[rules-users] Reclaiming memory usage
Edson Tirelli
ed.tirelli at gmail.com
Mon Jul 25 23:19:43 EDT 2011
Hi Chris,
Best way is to explicitly define the relationship with a temporal
constraint (although there are other ways). E.g.:
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( this before[0,5s] $dr ) from entry-point "My Stream")
then
As we evolve the product I believe we can add defaults and other types of
policies to the system that will allow for other ways to define these
relationships, but the system, at the moment, will use strict temporal logic
and if no temporal join is defined, it will cross product like it would with
non-temporal constraints... and that means keeping everything in memory.
Edson
2011/7/26 Chris Richmond <crichmond at referentia.com>
> **
> Ok, well how to make them marry only those alive(<100 years old) and ensure
> all those over 100 years old go out of memory?
>
> Chris
>
>
> On 7/25/2011 2:32 PM, Edson Tirelli wrote:
>
>
> Chris
>
> That defines the expiration policy for ReconfigEvent, but it does not
> define the relationship between ReconfigEvent and DataReading. Imagine a
> timeline, dotted with ReconfigEvents... what your rule is saying is for each
> DataReading event, match it with all the "periods where there is no
> ReconfigEvent", as the lifetime of DataReading is infinity.
>
> Maybe a simpler way of understanding it (without using the "not" for
> simplification) is think about this:
>
> declare Man
> @livesUpTo( 100 years )
> end
>
> rule "marriage"
> when
> $w : Woman( age > 18 )
> $m : Man( )
> then
> // marry woman and man
> end
>
> The rule above defines that each woman will merry every existing man,
> even if each of them only lives for 100 years.
>
> Edson
>
> 2011/7/26 Chris Richmond <crichmond at 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 at 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
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
>>
>>
>>
>> --
>> Edson Tirelli
>> JBoss Drools Core Development
>> JBoss by Red Hat @ www.jboss.com
>>
>>
>> _______________________________________________
>> rules-users mailing listrules-users at lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>>
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>>
>>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> JBoss by Red Hat @ www.jboss.com
>
>
> _______________________________________________
> rules-users mailing listrules-users at lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
> _______________________________________________
> 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
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