Hi
question title is quite clear, but requires some (may ?) contextual
informations.

I'm running a JavaEE application that uses neo4j 1.5.3 as storage back-end.
This graph is used through the following application stack

 * The neo4j DB is started through neo4j-jca-connector
(https://github.com/alexsmirnov/neo4j-connector) in embedded mode
 * That jca connector is accessed as a totally standard JavaEE resource in
my application code (ie injected through @Resource(mappedName =
"jca/Neo4j/resource", type=Neo4JConnectionFactory.class))
 * To not write our objects to neo4j ourselves, we also use an adaptation
layer called gaedo-blueprints
(http://riduidel.github.com/gaedo/site/0.4.1/gaedo-blueprints/index.html)
which access neo4j through blueprints 1.1. (well, it appears that, beside
developping my enterprise application, i'm also gaedo lead and only
developper).

So, after a recent modification in our code base, we started having
recuring DeadlockDetectedException.

Those exceptions always shows up deep in a stack of re-throwed exceptions,
with messages likes

Caused by: org.neo4j.kernel.DeadlockDetectedException:
JavaEETransactionImpl: txId=18 nonXAResource=null
jtsTx=com.sun.jts.jta.TransactionImpl@70faf570 localTxStatus=0
syncs=[com.sun.ejb.containers.ContainerSynchronization@6d65042c] can't wait
on resource RWLock[Node[6]] since => JavaEETransactionImpl: txId=18
nonXAResource=null jtsTx=com.sun.jts.jta.TransactionImpl@70faf570
localTxStatus=0
syncs=[com.sun.ejb.containers.ContainerSynchronization@6d65042c] <-
RWLock[Node[132736]] <- JavaEETransactionImpl: txId=18 nonXAResource=null
jtsTx=com.sun.jts.jta.TransactionImpl@70faf570 localTxStatus=0
syncs=[com.sun.ejb.containers.ContainerSynchronization@6d65042c] <-
RWLock[Node[6]]
at
org.neo4j.kernel.impl.transaction.RagManager.checkWaitOnRecursive(RagManage r.java:219)
at
org.neo4j.kernel.impl.transaction.RagManager.checkWaitOnRecursive(RagManage r.java:247)
at
org.neo4j.kernel.impl.transaction.RagManager.checkWaitOn(RagManager.java:18 6)
at
org.neo4j.kernel.impl.transaction.RWLock.acquireWriteLock(RWLock.java:321)
at
org.neo4j.kernel.impl.transaction.LockManager.getWriteLock(LockManager.java :130)
at org.neo4j.kernel.impl.core.NodeManager.acquireLock(NodeManager.java:737)
at
org.neo4j.kernel.impl.core.RelationshipImpl.delete(RelationshipImpl.java:14 1)
at
org.neo4j.kernel.impl.core.RelationshipProxy.delete(RelationshipProxy.java: 50)
at
com.tinkerpop.blueprints.pgm.impls.neo4j.Neo4jGraph.removeEdge(Neo4jGraph.j ava:314)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService.deleteCollection( BluePrintsBackedFinderService.java:355)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService.doDelete(BluePrin tsBackedFinderService.java:279)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService.access$300(BluePr intsBackedFinderService.java:56)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService$2.doPerform(BlueP rintsBackedFinderService.java:256)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService$2.doPerform(BlueP rintsBackedFinderService.java:252)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService$TransactionalOper ation.perform(BluePrintsBackedFinderService.java:72)
at
com.dooapp.gaedo.blueprints.BluePrintsBackedFinderService.delete(BluePrints BackedFinderService.java:252)

As our application do not directly deal with neo4j nodes, I can't even have
the slightest idea of what are the affected nodes.

So, here finally come my question : to your mind, what is the best way to
deal with DeadlockDetectedException ? (both in termes of code modification
to do to directly recover from them and ways to investigate how they happen
and how to avoid them).

Thanks