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[Bigdata-developers] NullPointerException for long property paths
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From: Stefan B. <ste...@wu...> - 2015-09-14 08:26:41
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Hi all! Only last week I started using Blazegraph and was impressed by the performance and support for property path queries. Currently we are evaluating different SPARQL engines and especially exploiting property path queries for a kind of backward-chaining reasoning (see [1] for more details). The queries contain very long and complicated property paths. When evaluating these queries (example query and full stack trace in the end of the message) I get a NullPointerException. The data I loaded with the DataLoader is just the LUBM ontology and just University0_0.owl from LUBM. The query (generated by a query rewriter [2]) returns all instances of lubm:Student under OWL QL semantics and thus encodes all necessary reasoning in the path expressions. Can you see what the actual problem with this query is? Is the query just too big, too many joins? What can I do fix this? Thank you very much! Stefan Bischof [1] S Bischof, M Krötzsch, A Polleres, S Rudolph: Schema-agnostic query rewriting in SPARQL 1.1. ISWC 2014 [2] http://citydata.wu.ac.at/SPR/ Query: PREFIX dc: <http://purl.org/dc/elements/1.1/> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX foaf: <http://xmlns.com/foaf/0.1/> PREFIX owl: <http://www.w3.org/2002/07/owl#> PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX lubm: <http://swat.cse.lehigh.edu/onto/univ-bench.owl#> SELECT * WHERE { { ?_v0 (((((rdfs:subClassOf|owl:equivalentClass)|^owl:equivalentClass)|((owl:intersectionOf/(rdf:rest)*)/rdf:first))|((owl:onProperty/((((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty)|(((owl:inverseOf|^owl:inverseOf)/(((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty))*)/(owl:inverseOf|^owl:inverseOf))))*)/(^owl:onProperty|rdfs:domain)))|((((owl:onProperty/((((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty)|(((owl:inverseOf|^owl:inverseOf)/(((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty))*)/(owl:inverseOf|^owl:inverseOf))))*)/(owl:inverseOf|^owl:inverseOf))/(((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty))*)/rdfs:range))* lubm:Student . { { ?p rdf:type ?_v0} UNION { ?_v1 ((((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty)|(((owl:inverseOf|^owl:inverseOf)/(((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty))*)/(owl:inverseOf|^owl:inverseOf))))*/(^owl:onProperty|rdfs:domain) ?_v0 . ?p ?_v1 _:b0 } } UNION { ?_v1 ((((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty)|(((owl:inverseOf|^owl:inverseOf)/(((rdfs:subPropertyOf|owl:equivalentProperty)|^owl:equivalentProperty))*)/(owl:inverseOf|^owl:inverseOf))))*/rdfs:range ?_v0 . _:b1 ?_v1 ?p } } } Full Stacktrace: java.util.concurrent.ExecutionException: java.util.concurrent.ExecutionException: org.openrdf.query.QueryEvaluationException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:188) at com.bigdata.rdf.sail.webapp.BigdataServlet.submitApiTask(BigdataServlet.java:281) at com.bigdata.rdf.sail.webapp.QueryServlet.doSparqlQuery(QueryServlet.java:632) at com.bigdata.rdf.sail.webapp.QueryServlet.doPost(QueryServlet.java:259) at com.bigdata.rdf.sail.webapp.RESTServlet.doPost(RESTServlet.java:248) at com.bigdata.rdf.sail.webapp.MultiTenancyServlet.doPost(MultiTenancyServlet.java:138) at javax.servlet.http.HttpServlet.service(HttpServlet.java:707) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:769) at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143) at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577) at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223) at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1125) at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515) at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185) at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1059) at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215) at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110) at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97) at org.eclipse.jetty.server.Server.handle(Server.java:497) at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311) at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:248) at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540) at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:610) at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:539) at java.lang.Thread.run(Thread.java:745) Caused by: java.util.concurrent.ExecutionException: org.openrdf.query.QueryEvaluationException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:188) at com.bigdata.rdf.sail.webapp.QueryServlet$SparqlQueryTask.call(QueryServlet.java:830) at com.bigdata.rdf.sail.webapp.QueryServlet$SparqlQueryTask.call(QueryServlet.java:649) at com.bigdata.rdf.task.ApiTaskForIndexManager.call(ApiTaskForIndexManager.java:68) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) ... 