4:40 a.m.
Hello,
I did some tests to get an opinion about the performance of drools (5.0.1).
At one test I have a rule with 10 objects (same object-type) declared as
condition and got an OutOfMemoryException. I noticed that the memory usage
increases when I insert the last facts into my
StatefulKnowledgeSession. On fact 7 it increases with 10MB, on fact 8 with
46MB and on fact 9 with 170MB.
I debuged a little bit in the drools-source and noticed that the
LeftTupleMemory increased exponential with the number of facts I inserted.
My question about this behaviour:
Is a condition limited to a handful of facts or do I have to change the
syntax to get it working? I know that I could insert the same object-types
as a list, but assume that I have 10 facts with different object-types.
Thanks in reply,
Christian
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4:55 a.m.
New subject: high memory usage for rules with more than 6 facts ascondition
What conditions are you placing on the rule?
If you haven't got any conditions on them then the number of possible combinations
(and so activations) that the rule can match will grow exponentially.
If you rule has 10 objects all of the same type and no conditions preventing them from
being set to the same value then:
With 1 object in working memory there will be only 1 activation.
With 2 objects in working memory then there will be 2 possible values for the first
object, 2 for the second, 2 for the third... eg 2*2*2*2*2*2*2*2*2*2 = 2^10 = 1024
activations
With 3 objects 3^10 = 59049 activations
With 4 objects 4^10 = 1048576 activations
With 5 objects 5^10 = 9765625 activations
With 6 objects 6^10 = 60466176 activations
With 7 objects 7^10 = 282475249 activations
With 8 objects 8^10 = 1073741824 activations
With 9 objects 9^10 = 3486784401 activations
With 10 objects 10^10 = 10000000000 activations
If you put some restrictions on so that you aren't matching every single combination
then your memory usage should shrink.
-----Original Message-----
From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-
bounces(a)lists.jboss.org] On Behalf Of murphy
Sent: 14 April 2010 10:41
To: rules-users(a)lists.jboss.org
Subject: [rules-users] high memory usage for rules with more than 6 facts
ascondition
Hello,
I did some tests to get an opinion about the performance of drools (5.0.1).
At one test I have a rule with 10 objects (same object-type) declared as
condition and got an OutOfMemoryException. I noticed that the memory usage
increases when I insert the last facts into my
StatefulKnowledgeSession. On fact 7 it increases with 10MB, on fact 8 with
46MB and on fact 9 with 170MB.
I debuged a little bit in the drools-source and noticed that the
LeftTupleMemory increased exponential with the number of facts I inserted.
My question about this behaviour:
Is a condition limited to a handful of facts or do I have to change the
syntax to get it working? I know that I could insert the same object-types
as a list, but assume that I have 10 facts with different object-types.
Thanks in reply,
Christian
--
View this message in context: http://n3.nabble.com/high-memory-usage-for-
rules-with-more-than-6-facts-as-condition-tp718114p718114.html
Sent from the Drools - User mailing list archive at Nabble.com.
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6:02 a.m.
New subject: high memory usage for rules with more than 6 facts ascondition
I had conditions with the same restrictions. I changed this to different
restrictions and no it works.
Maybe I should think a little bit more about how drools handles the facts
and conditions before I test a quick-and-dirty solution...
Thanks for your help!
Christian
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5:19 a.m.
Do you constrain the number of possible matches of 10 elements, which,
without constraints, is quite a number (10! = 3628800)?
Tests that produce a highly unlikely scenario aren't particularly useful.
-W
On Wed, Apr 14, 2010 at 11:40 AM, murphy <christian.niehues(a)its-telco.de> wrote:
Hello,
I did some tests to get an opinion about the performance of drools (5.0.1).
At one test I have a rule with 10 objects (same object-type) declared as
condition and got an OutOfMemoryException. I noticed that the memory usage
increases when I insert the last facts into my
StatefulKnowledgeSession. On fact 7 it increases with 10MB, on fact 8 with
46MB and on fact 9 with 170MB.
I debuged a little bit in the drools-source and noticed that the
LeftTupleMemory increased exponential with the number of facts I inserted.
My question about this behaviour:
Is a condition limited to a handful of facts or do I have to change the
syntax to get it working? I know that I could insert the same object-types
as a list, but assume that I have 10 facts with different object-types.
Thanks in reply,
Christian
--
View this message in context:
http://n3.nabble.com/high-memory-usage-for-rules-with-more-than-6-facts-a...
Sent from the Drools - User mailing list archive at Nabble.com.
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5:21 a.m.
I was assuming that repeated matches of the same element amon the 10 are
excluded (which they probably aren't), so Thomas' formula is the correct one.
-W
On Wed, Apr 14, 2010 at 12:19 PM, Wolfgang Laun <wolfgang.laun(a)gmail.com> wrote:
Do you constrain the number of possible matches of 10 elements,
which,
without constraints, is quite a number (10! = 3628800)?
Tests that produce a highly unlikely scenario aren't particularly useful.
-W
On Wed, Apr 14, 2010 at 11:40 AM, murphy <christian.niehues(a)its-telco.de> wrote:
>
> Hello,
>
> I did some tests to get an opinion about the performance of drools (5.0.1).
>
> At one test I have a rule with 10 objects (same object-type) declared as
> condition and got an OutOfMemoryException. I noticed that the memory usage
> increases when I insert the last facts into my
> StatefulKnowledgeSession. On fact 7 it increases with 10MB, on fact 8 with
> 46MB and on fact 9 with 170MB.
>
> I debuged a little bit in the drools-source and noticed that the
> LeftTupleMemory increased exponential with the number of facts I inserted.
>
> My question about this behaviour:
> Is a condition limited to a handful of facts or do I have to change the
> syntax to get it working? I know that I could insert the same object-types
> as a list, but assume that I have 10 facts with different object-types.
>
> Thanks in reply,
> Christian
>
> --
> View this message in context:
http://n3.nabble.com/high-memory-usage-for-rules-with-more-than-6-facts-a...
> Sent from the Drools - User mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
5344
days inactive
5344
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4 comments
3 participants
participants (3)
-
murphy -
Swindells, Thomas -
Wolfgang Laun