Edson

2011/7/26 Chris Richmond <crichmond@referentia.com>

Edson,

I was under the impression that this:

declare ReconfigEvent
@role( event )
@expires ( 5s )
end

would cover that, meaning that every ReconfigEvent would expire after 5s, thus causing to no longer be needed by the engine.

Thanks,
Chris
On 7/25/2011 12:17 PM, Edson Tirelli wrote:
   Chris,

   I haven't tried your code, but just looking at the rule, there is no temporal correlation between DataReading and ReconfigEvent, so if I am not mistaken, that will create a required interval of infinite time when the temporal reasoning is applied, meaning the engine has to keep the readings in memory forever.

   Adding a temporal constraint on the ReconfigEvent pattern on your rule or defining an explicit expiration policy for the DataReadings are ways to work around that.

   Edson

2011/7/26 Chris Richmond <crichmond@referentia.com>

Hello

I am performing a simple test of injecting an event every 1 millisecond
like so:

for (int x = 0; x < 100000; x++){
DataReading dr = new DataReading("Reading " + x, 12.0f);
myStream.insert(dr);
ksession.fireAllRules();
Thread.sleep(1);

}

The rule that evaluates this is simple. It basically delays "then" for
3s to see if a followup reading is inserted and makes sure that no
ReconfigEvent is active(5s expiration).

So if a reading comes in and a followup reading is not inserted within 3
seconds and there is is not an existing ReconfigEvent event alive, then
it should output and insert a ReconfigEvent, essentially disabling any
DataReading action on those events for the next 5 seconds or so. This
all works just fine as expected.

My question is, how come I don't get memory back when all 100,000 of my
events have been inserted. Memory goes up slowly over the course of
insertions, which I can understand, but once that loop is finished,
memory never reduces, so essentially, the application will eventually
run out of memory after some time. I should not have to explicitly
remove/retract events should I? Shouldn't they be removed from working
memory as soon as they are no longer viable? What should I be doing to
reclaim memory from the session/knowledgebase?

I have included the full Main program here and the Sample.drl file below it.

************FusionMain.java*****************

package com.sample;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseConfiguration;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderError;
import org.drools.builder.KnowledgeBuilderErrors;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.conf.EventProcessingOption;
import org.drools.io.ResourceFactory;
import org.drools.logger.KnowledgeRuntimeLogger;
import org.drools.logger.KnowledgeRuntimeLoggerFactory;
import org.drools.runtime.KnowledgeSessionConfiguration;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.conf.ClockTypeOption;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;

public class FusionMain {

@SuppressWarnings("restriction")
public static void main(String[] args) {

try {

KnowledgeSessionConfiguration config =
KnowledgeBaseFactory.newKnowledgeSessionConfiguration();
config.setOption( ClockTypeOption.get("realtime") );

KnowledgeBase kbase;
kbase = readKnowledgeBase();
StatefulKnowledgeSession ksession =
kbase.newStatefulKnowledgeSession();

WorkingMemoryEntryPoint myStream =
ksession.getWorkingMemoryEntryPoint("My Stream");

for (int x = 0; x < 100000; x++){
DataReading dr = new DataReading("Reading " + x, 12.0f);
myStream.insert(dr);
ksession.fireAllRules();
Thread.sleep(1);

}

} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

@SuppressWarnings("restriction")
private static KnowledgeBase readKnowledgeBase() throws Exception {
KnowledgeBuilder kbuilder =
KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"),
ResourceType.DRL);
KnowledgeBuilderErrors errors = kbuilder.getErrors();
if (errors.size() > 0) {
for (KnowledgeBuilderError error: errors) {
System.err.println(error);
}
throw new IllegalArgumentException("Could not parse knowledge.");
}

KnowledgeBaseConfiguration kbConfig =
KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
kbConfig.setOption( EventProcessingOption.STREAM );
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(kbConfig);
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());

return kbase;
}

}

*********Sample.drl*************************

package com.sample

import java.util.Date;

declare DataReading
@role( event )
end

declare ReconfigEvent
@role( event )
@expires ( 5s )
end

rule "Wait for follup reading or no config"
//lock-on-active
when

$dr: DataReading(reading > 10.0) from entry-point "My Stream"
not(DataReading(reading < 10.0, this after[0s,3s] $dr) from
entry-point "My Stream")
not(ReconfigEvent() from entry-point "My Stream")

then
System.err.println("Action: " + new Date(System.currentTimeMillis()));
System.err.println("Data reading " + $dr.getName() + " > 10");
ReconfigEvent rce = new ReconfigEvent();
entryPoints["My Stream"].insert( rce );

end

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--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
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rules-users mailing list
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rules-users mailing list
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https://lists.jboss.org/mailman/listinfo/rules-users

--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com