Re: [rules-users] Need clarification on how event expiration offset is calculated in 5.3.0.FINAL
Following up:
I verified that I am using STREAM mode on the knowledge base, that events
and rules are declared in the same package, and that the session clock is
in line with the events. The behavior I described previously is still
present even after adding and explicit expiration. I've created a JIRA at
https://issues.jboss.org/browse/JBRULES-3307 so that you can look into this
further. Thanks for your quick response.
Scott
2011/12/7 Edson Tirelli ed.tire...@gmail.com
Scott,
The event expiration algorithm in Drools works with compile time
analysis of temporal constraints. It calculates the transitive closure on
the temporal intervals created by each temporal constraint and from that it
infers the required time for an event to stay in memory, expiring them
after that. Some interactions are pretty hard to calculate manually, but as
you already realized, you can enable the Drools MBeans and use jconsole (or
visualvm as you mentioned) to inspect them.
In your case, first things first, I assume you are running the engine
in STREAM mode? the default is CLOUD mode, and in CLOUD mode there is no
expiration of events. Second, there was a bug in one of the released
versions of Drools (I think 5.2 or 5.3) that was fixed after where the
calculation was wrong if the events were in different packages. Finally,
you are using external timestamps for the events (on its attributes), so
make sure your clock is in line with the externally timestamped events.
If everything I mentioned is working as expected and your events are
still not being expired, please try adding an explicit expiration policy
(e.g., @expires( 1m ) ), and submit a bug (JIRA) with your findings.
Edson
2011/12/7 Scott Embler stemb...@gmail.com
Hi,
I've recently started using some of the temporal operators that drools
supports (coincides, starts, finishes, during) and have had trouble with
events not being expired, causing severe memory consumption.
I'd first like to make sure that I'm using these operators appropriately,
so as a test case I have rules like:
declare A
@role( event )
@timestamp( timestamp )
@duration( duration )
end
declare B
@role( event )
@timestamp( timestamp )
@duration( duration )
end
rule coincides events
when
$a: A() from entry-point a
$b: B(this coincides $a) from entry-point b
then insert(coincides); end
With classes like:
public class A{
public final long timestamp;
public final long duration;
public A(long timestamp, long duration){
this.timestamp = timestamp;
this.duration = duration;
}
}
//B is identical to A.
Using a knowledge base configured with stream mode, and a knowledge
session with a pseudo clock I'd run this test:
A a = new A(0, 1000);
B b = new B(0, 1000);
entryPointA.insert(a);
entryPointB.insert(b);
clock.advanceTime(1000, TimeUnit.MILLISECONDS);
ksession.fireAllRules();
In this test I'm expecting that the rule will fire to insert coincides
and expire both A and B. But instead, coincides is inserted, B is
expired, but A remains in memory permanently. If I use jvisualvm to
inspect the expirationOffset for A, I see that it is the Long.MAX value of
9223372036854775807. This behavior persists even after adding an explicit
expiration to A. I was under the impression that the offset would be zero
(of close to it) since Drools would only need to retain A until the clock
reaches A's endTimestamp. The documentation does not cover the calculation
of event expiration in great detail, so have I missed something? Thanks in
advance.
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--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
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[rules-users] Need clarification on how event expiration offset is calculated in 5.3.0.FINAL
Hi,
I've recently started using some of the temporal operators that drools
supports (coincides, starts, finishes, during) and have had trouble with
events not being expired, causing severe memory consumption.
I'd first like to make sure that I'm using these operators appropriately,
so as a test case I have rules like:
declare A
@role( event )
@timestamp( timestamp )
@duration( duration )
end
declare B
@role( event )
@timestamp( timestamp )
@duration( duration )
end
rule coincides events
when
$a: A() from entry-point a
$b: B(this coincides $a) from entry-point b
then insert(coincides); end
With classes like:
public class A{
public final long timestamp;
public final long duration;
public A(long timestamp, long duration){
this.timestamp = timestamp;
this.duration = duration;
}
}
//B is identical to A.
Using a knowledge base configured with stream mode, and a knowledge session
with a pseudo clock I'd run this test:
A a = new A(0, 1000);
B b = new B(0, 1000);
entryPointA.insert(a);
entryPointB.insert(b);
clock.advanceTime(1000, TimeUnit.MILLISECONDS);
ksession.fireAllRules();
In this test I'm expecting that the rule will fire to insert coincides
and expire both A and B. But instead, coincides is inserted, B is
expired, but A remains in memory permanently. If I use jvisualvm to
inspect the expirationOffset for A, I see that it is the Long.MAX value of
9223372036854775807. This behavior persists even after adding an explicit
expiration to A. I was under the impression that the offset would be zero
(of close to it) since Drools would only need to retain A until the clock
reaches A's endTimestamp. The documentation does not cover the calculation
of event expiration in great detail, so have I missed something? Thanks in
advance.
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] Need clarification on how event expiration offset is calculated in 5.3.0.FINAL
Scott,
The event expiration algorithm in Drools works with compile time
analysis of temporal constraints. It calculates the transitive closure on
the temporal intervals created by each temporal constraint and from that it
infers the required time for an event to stay in memory, expiring them
after that. Some interactions are pretty hard to calculate manually, but as
you already realized, you can enable the Drools MBeans and use jconsole (or
visualvm as you mentioned) to inspect them.
In your case, first things first, I assume you are running the engine
in STREAM mode? the default is CLOUD mode, and in CLOUD mode there is no
expiration of events. Second, there was a bug in one of the released
versions of Drools (I think 5.2 or 5.3) that was fixed after where the
calculation was wrong if the events were in different packages. Finally,
you are using external timestamps for the events (on its attributes), so
make sure your clock is in line with the externally timestamped events.
If everything I mentioned is working as expected and your events are
still not being expired, please try adding an explicit expiration policy
(e.g., @expires( 1m ) ), and submit a bug (JIRA) with your findings.
Edson
2011/12/7 Scott Embler stemb...@gmail.com
Hi,
I've recently started using some of the temporal operators that drools
supports (coincides, starts, finishes, during) and have had trouble with
events not being expired, causing severe memory consumption.
I'd first like to make sure that I'm using these operators appropriately,
so as a test case I have rules like:
declare A
@role( event )
@timestamp( timestamp )
@duration( duration )
end
declare B
@role( event )
@timestamp( timestamp )
@duration( duration )
end
rule coincides events
when
$a: A() from entry-point a
$b: B(this coincides $a) from entry-point b
then insert(coincides); end
With classes like:
public class A{
public final long timestamp;
public final long duration;
public A(long timestamp, long duration){
this.timestamp = timestamp;
this.duration = duration;
}
}
//B is identical to A.
Using a knowledge base configured with stream mode, and a knowledge
session with a pseudo clock I'd run this test:
A a = new A(0, 1000);
B b = new B(0, 1000);
entryPointA.insert(a);
entryPointB.insert(b);
clock.advanceTime(1000, TimeUnit.MILLISECONDS);
ksession.fireAllRules();
In this test I'm expecting that the rule will fire to insert coincides
and expire both A and B. But instead, coincides is inserted, B is
expired, but A remains in memory permanently. If I use jvisualvm to
inspect the expirationOffset for A, I see that it is the Long.MAX value of
9223372036854775807. This behavior persists even after adding an explicit
expiration to A. I was under the impression that the offset would be zero
(of close to it) since Drools would only need to retain A until the clock
reaches A's endTimestamp. The documentation does not cover the calculation
of event expiration in great detail, so have I missed something? Thanks in
advance.
___
rules-users mailing list
rules-users@lists.jboss.org
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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