will be fixed in 5.6
Thanks Jason and Wolfgang
Davide
On 05/14/2013 06:43 AM, Jason Barto wrote:
Thanks Wolfgang. I'll change over to the 5.3 libraries and carry on with
my testing. I'll also enter this issue into jira if it doesn't yet exist.
Sincerely,
Jason
On May 14, 2013 11:30 AM, "Wolfgang Laun" <wolfgang.laun(a)gmail.com>
wrote:
> Looks like a bug in Drools to me. It has the classic hallmark of a
> race condition: the NPE does not happen with every run (on my system),
> perhaps only with 85%.
>
> Moreover, with 5.4.0 I get a similar NPE and also:
> Exception in thread "main" java.util.NoSuchElementException
> at java.util.LinkedList.remove(LinkedList.java:788)
> at java.util.LinkedList.removeFirst(LinkedList.java:134)
> at
>
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:344)
> at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:342)
> at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:298)
> at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:123)
> at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:53)
> at overrun.Main.main(Main.java:64)
>
> 5.3.0 is the last version without this bug.
>
> -W
>
>
> On 14/05/2013, jpbarto <Jason.P.Barto(a)gmail.com> wrote:
> > First the specifics: JDK 1.6, Mac OSX, using Drools 5.5 Final
> >
> > The full source code and rules are pasted below but here's the gist, I
> have
> > a stateful knowledge session to which I am inserting events and running
> an
> > accumulate on the input events. I have a for loop generating the events
> > and
> > inserting them as rapidly as possible. In the rules I use an
> accumulator
> > to
> > calculate the average of the values contained within the events. The
> > behavior I'm observing is that if I insert ~120 events without any
> waiting
> > I
> > receive an NPE. If I Thread.sleep for even just 1ms the test goes off
> > without a hitch. Have I uncovered a bug which should be logged in
> JIRA? I
> > would check through JIRA to see if something similar has been logged but
> > I'm
> > so unfamiliar with the codebase, not to mention it could all just be
> user
> > error.
> >
> > The NPE is as follows:
> > Exception in thread "main" java.lang.NullPointerException
> > at
> > org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:1050)
> > at
> >
> org.drools.reteoo.AccumulateNode.modifyLeftTuple(AccumulateNode.java:345)
> > at
> >
>
org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateModifyChildLeftTuple(SingleLeftTupleSinkAdapter.java:259)
> > at
> >
> org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:676)
> > at
> >
>
org.drools.reteoo.ReteooWorkingMemory$EvaluateResultConstraints.execute(ReteooWorkingMemory.java:590)
> > at
> >
>
org.drools.common.PropagationContextImpl.evaluateActionQueue(PropagationContextImpl.java:350)
> > at
> >
> org.drools.rule.SlidingLengthWindow.assertFact(SlidingLengthWindow.java:119)
> > at
> org.drools.rule.BehaviorManager.assertFact(BehaviorManager.java:94)
> > at org.drools.reteoo.WindowNode.assertObject(WindowNode.java:167)
> > at
> >
>
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
> > at
> >
>
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
> > at
> org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
> > at
> org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
> > at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350)
> > at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311)
> > at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:127)
> > at
> org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:55)
> > at drools5fusioneval.Average.main(Average.java:66)
> >
> > ### Average.java ###
> > package drools5fusioneval;
> >
> > import java.io.IOException;
> > import java.util.Random;
> > import org.drools.KnowledgeBase;
> > import org.drools.KnowledgeBaseConfiguration;
