Question

我正在尝试使用Pellet推断数据，但我的应用程序总是崩溃在推理期间由于“OutOfMemoryError：Java堆空间”。

正如其他地方所建议的，我已经尝试过增加堆大小目前我正在使用这些VM参数：“ - XX：MaxPermSize = 256m -Xmx6144m“。此外，我要设置'PelletOptions.USE_CONTINUOUS = 真的'，但到目前为止我只能将崩溃延迟几分钟。（到目前为止最长的时间：30分钟。）

我将数据存储在Jena TDB triplestore中。它的总大小是170 MB 并包含962117条陈述。本体已经建模了保护并且在与隐士或者隐士合理时没有任何不一致事实++（当然在那时没有数据存在）。我的陈述喜欢推断已使用等效类建模（例如：A和（hasX some X）），逆属性（hasX＆lt; - ＆gt; isXOf）和一些传递属性。共有55个类：14个根类，11个等价类（一个根类的所有子类型）。目前有14个班级的实例已被添加到tripestore。

我也用pellint来分析我的本体，但我不确定是哪一个从这个结果中得出结论：

[Untyped classes]
- http://www.w3.org/2002/07/owl#AllDisjointClasses

[Untyped object roles]
- http://www.w3.org/2002/07/owl#topObjectPriority
- http://www.w3.org/2002/07/owl#members

[Untyped datatype roles]
- http://www.w3.org/2002/07/owl#qualifiedCardinality

[Untyped individuals]
- 4 BNodes

这是我创建InfModel的代码：

 Dataset dataset = TDBFactory.createDataset(..);
 Model model = dataset.getDefaultModel();

 OntModel ont = ModelFactory.createOntologyModel(PelletReasonerFactory.THE_SPEC,model);
 ont.read("file:.." , "RDF/XML");

 PelletOptions.USE_CONTINUOUS_RULES = true;
 Reasoner reasoner = PelletReasonerFactory.theInstance().create();
 reasoner = reasoner.bindSchema(ont);

 InfModel infModel = infModel = ModelFactory.createInfModel(reasoner, model);

这基本上就是我查询数据的方式：

 QueryExecution qe = QueryExecutionFactory.create("SELECT ...", infModel);
 Resultset rs = qe.execSelect();

 while(rs.hasNext())
 {
     QuerySolution sol = rs.nextSolution();
     ...
 }
 qe.close();

正如您所看到的，我在查询时收到了各种异常数据，准备或验证InfModel。你有什么想法，什么否则我可以尝试解决这个错误？

 java.lang.OutOfMemoryError: Java heap space
 at java.util.Arrays.copyOf(Unknown Source)
 at java.lang.AbstractStringBuilder.expandCapacity(Unknown Source)
 at java.lang.AbstractStringBuilder.append(Unknown Source)
 at java.lang.StringBuilder.append(Unknown Source)
 at java.net.URLStreamHandler.parseURL(Unknown Source)
 at sun.net.www.protocol.file.Handler.parseURL(Unknown Source)
 at java.net.URL.<init>(Unknown Source)
 at java.net.URL.<init>(Unknown Source)
 at sun.misc.URLClassPath$FileLoader.getResource(Unknown Source)
 at sun.misc.URLClassPath.getResource(Unknown Source)
 at java.net.URLClassLoader$1.run(Unknown Source)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
 at java.lang.ClassLoader.loadClass(Unknown Source)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorCheck.warn(QueryIteratorCheck.java:114)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorCheck.dump(QueryIteratorCheck.java:95)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorCheck.checkForOpenIterators(QueryIteratorCheck.java:68)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorCheck.close(QueryIteratorCheck.java:50)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorWrapper.closeIterator(QueryIteratorWrapper.java:50)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorBase.close(QueryIteratorBase.java:184)
 at com.hp.hpl.jena.sparql.engine.iterator.QueryIteratorCloseable.close(QueryIteratorCloseable.java:39)
 at com.hp.hpl.jena.sparql.engine.QueryExecutionBase.close(QueryExecutionBase.java:180)