1 more Caused by: org.openrdf.query.QueryEvaluationException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at com.bigdata.rdf.sail.Bigdata2Sesame2BindingSetIterator.hasNext(Bigdata2Sesame2BindingSetIterator.java:188) at info.aduna.iteration.IterationWrapper.hasNext(IterationWrapper.java:68) at org.openrdf.query.QueryResults.report(QueryResults.java:155) at org.openrdf.repository.sail.SailTupleQuery.evaluate(SailTupleQuery.java:76) at com.bigdata.rdf.sail.webapp.BigdataRDFContext$TupleQueryTask.doQuery(BigdataRDFContext.java:1705) at com.bigdata.rdf.sail.webapp.BigdataRDFContext$AbstractQueryTask.innerCall(BigdataRDFContext.java:1562) at com.bigdata.rdf.sail.webapp.BigdataRDFContext$AbstractQueryTask.call(BigdataRDFContext.java:1527) at com.bigdata.rdf.sail.webapp.BigdataRDFContext$AbstractQueryTask.call(BigdataRDFContext.java:699) ... 4 more Caused by: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at com.bigdata.relation.accesspath.BlockingBuffer$BlockingIterator.checkFuture(BlockingBuffer.java:1523) at com.bigdata.relation.accesspath.BlockingBuffer$BlockingIterator._hasNext(BlockingBuffer.java:1710) at com.bigdata.relation.accesspath.BlockingBuffer$BlockingIterator.hasNext(BlockingBuffer.java:1563) at com.bigdata.striterator.AbstractChunkedResolverator._hasNext(AbstractChunkedResolverator.java:365) at com.bigdata.striterator.AbstractChunkedResolverator.hasNext(AbstractChunkedResolverator.java:341) at com.bigdata.rdf.sail.Bigdata2Sesame2BindingSetIterator.hasNext(Bigdata2Sesame2BindingSetIterator.java:134) ... 11 more Caused by: java.util.concurrent.ExecutionException: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:188) at com.bigdata.relation.accesspath.BlockingBuffer$BlockingIterator.checkFuture(BlockingBuffer.java:1454) ... 16 more Caused by: java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at com.bigdata.rdf.sail.RunningQueryCloseableIterator.checkFuture(RunningQueryCloseableIterator.java:59) at com.bigdata.rdf.sail.RunningQueryCloseableIterator.close(RunningQueryCloseableIterator.java:73) at com.bigdata.rdf.sail.RunningQueryCloseableIterator.hasNext(RunningQueryCloseableIterator.java:82) at com.bigdata.striterator.ChunkedWrappedIterator.hasNext(ChunkedWrappedIterator.java:197) at com.bigdata.striterator.AbstractChunkedResolverator$ChunkConsumerTask.call(AbstractChunkedResolverator.java:222) at com.bigdata.striterator.AbstractChunkedResolverator$ChunkConsumerTask.call(AbstractChunkedResolverator.java:197) ... 4 more Caused by: java.util.concurrent.ExecutionException: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at com.bigdata.util.concurrent.Haltable.get(Haltable.java:273) at com.bigdata.bop.engine.AbstractRunningQuery.get(AbstractRunningQuery.java:1511) at com.bigdata.bop.engine.AbstractRunningQuery.get(AbstractRunningQuery.java:104) at com.bigdata.rdf.sail.RunningQueryCloseableIterator.checkFuture(RunningQueryCloseableIterator.java:46) ... 9 more Caused by: java.lang.Exception: task=ChunkTask{query=12f11bc0-b22a-48c8-89f7-a3603bae639a,bopId=58,partitionId=-1,sinkId=75,altSinkId=null}, cause=java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at com.bigdata.bop.engine.ChunkedRunningQuery$ChunkTask.call(ChunkedRunningQuery.java:1337) at com.bigdata.bop.engine.ChunkedRunningQuery$ChunkTaskWrapper.run(ChunkedRunningQuery.java:896) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at com.bigdata.concurrent.FutureTaskMon.run(FutureTaskMon.java:63) at com.bigdata.bop.engine.ChunkedRunningQuery$ChunkFutureTask.run(ChunkedRunningQuery.java:791) ... 3 more Caused by: java.util.concurrent.ExecutionException: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:188) at com.bigdata.bop.engine.ChunkedRunningQuery$ChunkTask.call(ChunkedRunningQuery.java:1317) ... 8 more Caused by: java.lang.RuntimeException: cause=java.lang.NullPointerException, state=JVMHashJoinUtility{open=false,joinType=Normal,joinVars=[],outputDistinctJVs=true,size=20,considered(left=26,right=312,joins=312)} at com.bigdata.bop.join.JVMHashJoinUtility.launderThrowable(JVMHashJoinUtility.java:1406) at com.bigdata.bop.join.JVMHashJoinUtility.acceptSolutions(JVMHashJoinUtility.java:431) at com.bigdata.bop.join.HashIndexOp$ChunkTask.acceptSolutions(HashIndexOp.java:433) at com.bigdata.bop.join.HashIndexOp$ChunkTask.call(HashIndexOp.java:338) at com.bigdata.bop.join.HashIndexOp$ChunkTask.call(HashIndexOp.java:237) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at com.bigdata.bop.engine.ChunkedRunningQuery$ChunkTask.call(ChunkedRunningQuery.java:1316) ... 8 more Caused by: java.lang.NullPointerException at com.bigdata.bop.join.JVMHashJoinUtility.acceptSolutions(JVMHashJoinUtility.java:410) ... 13 more |
