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Cypher Query en Neo4j Returns ''undefined''

Question

Construí un gráfico usando Neo4j, que consta de aproximadamente 1000 nodos y alrededor de 270,000 relaciones. El gráfico es una red de vuelo (los aeropuertos son nodos y los vuelos son relaciones) por lo que hay muchas relaciones de un nodo a otro. Estoy seguro de que también hay muchos ciclos en ciertas consultas (no estoy seguro de si eso es un problema). De todos modos, ciertas consultas funcionan bien, como estas:

start a=node(1), b=node(2) match p=a-[:flys_to*..1]->b return p;
start a=node(1), b=node(2) match p=shortestPath(a-[:flys_to]->b) return p;

Pero cuando intento otras consultas más complicadas, no hay ningún mensaje de error amigable; simplemente se bloquea durante aproximadamente 3 minutos (dependiendo de en qué dos nodos busco entre) y devuelve "No definido".

Una de las consultas que cuelga se ve así:

start a=node(1), b=node(2) match p=a-[:flys_to*..2]->b return p;

Además, una nota al margen interesante es que cuando escribo la siguiente consulta, instantáneamente devuelve "Indefinido":

start a=node(1), b=node(2) match p=a-[:flys_to]->b return p;

¿Tiene sentido esto o alguien tiene alguna idea sobre dónde podría comenzar a solucionar problemas?

Más información sobre este problema específico

Aquí hay un archivo comprimido de la base de datos: http://www.opensourcebanking.org/neo4j/

Estoy ejecutando esto en un entorno virtual sobre VMware. El host es OSX 10.8.2 y el invitado es Windows Server 2012. El JRE es 1.6.0_38 . Además, tengo la configuración de indexación automática en la propiedad del nodo ''iata'', y la propiedad de relación "flys_to".

Aquí hay algunas consultas Cypher y sus mensajes registrados relacionados:

La siguiente consulta devuelve ''undefined'' casi de inmediato:

start a=node(353), b=node(295)
match p=a-->b
return p;

Y esto es lo que obtengo en el registro:

SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container
org.neo4j.helpers.ThisShouldNotHappenError: Developer: Andres claims that: Unexpected traversal state encountered
    at org.neo4j.cypher.internal.pipes.matching.BidirectionalTraversalMatcher$StepCollisionDetector.includePath(BidirectionalTraversalMatcher.scala:101)
    at org.neo4j.kernel.StandardBranchCollisionDetector.evaluate(StandardBranchCollisionDetector.java:74)
    at org.neo4j.kernel.StandardBranchCollisionDetector.evaluate(StandardBranchCollisionDetector.java:37)
    at org.neo4j.kernel.impl.traversal.BidirectionalTraverserIterator.fetchNextOrNull(BidirectionalTraverserIterator.java:157)
    at org.neo4j.kernel.impl.traversal.BidirectionalTraverserIterator.fetchNextOrNull(BidirectionalTraverserIterator.java:41)
    at org.neo4j.helpers.collection.PrefetchingIterator.hasNext(PrefetchingIterator.java:55)
    at scala.collection.JavaConversions$JIteratorWrapper.hasNext(JavaConversions.scala:574)
    at scala.collection.Iterator$$anon$21.hasNext(Iterator.scala:371)
    at scala.collection.Iterator$$anon$21.hasNext(Iterator.scala:371)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at org.neo4j.cypher.internal.ClosingIterator$$anonfun$hasNext$1.apply$mcZ$sp(ClosingIterator.scala:36)
    at org.neo4j.cypher.internal.ClosingIterator$$anonfun$hasNext$1.apply(ClosingIterator.scala:35)
    at org.neo4j.cypher.internal.ClosingIterator$$anonfun$hasNext$1.apply(ClosingIterator.scala:35)
    at org.neo4j.cypher.internal.ClosingIterator.failIfThrows(ClosingIterator.scala:87)
    at org.neo4j.cypher.internal.ClosingIterator.hasNext(ClosingIterator.scala:35)
    at scala.collection.Iterator$class.foreach(Iterator.scala:660)
    at org.neo4j.cypher.internal.ClosingIterator.foreach(ClosingIterator.scala:31)
    at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
    at scala.collection.mutable.ListBuffer.$plus$plus$eq(ListBuffer.scala:128)
    at scala.collection.TraversableOnce$class.toList(TraversableOnce.scala:242)
    at org.neo4j.cypher.internal.ClosingIterator.toList(ClosingIterator.scala:31)
    at org.neo4j.cypher.PipeExecutionResult.createTimedResults(PipeExecutionResult.scala:73)
    at org.neo4j.cypher.PipeExecutionResult.dumpToString(PipeExecutionResult.scala:80)
    at org.neo4j.cypher.PipeExecutionResult.dumpToString(PipeExecutionResult.scala:125)
    at org.neo4j.cypher.javacompat.ExecutionResult.dumpToString(ExecutionResult.java:91)
    at org.neo4j.shell.kernel.apps.Start.exec(Start.java:71)
    at org.neo4j.shell.kernel.apps.ReadOnlyGraphDatabaseApp.execute(ReadOnlyGraphDatabaseApp.java:32)
    at org.neo4j.shell.impl.AbstractAppServer.interpretLine(AbstractAppServer.java:115)
    at org.neo4j.shell.kernel.GraphDatabaseShellServer.interpretLine(GraphDatabaseShellServer.java:92)
    at org.neo4j.shell.impl.AbstractClient.evaluate(AbstractClient.java:130)
    at org.neo4j.shell.impl.AbstractClient.evaluate(AbstractClient.java:114)
    at org.neo4j.server.webadmin.console.ShellSession.evaluate(ShellSession.java:101)
    at org.neo4j.server.webadmin.rest.console.ConsoleService.exec(ConsoleService.java:125)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:390)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:943)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