 java.lang.OutOfMemoryError: Java heap space
 at shared.SharedObjectFactory.build(SharedObjectFactory.java:303)
 at aterm.pure.PureFactory.makeAppl(PureFactory.java:191)
 at aterm.pure.PureFactory.makeAppl(PureFactory.java:185)
 at aterm.pure.PureFactory.makeAppl(PureFactory.java:228)
 at org.mindswap.pellet.utils.ATermUtils.makeLiteral(ATermUtils.java:245)
 at org.mindswap.pellet.ABox.addLiteral(ABox.java:1696)
 at org.mindswap.pellet.tableau.completion.rule.SomeValuesRule.applySomeValuesRule(SomeValuesRule.java:174)
 at org.mindswap.pellet.tableau.completion.rule.SomeValuesRule.apply(SomeValuesRule.java:64)
 at org.mindswap.pellet.tableau.completion.rule.AbstractTableauRule.apply(AbstractTableauRule.java:64)
 at org.mindswap.pellet.tableau.completion.SROIQStrategy.complete(SROIQStrategy.java:157)
 at org.mindswap.pellet.ABox.isConsistent(ABox.java:1423)
 at org.mindswap.pellet.ABox.isConsistent(ABox.java:1260)
 at org.mindswap.pellet.KnowledgeBase.consistency(KnowledgeBase.java:1987)
 at org.mindswap.pellet.KnowledgeBase.isConsistent(KnowledgeBase.java:2061)
 at org.mindswap.pellet.jena.PelletInfGraph.prepare(PelletInfGraph.java:247)
 at org.mindswap.pellet.jena.PelletInfGraph.prepare(PelletInfGraph.java:230)
 at com.hp.hpl.jena.rdf.model.impl.InfModelImpl.prepare(InfModelImpl.java:89)


 java.lang.OutOfMemoryError: Java heap space
 at org.mindswap.pellet.tableau.branch.DisjunctionBranch.tryBranch(DisjunctionBranch.java:197)
 at org.mindswap.pellet.tableau.branch.Branch.tryNext(Branch.java:117)
 at org.mindswap.pellet.tableau.completion.rule.ChooseRule.apply(ChooseRule.java:82)
 at org.mindswap.pellet.tableau.completion.rule.ChooseRule.apply(ChooseRule.java:56)
 at org.mindswap.pellet.tableau.completion.rule.AbstractTableauRule.apply(AbstractTableauRule.java:64)
 at org.mindswap.pellet.tableau.completion.SROIQStrategy.complete(SROIQStrategy.java:157)
 at org.mindswap.pellet.ABox.isConsistent(ABox.java:1423)
 at org.mindswap.pellet.ABox.isConsistent(ABox.java:1260)
 at org.mindswap.pellet.KnowledgeBase.consistency(KnowledgeBase.java:1987)
 at org.mindswap.pellet.KnowledgeBase.isConsistent(KnowledgeBase.java:2061)
 at org.mindswap.pellet.jena.PelletInfGraph.prepare(PelletInfGraph.java:247)
 at org.mindswap.pellet.jena.PelletInfGraph.prepare(PelletInfGraph.java:230)
 at org.mindswap.pellet.jena.PelletInfGraph.validate(PelletInfGraph.java:564)
 at com.hp.hpl.jena.rdf.model.impl.InfModelImpl.validate(InfModelImpl.java:111)

Answer 1

查询infModel显然导致Pellet生成数百个owl:differentFrom语句。解决方案是使用ModelExtractor：

ModelExtractor ext = new ModelExtractor(inf); 
Model m = ext.extractModel();
QueryExecution qe = QueryExecutionFactory.create("SELECT ...", m);

使用Pellet作为推理器的OutOfMemoryError

1 个答案: