# Internal Server Error when using resoning **URL:** \ **Category:** Support\ **Created:** [February 5, 2018, 1:48pm UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794 "2018-02-05T13:48:27Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![ReshmaDangol](https://avatars.discourse-cdn.com/v4/letter/r/c37758/32.png) [@ReshmaDangol](https://community.stardog.com/u/ReshmaDangol)\ **Post date:** [February 5, 2018, 1:48pm UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/1 "2018-02-05T13:48:27Z")
When attempting to run a query with reasoning enabled, I get Internal Server Error. I have tried it in a the Web Console and in the Command Line. What could be the issue and how to fix it? ---
**Author:** ![Fethi](https://avatars.discourse-cdn.com/v4/letter/f/bcef8e/32.png) [@Fethi](https://community.stardog.com/u/Fethi)\ **Post date:** [February 5, 2018, 2:05pm UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/2 "2018-02-05T14:05:18Z")
Can you display your query and the Error. ---
**Author:** ![zachary.whitley](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/zachary.whitley/32/94_2.png) [@zachary.whitley](https://community.stardog.com/u/zachary.whitley)\ **Post date:** [February 5, 2018, 3:08pm UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/3 "2018-02-05T15:08:03Z")
…and anything in stardog.log ---
**Author:** ![ReshmaDangol](https://avatars.discourse-cdn.com/v4/letter/r/c37758/32.png) [@ReshmaDangol](https://community.stardog.com/u/ReshmaDangol)\ **Post date:** [February 6, 2018, 3:12am UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/4 "2018-02-06T03:12:35Z")
I tried the sample query from star dog documentation “SELECT ?s { ?s a :C } LIMIT 10” Using DL reasoning ERROR 2018-02-06 03:14:08,827 [stardog-user-28] com.complexible.stardog.protocols.http.server.StardogHttpServiceLoader:accept(231): An unexpected exception was handled by the server org.openrdf.query.QueryEvaluationException: null at com.complexible.common.rdf.query.IteratorAsTupleQueryResult.hasNext(IteratorAsTupleQueryResult.java:81) ~[stardog-utils-rdf-5.2.0.jar:?] at org.openrdf.query.QueryResults.report(QueryResults.java:158) ~[sesame-query-4.0.0.jar:?] at org.openrdf.query.resultio.QueryResultIO.writeTuple(QueryResultIO.java:449) ~[sesame-queryresultio-api-4.0.0.jar:?] at com.complexible.stardog.protocols.http.server.ProtocolUtils.writeTupleResponse(ProtocolUtils.java:563) ~[stardog-protocols-http-server-5.2.0.jar:?] at com.complexible.stardog.protocols.http.server.ProtocolUtils.executeReadQuery(ProtocolUtils.java:470) ~[stardog-protocols-http-server-5.2.0.jar:?] at com.complexible.stardog.protocols.http.annex.QueryPanelService.executeQuery(QueryPanelService.java:179) ~[stardog-webconsole-annex-5.2.0.jar:?] at com.complexible.stardog.protocols.http.annex.QueryPanelService.post(QueryPanelService.java:120) ~[stardog-webconsole-annex-5.2.0.jar:?] at com.stardog.http.server.undertow.jaxrs.ExtractRoutes.lambda$handleIt$5(ExtractRoutes.java:196) ~[stardog-protocols-http-server-5.2.0.jar:?] at org.apache.shiro.subject.support.SubjectRunnable.doRun(SubjectRunnable.java:120) ~[shiro-core-1.2.3.jar:1.2.3] at org.apache.shiro.subject.support.SubjectRunnable.run(SubjectRunnable.java:108) ~[shiro-core-1.2.3.jar:1.2.3] at com.stardog.http.server.undertow.ErrorHandling.lambda$safeDispatch$1(ErrorHandling.java:71) ~[stardog-protocols-http-server-5.2.0.jar:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0\_151] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0\_151] at java.lang.Thread.run(Thread.java:748) [?:1.8.0\_151] Caused by: com.clarkparsia.pellet.api.exceptions.InconsistentOntologyException at com.clarkparsia.pellet.api.query.impl.DefaultQueryEngine.execute(DefaultQueryEngine.java:80) ~[stardog-reasoning-shared-5.2.0.jar:?] at com.clarkparsia.pellet.api.query.impl.AbstractQueryEngine.visit(AbstractQueryEngine.java:104) ~[stardog-reasoning-shared-5.2.0.jar:?] at com.clarkparsia.pellet.api.query.impl.AbstractQueryEngine.visit(AbstractQueryEngine.java:33) ~[stardog-reasoning-shared-5.2.0.jar:?] at com.clarkparsia.pellet.api.query.impl.SelectQueryImpl.accept(SelectQueryImpl.java:43) ~[stardog-reasoning-shared-5.2.0.jar:?] at com.clarkparsia.pellet.api.query.impl.AbstractQueryEngine.execute(AbstractQueryEngine.java:42) ~[stardog-reasoning-shared-5.2.0.jar:?] at com.complexible.stardog.reasoning.pellet.PelletUtils.executeQuery(PelletUtils.java:88) ~[stardog-reasoning-core-5.2.0.jar:?] at com.complexible.stardog.reasoning.pellet.PelletOp.computeNext(PelletOp.java:84) ~[stardog-reasoning-core-5.2.0.jar:?] at com.complexible.stardog.reasoning.pellet.PelletOp.computeNext(PelletOp.java:35) ~[stardog-reasoning-core-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.tryToComputeNext(AbstractSkippingIterator.java:143) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.hasNext(AbstractSkippingIterator.java:130) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.impl.SingleProjectionOp.computeNext(SingleProjectionOp.java:71) ~[stardog-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.impl.SingleProjectionOp.computeNext(SingleProjectionOp.java:30) ~[stardog-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.tryToComputeNext(AbstractSkippingIterator.java:143) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.hasNext(AbstractSkippingIterator.java:130) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.impl.SliceOp.