from:"Joel Cordeiro"

[Neo4j] HowTo: Dijkstra with Limited Depth

2011-11-14 Thread Joel Cordeiro

Hi there,

I'm having performance issues with Neo4J while using GraphAlgoFactory to
find a path between two nodes. I want to calculate the cost between the two
nodes (each relation type has a different cost), with the maximum depth of
3 (paths with more length can be discarded). I'm using the findAllPaths
method, since the findShorthestPath method takes into account the path
length and not the cost associated to it. But this is not the ideal
solution, because of the performance issues I'm having.

I'm thinking about using something like the Dijkstra algorithm, but with a
maximum depth of 3. I already took a look at the Neo4J source code and
found the class *org.neo4j.graphalgo.impl.shortestpath.Dijkstra, *which I
have tried to use with limitMaxRelationShipsToTraverse set to 3. Most of
the times it doesn't found any path, and  throws the exception:
java.lang.RuntimeException: Trying to decrease to a greater key
at
org.neo4j.graphalgo.impl.util.FibonacciHeap.decreaseKey(FibonacciHeap.java:318)
at
org.neo4j.graphalgo.impl.shortestpath.DijkstraPriorityQueueFibonacciImpl.decreaseValue(DijkstraPriorityQueueFibonacciImpl.java:103)
at
org.neo4j.graphalgo.impl.shortestpath.Dijkstra$DijstraIterator.next(Dijkstra.java:393)
at
org.neo4j.graphalgo.impl.shortestpath.Dijkstra.calculate(Dijkstra.java:516)

Is this class appropriate for what I want to accomplish? I also would like
to know if this is a good solution for the discribed problem, or if there
is a better solution out there.

Best regards,
Joel Filipe Antunes Cordeiro
jkorde...@gmail.com
j...@student.dei.uc.pt
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[Neo4j] org.neo4j.kernel.impl.nioneo.store.InvalidRecordException while trying to delete relationships of a node, followed by a delete of the node

2011-07-21 Thread Joel Cordeiro

Hi,

i'm getting the followed stack trace after trying to delete the
relationships of a node, followed by the delete of the node (the goal is to
remove the node from the store, which must have no relationships, before
doing that).

 org.neo4j.kernel.impl.nioneo.store.InvalidRecordException: Record[2592] not
in use
at
org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:230)
at
org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:97)
at
org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.disconnectRelationship(WriteTransaction.java:778)
at
org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.relDelete(WriteTransaction.java:729)
at
org.neo4j.kernel.impl.persistence.PersistenceManager.relDelete(PersistenceManager.java:166)
at
org.neo4j.kernel.impl.core.NodeManager.deleteRelationship(NodeManager.java:864)
at
org.neo4j.kernel.impl.core.RelationshipImpl.delete(RelationshipImpl.java:148)
at
org.neo4j.kernel.impl.core.RelationshipProxy.delete(RelationshipProxy.java:50)
at
pt.uc.dei.sdic.plugin.knowledge.neo4j.Neo4JRepository.remove(Neo4JRepository.java:1064)

The code i implemented to do that is the follow:

Node node = indexService.get(SDKE.FIELD_LOCAL_PATH,
sdkeID).getSingle();
Transaction t = graphDb.beginTx();
try
{
indexService.remove(node);
for(Relationship relation: node.getRelationships())
{
relation.delete();
}
node.delete();
t.success();
}
catch (Exception e)
{
t.failure();
LoggerFactory.getLogger(this.getClass()).error(e.getMessage(),
e);
}
finally
{
t.finish();
}

Can anyone figure out a reason for it?
I already read questions with similar stack traces on the mailing list, but
didn't found a solution to this.

Best regards,
Joel Filipe Antunes Cordeiro
jkorde...@gmail.com
j...@student.dei.uc.pt
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Re: [Neo4j] org.neo4j.kernel.impl.nioneo.store.InvalidRecordException while trying to delete relationships of a node, followed by a delete of the node

2011-07-21 Thread Joel Cordeiro

Yes, the data was inserted with BatchInserter on 1.4M04.

Joel Filipe Antunes Cordeiro
jkorde...@gmail.com
j...@student.dei.uc.pt


2011/7/21 Mattias Persson matt...@neotechnology.com

 Was your data inserted with the BatchInserter on 1.4.M05 or 1.4.M04 or
 similar?

 2011/7/21 Joel Cordeiro jkorde...@gmail.com

  Hi,
 
  i'm getting the followed stack trace after trying to delete the
  relationships of a node, followed by the delete of the node (the goal is
 to
  remove the node from the store, which must have no relationships, before
  doing that).
 
   org.neo4j.kernel.impl.nioneo.store.InvalidRecordException: Record[2592]
  not
  in use
  at
 
 
 org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:230)
  at
 
 
 org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:97)
  at
 
 
 org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.disconnectRelationship(WriteTransaction.java:778)
  at
 
 
 org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.relDelete(WriteTransaction.java:729)
  at
 
 
 org.neo4j.kernel.impl.persistence.PersistenceManager.relDelete(PersistenceManager.java:166)
  at
 
 
 org.neo4j.kernel.impl.core.NodeManager.deleteRelationship(NodeManager.java:864)
  at
 
 
 org.neo4j.kernel.impl.core.RelationshipImpl.delete(RelationshipImpl.java:148)
  at
 
 
 org.neo4j.kernel.impl.core.RelationshipProxy.delete(RelationshipProxy.java:50)
  at
 
 
 pt.uc.dei.sdic.plugin.knowledge.neo4j.Neo4JRepository.remove(Neo4JRepository.java:1064)
 
  The code i implemented to do that is the follow:
 
 Node node = indexService.get(SDKE.FIELD_LOCAL_PATH,
  sdkeID).getSingle();
 Transaction t = graphDb.beginTx();
 try
 {
 indexService.remove(node);
 for(Relationship relation: node.getRelationships())
 {
 relation.delete();
 }
 node.delete();
 t.success();
 }
 catch (Exception e)
 {
 t.failure();
 LoggerFactory.getLogger(this.getClass()).error(e.getMessage(),
  e);
 }
 finally
 {
 t.finish();
 }
 
  Can anyone figure out a reason for it?
  I already read questions with similar stack traces on the mailing list,
 but
  didn't found a solution to this.
 