> > import org.drools.KnowledgeBaseFactory;
> > import org.drools.builder.KnowledgeBuilder;
> > import org.drools.builder.KnowledgeBuilderFactory;
> > import org.drools.builder.ResourceType;
> > import org.drools.conf.EventProcessingOption;
> > import org.drools.io.ResourceFactory;
> > import org.drools.runtime.StatefulKnowledgeSession;
> > import org.drools.runtime.rule.WorkingMemoryEntryPoint;
> >
> > class AvgDFEChannel implements org.drools.runtime.Channel {
> > @Override
> > public void send(Object o) {
> > System.err.println ("Recieved channel message: "+ o);
> > }
> > }
> >
> > public class Average {
> > public static void main(String[] args) throws InterruptedException,
> > IOException {
> > KnowledgeBaseConfiguration kbconfig =
> > KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
> > kbconfig.setOption(EventProcessingOption.STREAM);
> >
> > KnowledgeBase kbase =
> > KnowledgeBaseFactory.newKnowledgeBase(kbconfig);
> >
> > KnowledgeBuilder kbuilder =
> > KnowledgeBuilderFactory.newKnowledgeBuilder();
> >
> >
>
kbuilder.add(ResourceFactory.newClassPathResource("drools5fusioneval/average.drl"),
> > ResourceType.DRL);
> > if (kbuilder.hasErrors()) {
> > System.err.println(kbuilder.getErrors().toString());
> > }
> > kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
> >
> > final StatefulKnowledgeSession session =
> > kbase.newStatefulKnowledgeSession();
> > session.registerChannel("heartbeat", new AvgDFEChannel ());
> > WorkingMemoryEntryPoint ep01 =
> > session.getWorkingMemoryEntryPoint("ep01");
> >
> > new Thread() {
> > public void run() {
> > session.fireUntilHalt();
> > }
> > }.start();
> >
> > Thread.sleep (5000); // give the engine time to get setup
> >
> > Server hiwaesdk = new Server ("hiwaesdk");
> > session.insert(hiwaesdk);
> > long LIMIT = 120;
> > Random rnd = new Random (System.nanoTime());
> >
> > for (long i = LIMIT; i > 0; i--) {
> > int j = rnd.nextInt (212);
> > ep01.insert (new IntEvent (j));
> > //Thread.sleep (0x1);
> > }
> >
> > System.out.println (hiwaesdk);
> > }
> > }
> >
> >
> > ### average.drl ###
> > package drools5fusioneval
> >
> > declare IntEvent
> > @role ( event )
> > @expires(15s)
> > end
> >
> > declare Statistics
> > opsec : long
> > total : long
> > end
> > global Statistics stats;
> >
> > rule "Init engine"
> > salience 100
> > when
> > then
> > stats = new Statistics ();
> > stats.setTotal (0);
> > stats.setOpsec (0);
> > drools.getWorkingMemory ().setGlobal ("stats", stats);
> > System.out.println ("Engine initialized");
> > end
> >
> > rule "number rule"
> > when
> > $e : IntEvent () from entry-point ep01
> > $s : Server (hostname == "hiwaesdk")
> > then
> > $s.currentTemp = $e.data;
> > stats.setOpsec (stats.getOpsec () + 1);
> > stats.setTotal (stats.getTotal () + 1);
> > end
> >
> > rule "average temp"
> > when
> > Number ($avg : intValue) from accumulate (
> > IntEvent ($temp : data) over window:length(10) from
> entry-point
> > ep01, average ($temp)
> > )
> > $s : Server (hostname == "hiwaesdk")
> > then
> > $s.avgTemp = $avg;
> > end
> >
> > rule "Heartbeat"
> > timer ( int: 5s 5s)
> > when
> > then
> > channels["heartbeat"].send ("Heartbeat: "+
stats.getOpsec () / 5
> +", "+
> > stats.getTotal ());
> > stats.setOpsec (0);
> > end
> >
> >
> >
> > --
> > View this message in context:
> >
> http://drools.46999.n3.nabble.com/NPE-from-reteoo-AccumulateNode-tp402381...
> > Sent from the Drools: User forum mailing list archive at Nabble.com.
> > _______________________________________________
> > rules-users mailing list
> > rules-users(a)lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
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4243
days inactive
4244
days old
4 comments
4 participants
participants (4)
-
Davide Sottara -
Jason Barto -
jpbarto
-
Wolfgang Laun