> All,

> I am using the node-neo4j library on Node.js against Neo4j 1.8GA. The
> node-neo4j library provides a Node class with a delete method that
> optionally deletes all relationships on a Node prior to deleting the Node.
> If the Node has multiple relationships,   the library gets all
> relationships on the Node and deletes them *in parallel*. If I'm reading
> the code right, the request to retrieve the relationships and the request
> to delete the retrieved relationships are all happening concurrently. In my
> scenario, I have Node A with relationships to Nodes B, C, D.  When I call
> delete on Node A, I get a DeadlockDetectedException (partial stack trace
> included below).   I'm not clear on what resource is being locked in this
> scenario. The Exception details seem very complete however I'm not quite
> sure how to interpret them.

> Thanks for your help.

> -brian

> Partial stack trace:

> Details: 'Transaction(0)[STATUS_ACTIVE,Resources=1] can't wait on resource
> RWLock[Relationship[27692]] since =>
> Transaction(0)[STATUS_ACTIVE,Resources=1] <-[:HELD_BY]- RWLock[Node[2241]]
> <-[:WAITING_FOR]- Transaction(0)[STATUS_ACTIVE,Resources=1] <-[:HELD_BY]-
> RWLock[Relationship[27692]]'.
> at
> org.neo4j.kernel.impl.transaction.RagManager.checkWaitOnRecursive(RagManage r.java:218)
> at
> org.neo4j.kernel.impl.transaction.RagManager.checkWaitOnRecursive(RagManage r.java:246)
> at
> org.neo4j.kernel.impl.transaction.RagManager.checkWaitOn(RagManager.java:18 5)
> at
> org.neo4j.kernel.impl.transaction.RWLock.acquireWriteLock(RWLock.java:349)
> at
> org.neo4j.kernel.impl.transaction.LockManager.getWriteLock(LockManager.java :164)
> at
> org.neo4j.kernel.impl.transaction.LockManager.getWriteLock(LockManager.java :130)
> at
> org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.getWriteLock(WriteTransact ion.java:870)
> at
> org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.disconnectRelationship(Wri teTransaction.java:809)
> at
> org.neo4j.kernel.impl.nioneo.xa.WriteTransaction.relDelete(WriteTransaction .java:689)
> at
> org.neo4j.kernel.impl.persistence.PersistenceManager.relDelete(PersistenceM anager.java:166)
> at
> org.neo4j.kernel.impl.core.NodeManager.deleteRelationship(NodeManager.java: 989)
> at
> org.neo4j.kernel.impl.core.RelationshipImpl.delete(RelationshipImpl.java:14 5)
> at
> org.neo4j.kernel.impl.core.RelationshipProxy.delete(RelationshipProxy.java: 62)
> at
> org.neo4j.server.rest.web.DatabaseActions.deleteRelationship(DatabaseAction s.java:609)
> at
> org.neo4j.server.rest.web.RestfulGraphDatabase.deleteRelationship(RestfulGr aphDatabase.java:446)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:3 9)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImp l.java:25)