  Best regards,
  Joel Filipe Antunes Cordeiro
  jkorde...@gmail.com
  j...@student.dei.uc.pt
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 --
 Mattias Persson, [matt...@neotechnology.com]
 Hacker, Neo Technology
 www.neotechnology.com
 ___
 Neo4j mailing list
 User@lists.neo4j.org
 https://lists.neo4j.org/mailman/listinfo/user

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Re: [Neo4j] org.neo4j.kernel.impl.nioneo.store.InvalidRecordException while trying to delete relationships of a node, followed by a delete of the node

2011-07-21 Thread Joel Cordeiro

Thank you for the answer. The data set is not critical. It is easy to
reinsert with the BatchInserter of 1.4.
What is critical on my dataset is to keep it updated at runtime, that's why
i need to add and remove nodes, and consequently their relationships.
How can i solve that issue?

Best regards,
Joel Filipe Antunes Cordeiro
jkorde...@gmail.com
j...@student.dei.uc.pt


2011/7/21 Mattias Persson matt...@neotechnology.com

 I'm sad to say that there was a bug in BatchInserter in M04 and M05 which
 could create some invalid relationship records. Is it a critical data set
 or
 is it easy to reinsert it with the BatchInserter of 1.4?

 2011/7/21 Joel Cordeiro jkorde...@gmail.com

  Yes, the data was inserted with BatchInserter on 1.4M04.
 
  Joel Filipe Antunes Cordeiro
  jkorde...@gmail.com
  j...@student.dei.uc.pt
 
 
  2011/7/21 Mattias Persson matt...@neotechnology.com
 
   Was your data inserted with the BatchInserter on 1.4.M05 or 1.4.M04 or
   similar?
  
   2011/7/21 Joel Cordeiro jkorde...@gmail.com
  
Hi,
   
i'm getting the followed stack trace after trying to delete the
relationships of a node, followed by the delete of the node (the goal
  is
   to
remove the node from the store, which must have no relationships,
  before
doing that).
   
 org.neo4j.kernel.impl.nioneo.store.InvalidRecordException:
  Record[2592]
not
in use
at
   
   
  
 
 org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:230)
at
   
   
  
 
 org.neo4j.kernel.impl.nioneo.store.RelationshipStore.getRecord(RelationshipStore.java:97)
at
   
   
  
 
 org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.disconnectRelationship(WriteTransaction.java:778)
at
   
   
  
 
 org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.relDelete(WriteTransaction.java:729)
at
   
   
  
 
 org.neo4j.kernel.impl.persistence.PersistenceManager.relDelete(PersistenceManager.java:166)
at
   
   
  
 
 org.neo4j.kernel.impl.core.NodeManager.deleteRelationship(NodeManager.java:864)
at
   
   
  
 
 org.neo4j.kernel.impl.core.RelationshipImpl.delete(RelationshipImpl.java:148)
at
   
   
  
 
 org.neo4j.kernel.impl.core.RelationshipProxy.delete(RelationshipProxy.java:50)
at
   
   
  
 
 pt.uc.dei.sdic.plugin.knowledge.neo4j.Neo4JRepository.remove(Neo4JRepository.java:1064)
   
The code i implemented to do that is the follow:
   
   Node node = indexService.get(SDKE.FIELD_LOCAL_PATH,
sdkeID).getSingle();
   Transaction t = graphDb.beginTx();
   try
   {
   indexService.remove(node);
   for(Relationship relation: node.getRelationships())
   {
   relation.delete();
   }
   node.delete();
   t.success();
   }
   catch (Exception e)
   {
   t.failure();
   
   LoggerFactory.getLogger(this.getClass()).error(e.getMessage(),
e);
   }
   finally
   {
   t.finish();
   }
   
Can anyone figure out a reason for it?
I already read questions with similar stack traces on the mailing
 list,
   but
didn't found a solution to this.
   
Best regards,
Joel Filipe Antunes Cordeiro
jkorde...@gmail.com
j...@student.dei.uc.pt
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   --
   Mattias Persson, [matt...@neotechnology.com]
   Hacker, Neo Technology
   www.neotechnology.com
   ___
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  ___
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 --
 Mattias Persson, [matt...@neotechnology.com]
 Hacker, Neo Technology
 www.neotechnology.com
 ___
 Neo4j mailing list
 User@lists.neo4j.org
 https://lists.neo4j.org/mailman/listinfo/user

___
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[Neo4j] HowTo: Dijkstra with Limited Depth

[Neo4j] org.neo4j.kernel.impl.nioneo.store.InvalidRecordException while trying to delete relationships of a node, followed by a delete of the node

Re: [Neo4j] org.neo4j.kernel.impl.nioneo.store.InvalidRecordException while trying to delete relationships of a node, followed by a delete of the node

Re: [Neo4j] org.neo4j.kernel.impl.nioneo.store.InvalidRecordException while trying to delete relationships of a node, followed by a delete of the node

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