What you can do on the akka level is to group the nodes that are updated so that you always batch updates that are of the same node (or node-pair) together, then you can even update all of them in the same tx which increases throughput.
Are you using the aspectj mapping? or simple mapping? (The first is more performant as it just writes through to the db (within a tx). Cheers, Michael ---- (michael)-[:SUPPORTS]->(YOU)-[:USE]->(Neo4j) Learn Online, Offline or Read a Book (in Deutsch) We're trading T-shirts for cool Graph Models Am 14.03.2014 um 12:11 schrieb Michael Azerhad <[email protected]>: > Hi Michael, > > The whole works :) except one improvement I want to make: > > The deadlock was caused due to multiple threads (Akka Actor) updating the > same Node or its relationships in parallel transaction. > Is there a Neo4j way to avoid taking a transaction that would share objects > with another one? > Or should I play with classic (independent of Neo4j lib) thread > synchronisation. > > > > On Friday, March 14, 2014 9:21:00 AM UTC+1, Michael Hunger wrote: > Yep your code was correct except the tx close. > > You want to wrap that into a try-with-resource block, not sure how that looks > in scala. > > Remote server has no transactions (currently) each request is one tx. > > Cheers, > > Michael > > ---- > (michael)-[:SUPPORTS]->(YOU)-[:USE]->(Neo4j) > Learn Online, Offline or Read a Book (in Deutsch) > We're trading T-shirts for cool Graph Models > > > > > > > > Am 14.03.2014 um 03:18 schrieb Michael Azerhad <[email protected]>: > >> I've just fixed the deadlock: I was missing the "tx.close()" statement at >> the end of each of my transaction. >> Now I seek for the reason why my cars is empty, after the save.. using >> embedded mode. >> When using REST mode, it still works. >> >> I would just like to have the confirmation that the way I exposed above is >> correct. >> I will then search myself for the reason :) >> >> Thanks a lot :) >> >> On Friday, March 14, 2014 2:57:16 AM UTC+1, Michael Azerhad wrote: >> It sounds to be a deadlock: >> >> A deadlock scenario has been detected and avoided. This means that two or >> more transactions, which were holding locks, were wanting to await locks >> held by one another,which would have resulted in a deadlock between these >> transactions. This exception was thrown instead of ending up in that >> deadlock. >> >> >> See the deadlock section in the Neo4j manual for how to avoid this: >> http://docs.neo4j.org/chunked/stable/transactions-deadlocks.html >> >> >> Details: 'Transaction(98, >> owner:"play-akka.actor.default-dispatcher-6")[STATUS_ACTIVE,Resources=1] >> can't wait on resource RWLock[NodeLock[id=0]] since => >> Transaction(98,owner:"play-akka.actor.default-dispatcher-6")[STATUS_ACTIVE,Resources=1] >> <-[:HELD_BY]- RWLock[NodeLock[id=3]] <-[:WAITING_FOR]- Transaction(101, >> owner:"play-akka.actor.default-dispatcher-9")[STATUS_ACTIVE,Resources=1] >> <-[:HELD_BY]- RWLock[NodeLock[id=0]]'. >> at >> org.springframework.data.neo4j.support.Neo4jExceptionTranslator.translateExceptionIfPossible(Neo4jExceptionTranslator.java:67) >> at >> org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) >> at >> org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) >> at >> org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) >> at >> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) >> at >> org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) >> at $Proxy57.save(Unknown Source) >> at >> com.myApp.infrastructure.persistence.user.Neo4jUserRepository.save(Neo4jUserRepository.scala:15) >> >> >> On Friday, March 14, 2014 2:45:17 AM UTC+1, Michael Hunger wrote: >> How does it fail? >> D >> Am 14.03.2014 um 01:54 schrieb Michael Azerhad <[email protected]>: >> >>> Hi, >>> >>> I try to update the relationship of a Node that is a collection. >>> Example: User has a list of Cars. >>> >>> Firstly, I saved the User with the Cars set beforehand, and the whole works >>> with embedded mode and REST mode. >>> >>> Now, I want to add one Car to the list of this User. >>> >>> So I tried the following: (Scala code but easy to figure out) >>> >>> val tx = graphDatabaseService.beginTx() >>> val user = userRepository.findById(1) >>> user.cars.clear() //cars being the relationships (Set[Cars]) >>> user.cars.add(new Car("Ferrari")) >>> userRepository.save(user) // fail with embedded but >>> works with REST mode ! >>> tx.success() >>> >>> >>> Is it the right way to update the collection ? >>> Is there something special on the embedded mode handling ? >>> >>> Thanks, >>> >>> Michael >>> >>> >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Neo4j" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> For more options, visit https://groups.google.com/d/optout. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Neo4j" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. > > > -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Neo4j" group. 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