\_hasNext(SliceOp.java:87) ~[stardog-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.impl.SliceOp.computeNext(SliceOp.java:95) ~[stardog-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.impl.SliceOp.computeNext(SliceOp.java:26) ~[stardog-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.tryToComputeNext(AbstractSkippingIterator.java:143) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.hasNext(AbstractSkippingIterator.java:130) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.util.AutoCloseOperator.computeNext(AutoCloseOperator.java:112) ~[stardog-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.util.AutoCloseOperator.computeNext(AutoCloseOperator.java:25) ~[stardog-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.tryToComputeNext(AbstractSkippingIterator.java:143) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.common.collect.AbstractSkippingIterator.hasNext(AbstractSkippingIterator.java:130) ~[stardog-utils-common-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.util.OpBasedBindingSetIteration.computeNext(OpBasedBindingSetIteration.java:110) ~[stardog-5.2.0.jar:?] at com.complexible.stardog.plan.eval.operator.util.OpBasedBindingSetIteration.computeNext(OpBasedBindingSetIteration.java:34) ~[stardog-5.2.0.jar:?] at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143) ~[guava-18.0.jar:?] at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138) ~[guava-18.0.jar:?] at com.complexible.common.rdf.query.IteratorAsTupleQueryResult.hasNext(IteratorAsTupleQueryResult.java:77) ~[stardog-utils-rdf-5.2.0.jar:?] … 13 more ---
**Author:** ![Fethi](https://avatars.discourse-cdn.com/v4/letter/f/bcef8e/32.png) [@Fethi](https://community.stardog.com/u/Fethi)\ **Post date:** [February 6, 2018, 11:24am UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/5 "2018-02-06T11:24:53Z")
I think that the clause “where” is missing try this: SELECT ?s WHERE{ ?s a :C } LIMIT 10 ---
**Author:** ![pavel](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/pavel/32/18_2.png) [@pavel](https://community.stardog.com/u/pavel)\ **Post date:** [February 6, 2018, 11:41am UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/6 "2018-02-06T11:41:39Z")
We’ll improve the error message but the ultimate problem is that your ontology is inconsistent. You can use the `stardog reasoning consistency myDb` command to double check it or `stardog reasoning explain --inconsistency` to explain it. Best, Pavel ---
**Author:** ![pavel](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.stardog.com/pavel/32/18_2.png) [@pavel](https://community.stardog.com/u/pavel)\ **Post date:** [February 6, 2018, 11:42am UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/7 "2018-02-06T11:42:05Z")
`WHERE` keyword is optional in SELECT queries in SPARQL. Best, Pavel ---
**Author:** ![ReshmaDangol](https://avatars.discourse-cdn.com/v4/letter/r/c37758/32.png) [@ReshmaDangol](https://community.stardog.com/u/ReshmaDangol)\ **Post date:** [February 6, 2018, 1:05pm UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/8 "2018-02-06T13:05:13Z")
> ./stardog reasoning explain -v myDB --inconsistency Resulted in this: Java heap space The detailed stack trace for the error is: com.complexible.stardog.cli.CliException: Java heap space at com.complexible.stardog.cli.impl.ConnectionCommand.call(ConnectionCommand.java:80) at com.complexible.stardog.cli.CLIBase.execute(CLIBase.java:55) at com.complexible.stardog.cli.CLI.main(CLI.java:120) Caused by: com.complexible.stardog.protocols.http.client.BaseHttpClient$HttpClientException: Java heap space at com.complexible.stardog.protocols.http.client.BaseHttpClient.checkResponseCode(BaseHttpClient.java:486) at com.complexible.stardog.protocols.http.client.BaseHttpClient.execute(BaseHttpClient.java:320) at com.complexible.stardog.protocols.http.client.HttpClientImpl.connect(HttpClientImpl.java:171) at com.complexible.stardog.protocols.http.client.HttpConnection.create(HttpConnection.java:89) at com.complexible.stardog.protocols.http.client.HttpDriver.connect(HttpDriver.java:72) at com.complexible.stardog.api.DriverManager.getConnection(DriverManager.java:83) at com.complexible.stardog.api.ConnectionConfiguration.connect(ConnectionConfiguration.java:130) at com.complexible.stardog.cli.impl.ConnectionCommand.connect(ConnectionCommand.java:129) at com.complexible.stardog.cli.impl.ConnectionCommand.call(ConnectionCommand.java:67) ... 2 more ---
**Author:** ![ReshmaDangol](https://avatars.discourse-cdn.com/v4/letter/r/c37758/32.png) [@ReshmaDangol](https://community.stardog.com/u/ReshmaDangol)\ **Post date:** [February 7, 2018, 3:24am UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/9 "2018-02-07T03:24:56Z")
So, finally I made sure that the dataset is consistent. My query: `SELECT (COUNT(*) as ?instanceCount) WHERE { ?s ?o. ?o ?s. }` This returns Internal Server Error. No new log in Stardog.log Using SL reasoning ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex030/uploads/stardog/original/2X/e/ed66b48a616f505106a4acde3c9cee7e6da9bc67.svg) [@system](https://community.stardog.com/u/system)\ **Post date:** [February 21, 2018, 3:25am UTC](https://community.stardog.com/t/internal-server-error-when-using-resoning/794/10 "2018-02-21T03:25:08Z")
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