La siguiente consulta funciona bien. Devuelve 426 filas y no se registra nada.

start a=node(353), b=node(295)
match p=a-[:flys_to*..1]->b
return p;

La siguiente consulta devuelve ''indefinido'' después de unos 10-15 minutos:

start a=node(353), b=node(295)
match p=a-[:flys_to*..2]->b
return p;

Iniciar sesión:

SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container
java.lang.OutOfMemoryError: Java heap space
    at org.neo4j.cypher.internal.pipes.matching.AddedHistory.toSeq(History.scala:87)
    at org.neo4j.cypher.internal.pipes.matching.AddedHistory.toMap(History.scala:75)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.isMatchSoFar(PatternMatcher.scala:166)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.org$neo4j$cypher$internal$pipes$matching$PatternMatcher$$traverseNextNodeFromRelationship(PatternMatcher.scala:98)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher$$anonfun$4.apply(PatternMatcher.scala:150)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher$$anonfun$4.apply(PatternMatcher.scala:150)
    at scala.collection.immutable.Stream$$anonfun$map$1.apply(Stream.scala:175)
    at scala.collection.immutable.Stream$$anonfun$map$1.apply(Stream.scala:175)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:634)
    at scala.collection.immutable.Stream$Cons.tail(Stream.scala:626)
    at scala.collection.immutable.Stream.foldLeft(Stream.scala:302)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.traverseRelationship(PatternMatcher.scala:150)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.traverseNextSpecificNode(PatternMatcher.scala:61)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.traverseNode(PatternMatcher.scala:72)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.foreach(PatternMatcher.scala:36)
    at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48)
    at scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:99)
    at scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:250)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.toBuffer(PatternMatcher.scala:28)
    at scala.collection.TraversableLike$class.toStream(TraversableLike.scala:571)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.toStream(PatternMatcher.scala:28)
    at scala.collection.TraversableLike$class.toIterator(TraversableLike.scala:570)
    at org.neo4j.cypher.internal.pipes.matching.PatternMatcher.toIterator(PatternMatcher.scala:28)
    at scala.collection.Iterator$$anon$21.hasNext(Iterator.scala:371)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at scala.collection.Iterator$$anon$19.hasNext(Iterator.scala:334)
    at org.neo4j.cypher.internal.ClosingIterator$$anonfun$hasNext$1.apply$mcZ$sp(ClosingIterator.scala:36)
    at org.neo4j.cypher.internal.ClosingIterator$$anonfun$hasNext$1.apply(ClosingIterator.scala:35)
    at org.neo4j.cypher.internal.ClosingIterator$$anonfun$hasNext$1.apply(ClosingIterator.scala:35)
    at org.neo4j.cypher.internal.ClosingIterator.failIfThrows(ClosingIterator.scala:87)
    at org.neo4j.cypher.internal.ClosingIterator.hasNext(ClosingIterator.scala:35)

Answer 1

¿ allShortestPaths utilizar allShortestPaths o allShortestPaths para sus consultas?

 start a=node(1), b=node(2) match p=allShortestPaths(a-[:flys_to*..2]->b) return p;


+--------------------------------------------------------------------------------------------------------+
| p                                                                                                      |
+--------------------------------------------------------------------------------------------------------+
| [Node[1]{iata:"ABE"},:flys_to[224044] {},Node[546]{iata:"SFO"},:flys_to[24211] {},Node[2]{iata:"ABI"}] |
| [Node[1]{iata:"ABE"},:flys_to[224044] {},Node[546]{iata:"SFO"},:flys_to[24210] {},Node[2]{iata:"ABI"}] |
....
| [Node[1]{iata:"ABE"},:flys_to[66032] {},Node[146]{iata:"DFW"},:flys_to[1] {},Node[2]{iata:"ABI"}]      |
| [Node[1]{iata:"ABE"},:flys_to[66032] {},Node[146]{iata:"DFW"},:flys_to[0] {},Node[2]{iata:"ABI"}]      |
+--------------------------------------------------------------------------------------------------------+
28 rows
20 ms
 start a=node(1), b=node(2) match p=shortestPath(a-[:flys_to*..2]->b) return p;

+--------------------------------------------------------------------------------------------------------+
| p                                                                                                      |
+--------------------------------------------------------------------------------------------------------+
| [Node[1]{iata:"ABE"},:flys_to[224044] {},Node[546]{iata:"SFO"},:flys_to[24211] {},Node[2]{iata:"ABI"}] |
+--------------------------------------------------------------------------------------------------------+
1 row
1 ms

Answer 2

Para mí, esto devuelve 426 filas:

start a=node(353), b=node(295)
match p=a-->b
return p;