Mattias, thanks for the suggestion, but to clarify, we're using the server as-is, with the REST API; we're not using the Java API. Is there any way we can specify locking like you suggest via the server config or similar?
Aseem On Mon, Nov 21, 2011 at 12:26 AM, Mattias Persson <matt...@neotechnology.com > wrote: > I think for such a scenario you'd need read locks which gets upgraded to > write locks when modifying. Consider this simple scenario w/o read locks: > > Thread ONE: get relationship R > Thread TWO: get relationship R > Thread TWO: delete relationship R and commit transaction > Thread ONE: do any modification on relationship R... BOOM Exception > > If read locks were to be taken when getting relationships: > > Thread ONE: get relationship R > Thread TWO: get relationship R > Thread TWO: would like to delete relationship R, but will have to wait > until Thread ONE releases its read lock on it > Thread ONE: do some modification on relationship R and commit transaction > Thread TWO: lock from Thread ONE was released so delete relationship R and > commit transaction > > Unfortunately you cannot provide different isolation levels in neo4j at the > moment, but you could mimic that behavior yourself using > LockManager/LockReleaser (from graphDb.getConfig()) > > 2011/11/21 Aseem Kishore <aseem.kish...@gmail.com> > > > Hey guys, > > > > If we put our app under a bit of load, creating and removing nodes and > > relationships concurrently, sometimes we get back a 500 Internal Server > > Error from the REST API when we do a traverse or Cypher query. Here's an > > example stack trace: > > > > https://gist.github.com/1381423 > > > > We're running Neo4j. 1.4 still, but does this stack trace provide any > > insight/ideas into what might be wrong, what we could do as a workaround, > > etc.? Can I provide any other info that would help? > > > > It goes without saying that our assumption is that Neo4j shouldn't be > > failing/crashing on queries; our expectation was that operations are > > transactional, etc. > > > > Thanks! > > > > Aseem > > _______________________________________________ > > Neo4j mailing list > > User@lists.neo4j.org > > https://lists.neo4j.org/mailman/listinfo/user > > > > > > -- > 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 > _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
