[Pellet-users] Out of memory when using rules

[James Howison]

I'm interested in other answers you might get, but have you tried  
setting PelletOptions.USE_CONTINUOUS_RULES = true;?  That's the advice  
I got here recently when dealing with out of heap space errors with  
SWRL rules:

http://lists.owldl.com/pipermail/pellet-users/2008-March/002458.html

On Apr 6, 2008, at 10:52 AM, Somaya Aboulwafa wrote:
> I forgot to say that i have tried this using both Jena and OWLAPI.  
> When
> using OWLAPI I got the following exception:
>
> Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
>
> at java.util.Arrays.copyOf(Unknown Source)
>
> at java.util.BitSet.ensureCapacity(Unknown Source)
>
> at java.util.BitSet.expandTo(Unknown Source)
>
> at java.util.BitSet.set(Unknown Source)
>
> at org.mindswap.pellet.DependencySet.<init>(*DependencySet.java:97*)
>
> at org.mindswap.pellet.RuleBranch.tryBranch(*RuleBranch.java:149*)
>
> at org.mindswap.pellet.RuleStrategy.createDisjunctionsFromBinding(*
> RuleStrategy.java:413*)
>
> at org.mindswap.pellet.RuleStrategy.applyRULERule(*RuleStrategy.java: 
> 148*)
>
> at org.mindswap.pellet.RuleStrategy.complete(*RuleStrategy.java:319*)
>
> at org.mindswap.pellet.ABox.isConsistent(*ABox.java:1605*)
>
> at org.mindswap.pellet.ABox.isConsistent(*ABox.java:1489*)
>
> at org.mindswap.pellet.KnowledgeBase.consistency(*KnowledgeBase.java: 
> 1568*)
>
> at  
> org.mindswap.pellet.KnowledgeBase.isConsistent(*KnowledgeBase.java: 
> 1589*)
>
> at org.mindswap.pellet.KnowledgeBase.ensureConsistency(*
> KnowledgeBase.java:1595*)
>
> at org.mindswap.pellet.KnowledgeBase.classify(*KnowledgeBase.java: 
> 1601*)
>
> at org.mindswap.pellet.KnowledgeBase.realize(*KnowledgeBase.java: 
> 1630*)
>
> at  
> org.mindswap.pellet.KnowledgeBase.getInstances(*KnowledgeBase.java: 
> 2710*)
>
> at org.mindswap.pellet.owlapi.Reasoner.getIndividuals(*Reasoner.java: 
> 550*)
>
> at Trial1.PolicyReasoningOWLapi.main(*PolicyReasoningOWLapi.java:44*)
>
> And When using Jena I got the following similar exception:
>
> Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
>
> at java.util.Arrays.copyOf(Unknown Source)
>
> at java.util.BitSet.ensureCapacity(Unknown Source)
>
> at java.util.BitSet.expandTo(Unknown Source)
>
> at java.util.BitSet.set(Unknown Source)
>
> at org.mindswap.pellet.DependencySet.<init>(*DependencySet.java:97*)
>
> at org.mindswap.pellet.RuleBranch.tryBranch(*RuleBranch.java:149*)
>
> at org.mindswap.pellet.RuleStrategy.createDisjunctionsFromBinding(*
> RuleStrategy.java:413*)
>
> at org.mindswap.pellet.RuleStrategy.applyRULERule(*RuleStrategy.java: 
> 148*)
>
> at org.mindswap.pellet.RuleStrategy.complete(*RuleStrategy.java:319*)
>
> at org.mindswap.pellet.ABox.isConsistent(*ABox.java:1605*)
>
> at org.mindswap.pellet.ABox.isConsistent(*ABox.java:1489*)
>
> at org.mindswap.pellet.KnowledgeBase.consistency(*KnowledgeBase.java: 
> 1568*)
>
> at  
> org.mindswap.pellet.KnowledgeBase.isConsistent(*KnowledgeBase.java: 
> 1589*)
>
> at  
> org.mindswap.pellet.jena.PelletInfGraph.prepare(*PelletInfGraph.java: 
> 267*
> )
>
> at com.hp.hpl.jena.ontology.impl.OntModelImpl.prepare(*
> OntModelImpl.java:2598*)
>
> at Trial1.PolicyReasoningJena.main(*PolicyReasoningJena.java:38*)
> Thanks in advance,
> Somaya
>
> On Sun, Apr 6, 2008 at 3:09 PM, Somaya Aboulwafa <somaya.ahmad at gmail.com 
> >
> wrote:
>
>> *Hi all,*
>> *I'm in need for help on how to troubleshoot this problem. I got an  
>> out of
>> memory exception (heap space). I use an ontology generated by  
>> **Protege
>> (with OWL Plugin 3.3.1, Build 430) and I use Pellet 1.5.1 APIs. My  
>> ontology
>> has some classes and individuals and only one rule. The rule is as  
>> follows:
>> *
>>
>> *Agent(?x), IsInactivestaff(?C), hasCred(?X,?C), CoursesProh(?P) ->
>> hasAD(?X,?P)*
>>
>> *However, when I write the rules as follows, then I got no  
>> exception and
>> the inference works fine:*
>>
>> *Agent(?x), IsInactivestaff(?C), hasCred(?X,?C) -> hasAD(? 
>> X,Proh_Teach)*
>>
>> *Where: Proh_Teach is an individual of class CoursesProh*
>> *I have removed all the enumerated classes. As I read in some  
>> previous
>> posts that it might make a problem with pellet. Also I don't use  
>> min/max
>> cardinalities. Moreover I have increased the JVM allocated memory  
>> to 500M,
>> but it doesn't work.*
>>
>> *I don't know where the problem? Do I need to re-design my ontology  
>> differently? Or there is something wrong with the first rule?*
>>
>> * **Plz let me know if I should send my OWL files.*
>>
>> * *
>>
>> *Regards,*
>>
>> *Somaya*
>>
>>
>>
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